text:
Released June 10, 2022
Category: Week 5
This week includes…..
• Weather synopsis
• Predicted grasshopper development
• Predicted alfalfa weevil development
• Predicted cereal leaf beetle development
• Predicted bertha armyworm development
• Predicted wheat midge development
• Weekly wind trajectory report
• Field heroes NEW Pest & Predator podcast links
• Provincial entomologist updates
• Links to crop reports
• Previous posts
….and catch Monday's Insect of the Week for Week 5 – it's the sugarbeet wireworm, Limonius californicus!
Wishing everyone good weather!
To receive free Weekly Updates automatically, please subscribe to the website!
Questions or problems accessing the contents of this Weekly Update? Please contact us so we can connect you to our information. Past "Weekly Updates" can be accessed on our Weekly Update page.
Weather synopsis
TEMPERATURE: The 2022 growing season has been cooler than normal, particularly in Manitoba. This past week (May 30 – June 5, 2022) average daily temperatures were similar to the previous week. The average temperature across the prairies was 1 °C cooler than normal (Fig. 1). Temperatures were warmest in Alberta and coolest in Manitoba.
Figure 1. Seven-day average temperature (°C) across the Canadian prairies for the period of May 30-June 5, 2022.
Average 30-day temperatures (May 7 – June 5, 2022) were warmest in southern Manitoba and southeastern Saskatchewan (Fig. 2). The average temperature across the prairies was similar to long-term average values. Temperature anomalies (difference between observed and climate normals) over the past 30 days indicate that temperatures across southern Saskatchewan and southern Alberta were cooler than average (Fig. 3).
Figure 2. 30-day average temperature (°C) across the Canadian prairies for the period of May 7-June 5, 2022.
Figure 3. 30-day average temperature anomaly (°C difference from climate normals) observed across the Canadian prairies for the period of May 7-June 5, 2022.
The growing season (April 1 – June 5, 2022) has been cooler in Manitoba than in Saskatchewan and Alberta (Fig. 4; Table 1). The average growing season temperature for the prairies has been 1.5 °C cooler than climate normal values.
Figure 4. Growing season average temperature (°C) observed across the Canadian prairies for the period of April 1 to June 5, 2022.
PRECIPITATION: Rainfall has been well below normal for Alberta and western Saskatchewan while rainfall amounts have been well above normal for eastern Saskatchewan and Manitoba in 2022. Seven-day cumulative rainfall ranged between 0 and 62 mm with the highest rainfall amounts occurring across Manitoba (Fig. 5). This week southwestern Saskatchewan and southern Alberta received 10-20 mm of rain.
Figure 5. Seven-day cumulative rainfall (mm) observed across the Canadian prairies for the period of May 30-June 5, 2022.
Rain (30-day accumulation) amounts have been well above average across the eastern prairies, particularly southeastern Manitoba; rain amounts have been well below normal in Alberta and western Saskatchewan (Figs. 6 and 7).
Figure 6. 30-day cumulative rainfall (mm) observed across the Canadian prairies the past 30 days (May 29-June 5, 2022).
Figure 7. Growing season cumulative rain anomaly (% if climate normals) observed across the Canadian prairies for the period of May 7-June 5, 2022.
Growing season rainfall for April 1 – June 5, 2022, continues to be greatest across Manitoba and eastern Saskatchewan; conditions have been well below normal across most of Saskatchewan and Alberta (Fig. 8; Table 1).
Figure 8. Growing season cumulative rainfall (mm) observed across the Canadian prairies for the period of April 1 to June 5, 2022.
Growing degree day (GDD) maps for Base 5 ºC and Base 10 ºC (April 1-June 6, 2022) can be viewed by clicking the hyperlinks. Over the past 7 days (May 31-June 6, 2022), the lowest temperatures recorded across the Canadian prairies ranged from < -4 to >8 °C while the highest temperatures observed ranged from <6 to >24 °C. Some areas of the prairies hit warmer temperatures with a slight bump in the number of sites experiencing days at or above 25 °C across the prairies – a maximum of 4 days. Access these maps and more using the AAFC Maps of Historic Agroclimate Conditions interface.
The maps above are all produced by Agriculture and Agri-Food Canada. Growers can bookmark the AAFC Current Conditions Maps for the growing season. Historical weather data can be accessed at the AAFC Drought Watch Historical website, Environment Canada's Historical Data website, or your provincial weather network. The AAFC Canadian Drought Monitor also provides geospatial maps updated monthly.
Predicted grasshopper development
The grasshopper (Acrididae: Melanoplus sanguinipes) model predicts development using biological parameters known for the pest species and environmental data observed across the Canadian prairies on a daily basis. Review lifecycle and damage information for this pest. Review the historical grasshopper maps based on late-summer adult in-field counts performed across the prairies.
Model simulations were used to estimate percent grasshopper egg development and hatch as of June 5, 2022. Recent warmer temperatures in Saskatchewan and Alberta have resulted in increased rates of grasshopper development. In contrast, cooler/wetter conditions across eastern Saskatchewan and Manitoba have resulted in delayed development. Last week, average embryological development was 73%.
This week, average egg development is predicted to be 76% and is similar to the long-term development rate (Fig. 1). Hatch is progressing across southern and central regions of Alberta and Saskatchewan (Fig. 2). This week grasshoppers (1-3rd instars) were abundant at specific locations across west-central Saskatchewan. Some fields were showing signs of grasshopper feeding.
Figure 1. Predicted grasshopper (Melanoplus sanguinipes) embryological development (%) across the Canadian prairies as of June 5, 2022.
Figure 2. Predicted grasshopper (Melanoplus sanguinipes) hatch (%) across the Canadian prairies as of June 5, 2022.
Risk estimates, based on meteorological inputs, were used to assess the impact of weather on potential grasshopper development and population growth potential (Fig. 3). A bioclimate simulation model was developed to assess how climatic factors influence occurrence and relative abundance. Potential risk is based on weekly growth index values. Grasshopper risk is greatest in areas that are warmer and drier than normal. As of June 5, 2022, model output indicates that potential risk is greatest across eastern Alberta and western Saskatchewan. Cooler/wetter conditions in eastern Saskatchewan and Manitoba are predicted to reduce potential risk.
Hatch is progressing across southern Alberta and western Saskatchewan (Fig. 3). Last week, grasshopper hatchlings were collected in an area between Saskatoon and Kindersley. Southern Alberta and western Saskatchewan have received the least amount of rain during the growing season. Grasshopper risk can be greater when conditions are warm and dry.
Figure 3. Predicted risk for the migratory grasshopper (Melanoplus sanguinipes) across the Canadian prairies as of June 5, 2022.
Grasshopper Scouting Tips:
● Review grasshopper diversity and photos of nymphs, adults, and non-grasshopper species to aid in-field scouting from egg hatch and onwards.
● Access the PPMN's Grasshopper Monitoring Protocol as a guide to help implement in-field monitoring.
● Review grasshopper lifecycle, damage and scouting and economic thresholds to support sound management decisions enabling the preservation of beneficial arthropods and mitigation of economic losses.
Biological and monitoring information (including tips for scouting and economic thresholds) related to grasshoppers in field crops is posted by Manitoba Agriculture and Resource Development, Saskatchewan Agriculture, Alberta Agriculture and Forestry, the BC Ministry of Agriculture, and the Prairie Pest Monitoring Network. Also, refer to the grasshopper pages within the "Field Crop and Forage Pests and their Natural Enemies in Western Canada: Identification and management field guide" (2018) accessible as a free downloadable PDF in either English or French on our new Field Guides page.
Predicted alfalfa weevil development
The alfalfa weevil (AAW) (Curculionidae: Hypera postica) model predicts development using biological parameters known for the pest species and environmental data observed across the Canadian prairies on a daily basis. Review lifecycle and damage information for this pest.
Model simulations for alfalfa weevil (AAW) indicate the appearance of first and second instar larvae should be occurring across the prairies. Development in southern Manitoba (Fig. 1) is slower than development in southern Alberta (Fig. 2). Development is similar to long-term average values.
Figure 1. Predicted status of alfalfa weevil (Hypera postica) populations near Winnipeg MB as of June 5, 2022.
Figure 2. Predicted status of alfalfa weevil (Hypera postica) populations near Medicine Hat AB as of June 5, 2022.
Additional information can be accessed by reviewing the Alfalfa Weevil Page extracted from the "Field crop and forage pests and their natural enemies in western Canada – Identification and management field guide" (2018) accessible as a free downloadable PDF in either English or French on our new Field Guides page.
Predicted cereal leaf beetle development
The cereal leaf beetle (CLB) (Chysomelidae: Oulema melanopus) model predicts larval development using biological parameters known for the pest species and environmental data observed across the Canadian prairies on a daily basis. Review lifecycle and damage information for this pest.
Warmer conditions in southern Alberta and southwestern Saskatchewan are predicted to result in more rapid development of cereal leaf beetle (CLB) populations compared to southern Manitoba. CLB model output suggests that the hatch should be nearly complete for southern Alberta and Saskatchewan. First and second instar are predicted to be present in these areas (Fig. 1). As a result of cooler conditions, egg development is predicted to be delayed in southern Manitoba (Fig. 2). First instar larvae should begin to occur by the end of this week in Manitoba.
Figure 1. Predicted status of cereal leaf beetle (Oulema melanopus) populations near Lethbridge AB as of June 5, 2022.
Figure 2. Predicted status of cereal leaf beetle (Oulema melanopus) populations near Brandon MB as of June 5, 2022.
Access scouting tips for cereal leaf beetle or find more detailed information by accessing the Oulema melanopus page from the "Field crop and forage pests and their natural enemies in western Canada – Identification and management field guide" (2018; accessible as a free downloadable PDF in either English or French on our new Field Guides page.
Predicted bertha armyworm development
Compared to average development, bertha armyworm (BAW) pupal development in 2022 continues to be delayed for the Peace River region, Manitoba and southern and eastern regions of Saskatchewan (Fig. 1). Pupal development across southern and central Alberta and Saskatchewan is similar to long-term average values. Development in this region is 60-75% complete.
We suggest that BAW pheromone traps be placed in fields when pupal development is 75-80% to ensure that traps are in place prior to emergence of adults. Based on current runs, it is advisable that traps for Alberta and Saskatchewan be placed in fields by the end of this week (June 6-10). Traps should be put out in Manitoba and the Peace River region next week.
Figure 1. Predicted bertha armyworm (Mamestra configurata) pupal development (%) across the Canadian prairies as of June 5, 2022.
Refer to the PPMN Bertha armyworm monitoring protocol for help when performing in-field scouting or eview the 2019 Insect of the Week which featured bertha armyworm and its doppelganger, the clover cutworm!
Biological and monitoring information related to bertha armyworm in field crops is posted by the provinces of Manitoba, Saskatchewan, Alberta and the Prairie Pest Monitoring Network. Also, refer to the bertha armyworm pages within the "Field Crop and Forage Pests and their Natural Enemies in Western Canada: Identification and management field guide" (2018) accessible as a free downloadable PDF in either English or French on our new Field Guides page.
Predicted wheat midge development
Wheat midge (Sitodiplosis mosellana) overwinter as larval cocoons in the soil. Soil moisture conditions in May and June can have significant impacts on wheat midge emergence. Adequate rainfall promotes termination of diapause and movement of larvae to the soil surface where pupation occurs. Insufficient rainfall in May and June can result in delayed movement of larvae to the soil surface. Elliott et al. (2009) reported that wheat midge emergence was delayed or erratic if rainfall did not exceed 20-30 mm during May. Olfert et al. (2016) ran model simulations to demonstrate how rainfall impacts wheat midge population density. The Olfert et al. (2020) model indicated that dry conditions may result in:
a. Delayed adult emergence and oviposition
b. Reduced numbers of adults and eggs
As of June 5, 2022, normal to above normal rainfall in Manitoba, eastern Saskatchewan and the British Columbia Peace River region should be sufficient to promote the movement of wheat midge larvae to the soil surface this year (Fig. 1). Warmer temperatures in central Manitoba are expected to advance larval development over the next seven days. Current development for eastern Saskatchewan and Manitoba is similar to long-term average rates.
Figure 1. Percent of wheat midge larval population (Sitodiplosis mosellana) that has moved to the soil surface across western Canada, as of June 5, 2022.
Information related to wheat midge biology and monitoring can be accessed by linking to your provincial fact sheet (Saskatchewan Agriculture or Alberta Agriculture & Forestry). Alberta Agriculture and Forestry has a YouTube video describing in-field monitoring for wheat midge.
Additional information can be accessed by reviewing the Wheat midge pages extracted from the "Field Crop and Forage Pests and their Natural Enemies in Western Canada: Identification and Field Guide" (2018) accessible as a free downloadable PDF in either English or French on our new Field Guides page.
Weekly Wind Trajectory Report for June 6
Access background information on how and why wind trajectories are monitored. Reverse and forward trajectories are available in this report.
1. REVERSE TRAJECTORIES (RT)
Since May 1, 2022 the majority of reverse trajectories that have crossed the prairies originated from the Pacific Northwest (Idaho, Oregon and Washington) (Fig. 1). Relative to previous weeks, there was a significant decrease in the number of trajectories that were predicted to cross over the prairies from May 31 – June 6, 2022. This week reverse trajectories generally originated over the arctic before entering the prairies.
Figure 1. Average number (based on a 5-day running average) of reverse trajectories (RT) crossing the prairies for the period of May 1-June 6, 2022.
a. Pacific Northwest (Idaho, Oregon, Washington) – The majority of Pacific Northwest reverse trajectories have been reported to pass over southern and central Alberta and western Saskatchewan (Fig. 2). This past week (May 31-June 6, 2022) the ECCC model predicted that 26 reverse trajectories passed over the prairies. This is a significant decrease compared to the previous week (n=124).
Figure 2. Total number of dates with reverse trajectories originating over the Idaho, Oregon, and Washington that have crossed the prairies between April 1 and June 6, 2022.
b. Mexico and southwest USA (Texas, California) – This past week (May 31 to June 6, 2022) reverse trajectories that originated from Mexico, California or Texas crossed over Carman and Selkirk (May 31, 2022). Since April 1, reverse trajectories were reported for Manitoba (Portage, Selkirk, Brandon, Carman, Russell) and eastern Saskatchewan (Gainsborough, Grenfell) (Fig. 3).
Figure 3. The total number of dates with reverse trajectories originating over Mexico, California and Texas that have crossed the prairies between April 1 and June 6, 2022.
c. Oklahoma and Texas – Since April 1, reverse trajectories were reported for Manitoba and eastern Saskatchewan (Fig. 4). This past week (May 31 to June 6, 2022) there has been an increase in the number of reverse trajectories that have crossed over southeastern Saskatchewan (Weyburn and Gainsborough) and Manitoba (Portage and Brandon).
Figure 4. The total number of dates with reverse trajectories originating over Texas and Oklahoma that have crossed the prairies between May 1 and June 6, 2022.
d. Nebraska and Kansas – Reverse trajectories, originating from Kansas and Nebraska, have crossed southeastern Saskatchewan and southern Manitoba (Fig. 5). This past week (May 31 to June 6, 2022) the ECCC model predicted that 6 reverse trajectories passed over the prairies. This is a significant decrease compared to the previous week (n=27).
Figure 5. The total number of dates with reverse trajectories originating over Kansas and Nebraska that have crossed the prairies between April 1 and June 6, 2022.
2. FORWARD TRAJECTORIES (FT)
The following map presents the total number of dates (since April 1, 2022) with forward trajectories (originating from Mexico and USA) that were predicted to cross the Canadian prairies (Fig. 6). This week (May 31 to June 6, 2022) there were fewer (n=12) forward trajectories predicted to cross the prairies than the previous week (n=45). Results indicate that the greatest number of forward trajectories entering the prairies have originated from the Pacific Northwest (Idaho, Oregon, Washington), Montana and Wyoming.
Figure 6. Total number of dates with forward trajectories, originating from various regions of the United States and Mexico, crossing the prairies between April 1 and June 6, 2022.
View historical PPMN wind trajectory reports by following this link which sorts the reports from most recent to oldest.
Provincial insect pest report links
Provincial entomologists provide insect pest updates throughout the growing season so link to their information:
MANITOBA'S Crop Pest Updates for 2022 are up and running! Access a PDF copy of the June 8, 2022 issue here. Bookmark their Crop Pest Update Index to readily access these reports and also bookmark their insect pest homepage to access fact sheets and more!
• Diamondback moth pheromone trap monitoring update for MB – "So far, diamondback moth has been found in 25 traps. Levels are generally very low, with the exception that some moderate counts have occurred in the Eastern and Central region, particularly over the past few weeks." Read the report on Page 7 of the June 8, 2022 issue OR review a more detailed summary of cumulative trap counts from 38 sites deployed across the province.
• Armyworm pheromone trap monitoring is underway in MB – "So far, counts have generally been quite low, with armyworm moths only being caught in 6 traps." Read the report on Page 7-8 of the June 8, 2022 issue.
SASKATCHEWAN'S Crop Production News for 2022 is up and running! Access the online Issue #1 for May 24-30, 2022 here. Bookmark their insect pest homepage to access important information! Crops Blog Posts are updated through the growing season.
• Diamondback moth pheromone trap monitoring update for SK – Access this link to review counts summarized regionally. So far, "diamondback moth is arriving in Saskatchewan, but numbers are currently low".
ALBERTA'S Insect Pest Monitoring Network webpage links to insect survey maps, live feed maps, insect trap set-up videos, and more. There is also a Major Crops Insect webpage. The new webpage does not replace the Insect Pest Monitoring Network page. Remember, AAF's Agri-News occasionally includes insect-related information. Twitter users can connect to #ABBugChat Wednesdays at 10:00 am.
• Diamondback moth pheromone trap monitoring update for AB – Cumulative counts arising from weekly data are available so refer to the Live Map. So far, low numbers of diamondback moth have been intercepted across the province.
• Cutworm live monitoring map for AB – Reports are starting to come in so refer to the Live Map to review areas where cutworms are being found. So far, black army and pale western cutworms have been reported. Use this online form to report cutworms in Alberta.
Crop report links
Click the provincial name below to link to online crop reports produced by:
• Manitoba Agriculture and Resource Development (or access a PDF copy of the June 7, 2022 report).
• Saskatchewan Agriculture (or access a PDF copy of the May 31-June 6, 2022 report).
• Alberta Agriculture and Forestry (or access a PDF copy of the May 31, 2022 report).
The following crop reports are also available:
• The United States Department of Agriculture (USDA) produces a Crop Progress Report (access a PDF copy of the June 6, 2022 edition).
• The USDA's Weekly Weather and Crop Bulletin (access a PDF copy of the June 7, 2022 edition).
As the growing season progresses, the various Weekly Update topics move on and off the priority list for in-field scouting but they should be kept at hand to support season-long monitoring. Click to review these earlier 2022 Posts (organized alphabetically):
• 2021 Risk and forecast maps
• Crop protection guides (Wk02)
• Cutworms (Wk02)
• European corn borer – Canadian standardized assessment 2.0 (Wk02)
• Field heroes (Wk04)
• Field guides – New webpage to access (Wk02)
• Flea beetles (Wk01; IOTW)
• iNaturalist.ca (Wk02)
• Invasive insect species – Early detection (Wk02)
• Scouting charts – canola and flax (Wk03)
• Ticks and Lyme disease (Wk02)
• Wind trajectory reports released in 2022
• Wireworms – New field guide (Wk02)
Sugarbeet wireworm (Limonius californicus) – a big pest in some fields
Continuing our series on Prairie wireworms, this week we highlight the sugarbeet wireworm, Limonius californicus.
This species is less abundant than Hypnoidus bicolor or the Prairie grain wireworm (Selatosomus aeripennis destructor), but some fields have a major problem with this species. Limonius californicus wireworms are 17-22 mm long at maturity and can be aggressive feeders. The literature reports it is more likely to be found in irrigated fields.
The life cycle of L. californicus on the Prairies is not well known. Our current information is based on lab studies in California in the 1940s, where larvae lived for 2-5 years before undergoing metamorphosis into adult click beetles.
Wireworm size varies within a species
depending on age. Photo: W. van Herk, AAFC-Agassiz
AAFC has recently released a new field guide on Prairie pest wireworms. It has information on biology, monitoring and management, and research on wireworms on the Prairies. Preview pages extracted from the guide highlighting Limonius californicus by clicking here.
Free digital copies in both official languages can be downloaded at these links:
Download English guide
Download French guide HERE
Free hard copies are also available while supplies last. Email Haley Catton at haley.catton@agr.gc.ca to request your copy.
– A new pheromone has recently been discovered by researchers at Simon Fraser University AAFC that attracts male beetles. This pheromone will help monitoring efforts.
Gries R, Alamsetti SK, van Herk WG, Catton HA, Meers S, Lemke E, Gries G (2021) Limoniic acid – major sex pheromone component of the click beetles Limonius canus and L. californicus. Journal of Chemical Ecology 41:123-133. https://doi.org/10.1007/s10886-020-01241-y
Van Herk, W. G., Labun, T. J., & Vernon, R. S. (2019). Efficacy of diamide, neonicotinoid, pyrethroid, and phenyl pyrazole insecticide seed treatments for controlling the sugar beet wireworm, Limonius californicus (Coleoptera: Elateridae), in spring wheat. Journal of the Entomological Society of British Columbia, 115, 86-100.
Week 5 and things are starting to heat up! Be sure to catch the Insect of the Week – it's cereal leaf beetle! This week there's more updated information coming your way and be sure to review the Previous Posts to keep all of the PPMN's nsect monitoring resources at hand!
Stay safe and good scouting to you!
TEMPERATURE: This past week (May 24-30, 2021) the average temperature across the prairies was 1 °C cooler than normal (Fig. 1). Temperatures were warmest across most of Alberta and coolest across Saskatchewan and central regions of Manitoba. Across the prairies, the average 30-day (May 1-30) temperature was almost 2 °C warmer than last week and similar to climate normal values. Warmest temperatures were observed across southern Manitoba (Table 1; Fig. 2).
Figure 1. 7-day average temperature (°C) observed across the Canadian prairies for the period of May 24-30, 2021.
Figure 2. 30-day average temperature (°C) observed across the Canadian prairies for the period of May 1-30, 2021.
The 2021 growing season (April 1 – May 31) has been characterized by near-normal temperatures. Temperatures have been warmest for southern Manitoba, western Saskatchewan and southern Alberta (Table 2; Fig. 3).
Figure 3. Growing season average temperature (°C) observed across the Canadian prairies for the period of April 1-May 30, 2021.
The growing degree day map (GDD) (Base 5 ºC, April 1-May 31, 2021) is provided below (Fig. 4) while the growing degree day map (GDD) (Base 10 ºC, April 1-May 31, 2021) is shown in Figure 5.
Figure 4. Growing degree day map (Base 5 °C) observed across the Canadian prairies for the growing season (April 1-May 31, 2021).
Image has not been reproduced in affiliation with, or with the endorsement of the Government of Canada and was retrieved (03Jun2021). Access the full map at https://www.agr.gc.ca/DW-GS/current-actuelles.jspx?lang=eng&jsEnabled=true
Figure 5. Growing degree day map (Base 10 °C) observed across the Canadian prairies for the growing season (April 1-May 31, 2021).
Several areas were on the receiving end of frost and many folks are still watching to see how their crops recover. The lowest temperatures recorded ranged from <-14 to >0 °C (Fig. 6) while the highest temperatures (°C) observed across the Canadian prairies the past seven days ranged from <11 to >25 °C (Fig. 7).
Figure 6. Lowest temperatures (°C) observed across the Canadian prairies the past seven days (May 27-Jun 2, 2021).
Image has not been reproduced in affiliation with, or with the endorsement of the Government of Canada and was retrieved (03Jun2021) although PDF file format was not available. Access the full map at https://www.agr.gc.ca/DW-GS/current-actuelles.jspx?lang=eng&jsEnabled=true
Figure 7. Highest temperatures (°C) observed across the Canadian prairies the past seven days (May 27-Jun 2, 2021).
PRECIPITATION: This week, significant precipitation was reported across central regions of Saskatchewan and Alberta while minimal rain was reported across Manitoba and western Alberta (Fig. 8). Rainfall amounts for the period of May 1-30 (30-day accumulation) were 123 % of long-term average values. Rainfall amounts have been near normal to above normal for large areas of Alberta and southern Saskatchewan. Well above normal rain was reported for Edmonton and Regina. Below normal rainfall amounts were reported for central and northern areas of the Peace River region and across Manitoba (Table 1; Fig. 9).
Figure 8. 7-day cumulative rainfall (mm) observed across the Canadian prairies for the period of May 24-30, 2021.
Figure 9. 30-day cumulative rainfall (mm) observed across the Canadian prairies for the period of May 1-30, 2021.
Average growing season (April 1 – May 30) precipitation was 105 % of normal with the greatest precipitation occurring near Edmonton and across eastern Saskatchewan. Most of Manitoba and the Peace River region have had 60 % or less of normal precipitation during the 2021 growing season so far (Table 2; Fig. 10).
Figure x. Growing season cumulative rainfall (mm) observed across the Canadian prairies for the period of April 1-May 30, 2021.
The maps above are all produced by Agriculture and Agri-Food Canada. Growers can bookmark the AAFC Current Conditions Maps for the growing season. Historical weather data can be access at the AAFC Drought Watch Historical website, Environment Canada's Historical Data website, or your provincial weather network.
Access ALL the PPMN's Wind Trajectory reports (Weekly and Daily).
Access Environment and Climate Change Canada's weather radar mapping interface. Options to access preceeding precipitation events include clicking off either an 1 or 3 hours time interval, using an 8-colour or 14-colour index. or changing the base map.
Access background information for how and why wind trajectories are monitored in this post.
This past week there were an increasing number of reverse trajectories moving north from the Pacific Northwest (Idaho, Oregon and Washington) (Fig. 1). Though this US region can be a source of diamondback moths, the ECCC models predict air movement, not actual occurrence of diamondback moths.
Figure 1. The average number (based on a 5 day running average) of reverse trajectories that have crossed the prairies for the period of May 15 – June 3 2021.
a. Pacific Northwest (Idaho, Oregon, Washington) – This week there were 53 trajectories (compared to 36 last week) that crossed Alberta, Manitoba and Saskatchewan. In previous years, the majority of Pacific Northwest reverse trajectories usually have been reported to pass over southern Alberta. However, tis growing season, PNW trajectories have crossed all parts of the prairies (Figs. 2 and 3).
Figure 2. Total number of reverse trajectories originating across Idaho, Oregon, and Washington and have crossed specific prairie locations between March 18 and June 3, 2021.
Figure 3. Total number of dates with reverse trajectories originating over the Pacific Northwest (Idaho, Oregon, and Washington) and have crossed the prairies between March 24 and June 3, 2021.
b. Mexico and southwest USA (Texas, California) – Compared to previous years, there has been a noticeable increase in the number of trajectories from the southern US. The majority of these trajectories have crossed Manitoba and eastern Saskatchewan (Fig. 4). This week there were no trajectories (compared to 54 last week) that originated in Mexico or the southwest USA that crossed the prairies (Fig. 5).
Figure 4. Total number of reverse trajectories originating across Mexico, California and Texas and have crossed specific prairie locations between March 18 and June 3, 2021.
Figure 5. The total number of dates with reverse trajectories originating over Mexico, California and Texas and have crossed the prairies between March 24 and June 3, 2021.
c. Oklahoma and Texas – The majority of these trajectories have passed over Manitoba and eastern Saskatchewan (Fig. 6). This week there were no trajectories (compared to 51 last week) originating in Oklahoma or Texas that passed over the prairies (Fig. 7).
Figure 6. Total number of reverse trajectories originating across Oklahoma and Texas and have crossed specific prairie locations between March 18 and June 3, 2021.
Figure 7. The total number of dates with reverse trajectories originating over Oklahoma and Texas and have crossed the prairies between March 24 and June 3, 2021.
d. Kansas and Nebraska – Similar to results for Oklahoma and Texas, the majority of these trajectories crossed Manitoba and eastern Saskatchewan (Fig. 8). This week there was one trajectory that originated in Kansas or Nebraska that passed over Carman, Manitoba (Fig. 9). Relative to the reverse trajectories associated with Oklahoma and Texas, the trajectories from Kansas and Nebraska have crossed further into Alberta (Fig. 9).
Figure 8. Total number of reverse trajectories originating across Kansas and Nebraska and have crossed specific prairie locations between March 18 and June 3, 2021.
Figure 9. The total number of dates with reverse trajectories originating over Kansas and Nebraska and have crossed the prairies between March 24 and June 3, 2021.
a. Continuing a trend that began last week, this week there was a decrease in the number of forward trajectories that were predicted to cross the prairies (Fig. 10). The dates on the graph report when the trajectories originated in the USA (blue bars). These trajectories generally require 3-5 days to enter the prairies (red line). The data suggests that, compared to this week, there will be decreased potential for the introduction of DBM to the prairies.
Figure 10. The average number (based on a 5-day running average) of forward trajectories that were predicted to cross the prairies for the period of May 15-June 3, 2021.
Alert: Bertha armyworm development
Model simulations to May 30, 2021, indicate that BAW pupal development is 45-60 % complete across the prairies (Fig. 1). Recent warm conditions in Alberta and southern Manitoba have resulted in the rapid development of BAW pupae (Fig. 2 C). The weather forecast for this week suggests that above-normal temperatures will occur. This could result in faster development of BAW pupae. BAW traps should be placed in fields when pupal development is approximately 80 %.
Figure 1. Predicted bertha armyworm (Mamestra configurata) pupal development across the Canadian prairies as of May 30, 2021.
IMPORTANT: Table 1 provides estimates for when the pheromone-baited green unitrap should be deployed. Based on weather conditions up to May 30, 2021, and model output, BAW adults (Fig. 2 D) may begin to emerge by mid to late June. Typically, moths emerge over an ~6 week period so cumulative counts of moths intercepted in these green unitraps provides insight into anticipated risk and prioritization for in-field scouting of the damaging larval stages later this summer.
Figure 2. The egg stage (A), larval stage (B), pupal stage (C), and adult stage (D) of bertha armyworm.
Photos: Jonathon Williams (AAFC-Saskatoon).
Model projections to June 30 predict that development near Regina (Fig. 3) will be more advanced than at Grande Prairie (Fig. 4). The model predicts that egg hatch will begin in late June near Regina.
Figure 3. Predicted development of bertha armyworm (Mamestra configurata) populations near Regina, Saskatchewan, as of May 30, 2021 (projected to June 30, 2021).
Figure 4. Predicted development of bertha armyworm (Mamestra configurata) populations near Grande Prairie, Alberta as of May 30, 2021 (projected to June 30, 2021).
Biological and monitoring information related to bertha armyworm in field crops is posted by the provinces of Manitoba, Saskatchewan, Alberta and the Prairie Pest Monitoring Network. Also, refer to the bertha armyworm pages within the "Field Crop and Forage Pests and their Natural Enemies in Western Canada: Identification and management field guide" which is a free downloadable document as both an English-enhanced or French-enhanced version.
The grasshopper simulation model will be used to monitor grasshopper development across the prairies. Weekly temperature data collected across the prairies is incorporated into the simulation model which calculates estimates of grasshopper development stages based on biological parameters for Melanoplus sanguinipes (Migratory grasshopper).
Model simulations were used to estimate grasshopper egg development as of May 30, 2021. Average development of eggs is 78 % and is well ahead of the long-term average of 67 %. Warm conditions across southeastern Saskatchewan and southern Manitoba (May 1-30) have been responsible for the advanced development of eggs near Regina, Saskatoon, Brandon and Winnipeg (Fig. 1). Egg development is predicted to exceed 80 % across most of the southern prairies (Fig. 2).
Figure 1. Predicted percent embryonic development of grasshopper eggs across the Canadian prairies as of May 30, 2021.
Figure 2. Predicted grasshopper (Melanoplus sanguinipes) embryological development (%) across the Canadian prairies as of May 30, 2021.
First hatchlings usually are observed once eggs reach 80 % development. As of May 30, hatch was predicted to be occurring across most of the prairies with hatch rates approaching 15-20 % across southern Manitoba and Saskatchewan (Fig. 3).
Figure 3. Predicted grasshopper (Melanoplus sanguinipes) hatch (%) across the Canadian prairies as of May 30, 2021.
The model was projected to June 15 to determine potential development at Saskatoon and Brandon over the next two weeks (Figs. 4 and 5). Results suggest that by June 15 hatch could be greater than 65 % at both locations and nymph populations will consist of first, second, and third instars. Drought conditions tend to favour the development of grasshopper populations while delaying crop development. If dry conditions persist, crop development may be delayed across Manitoba. This may result in conditions conducive to crop damage from grasshoppers as hatch progresses in June. Monitor roadsides and field margins to assess the development and densities of local grasshopper populations.
Figure 4. Predicted development of M. sanguinipes populations near Saskatoon, Saskatchewan as of May 30, 2021 (projected to June 15, 2021).
Figure 5. Predicted development of M. sanguinipes populations near Brandon, Manitoba as of May 30, 2021 (projected to June 15, 2021).
Biological and monitoring information related to grasshoppers in field crops is posted by Manitoba Agriculture and Resource Development, Saskatchewan Agriculture, Alberta Agriculture and Forestry, the BC Ministry of Agriculture and the Prairie Pest Monitoring Network. Also refer to the grasshopper pages within the "Field Crop and Forage Pests and their Natural Enemies in Western Canada: Identification and management field guide" (accessible in either English-enhanced or French-enhanced versions).
The cereal leaf beetle (CLB) model predicts that egg hatch is progressing across the prairies. The graphs provide a comparison of development at Lacombe (Fig. 1) and at Lethbridge (Fig. 2). The simulation indicates that second instar larvae will be observed over the next few days.
Figure 1. Predicted status of cereal leaf beetle (Oulema melanopus) populations near Lacombe, Alberta as of May 30, 2021 (projected to June 15, 2021).
Figure 2. Predicted status of cereal leaf beetle (Oulema melanopus) populations near Lethbridge, Alberta as of May 30, 2021 (projected to June 15, 2021).
Lifecycle and Damage:
Adult: Adult cereal leaf beetles (CLB) have shiny bluish-black wing covers (Fig. 3). The thorax and legs are light orange-brown. Females (4.9 to 5.5 mm) are slightly larger than males (4.4 to 5 mm). Adult beetles overwinter in and along the margins of grain fields in protected places such as in straw stubble, under crop and leaf litter, and in the crevices of tree bark. They favour sites adjacent to shelterbelts, deciduous and conifer forests. They emerge in the spring once temperatures reach 10-15 ºC and the adults are active for about 6 weeks. They usually begin feeding on grasses, then move into winter cereals and later into spring cereals.
Figure 3. Adult Oulema melanopus measure 4.4-5.5 mm long (Photo: M. Dolinski).
Egg: Eggs are laid approximately 14 days following the emergence of the adults. Eggs are laid singly or in pairs along the midvein on the upper side of the leaf and are cylindrical, measuring 0.9 mm by 0.4 mm, and yellowish in colour. Eggs darken to black just before hatching.
Larva: The larvae hatch in about 5 days and feed for about 3 weeks, passing through 4 growth stages (instars). The head and legs are brownish-black; the body is yellowish. Larvae are usually covered with a secretion of mucus and fecal material, giving them a shiny black, wet appearance (Fig. 4). When the larva completes its growth, it drops to the ground and pupates in the soil.
Figure 4. Larval stage of Oulema melanopus with characteristic feeding damage visible on leaf (Photo: M. Dolinski).
Pupa: Pupal colour varies from a bright yellow when it is first formed, to the colour of the adult just before emergence. The pupal stage lasts 2 – 3 weeks. Adult beetles emerge and feed for a couple of weeks before seeking overwintering sites. There is one generation per year.
Fact sheets for CLB are published by the province of Alberta and available from the Prairie Pest Monitoring Network. Also access the Oulema melanopus page from the "Field crop and forage pests and their natural enemies in western Canada – Identification and management field guide" (2018; accessible in either English-enhanced or French-enhanced versions).
Model simulations for alfalfa weevil (AAW) predict, as of May 30, that egg hatch should be nearly complete across Manitoba and Saskatchewan. First instar larvae should be appearing across most of Manitoba (Fig. 1). The following graphs indicate that development is more advanced near Winnipeg (Fig. 2) than near Lethbridge (Fig. 3). This week, larval populations in southern Manitoba should be primarily in the second instar while populations in southern Alberta may consist of first instar larvae. Results suggest that by June 15, populations will be in the second and third larval instars across southern Alberta and that Manitoba populations will be in third and fourth instar stages.
Figure 1. Predicted development of Hypera postica (alfalfa weevil) populations across the prairies as of May 30, 2021.
Figure 2. Predicted status of alfalfa weevil (Hypera postica) development for populations near Winnipeg, Manitoba as of May 30, 2021 (projected to June 15, 2021).
Figure 3. Predicted status of alfalfa weevil (Hypera postica) development for populations near Lethbridge, Alberta as of May 30, 2021 (projected to June 15, 2021).
The larval stage of this weevil feeds on alfalfa leaves in a manner that characterizes the pest as a "skeletonizer" (Fig. 4). The green larva features a dorsal white line down the length of its body, has a dark brown head capsule, and will grow to 9 mm long.
Figure 4. Developmental stages of the alfalfa weevil (Hypera postica). Composite image: J. Soroka (AAFC-Saskatoon).
Alfalfa growers are encouraged to check the Alfalfa Weevil Fact Sheet prepared by Dr. Julie Soroka (AAFC-Saskatoon). Additional information can be accessed by reviewing the Alfalfa Weevil Page extracted from the "Field crop and forage pests and their natural enemies in western Canada – Identification and management field guide" (2018; accessible in either English-enhanced or French-enhanced versions).
Field heroes
The Field Heroes campaign continues to raise awareness of the role of beneficial insects in western Canadian crops.
Two NEW Field Heroes resources for 2021 include:
The NEW Pests and Predators Field Guide is filled with helpful images for quick insect identification and plenty of tips to manage the pests AND natural enemies in your fields. Claim your free copy at http://fieldheroes.ca/fieldguide/ or download for free to arm your in-field scouting efforts!
Real Agriculture went live in 2021 with Season 2 of the Pest and Predators podcast series!
• NEW – Episode 10 – Good bugs relocate for work (June 1, 2021)
• Episode 9 – Secret agents in the stubble (May 18, 2021)
• Episode 8 – Good vs pea leaf weEVIL (May 4, 2021)
• Episode 7 – Powerful parasitoids: Better than fiction (April 20, 2021)
• Recap of SEASON 1: Episode 1 – Do you know your field heroes? Episode 2 – An inside look at the Prairie Pest Monitoring Network. Episode 3 – How much can one wasp save you? Episode 4 – Eat and be eaten — grasshoppers as pests and food Episode 5 – Killer wasp has only one target — wheat stem sawfly Episode 6 – Plentiful parasitoids
Access ALL the Field Heroes links here and be sure to follow @FieldHeroes!
• MANITOBA'S Crop Pest Updates for 2021 are now available! Access the June 2, 2021, report here. Be sure to bookmark their Crop Pest Update Index to readily access these reports! Also bookmark their insect pest homepage to access fact sheets and more!
Bertha armyworm pheromone trap monitoring update for MB – Cooperators will soon deploy pheromone traps according to details provided on page 7 of the June 2, 2021, report.
Diamondback moth pheromone trap monitoring update for MB – Refer to the summary updated twice a week. So far extremely low numbers have been intercepted in Manitoba. Read the details on page 7 of the June 2, 2021, report.
• SASKATCHEWAN'S Crop Production News will soon be available. Access the new Crops Blog Posts and review Saskatchewan's 2020 insect pest surveying results in order to prepare for 2021. Be sure to bookmark their insect pest homepage to access important information!
Bertha armyworm pheromone trap monitoring update for SK – Cooperators will soon deploy pheromone traps at sites across the province.
Diamondback moth pheromone trap monitoring update for SK – follow this link to find current DBM counts. At this point, extremely low numbers have been intercepted but monitoring continues. Seven moths were reported across the entire province so far (2021May19 Carter, pers. comm.).
• ALBERTA'S Insect Pest Monitoring Network webpage links to insect survey maps, live feed maps, and insect trap set-up videos and more. There is also a Major Crops Insect webpage. The new webpage does not replace the Alberta Insect Pest Monitoring Network page. Remember, AAF's Agri-News occasionally includes insect-related information or Twitter users can connect to #ABBugChat Wednesdays at 10:00 am.
Bertha armyworm pheromone trap monitoring update for AB – Cooperators will soon deploy pheromone traps so refer to the Live Map starting next week.
Diamondback moth pheromone trap monitoring update for AB – Refer to the Live Map which still reports extremely low numbers of moths intercepted so far (as of 03Jun2021).
Cutworm reporting tool for AB – Refer to the Live Map which reports three sites with cutworms (as of 03Jun2021).
• Manitoba Agriculture and Resource Development (subscribe to receive OR access a PDF copy of the June 1, 2021 report).
• Saskatchewan Agriculture (or access a PDF copy of the May 25-31, 2021 report).
• The USDA's Weekly Weather and Crop Bulletin (access a PDF copy of the Jun 2, 2021 edition).
• 2020-2021 Risk and forecast maps
• Flea beetles (Wk02)
• Flea beetles – predicted geographic distribution and abundance (Wk04)
• Ladybird beetles (Wk03)
• Pea leaf weevil (Wk03)
• Slugs and their parasites (Wk04)
• Wind trajectories for monitoring insect movement (Wk02)
• Wireworms (Wk02)
Cereal leaf beetle (AAFC)
This week's Insect of the Week is the cereal leaf beetle (Oulema melanopus). Wheat is their preferred host, but they also feed on oat, barley, corn, rye, triticale, reed canary grass, ryegrass, fescue, wild oat, millet and other grasses. Adults and larvae feed on the leaf tissue of host plants. Yield quality and quantity is decreased if the flag leaf is stripped. It is also interesting to note that larvae carry all their own fecal waste with them as protection from predators and parasitoids.
Cereal leaf beetle damage (Bugwood, Bob Hammon)
Adults are 6-8 millimeters (0.25-0.31 inches) long with reddish legs and thorax (middle section between head and abdomen) and metallic bluish-black head and elytra (wing coverings). Mature larvae are 4-5 mm long (0.16-0.20 inches) with a hump-back body.
Cereal leaf beetle larva (AAFC)
Biological control utilizing the parasitoid wasp Tetrastichus julis has proven effective in combating cereal leaf beetle populations. For more information on this insect, see past Insect of the Week instalment on Tetrastichus julis or the AAFC factsheet Biological Control at its Best: Using the T. julis Wasp to Control the Cereal Leaf Beetle.
Biological and monitoring information related to cereal leaf beetle in field crops is posted by the provinces of Alberta and Manitoba. For more information, visit the cereal leaf beetle page from the Field Crop and Forage Pests and their Natural Enemies in Western Canada: Identification and Management field guide. (en français : Guide d'identification des ravageurs des grandes cultures et des cultures fourragères et de leurs ennemis naturels et mesures de lutte applicables à l'Ouest canadien).
Wind trajectories
Agriculture and Agri-Food Canada (AAFC) and Environment and Climate Change Canada (ECCC) have been working together to study the potential of trajectories for monitoring insect movements since the late 1990s.
The entire list of 2020 Wind Trajectory Reports is available here.
→ Read the WEEKLY Wind Trajectory Report for Wk05 (released May 25, 2020).
Scouting for insect pests in field crops needs to step up a notch now across the prairies. Several of the economic pests Canadian growers contend with are now developing into the more damaging stages of their lifecycles.
Access information to support your in-field insect monitoring efforts in the complete Weekly Update either as a series of Posts for Week 5 OR a downloadable PDF.
Questions or problems accessing the contents of this Weekly Update? Please e-mail Dr. Meghan Vankosky or Jennifer Otani. Past "Weekly Updates" can be accessed on our Weekly Update page.
Peas and Faba Beans Pests / Feature Entomologist: Shelley Barkley
Faba Bean cc by 2.0 Michael Major
This week's Insect of the Week feature crops are peas and faba beans, two important Prairie pulse crops. Our feature entomologist this week is Shelley Barkley (Alberta Agriculture and Forestry).
Pea Field
cc by 2.0 Gilles San Martin
Peas and faba beans are relative newcomers to Prairie large-scale agriculture. Up until the 70s, a typical crop rotation may have been some combination of cereal and summer fallow. Dr. Al Slinkard was hired by the University of Saskatchewan-Crop Development Centre (CDC) in 1972 as a pulse breeder, starting a major transformation of Prairie agriculture. First came dry peas and lentils followed by many other pulse crops. Now there is a team of four pulse breeders at the CDC to carry on Dr. Slinkard's legacy. And of course, let's not forgot about the many federal, provincial, university and private industry Prairie pulse breeders that have come along since the 70s.
In 2019, dry peas were grown on 1.7 million hectares (4.3 million acres) on the Prairies, yielding 4.2 million tonnes (4.6 million US tons). Faba beans were grown (37,300 hectares / 92,100 acres) and yielded 107,000 tonnes (118,000 US tons).
There are a number of pests that attack these crops with several common to both crops. Monitoring and scouting protocols are found in the Field Crop and Forage Pests and their Natural Enemies in Western Canada: Identification and Management and the Cutworm Pests of Crops on the Canadian Prairies: Identification and Management Field Guide. More detailed protocols exist for some of the pests.
Pea Pests
Alfalfa caterpillar
Alfalfa looper
Army cutworm
Bertha armycutworm
Clover root curculio
Green cloverworm
Pale western cutworm
Pea leaf weevil
Saltmarsh caterpillar
Seedcorn maggot
Wireworms
Faba Bean Pests
cc by 2.0 Mike Dolinski
Entomologist of the Week: Shelley Barkley
Name: Shelley Barkley
Affiliation: Alberta Agriculture and Forestry
Contact Information: shelley.barkley@gov.ab.ca, @Megarhyssa
How do you contribute in insect monitoring or surveillance on the Prairies?
I am managing the insect monitoring and surveillance program for Alberta Agriculture and Forestry in 2020.
In your opinion, what is the most interesting field crop pest on the Prairies?
It is not a field crop pest, but lily leaf beetle tops my list. So stunningly beautiful, but so devastating to lilies. I am in a war to bring these animals to a tolerable level in my lily bed without having to resort to removing the lilies.
Of the field crop pests, I think bertha armyworm is very interesting, especially how it has capitalized on the introduction of canola. Bertha armyworm have taught me population dynamics, and shown me biocontrol at work in the field. You can read that stuff in a text book, but once you see it in real life you have a new appreciation for nature…and science fiction movies.
What is your favourite beneficial insect?
Ambush bugs are my favourite. I think this species was a model for dragons on Game of Thrones and other works of dragon fiction. All the bumps and lumps on its head and thorax. And those front legs…if only I could have guns like that!
Tell us about an important project you are working on right now.
Delivering insect survey results to the agriculture industry in AB in a timely fashion is my most important current project. I am supporting the industry to the best of my ability.
What tools, platforms, etc. do you use to communicate with your stakeholders?
Twitter, and email are my go to. I also enjoy sharing my photography.
A busy week – seeding is underway across the prairies! Our many field crop entomologists and their integral cooperators are busy deploying various insect monitoring equipment in fields too.
This week marks the return of the Insect of the Week for the 2019 growing season! The initial four weeks will feature invasive species of insects then we will transition to arthropod doppelgangers in an effort to support in-field scouting efforts with identification tips.
The Prairie Pest Monitoring Network is also excited to support the new Prairie Crop Disease Monitoring Network (PCDMN) by promoting their 2019 Cereal Rust Risk Report. This is a new initiative and reports will be available to support in-field scouting.
Access the complete Weekly Update either as a series of Posts for Week 05 (May 9, 2019) OR a downloadable PDF version is available.
Questions or problems accessing the contents of this Weekly Update? Please e-mail either Dr. Meghan Vankosky or Jennifer Otani. Past "Weekly Updates" can be accessed on our Weekly Update page.
Subscribe to the Blog by following these easy steps!
Weather synopsis – Daily average temperatures continue to be cooler than normal for the early growing season. This past week (April 30-May 7, 2019), the average temperature (0.5 °C) was approximately 6 °C cooler than normal (Fig. 1). The warmest temperatures were observed in southern AB and southeastern SK (Fig. 1). Average 30-day temperatures were well below normal (Fig. 3). Across the prairies, average temperatures (April 9-May 6) was 0 to -3 °C below normal (Fig. 2).
Figure 1. Average Temperature (°C) across the Canadian prairies the past seven days (April 30-May 7, 2019).
Figure 2. Average Temperature (°C) across the Canadian prairies the past 30 days (April 7-May 7, 2019).
Figure 3. Mean temperature differences from Normal across the Canadian prairies from April 9-May 6, 2019.
Image has not been reproduced in affiliation with, or with the endorsement of the
Government of Canada and was retrieved (09May2019).
Access the full map at http://www.agr.gc.ca/DW-GS/current-actuelles.jspx?lang=eng&jsEnabled=true
Seven day cumulative rainfall shows that minimal rain was observed across large areas in MB and SK (Fig. 4). Rainfall (30 day accumulation) amounts (Fig. 5) have been well below average for most of the prairies (66% of average) (Fig. 6). Rainfall amounts across southern SK are normal to above normal (Fig. 6).
Figure 4. Cumulative precipitation observed the past seven days across the Canadian prairies (April 30-May 7, 2019).
Figure 5. Cumulative precipitation observed the past 30 days across the Canadian prairies (April 7-May 7, 2019).
Figure 6. Percent of average precipitation across the Canadian prairies the past 30 days (as of May 8, 2019).
Soil moisture values are low across large generally low.
Figure 7. Modelled soil moisture (%) across the Canadian prairies as of May 7, 2019.
The growing degree day map (GDD) (Base 5 ºC, March 1 – June 18, 2017) is below:
Figure 8. Growing degree day (Base 5 ºC) across the Canadian prairies for the growing season (April 1-May 6, 2019).
The growing degree day map (GDD) (Base 10 ºC, March 1 – June 18, 2017) is below:
Figure 9. Growing degree day (Base 10 ºC) across the Canadian prairies for the growing season (April 1-May 6, 2019).
In a continuing effort to produce timely information, the wind trajectory reports are available in two forms:
DAILY REPORTS, as they can be generated, are accessible as a downloadable PDF file on this page.
WEEKLY REPORTS can be retrieved by clicking this hyperlink with the most recent version available here.
2018 Insect Field Guide
Get your copy of the newly updated version of the Insect Field Guide!
Field Crop and Forage Pests and their Natural Enemies in Western Canada: IDENTIFICATION AND MANAGEMENT FIELD GUIDE
Find links to download the FREE Insect Field Guide.
Cutworms
Cutworms (Noctuidae) – A field guide is available to help growers scout and manage Cutworms. Cutworm Pest of Crops is available for free in either English or French and is posted on the Cutworm Field Guide page!
Several species of cutworms can be present in fields (Refer to downloadable PDF below). They range in colour from shiny opaque, to tan, to brownish-red with chevron patterning. Cutworm biology, species information, plus monitoring recommendations are available in the Prairie Pest Monitoring Network's Cutworm Monitoring Protocol. Also refer to Manitoba Agriculture cutworm fact sheet which includes action and economic thresholds for cutworms in several crops.
In 2018, the Insect of the Week featured two economically important species of cutworms and some of the important natural enemies that help regulate these pests:
Wk01 (May 07, 2018) – Glassy cutworm
Wk02 (May 14, 2018) – Darksided cutworm
Wk03 (21 May, 2018) – Ground beetles: cutworm natural enemies
Scout fields that are "slow" to emerge, are missing rows, include wilting or yellowing plants, have bare patches, or appear highly attractive to birds – these are areas warranting a closer look. Plan to follow-up by walking these areas later in the day when some cutworm species move above-ground to feed. Start to dig below the soil surface (1-5 cm deep) near the base of a symptomatic plant or the adjacent healthy plant. If the plant is well-established, check within the crown in addition to the adjacent soil. The culprits could be wireworms or cutworms.
CutwormSeasonalChart_Floate
For Albertans….. If you find cutworms, please consider using the Alberta Pest Surveillance Network's "2019 Cutworm Reporting Tool" then view the live 2019 cutworm map which is updated daily.
Flea beetles
Flea Beetles (Chrysomelidae: Phyllotreta species)– Reminder – Be on the lookout for flea beetle damage resulting from feeding on canola cotyledons but also on the stem. Two species, Phyllotreta striolata and P. cruciferae, will feed on all cruciferous plants but they can cause economic levels of damage in canola during the seedling stages.
Remember, the Action Threshold for flea beetles on canola is 25% of cotyledon leaf area consumed. Watch for shot-hole feeding in seedling canola but also watch the growing point and stems of seedlings which are particularly vulnerable to flea beetle feeding.
Estimating flea beetle feeding damage can be challenging. Using a visual guide to estimate damage can be helpful. Canola Watch circulated this article but also use the two images (copied below for reference) produced by Dr. J. Soroka (AAFC-Saskatoon) – take it scouting!
Figure 1. Canola cotyledons with various percentages of leaf area consume owing to flea beetle feeding damage (Photo: Soroka & Underwood, AAFC-Saskatoon).
Figure 2. Percent leaf area consumed by flea beetles feeding on canola seedlings (Photo: Soroka & Underwood, AAFC-Saskatoon).
Refer to the flea beetle page from the "Field Crop and Forage Pests and their Natural Enemies in Western Canada: Identification and management field guide" as an English-enhanced or French-enhanced version.
Alfalfa Weevil (Hypera postica) – Degree-day maps of base 9°C are produced using the Harcourt/North Dakota models (Soroka et al. 2015). Models predicting the development of Alfalfa weevil (AAW) across the prairies are updated weekly to help growers time their in-field scouting for second-instar larvae.
AAW model runs indicate that oviposition should have begun in the Brooks (Rosemary) AB (Fig. 1) and Regina SK regions (Fig. 2). Note that this week's cool temperatures have reduced oviposition rates (based on model predictions).
Figure 1. Predicted status of alfalfa weevil populations near Swift Current SK as of May 7, 2019.
The larval stage of this weevil feeds on alfalfa leaves in a manner that characterizes the pest as a "skeletonizer". The green larva featuring a dorsal, white line down the length of its body has a dark brown head capsule and will grow to 9mm long.
Alfalfa growers are encouraged to check the Alfalfa Weevil Fact Sheet prepared by Dr. Julie Soroka (AAFC-Saskatoon). Additional information can be accessed by reviewing the Alfalfa Weevil Page extracted from the "Field crop and forage pests and their natural enemies in western Canada – Identification and management field guide" (Philip et al. 2015). The guide is available in both a free English-enhanced or French-enhanced version.
Pea Leaf Weevil (Sitona lineatus) – The PLW model was run for Red Deer AB (Fig. 1) and Saskatoon SK (Fig. 2). The predictive model outputs suggest that PLW adults are active but oviposition has not begun.
Figure 1. Predicted status of pea leaf weevil populations near Red Deer as of May 7, 2019.
Figure 2. Predicted status of pea leaf weevil populations near Saskatoon SK as of May 7, 2019.
Pea leaf weevils emerge in the spring primarily by flying (at temperatures above 17ºC) or they may walk short distances. Pea leaf weevil movement into peas and faba beans is achieved primarily through flight. Adults are slender, greyish-brown measuring approximately 5 mm in length (Fig. 3, Left).
The pea leaf weevil resembles the sweet clover weevil (Sitona cylindricollis) but the former is distinguished by three light-coloured stripes extending length-wise down thorax and sometimes the abdomen. All species of Sitona, including the pea leaf weevil, have a short snout.
Figure 3. Comparison images and descriptions of four Sitona species adults including pea leaf weevil (Left).
Adults will feed upon the leaf margins and growing points of legume seedlings (alfalfa, clover, dry beans, faba beans, peas) and produce a characteristic, scalloped (notched) edge. Females lay 1000 to 1500 eggs in the soil either near or on developing pea or faba bean plants from May to June.
Biological and monitoring information related to pea leaf weevil in field crops is posted by the province of Alberta and in the PPMN monitoring protocol.
Also refer to the pea leaf weevil page within the "Field Crop and Forage Pests and their Natural Enemies in Western Canada: Identification and management field guide" – both English-enhanced or French-enhanced versions are available. A review of this insect was published in 2011 in Prairie Soils and Crops by Carcamo and Vankosky.
Cereal leaf beetle (Oulema melanopus) – The cereal leaf beetle model indicates that oviposition is well underway in Lethbridge AB as of May 7, 2019 (Fig. 1).
Figure 1. Predicted status of cereal leaf beetle populations near Lethbridge AB as of April 30, 2019
Adult: Adult cereal leaf beetles (CLB) have shiny bluish-black wing-covers (Fig. 2). The thorax and legs are light orange-brown. Females (4.9 to 5.5 mm) are slightly larger than the males (4.4 to 5 mm). Adult beetles overwinter in and along the margins of grain fields in protected places such as in straw stubble, under crop and leaf litter, and in the crevices of tree bark. They favour sites adjacent to shelter belts, deciduous and conifer forests. They emerge in the spring once temperature reaches 10-15 ºC and are active for about 6 weeks. They usually begin feeding on grasses, then move into winter cereals and later into spring cereals.
Egg: Eggs are laid approximately 14 days following the emergence of the adults. Eggs are laid singly or in pairs along the mid vein on the upper side of the leaf and are cylindrical, measuring 0.9 mm by 0.4 mm, and yellowish in colour. Eggs darken to black just before hatching.
Figure 3. Larval stage of Oulema melanopus with characteristic feeding
damage visible on leaf (Photo: M. Dolinski).
Fact sheets for CLB are published by the province of Alberta and available from the Prairie Pest Monitoring Network. Also access the Oulema melanopus page from the new "Field crop and forage pests and their natural enemies in western Canada – Identification and management field guide".
Grasshopper Simulation Model Output – The grasshopper simulation model will be used to monitor grasshopper development across the prairies. Weekly temperature data collected across the prairies is incorporated into the simulation model which calculates estimates of grasshopper development stages based on biological parameters for Melanoplus sanguinipes (Migratory grasshopper).
This week, cool temperatures this week were predicted to result in minimal embryological development. As of May 7, 2019, predicted development was 60% and is similar to long term average values (Fig. 1). As embryological development approaches 100%, scouting for nymphs of pest species of grasshoppers should begin.
Figure 1. Predicted grasshopper (Melanoplus sanguinipes) embryological development across the Canadian prairies as of May 7, 2019.
Reminder – The Prairie Pest Monitoring Network's 2019 Grasshopper Forecast Map was released in March. Review all the current risk and forecast maps by linking here. While spring temperatures, soil moisture conditions, and precipitation can all have an impact on overwintered grasshopper eggs, areas highlighted orange or red in the 2019 forecast map should be vigilant this spring by performing in-field scouting to assess nymph densities.
Biological and monitoring information related to grasshoppers in field crops is posted by Manitoba Agriculture, Saskatchewan Agriculture, Alberta Agriculture and Forestry, the BC Ministry of Agriculture and the Prairie Pest Monitoring Network. Also refer to the grasshopper pages within the new "Field Crop and Forage Pests and their Natural Enemies in Western Canada: Identification and management field guide" as an English-enhanced or French-enhanced version.
Provincial Insect Pest Reports
Provincial entomologists provide insect pest updates throughout the growing season so we link to their most recent information:
• Manitoba's Insect and Disease Updates for 2019 will be posted here and includes updates from Dr. John Gavloski.
• Saskatchewan's Crop Production News for 2019 will be posted here and frequently includes updates from Dr. James Tansey and Mr. Carter Peru.
• Alberta Agriculture and Forestry's Call of the Land regularly includes insect pest updates from Mr. Scott Meers. The most recent Call of the Land was posted March 18-22, 2019 but did not include an insect update.
Crop reports
Crop reports are produced by:
Manitoba Agriculture (May 7, 2019)
Saskatchewan Agriculture (August 30-May 6, 2019)
Alberta Agriculture and Forestry Crop Report (2019 reports will be available here)
The United States Department of Agriculture (USDA) produces a Crop Progress Report (view the May 6, 2019 edition).
The USDA's Weekly Weather and Crop Bulletin (view the May 7, 2019 edition).
Click to review these earlier 2019 Posts:
2019 Risk and forecast maps – Week 2
Insect scouting chart for Canola – Week 4
Insect scouting chart for Flax – Week 4
Ticks and Lyme disease – Week 4
Wind trajectories – Weeks 1-4
Invasive species: Brown marmorated stink bug
This week's Insect of the Week is the brown marmorated stink bug (Halyomorpha halys). Stink bugs get their name from the foul odour they release when threatened. Brown marmorated stink bug is not known to be established in the Prairies, but the species has been found in the Southern Interior of BC, in Ontario and Quebec. Feeding causes damage to seeds and seed pods, reducing yield. Nymphs and adults prefer field corn and soybean, but infestations have been reported on rape, pea, sunflower and cereals in the USA. They have also been known to attack tree fruits, berries, vegetables and many ornamental trees and shrubs.
Brown marmorated stink bug – adult (CC-BY 2.0 Katja Schulz)
Additional information and fact sheets for this insect have been posted by Ontario Ministry of Agriculture, Food, and Rural Development, and BC Ministry of Agriculture and Seafood. You can also check out our Insect of the Week page.
This insect is featured in our Field Crop and Forage Pests and their Natural Enemies Field Guide which is available for download from the Insect Field Guide page.
Prairie Crop Disease Monitoring Network (PCDMN)
New for 2019 – The Prairie Crop Disease Monitoring Network (PCDMN) represents the combined effort of our prairie pathologists who work together to support in-field disease management in field crops.
In 2019, the PCDMN will release a series of weekly Cereal Rust Risk Reports throughout May and June. Information related to trajectory events based on forecast and diagnostic wind fields and cereal rust risk is experimental, and is OFFERED TO THE PUBLIC FOR INFORMATIONAL PURPOSES ONLY.
Background: Agriculture and AgriFood Canada (AAFC) and Environment and Climate Change Canada (ECCC) have been working together to study the potential of trajectories for monitoring insect movements since the late 1990s. Trajectory models are used to deliver an early-warning system for the origin and destination of migratory invasive species, such as diamondback moth. In addition, plant pathologists have shown that trajectories can assist with the prediction of plant disease infestations and are also beginning to utilize these same data. An introduction will be presented of efforts to identify wind trajectory events that may bring rust urediniospores into Western Canada from epidemic areas in the central and Pacific northwest (PNW) regions of the USA. Identification of potential events as well as an assessment of epidemic severity from source locations, and prairie weather conditions, will be used to assess the need for prompt targeted crop scouting for at-risk regions of the Canadian Prairies.
This week, two documents are available from the PCDMN:
An introduction to cereal rust risk and wind trajectories from the USA.
WIND TRAJECTORY AND CEREAL RUST RISK REPORT for May 7, 2019
Synopsis of May 7, 2019, Weekly Cereal Rust Risk Report:
1. Pacific Northwest – Given limited stripe rust development in the PNW, a relatively low number of recent wind trajectories from the PNW, cool Prairie weather conditions, and early stages of Prairie crop development, as of early May the risk of stripe rust appearance from the PNW is limited and scouting for this disease is not urgent.
2. Texas-Nebraska corridor – Given limited leaf and stripe rust development in this corridor, a relatively low number of recent wind trajectories from this area, cool Prairie weather conditions, and early stages of Prairie crop development, as of early May the risk of leaf and stripe rust appearance from the Texas-Nebraska corridor is limited and scouting for these diseases is not urgent.
3. Where farmers or consultants noticed stripe rust development on winter wheat in the fall of 2018, it is recommended to scout winter wheat fields that have resumed growth this spring. Scouting is especially critical where the variety being grown is susceptible to stripe rust. Currently, there are no early spring reports of stripe rust on winter wheat.
Insect of the Week – Wireworms
This week's Insect of the Week is a frustrating pest of many crops: wireworm. Wireworms are the soil-dwelling larval stage of the click beetles (Elateridae). There are hundreds of click beetle species in the prairies, but the term wireworm refers to those that are pests, which in Canada is approximately 20 species. With the loss of effective insecticides (e.g. lindane), wireworms have re-emerged in recent years as primary pests of potato, cereals, and vegetables. On the prairies, we have 3 predominant pest species (Selatosomus destructor, Limonius californicus, and Hypnoidus bicolor; see photo), and their larvae vary (among other things) in life history (2-7 years), color (white to orange), cuticle thickness, distribution, behaviour, and susceptibility to insecticides.
Wireworms are patchy in distribution, difficult to monitor, and difficult to kill. We have a lot to learn about these resilient pests. Since the mid-1990's AAFC has had a national research team (Bob Vernon et al.) screening for effective insecticides and developing trapping and monitoring methods, cultural controls (e.g., crop rotation), and biocontrols to manage the adult and larval forms of these pests.
For more information about wireworms, check out our Insect of the Week page!
The three most troublesome wireworm species on the prairies in their adult and larval stages. Note the different sizes and colours. From left to right, S. destructor, L. californicus, H. bicolor.
Photo by David Shack, AAFC-Lethbridge.
For more information, please contact Dr. Haley Catton (AAFC-Lethbridge) or Dr. Wim van Herk (AAFC-Agassiz)
Also link here to access a summary of Wireworm surveying (2004-2017) conducted across the Canadian prairies by van Herk and Vernon (AAFC-Agassiz).
Access the complete Weekly Update either as a series of Posts for Week 05 (June 7, 2018) OR a downloadable PDF version. Also review the "Insect of the Week" for Week 5!
Subscribe to the Blog by following these three steps!
Weather synopsis – This past week (May 28-June 4, 2018), the average temperature was very similar to the long term normal (Fig. 1). The warmest weekly temperatures occurred across Manitoba. The 30-day average temperature (April 29 – May 29) was approximately 2 °C warmer than long term average (Fig. 2). Across the prairies, the average temperature for May was up to 5 °C warmer than average.
Figure 1. Weekly (May 28–June 4, 2018) average temperature (°C) .
Figure 2. The 30 day (April 29 – May 29, 2018) average temperature (°C).
Weekly precipitation was above average and 30-day total rainfall is approximately 20% less than average (Figs. 3 and 4).
Figure 3. Weekly (May 28 – June 4, 2018) cumulative precipitation (mm).
Figure 4. The 30-day (May 28 – June 4, 2018) cumulative precipitation (mm).
Accumulated precipitation for the growing season (April 01-June 4, 2018) is shown below.
The map below reflects the Highest Temperatures occurring over the past 7 days (May 29-June 4, 2018) across the prairies.
The map below reflects the Lowest Temperatures occurring over the past 7 days (May 29-June 4, 2018) across the prairies.
The growing degree day map (GDD) (Base 10ºC, March 1 – June 3, 2018) is below:
The growing degree day map (GDD) (Base 5ºC, March 1 – June 3, 2018) is below:
The maps above are all produced by Agriculture and Agri-Food Canada. Growers may wish to bookmark the AAFC Drought Watch Maps for the growing season.
Background: Agriculture and Agri-Food Canada (AAFC) and Environment and Climate Change Canada (ECCC) have been working together to study the potential of trajectories to deliver an early-warning system for the origin and destination of migratory invasive agricultural pests.
We receive two types of model output from ECCC: reverse trajectories (RT) and forward trajectories (FT):
(i) 'Reverse trajectories' (RT) refer to air currents that are tracked back in time from specified Canadian locations over a five-day period prior to their arrival date.
(ii) 'Forward trajectories' (FT) have a similar purpose; however, the modelling process begins at sites in USA and Mexico. The model output predicts the pathway of a trajectory. Again, of interest are the winds that eventually end up passing over the Prairies.
The number of Reverse Trajectories (RTs), crossing the prairies in May 2018, was lower than the long term average (2007 – 2017). The total number of incoming trajectories (sum of Pacific Northwest and southwest USA/Mexico) for 2018 was less than similar values for 2017 and 2007 – 2017. Based on RTs by region, the number of RTs from the Pacific Northwest (PNW) was less than 2007 – 2017 and 2017. To date, the RTs originating in the southwest USA/Mexico in 2018, have been greater in number than in 2017 and less than the long term average (Fig. 1).
Figure 1. Total number of reverse trajectories by geographic region (Pacific Northwest and
Mexico and the southwest USA) for May 2018.
Weather forecasts (7 day):
Winnipeg: https://weather.gc.ca/city/pages/mb-38_metric_e.html Brandon: https://weather.gc.ca/city/pages/mb-52_metric_e.html Saskatoon: https://weather.gc.ca/city/pages/sk-40_metric_e.html Regina: https://weather.gc.ca/city/pages/sk-32_metric_e.html Edmonton: https://weather.gc.ca/city/pages/ab-50_metric_e.html Lethbridge: https://weather.gc.ca/city/pages/ab-30_metric_e.html Grande Prairie: https://weather.gc.ca/city/pages/ab-31_metric_e.html
Wireworm distribution map
The following maps summarize the main results of a survey of pest species of wireworms of the Canadian Prairie Provinces. Samples (both larvae and beetles) were submitted to Dr. Bob Vernon's lab in Agassiz, BC, from 2004 to 2017, and identified by Dr. Wim van Herk (Fig. 1). Species identifications were confirmed with barcoding.
Figure 1. Sampling locations for click beetles and wireworm larvae (Coleoptera: Elateridae) submitted for wireworm surveying from 2004-2017.
Approximately 600 samples were submitted, with the number of larvae per sample typically less than five (Fig. 1). More samples are welcome, particularly from areas currently not well represented on the maps. Please provide either the legal land description or latitude and longitude coordinates with a sample. Any information on the cropping history or whether fields were irrigated is helpful.
The main findings of this survey are that:
1. Wireworms are re-emerging as primary pests of cereals and other crops, particularly in southern Alberta and Saskatchewan. This can be attributed to several factors, including changes in seeding and cultivation resulting in higher soil moisture and increased food availability, and therefore greater wireworm survival; the elimination of effective insecticides such as lindane and the decline of organochlorine residues in the soil; and the present lack of insecticides that actually kill wireworms.
2. Limonius californicus is generally the predominant pest species in fields reporting heavy wireworm damage, occasionally building up to very high populations and resulting in complete crop wrecks (Fig. 2). This was not the case when Glen et al. (1943) or Doane (1977) conducted their surveys; L. californicus was considered a minor species at those times. Selatosomus destructor (Fig. 3) and Hypnoidus bicolor (Fig. 4) are still the most common species. The pest status of another commonly found species, the predaceous Aeolus mellillus (Fig. 5), is unclear. The following species listed by Glen et al. (1943) as pests of agriculture in the Prairie Provinces were found also, but infrequently: Agriotes mancus, A. criddlei, A. stabilis, Hemicrepidius memnonius, L. pectoralis, and various Dalopius sp.
Figure 2. Distribution of Limonius californicus (Coleoptera: Elateridae) submitted for wireworm surveying from 2004-2017.
Figure 3. Distribution of Selatosomus destructor (Coleoptera: Elateridae) submitted for wireworm surveying from 2004-2017.
Figure 4. Distribution of Hypniodes bicolor (Coleoptera: Elateridae) submitted for wireworm surveying from 2004-2017.
Figure 5. Distribution of Aeolus mellillus (Coleoptera: Elateridae) submitted for wireworm surveying from 2004-2017.
3. Multiple pest species are frequently found in the same fields where damage is reported (i.e. about 25% of the time, despite the small number of larvae per sample). This is particularly important as pest species can vary considerably in the type of damage they cause (e.g. it remains unclear if H. bicolor is damaging to potato), their life history (e.g. duration of the larval stage), and susceptibility to insecticides.
Details related to the biology and management of these species are reviewed in van Herk and Vernon (2014) and Vernon and van Herk (2013).
These maps are only possible thanks to the collections done by a large team of local entomologists and agrologists. We are extremely grateful to them; thank you to everyone who participated! A special thank you to Ted Labun and colleagues at Syngenta Crop Protection (Canada), and to Bayer CropScience, for providing the bulk of the samples.
Please do not distribute or use the contents of this post, including any maps, without obtaining prior permission.
Obtain further information or arrange shipment of wireworm or click beetle samples by contacting:
Dr. Wim van Herk
Agassiz Research and Development Centre
6947 Highway 7, Agassiz, BC, V0M 1A0
wim.vanherk@agr.gc.ca
Further wireworm reading:
Burrage RH (1964) Trends in damage by wireworms (Coleoptera: Elateridae) in grain crops in Saskatchewan, 1954–1961. Canadian Journal of Plant Science, 44: 515–519. https://doi.org/10.4141/cjps64-102
Doane JF (1977) Spatial pattern and density of Ctenicera destructor and Hypolithus bicolor (Coleoptera: Elateridae) in soil in spring wheat. The Canadian Entomologist 109: 807–822. https://doi.org/10.4039/Ent109807-6
Doane JF (1977) The flat wireworm, Aeolus mellillus: studies on seasonal occurrence of adults and incidence of the larvae in the wireworm complex attacking wheat in Saskatchewan. Environmental Entomology 6: 818–822. https://doi.org/10.1093/ee/6.6.818
Glen R, King KM, Arnason AP (1943) The identification of wireworms of economic importance in Canada. Canadian Journal of Research 21: 358-387. https://doi.org/10.1139/cjr43d-030
van Herk WG, Vernon RS (2014) Click beetles and wireworms (Coleoptera: Elateridae) of Alberta, Saskatchewan, and Manitoba. In: Arthropods of Canadian Grasslands (Volume 4): Biodiversity and Systematics Part 2. (Edited by D.J. Giberson and H.A. Carcamo). Biological Survey of Canada, pp. 87-117. https://biologicalsurvey.ca/monographs/read/17
Vernon RS, van Herk WG (2013) Wireworms as pests of potato. In: Insect pests of potato: Global perspectives on biology and management. (Edited by P. Giordanengo, C. Vincent, A. Alyokhin). Academic Press, Elsevier, Amsterdam, pp 103–164. https://www.elsevier.com/books/insect-pests-of-potato/alyokhin/978-0-12-386895-4
Zacharuk RY (1962) Distribution, habits, and development of Ctenicera destructor (Brown) in western Canada, with notes on the related species C. aeripennis (Kby.) (Coleoptera: Elateridae). Canadian Journal of Zoology 40: 539–552. https://doi.org/10.1139/z62-046
As of June 4, 2018, predicted hatch was 51% (31% last week; long term average was 11%). Hatch is predicted to be nearly complete in southeast AB and southern MB (Fig. 1). Grasshopper populations are primarily in the first instar (Fig. 2).
Figure 1. Grasshopper hatch (%) based on model simulations, for April 1-June 4, 2018.
Figure 2. Percent of grasshopper population that is in the first instar, based on model simulations, for April 1-June 4, 2018.
Cereal leaf beetle (Oulema melanopus) – Model output indicates that CLB are primarily in the larval stage (Fig. 1).
Figure 1. Percent of cereal leaf beetle population that is in the larval stage, based on model simulations, for April 1-June 4, 2018.
Bertha armyworm (Lepidoptera: Mamestra configurata) – The BAW model is predicting that pupae are developing rapidly in the soil and that development is well ahead of average (Fig. 1). Development is expected to be 5 – 6 days faster than average.
Though cooler temperatures have slowed BAW development, moths are predicted to emerge 10 days ahead of average (Table 1). Pupal development is approximately 82% (Fig. 1). Model output predicts that emergence may begin as early as June 9th.
Table 1. Projected dates for BAW adult emergence for June 4, 2018 (projected to June 30, 2018).
Figure 1. Predicted bertha armyworm pupal development (as of June 3, 2018).
Biological and monitoring information related to bertha armyworm in field crops is posted by the provinces of Manitoba, Saskatchewan, Alberta and the Prairie Pest Monitoring Network. Also refer to the bertha armyworm pages within the new "Field Crop and Forage Pests and their Natural Enemies in Western Canada: Identification and management field guide" – both English-enhanced or French-enhanced versions are available.
Pea Leaf Weevil (Sitona lineatus) – The PLW model predicts that oviposition is occurring across southern and central regions of the prairies (example Red Deer (Fig. 9).
Figure 1. Predicted pea leaf weevil phenology at Red Deer AB.
Values are based on model simulations, for April 1-May 28, 2018 (projected to July 15, 2018).
Reminder – The 2017 risk map for pea leaf weevils was released in March 2018. The map is based on the number of feeding notches observed in peas (Fig. 3).
Figure 3. Estimates of pea leaf weevil (S. lineatus) densities based on feeding notches observed in peas grown in Alberta and Saskatchewan in 2017.
Alfalfa Weevil (Hypera postica) – The AAW model runs for Swift Current SK indicate that oviposition is well underway in southern Saskatchewan (Fig. 1). Larvae should be primarily second and third instars. Fourth instar larvae may be occurring as well.
Figure 1. Average developmental alfalfa weevil stage.
Values are based on model simulations, for April 1-June 4, 2018.
Use the photo below as a visual reference to identify alfalfa weevil larvae. Note the white dorsal line, the tapered shape of the abdomen and the dark head capsule.
Cabbage seedpod weevil
Cabbage seedpod weevil (Ceutorhynchus obstrictus) – There is one generation of CSPW per year and the overwintering stage is the adult which is an ash-grey weevil measuring 3-4mm long (Refer to lower left photo). Adults typically overwinter in soil beneath leaf litter within shelter belts and roadside ditches.
Begin sampling when the crop first enters the bud stage and continue through the flowering.
Sweep-net samples should be taken at ten locations within the field with ten 180° sweeps per location.
Count the number of weevils at each location. Samples should be taken in the field perimeter as well as throughout the field.
Adults will invade fields from the margins and if infestations are high in the borders, application of an insecticide to the field margins may be effective in reducing the population to levels below which economic injury will occur.
An insecticide application is recommended when three to four weevils per sweep are collected and has been shown to be the most effective when canola is in the 10 to 20% bloom stage (2-4 days after flowering starts).
Consider making insecticide applications late in the day to reduce the impact on pollinators. Whenever possible, provide advanced warning of intended insecticide applications to commercial beekeepers operating in the vicinity to help protect foraging pollinators.
High numbers of adults in the fall may indicate the potential for economic infestations the following spring.
Damage: Adult feeding damage to buds is more evident in dry years when canola is unable to compensate for bud loss. Adults mate following a pollen meal then the female will deposit a single egg through the wall of a developing pod or adjacent to a developing seed within the pod (refer to lower right photo). Eggs are oval and an opaque white, each measuring ~1mm long. Typically a single egg is laid per pod although, when CSPW densities are high, two or more eggs may be laid per pod.
There are four larval instar stages of the CSPW and each stage is white and grub-like in appearance ranging up to 5-6mm in length (refer to lower left photo). The first instar larva feeds on the cuticle on the outside of the pod while the second instar larva bores into the pod, feeding on the developing seeds. A single larva consumes about 5 canola seeds. The mature larva chews a small, circular exit hole from which it drops to the soil surface and pupation takes place in the soil within an earthen cell. Approximately 10 days later, the new adult emerges to feed on maturing canola pods. Later in the season these new adults migrate to overwintering sites beyond the field.
Please find additional detailed information for CSPW in fact sheets posted by Alberta Agriculture and Forestry, Saskatchewan Agriculture, or the Prairie Pest Monitoring Network.
Manitoba's Insect and Disease Update for 2018 will be posted soon. Review the most recent update (June 4, 2018) prepared by John Gavloski and Holly Derksen. The insect update notes flea beetles in canola and cutworms with monitoring for alfalfa weevil larvae underway. Diamondback moth trap numbers remain low and bertha armyworm pheromone traps will go up this week.
Saskatchewan's Crop Production News for 2018 is now posted. Access Report #1 posted May 31, 2018, and be sure to review the articles posted for flea beetles and pea leaf weevils to prepare for field scouting. Also know that Saskatchewan growers can review diamondback moth pheromone trap counts in the upper right of the diamondback moth page.
Access Alberta Agriculture and Forestry's Call of the Land for insect pest updates from Scott Meers. The most recent Call of the Land (posted on May 31, 2018) and highlights scouting for flea beetles with the warmer weather, glassy cutworms in perennial forages crops and more recently in the irrigated acres to the south of the province (please report using online cutworm reporting tool), relatively low numbers of diamondback moth on pheromone traps in the 4th week of monitoring and relatively low pea leaf weevil numbers so far based on field assessments completed in southern Alberta to date.
Manitoba Agriculture, Rural Development (June 4, 2018)
Saskatchewan Agriculture Crop Report (May 22-28, 2018)
Alberta Agriculture and Forestry Crop Report (May 29, 2018)
The United States Department of Agriculture (USDA) produces a Crop Progress Report (view the June 4, 2018 edition).
The USDA's Weekly Weather and Crop Bulletin (view the June 5, 2018 edition).
Monarch migration
We continue to track the migration of the Monarch butterflies as they move north by checking the 2018 Monarch Migration Map! A screen shot of the map has been placed below as an example (retrieved 29May2018) but follow the hyperlink to check the interactive map!
Visit the Journey North website to learn more about migration events in North America and visit their monarch butterfly website for more information related to this fascinating insect.
The following is a list of 2018 Posts – click to review:
Cereal aphid manager (CAM) – Week 2
Crop protection guides – Week 2
Cutworms – Week 4
Flea beetles – Week 4
PMRA Pesticide Label Mobile App – Week 4
Scouting charts (canola and flax) – Week 3
Weather radar – Week 3
Insect of the Week – Pea leaf weevil
This week's "Insect of the Week" is the Pea Leaf Weevil. Larval hosts are field peas and faba beans. Adults can spread to other cultivated and wild legumes, such as alfalfa, beans and lentils. Each adult female lays up to 300 eggs in one summer! The eggs hatch in the soil near developing plants and larvae move to feed on nitrogen-fixing nodules. This results in partial or complete inhibition of nitrogen fixation by the plant, causing poor plant growth. Adults feed on leaves and growing points of seedlings, causing notches in leaf margins.
Adult, larval and egg stages overlap and all three can be present over most of the growing season. For more information about Pea Leaf Weevil risk in your area, see the 2017 Insect Risk Maps page. Also, we have posted a NEW Pea Leaf Weevil monitoring protocol.
For more information on the pea leaf weevil, see the Insect of the Week page.
Pea leaf weevil – adult, eggs (Mike Dolinski, MikeDolinsky@hotmail.com)
Remember the NEW Cutworm Field Guide is free and downloadable in 2017!
Weekly Update – Greetings!
Access the complete Weekly Update either as a series of Posts for Week 5 (Jun 1, 2017) OR a downloadable PDF version.
Questions or problems accessing the contents of this Weekly Update? Please e-mail either Dr. Owen Olfert or Jennifer Otani. Past "Weekly Updates" can be accessed on our Weekly Update page.
Weekly Update – Weather Synopsis
Weather synopsis – Across the prairies, this week's average temperatures were slightly cooler than normal.
After a wetter week in central and northern Alberta, the most current 7-day rainfall was greater in the east of central Alberta into central Saskatchewan down into Manitoba.
The 30-day rainfall amounts were average to below average across the southern prairies.
The map below reflects the Accumulated Precipitation for the Growing Season so far for the prairie provinces (i.e., April 1-May 31, 2017):
The map below shows the Lowest Temperatures the Past 7 Days (May 25-31, 2017) across the prairies:
Whereas the map below shows the Highest Temperatures the Past 7 Days (May 25-31, 2017):
The updated growing degree day map (GDD) (Base 5ºC, March 1 – May 28, 2017) is below:
While the growing degree day map (GDD) (Base 10ºC, March 1 – May 28, 2017) is below:
2017 Wind Trajectories
THE WEEK OF MAY 29, 2017: Wind trajectory data processing by AAFC-Saskatoon Staff began in April. Reverse Trajectories track arriving air masses back to their point of origin while Forward Trajectories predict favourable winds expected to arrive across the Canadian Prairies for the week of May 23, 2017:
Reverse trajectories (RT)
Overall, the number of RTs entering the prairies from the Pacific
Northwest has been lower than average. The map (Fig. 1) shows that the greatest number
of RTs from the Pacific Northwest continued to be across southern Alberta.
Figure 1. Number of Reverse Trajectories (RT) originating in the Pacific Northwest that
arrived at sites across the Canadian prairies from April 1-May 29, 2017.
Winnipeg: https://weather.gc.ca/city/pages/mb-38_metric_e.html
Brandon: https://weather.gc.ca/city/pages/mb-52_metric_e.html
Saskatoon: https://weather.gc.ca/city/pages/sk-40_metric_e.html
Regina: https://weather.gc.ca/city/pages/sk-32_metric_e.html
Edmonton: https://weather.gc.ca/city/pages/ab-50_metric_e.html
Lethbridge: https://weather.gc.ca/city/pages/ab-30_metric_e.html
Grande Prairie: https://weather.gc.ca/city/pages/ab-31_metric_e.html
Weekly Update – Flea beetles
Flea Beetles (Chrysomelidae: Phyllotreta species) – Be on the lookout for flea beetle damage resulting from feeding on canola cotyledons but also on the stem. Two species, Phyllotreta striolata and P. cruciferae, will feed on all cruciferous plants but they can cause economic levels of damage in canola during the seedling stages.
Figure 1. Canola cotyledons with various percentages of leaf area consume owing to
flea beetle feeding damage (Photo: Soroka & Underwood, AAFC-Saskatoon).
Figure 2. Percent leaf area consumed by flea beetles feeding on canola seedlings
(Photo: Soroka & Underwood, AAFC-Saskatoon).
Refer to the flea beetle page from the new "Field Crop and Forage Pests and their Natural Enemies in Western Canada: Identification and management field guide" as an English-enhanced or French-enhanced version.
Weekly Update – Cutworms
Cutworms (Noctuidae) – NEW – Just in time for spring scouting! A new field guide is now available to help growers scout and manage Cutworms! Cutworm Pest of Crops is now available for free in either English or French and is featured at our new Cutworm Field Guide!
Keep an eye on fields that are "slow" to emerge, are missing rows, include wilting or yellowing plants, have bare patches, or appear highly attractive to birds – these are areas warranting a closer look. Plan to follow-up by walking these areas later in the day when some cutworm species move above-ground to feed. Start to dig below the soil surface (1-5 cm deep) near the base of a symptomatic plant or the adjacent healthy plant. If the plant is well-established, check within the crown in addition to the adjacent soil. The culprits could be wireworms or cutworms.
Several species of cutworms can be present in fields. They range in colour from shiny opaque, to tan, to brownish-red with chevron patterning. Cutworm biology, species information, plus monitoring recommendations are available in the Prairie Pest Monitoring Network's Cutworm Monitoring Protocol. Also refer to the Manitoba Agriculture cutworm fact sheet which includes action and economic thresholds for cutworms in several crops.
For Albertans….. If you find cutworms, please consider using the Alberta Pest Surveillance Network's "2017 Cutworm Reporting Tool". The map now has reports of pale western and redbacked cutworms in central and southern Alberta so view the live 2017 cutworm map.
Check the Insect of the Week – the month of May highlighted cutworms! Be sure to read more about Pale western cutworms, Redbacked cutworms, Army cutworms, Dingy cutworms.
Weekly Update – Cereal leaf beetle
Cereal leaf beetle (Oulema melanopus) – As of May 29, 2017, the CLB model indicates that larvae should be present across the southern prairies (Fig. 1). Compared to Lethbridge AB, populations near Brandon MB are predicted to be delayed by approximately five days. At Lethbridge, the hatch should be almost complete, while hatch should be approximately 50% complete near Brandon.
Figure 1. Predicted percent of Cereal leaf beetle (Oulema melanopus) in larval stage
across the Canadian prairies as of May 29, 2017.
Figure 2. Adult Oulema melanopus (~4.4-5.5 mm long).
Figure 3. Larval stage of Oulema melanopus with characteristic feeding damage visible on leaf.
Weekly Update – Alfalfa weevil
Alfalfa Weevil (Hypera postica) – Reminder – Biological information and photos of all life stages of this insect can reviewed on the Week 4 post. The larval stage of this weevil feeds on alfalfa leaves in a manner that characterizes the pest as a "skeletonizer".
Degree-day maps of base 9°C are now being produced by Soroka, Olfert, and Giffen (2016) using the Harcourt/North Dakota models. Models predicting the development of Alfalfa weevil across the prairies are updated weekly to help growers time their in-field scouting for second-instar larvae. Compare the following predicted development stages and degree-day values from Soroka (2015) to the map below.
As of May 29, 2017, embryological development (hatch) is predicted to be greatest across south and central regions of the prairies (Fig. 2).
Figure 1. Heat units accumulated necessary for the development of Alfalfa weevil (Hypera postica)
across the Canadian prairies (April 1-May 29, 2017).
The map below reflects the predicted stage of development of alfalfa weevil (as of May 29th) and suggests the percent of the population at first instar stage across the Canadian prairies (as of May 29th).
Figure 2. Predicted percent of H. postica population at first instar stage
across the Canadian prairies (as of May 29, 2017).
Alfalfa growers are encouraged to check the Alfalfa Weevil Fact Sheet prepared by Dr. Julie Soroka (AAFC-Saskatoon) and additional information can be accessed by reviewing the Alfalfa Weevil Page extracted from the "Field crop and forage pests and their natural enemies in western Canada – Identification and management field guide" (Philip et al. 2015). That guide is available in both a free English-enhanced or French-enhanced version.
Weekly Update – Pea leaf weevil
Pea Leaf Weevil (Sitona lineatus) – This week is our PLW Blitz featuring this pest with:
-The Insect of the Week,
-Updated model outputs and phenological predictions for 2017 (as of May 29, 2017), and
– A NEWLY UPDATED Monitoring Protocol (Vankosky et al. 2017)!
The PLW model was run for Lethbridge AB and Saskatoon SK. Current weather data was used then extended by Long Term Normal climate data (May 30-Jun 30) in order to predict pea leaf weevil phenology. Compared to last week, model output indicated that oviposition has been delayed by ~5-7 days. As of May 29th, phenologies for eggs and larvae were predicted to be similar for both locations (Fig. 1-2).
Figure 1. Pea leaf weevil model predicting phenology for 2017 near Saskatoon SK.
Figure 2. Pea leaf weevil model predicting phenology for 2017 near Lethbridge AB.
Biological and monitoring information related to pea leaf weevil in field crops is posted by the province of Alberta and a NEWLY UPDATED PPMN monitoring protocol is available!
Weekly Update – Predicted Grasshopper Development
As of May 29, 2017, predicted mean embryological development was 77% (70% last week); the greatest development was predicted to be across southern regions in all three provinces, particularly southern Alberta (Fig. 1). Hatch was predicted for a few, isolated locations with approximately 7% hatch (Fig. 1).
Figure 1. Predicted embryological development of Migratory grasshopper (Melanoplus
sanguinipes) eggs across the Canadian prairies as of May 29, 2017.
For comparison, the map below (Fig. 2) indicates that the predicted M. sanguinipes hatch is actually slower than normal. This week, 93% of the population should be in the egg stage and 6.5% in the first instar. Predicted warm conditions for May 31 and June 1 should result in completion of the egg stage. Though it is still early in the growing season, grasshopper hatch can vary across the prairies.
Figure 2. Predicted embryological development of Migratory grasshopper (Melanoplus sanguinipes) eggs
across the Canadian prairies as of May 29, 2017, using Long Term Normal data.
– Review the predicted M. sanguinipes phenologies generated for Week 4 for Regina SK, Lethbridge AB and Grande Prairie AB.
– The Prairie Pest Monitoring Network's 2017 Grasshopper Forecast Map can be viewed here.
Biological and monitoring information related to grasshoppers in field crops is posted by Manitoba Agriculture, Food and Rural Development, Saskatchewan Agriculture, Alberta Agriculture and Forestry, the BC Ministry of Agriculture and the Prairie Pest Monitoring Network. Also refer to the grasshopper pages within the new "Field Crop and Forage Pests and their Natural Enemies in Western Canada: Identification and management field guide" as an English-enhanced or French-enhanced version.
Weekly Update – Wheat midge
Wheat Midge (Sitodiplosis mosellana) – Predictive modelling will be used again to help forecast wheat midge emergence across the Canadian prairies. The maps below predicts the geographic distribution and corresponding accumulation of heat units necessary for wheat midge to emerge from puparia developing in the soil.
Since last week, the wheat midge model indicates that wheat midge larvae should be moving to the soil surface this week and the adult emergence has been delayed by 5-7 days (i.e., now predicted to start the first week of June).
Review the 2017 wheat midge forecast map circulated in January by accessing the Risk and Forecast Maps Post.
Information related to wheat midge biology and monitoring can be accessed by linking to your provincial fact sheet (Saskatchewan Agriculture or Alberta Agriculture & Forestry). A review of wheat midge on the Canadian prairies was published by Elliott, Olfert, and Hartley in 2011.
More information about Wheat midge can be found by accessing the pages from the new "Field Crop and Forage Pests and their Natural Enemies in Western Canada: Identification and Field Guide". View ONLY the Wheat midge pages but remember the guide is available as a free downloadable document as both an English-enhanced or French-enhanced version.
Weekly Update – Predicted Bertha Armyworm Development
Bertha armyworm (Lepidoptera: Mamestra configurata) – As of May 28th, predicted pupal development is well underway. We are fortunate to have two methods projecting pupal development:
–> Figure 1 reflects pupal development BASED ON DEGREE DAYS ONLY.
–> Figure 2 reflects pupal development BASED ON CLIMEX MODELLING (i.e., incorporates environmental data + biological data for organisms) AND legend is designed to estimate WHEN PHEROMONE TRAPS SHOULD BE DEPLOYED (i.e., pheromone traps are best deployed at ~80% pupal development).
Figure 1. Predicted stage of pupal development of overwintered Bertha armyworm (based on Degree-Day heat units) set to emerge in 2017.
FIGURE 2. Predicted pupal development of Bertha armyworm (based on Climex model and legend designed to reflect that pheromone traps are best deployed at ~80% pupal development).
More specifically, Figure 2 shows the average pupal development is 50% (36% last week), and as high as 75% at a number of locations. The three graphs below show that adult emergence is predicted to be six days sooner in the Winnipeg region than in fields near Vegreville and ten days sooner than the Yorkton area.
IMPORTANT – The table indicates predicted dates of first appearance of adults for specific locations across the prairies. We generally suggest that traps go out when pupal development is at 80%. Adult emergence generally occurs within 5-7 days after 80% development. As of May 29, 2017, there is a large area in southern Alberta that is greater than 70%.
Reminder – These maps will be updated weekly to aid those who deploy and monitor this moth using pheromone traps. The video below posted by Alberta Agriculture and Forestry's Scott Meers describes how pheromone traps are used to monitor this important pest of canola.
Provincial entomologists provide insect pest updates throughout the growing season so we have attempted to link to their most recent information:
Manitoba's Insect and Disease Update for 2017 is prepared by John Gavloski and Pratisara Bajracharya and have now been posted (May 24, 2017, May 31, 2017). Read the latest issue which:
– Reports low insect pest issues so far in that province.
– Notes a limited amount of spraying for cutworms.
– Includes detailed flea beetle monitoring tips.
– Reports low numbers through May in Diamondback pheromone traps.
– And finally, Manitoba Agriculture is advising Manitoban cooperators to deploy Bertha armyworm pheromone traps June 5-10, 2017.
Saskatchewan's 2017 Crop Production News – Issue #1 (date) is now posted and includes insect pest information prepared by Scott Hartley and Danielle Stephens. Read the latest update including:
– Information on wireworms, cutworms and other arthropods that will be present in the soil during scouting.
Watch for Alberta Agriculture and Forestry's Call of the Land and access the most recent Insect Update (June 1, 2017) provided by Scott Meers who:
– Emphasized the importance of scouting for flea beetle feeding in canola and application of action threshold of 25% when examining the cotyledons.
– Noted lower reports of cutworms last week.
– And finally, Albertan cooperators are advised to target June 12, 2017 to deploy Bertha armyworm pheromone traps across that province.
• Manitoba Agriculture, Rural Development (May 29, 2017)
• Saskatchewan Agriculture Crop Report (May 23-29, 2017)
• Alberta Agriculture and Forestry Crop Report (May 23, 2017)
International reports are produced by:
• The United States Department of Agriculture's Crop Progress Report (May 30, 2017)
Weekly Update – Weather Radar
If your fields are near one of Environment Canada's PRAIRIE Radar Stations, consider accessing weather radar maps in video format show either the past 1 OR 3 hours of spatio-temporal maps of precipitation events. These maps can help growers review where and how much precipitation fell nearby.
Screen shots of Environment Canada's webpages are below for reference and red text and arrows have been added to help you navigate the webpage.
Weekly Update – PMRA Pesticide Label Mobile App
Health Canada's Pest Management Regulatory Agency launched a new mobile app to access pesticide labels registered for use in Canada. The App helps homeowners, farmers, industry, provincial and federal organizations access details for pest control products from a smartphone or tablet (Fig. 1).
Users can save searches, download product labels to their 'Favourites' which can even be accessed while offline. 'Favourites' will also auto-update when accessed online. Pesticide labels can be searched based by product name or active ingredient (e.g., to review detailed explanations on proper product use and necessary precautions).
Users can download the app on their mobile device.
If you have any questions, please contact the PMRA's Information Service.
Figure 1. Screenshot view of Pesticide Label download page (retrieved 31May2017).
Weekly Update – Monarch migration
We again track the migration of the Monarch butterflies as they move north by checking the 2017 Monarch Migration Map! A screen shot of the map has been placed below as an example (retrieved 01Jun2017) but follow the hyperlink to check the interactive map! They've migrated into southern Ontario and Quebec!
Weekly Update – Brood X Cicadas
Cicadas are well known for their long life cycles. Some species follow an annual life cycle but the more "famous" have broods that emerge on 13- or 17-year cycles. The big news this year in North America is that Brood X cicadas are emerging 4 years earlier than anticipated!
Researchers originally following the emergence of Brood VI cicadas in South Carolina and Georgia observed Brood X cicadas emerging this spring. The phenomenon was then observed in North Carolina, Virginia, Maryland, the District of Columbia, Ohio and Indiana.
Researchers continue to follow the emergence of both broods of cicadas but the earlier-than-expected appearance of Brood X is described to be related to, "warming climate, with more warm weeks a year during which the underground nymphs can grow" which, "could be triggering some cicadas to emerge ahead of their brood". Read the Scientific American article to learn more.
Weekly Update – Previous Posts
Canola scouting chart
Crop protection guides
Flax scouting chart
Iceberg reports
Lily leaf beetle
Ticks and Lyme disease
Forest tent caterpillars in Saskatchewan
Thanks to Scott Hartley who provided this update – Forest tent caterpillars have been reported in
high numbers across the province of Saskatchewan, primarily in urban areas, parks and
shelterbelts. Trees are the main host to this insect. Although there have been reports
of the caterpillars in alfalfa and canola, feeding damage will not be
significant.
Bacillus thuringiensis
var. kurstaki (Btk) is the recommended control product as it is specific to
moth and butterfly larvae (caterpillars). It is not considered dangerous to
pollinators due to the ingestion mode of action and as they are in a different
insect order the kurstaki strain of Bt is not toxic to the bees that may be
foraging in flowering trees. Although other chemical insecticides are
registered, they tend to affect a broad spectrum of insects including foraging
pollinators.
Across the prairies, meteorological conditions were similar to long term average values for the period of May 22-29, 2016. The average temperature was 11.2 °C and was similar to the previous seven days. For the second week in a row temperatures were warmer in Manitoba and eastern Saskatchewan than western Saskatchewan and Alberta.
This week's rainfall was generally greater than long term average amounts. The region northeast of Edmonton and locations within southeastern Manitoba reported significant rainfall amounts while lower amounts were reported for southern Alberta and most of Saskatchewan. The map below shows the Accumulated Precipitation the past 7 days (i.e., May 22-29, 2016):
Compared to last week, soil moisture levels were predicted improve across most of the prairies:
The west was cooler compared to the east in terms of overnight temperatures over the last week. The map below shows the Lowest Temperatures the Past 7 Days (May 24-30, 2016) across the prairies:
The map below shows the Highest Temperatures the Past 7 Days (May 24-30, 2016):
Weekly Update – Canola scouting chart
We again post our generalized canola scouting chart to aid in-field scouting on the Canadian prairies. The version below contains hyperlinks to help growers learn more about some of our insect pests and how to monitor for them.
Weekly Update – Diamondback moth
Diamondback moth (Plutellidae: Plutella xylostella) – Pheromone traps attracting male Diamondback moths (Fig. 1) have been deployed across the prairies.
Figure 1. Diamondback moth.
Counts will be reported by the provincial staff in Saskatchewan. Manitoba Agriculture and Rural Initiatives posted low DBM counts which can be reviewed within their second Insect Report. Alberta Agriculture and Forestry has a live 2016 map reporting Diamondback moth pheromone trap interceptions. A copy of the map (retrieved June 1, 2016) is below for reference.
Larval Monitoring:
Once the diamondback moth is present in the area, it is important to monitor individual canola fields for larvae. Remove the plants in an area measuring 0.1 m2 (about 12″ square), beat them on to a clean surface and count the number of larvae (Fig. 2) dislodged from the plant. Repeat this procedure at least in five locations in the field to get an accurate count.
Figure 2. Diamondback larva measuring ~8mm long.
Note brown head capsule and forked appearance of prolegs on posterior.
Figure 3. Diamondback moth pupa within silken cocoon.
Economic threshold for diamondback moth in canola at the advanced pod stage is 20 to 30 larvae/ 0.1 m2 (approximately 2-3 larvae per plant). Economic thresholds for canola or mustard in the early flowering stage are not available. However, insecticide applications are likely required at larval densities of 10 to 15 larvae/ 0.1 m2 (approximately 1-2 larvae per plant).
Biological and monitoring information for DBM is posted by Manitoba Agriculture, Food and Rural Development, Saskatchewan Agriculture, Alberta Agriculture and Forestry, and the Prairie Pest Monitoring Network.
More information about Diamondback moths can be found by accessing the pages from the new "Field Crop and Forage Pests and their Natural Enemies in Western Canada: Identification and Field Guide". View ONLY the Diamondback moth page but remember the guide is available as a free downloadable document as both an English-enhanced or French-enhanced version.
Reminder – Flea Beetles (Chrysomelidae: Phyllotreta species) – Remember, the Action Threshold for flea beetles on canola is 25% of cotyledon leaf area consumed. Shot-hole feeding is the traditional damage in seedling canola but watch the growing point and stems of seedlings.
Estimating flea beetle feeding damage can be challenging. Using a visual guide to estimate damage can be helpful. Canola Watch circulated this article but also use the images (copied below for reference) produced by Dr. J. Soroka (AAFC-Saskatoon) – take them scouting!
Also refer to the previous Flea beetle post on the Blog.
Cutworms (Noctuidae) – Reminder – Keep an eye on fields that are "slow" to emerge, are missing rows, include wilting or yellowing plants, have bare patches, or appear highly attractive to birds – these are areas warranting a closer look. Plan to follow-up by walking these areas later in the day when some cutworm species move above-ground to feed. Start to dig below the soil surface (1-5 cm deep) near the base of a symptomatic plant or the adjacent healthy plant. If the plant is well-established, check within the crown in addition to the adjacent soil. The culprits could be wireworms or cutworms.
Several species of cutworms can be present in fields. They range in colour from shiny opaque, to tan, to brownish-red with chevron patterning. Cutworm biology, species information, plus monitoring recommendations are available in the Prairie Pest Monitoring Network's Cutworm Monitoring Protocol. Also refer to Manitoba Agriculture and Rural Initiatives cutworm fact sheet which includes action and economic thresholds for cutworms in several crops.
More information about cutworms can be found by accessing the pages from the new "Field Crop and Forage Pests and their Natural Enemies in Western Canada: Identification and Field Guide". View an excerpt of ONLY the Cutworm pages from the new "Field Crop and Forage Pests and their Natural Enemies in Western Canada: Identification and management field guide". The guide is available as a free downloadable document as both an English-enhanced or French-enhanced version.
For Manitobans….Last week's Insect Update includes great photos of dingy and redbacked cutworms plus monitoring tips which include how to discern these two species from one another.
For Saskatchewanians….Cutworms have been reported in several areas of the Province this spring. Affected crops include pea, lentil, barley and canola. If damage is significant and re-seeding is an option, seed first then spray an insecticide registered for cutworms in the applicable crop. Recommended economic thresholds for cutworms are:
– 25 to 30 per cent stand reduction (canola)
– 3 to 6 cutworms / square metre (wheat, barley, oats)
– 2 to 3 cutworms / sq. metre (pea, lentil)
– 4 to 5 / sq. metre (flax)
For Albertans….. Cutworms have been reported throughout the province the past week! If you find cutworms, please consider using the Alberta Pest Surveillance Network's "2016 Cutworm Reporting Tool". Once data entry occurs, your growers can view the live 2016 cutworm map. A screen shot of the live map has been retrieved (01Jun2016) below for your reference and this week it includes additional reporting sites!
Alfalfa Weevil (Hypera postica) – The larval stage of this weevil feeds on alfalfa leaves in a manner that characterizes the pest as a "skeletonizer". The green larva featuring a dorsal, white line down the length of its body has a dark brown head capsule and will grow to 9mm long. Alfalfa growers are encouraged to check the Alfalfa Weevil Fact Sheet prepared by Dr. Julie Soroka (AAFC-Saskatoon).
Degree-day maps of base 9°C are now being produced by Soroka, Olfert, and Giffen (2016) using the Harcourt/North Dakota models. The aim or the modelling is to predict the development of Alfalfa weevil (Hypera postica) across the prairies and to help growers time their in-field scouting as second-instar larvae are predicted to occur. Compare the following predicted development stages and degree-day values copied below (Soroka 2015) to the map below.
This week, alfalfa growers situated within ANY shade of purple should prioritize scouting for second instar larvae and compare it to the action threshold for alfalfa weevil which varies according to end use and crop stage.
Use the figure below as a visual reference to identify alfalfa weevil larvae. Note the white dorsal line, the tapered shape and the dark head capsule.
Bertha armyworm (Lepidoptera: Mamestra configurata) – Bertha armyworm (BAW) pupal development is progressing well. Pheromone traps should be deployed in areas highlighted yellow in the map below.
Those monitoring BAW pheromone traps may want to compare trap "catches" to the following reference photo kindly shared by Saskatchewan Agriculture below:
Grasshoppers (Acrididae) – This past week, warm conditions conditions in Saskatchewan were predicted to result in enhanced development.
For the week of May 29, 2016, the predicted mean embryological development was 87% and indicates that grasshopper hatch will continue to progress over the next week to ten days. The model predicted that 23% of the hatch is complete (compared to 13% predicted last week). Approximately 15% of the population was predicted to be in the first instar and 7% in the second instar.
The following image showing various stages of the clearwinged grasshopper is provided below – note that adults have wings extending the length of the abdomen whereas nymphs lack wings but develop wing buds that will eventually mature to wings.
Biological and monitoring information related to grasshoppers in field crops is posted by the provinces of Manitoba, Saskatchewan, Alberta, British Columbia and the Prairie Pest Monitoring Network. Also refer to the grasshopper pages within the new "Field Crop and Forage Pests and their Natural Enemies in Western Canada: Identification and management field guide" – both English-enhanced or French-enhanced versions are available.
– Manitoba's Insect and Disease Update (May 25, 2016, prepared by John Gavloski and Pratisara Bajracharya).
– Saskatchewan's Unofficial Insect Update – which included Pea leaf weevil, cutworms, and forest tent caterpillars.
– Watch for Alberta Agriculture and Forestry's Call of the Land for updates from Scott Meers who recently gave a summary (posted on May 26, 2016).
Weekly Update – Crop Protection Guides
Reminder – Crop Protection Guides – If you don't have a copy of your province's Crop Protection Guide, please make use of these links to access:
Saskatchewan's Crop Protection Guide
Manitoba's Guide to Crop Protection Guide
Alberta's Crop Protection or Blue Book
Western Committee on Crop Pests Guidelines for the Control of Crop Pests
If fields are near one of Environment Canada's radar stations, consider accessing weather radar maps in video format that show either the past 1 OR 3 hours of spatio-temporal maps of precipitation events. These maps can help growers review where and how much precipitation fell nearby.
Screen shots of Environment Canada's webpages are below for reference and red text and arrows have been added to help you navigate.