A bizarre invasive worm with its mouth in the middle of its belly has been found in the United States for the first time, according to new research. 
 
 The New Guinea flatworm (Platydemus manokwari) is only a couple of millimeters thick but grows to be up to 2.5 inches (65 millimeters) long. As its name suggests, the worm is a New Guinea native, but it has been spreading across the globe, hitching rides on exotic plants and in soil. The worm wraps itself around snails and ingests them with a mouthlike structure on its underside. As an invasive species, it's a threat to native snails — so much so that the Invasive Species Specialist Group of the International Union for Conservation of Nature (IUCN) lists it among the 100 worst invasive species in the world. 
 
 The flatworm had previously been detected in the wild in 15 countries, as well as in a greenhouse in France, but this is the first time it's been found in North America. A multinational group of researchers, led by scientists at the Muséum National d'Histoire Naturelle in France, combed through flatworm specimens and photographs collected by locals around the world. [See Photos of Bizarre Flatworm & Other Destructive Invasive Species] 
 
 Spreading threat 
 
 The researchers discovered P. manokwari in five countries and territories where it had never been reported before: New Caledonia, a small collection of islands in the southwest Pacific; Singapore; the Solomon Islands, also in the southwest Pacific; Puerto Rico; and Florida. 
 
 A New Guinea flatworm discovered in Coral Gables, Florida. This is the first report of this invasive flatworm on the American continent. Credit: Courtesy of Makiri Sei. CC- BY 4.0 
 
 The introduction of the species appeared to be recent in many of these cases. The worm probably arrived in Florida in or around 2012, the researchers reported in the open-access journal PeerJ. Since then, it seems to have established itself and can now be found in multiple places in Miami-Dade County. 
 
 In Puerto Rico, the worm showed up in San Juan, the capital, in 2014. The first discovery of the worm in the Solomon Islands also occurred in 2014, on Guadalcanal. 
 
 Wormy genetics 
 
 The researchers also discovered two genetic groups, or haplotypes, of the worm. These two groups are virtually indistinguishable except on the level of their genetic codes. One, dubbed the "Australian haplotype," was found only in Australia and the Solomon Islands. The other, dubbed the "World haplotype," has been found in France, New Caledonia, French Polynesia, Singapore, the Solomon Islands and Puerto Rico. The specimens found in Florida also belonged to this World haplotype. 
 
 The genetic findings suggest that both haplotypes of worm exist in their native New Guinea, but that for unknown reasons, only the World haplotype has spread significantly, the researchers wrote. 
 
 The discovery of the flatworm in the United States is particularly concerning because the flatworm had previously been confined mostly to small islands, they added. From Florida, however, P. manokwari could easily spread to the rest of the United States and the Americas. 
 
 Follow Stephanie Pappas on Twitter and Google+. Follow us @livescience, Facebook & Google+. Original article on Live Science. 

 Variation within localities was strikingly different between Dodo Creek, Solomon Islands and the rest of the studied localities. All specimens from France (3), New Caledonia (9 from different localities), Singapore, Florida and Puerto Rico (2 in each case) were identical and displayed the World haplotype; all specimens from Townsville had the Australian haplotype with a minor difference of one base for one specimen (haplotype Australian 2). Sequences from Henderson (Solomon Islands) were identical in the five specimens, with haplotype Australian 1. In contrast, the ten specimens from Dodo Creek included three animals with haplotype Australian 1 and seven with haplotype World. The Solomon Islands were thus the only country in which genetic variation among specimens was observed. 
 
 The analysis of the 21 long sequences also revealed the same two haplotypes, World and Australian. The difference between the two haplotypes was 42 bases, on a total of 848 ( p -distance: 4.8%; kimura-2 parameter distance: 5.0%). A minor variation was found in the Australian haplotype, with one specimen having a one-base difference (distance from this specimen to the World haplotype: p -distance: 5.0%; kimura-2 parameter distance: 5.2%); this haplotype is designated as “Australian 2” and the other, major haplotype is designated as “Australian 1”. No variation was found in the World haplotype (15 sequences from four countries) for these long sequences. A tree constructed from these sequences shows two well differentiated branches, with identical sequences in the World haplotype branch and minor variation in the Australian haplotype branch ( Fig. 6 ). 
 
 The analysis of the 38 “short” sequences showed that only two haplotypes were present. One haplotype was found in specimens from France, French Polynesia, New Caledonia, Singapore, Florida and Puerto Rico, and certain specimens from the Solomon Islands; we designate it as the “World haplotype”. One haplotype was found only in specimens from Australia and certain specimens from the Solomon Islands; we designate it as the “Australian haplotype”. The difference between the two haplotypes was 15 bases, on a total of 401 ( p -distance: 3.7%; kimura-2 parameter distance: 3.8%); no individual variation of these “short” sequences was found in any of the two haplotypes. A tree constructed from these sequences shows two well differentiated branches, with identical sequences in each of the branches ( Fig. 5 ). 
 
 We obtained COI sequences from 38 individuals. Of these, 21 were “long” sequences, obtained with two pairs of primers, and 17 were “short” sequences, when only one pair of primers provided results. 
 
 The dimensions and characters that were compared between specimens of the two haplotypes included body length and width, the distance of the mouth and gonopore from the anterior end, the lengths of the oesophagus, pharynx and pharyngeal pouch, distance between the common sperm duct and common ovovitelline duct, distance from the common sperm duct to the tip of the penis papilla, penis length and penis width at it base, length of the male atrium, length of the female atrium, length of the glandular canal, length of the common ovovitelline duct and depth of the viscid gland. Sexually mature specimens of P. manokwari from the Solomon Islands were found to be considerably smaller (22–28 mm long) than those from Caen, France (44.5 mm long) and Townsville, Australia (45 mm long). The only characters that were found that may possibly differentiate between the two haplotypes are the length of the penis papilla expressed as a percentage of the total body length ( Table 2 ), and the shape of the penis papilla. Specimens of the World haplotype generally exhibited a finger-shaped or elongate conical penis papilla that was 1.4–1.7% of the body length, similar in appearance of the copulatory organs of P. manokwari figured by de Beauchamp (Figs. 1A and 1B in de Beauchamp, 1962 ) whereas in specimens of the Australian haplotype the penis papillae tended to be a low regular conical shape with a length less than 1% of the total body length (0.7–0.9% of the body length), closely resembling the copulatory organs of P. manokwari figured by de Beauchamp (Fig. 1 in de Beauchamp, 1972 ) and by Winsor (1990) (Fig. 1 in Winsor, 1998 ). 
 
 The flatworms ( Figs. 1 – 4 ) presented the following morphological characteristics: body broadest in the middle, tapering evenly anteriorly but more abruptly posteriorly; two large prominent eyes back from the tip of the elongate snout-like head; dorsum a dark olive brown colour; pale cream median dorsal longitudinal stripe beginning just behind the eyes and continuing to the posterior tip; olive brown colour grading to grey at anterior tip; two thin submarginal cream stripes with fine lower greyish margin running laterally from the anterior end along the length of the body; ventral surface a pale finely mottled light brown. These features are consistent with those of Platydemus manokwari de Beauchamp, 1963 (Platyhelminthes, Continenticola, Geoplanidae, Rhynchodeminae) ( de Beauchamp, 1962 ; Justine et al., 2014 ; Kawakatsu, Ogren & Muniappan, 1992 ; Winsor, 1990 ). 
 
 Time of invasion and other remarks 
 
 In France, after the first finding of P. manokwari (October 2013), the hothouse of the Jardin des Plantes in Caen in which the species was found was closed and public access restricted. In April 2014, a thorough search was performed in the same hothouse. Several species of land planarians were found (some are still unidentified), including four adult specimens of P. manokwari. A citizen-based survey of land planarians in France (Thévenot, Justine & Rome, 2014), supported by important media involvement (list of links: https://peerj.com/articles/297/#links), yielded hundreds of records of non-indigenous land planarians in France (Justine, 2014; Justine, Thévenot & Winsor, 2014) but never a record of P. manokwari in the wild. 
 
 The presence of the species in Singapore had already been noted in 2010, according to unpublished observations listed in Table 1, and the species is probably spreading; according to the observations of one of us (AWKH), the species was not present in his garden before 2013. Local observations show that P. manokwari predates the introduced giant African snail, Achatina fulica Bowdich, 1822. 
 
 The detection of P. manokwari in New Caledonia is recent (2014). After the discovery of the first specimens in the capital city, Nouméa, in April 2014, a survey was conducted from September 2014 to April 2015. Specimens were found in several places in the mainland, including Southern and Northern Provinces, and in two of the three Loyalty Islands, Maré and Lifou. The current extensive distribution of such a cryptic species, evidenced after only eight months of survey, suggests that the introduction of P. manokwari is not recent. Moreover, discussions with scientists involved in the observation of soil species revealed that the flatworm had been observed several years ago, but no substantiated proof of these observations could be found. Since a number of endemic land planarians exist in New Caledonia (Schröder, 1924; Winsor, 1991), it could not be ascertained if these earlier observations were actually of P. manokwari, or of other species. P. manokwari was not detected when large surveys were conducted in the 1990s (Gargominy et al., 1996)—it is thus likely that its introduction occurred in the last 20 years. Local observations show that P. manokwari predates introduced A. fulica. 
 
 In Wallis and Futuna, our records of P. manokwari are based only on two photographs taken by one of us (JYM), in 2007 in Uvea (Wallis Islands) and in 2008 in Futuna (Hoorn Islands). These two island groups are separated by more than 100 km of sea. No more recent records are available. 
 
 The presence of P. manokwari on Guam has been known since 1977 (Eldredge & Smith, 1995; Hopper & Smith, 1992). Our records, dated 2004, confirm the continuing presence of the species; to our knowledge, no more recent records are available. 
 
 In the USA, the accidental introduction of P. manokwari through human agency to Florida is probably recent, with our first specimens found in August 2012. The species is apparently now well established, with several different locations found in 2014 in Miami Dade County (Table 1). The introduction of P. manokwari to Puerto Rico is also probably recent, with the first specimens found in December 2014, in a single locality, San Juan (Table 1). To our knowledge, no survey aiming specifically at detecting P. manokwari has been done in other parts of Florida or in other US states. Land planarians are often photographed by amateurs; however, a survey of various websites and various Google searches (December 2014) did not reveal any photographic report of P. manokwari in the US. 
 
 The introduction of the species to Guadalcanal, Solomon Islands also seems recent (2014). Specimens of P. manokwari were found in fields invaded by the introduced Giant African snail, Achatina fulica. Although the report of these flatworms in Guadalcanal is recent, we do not know if this is truly an indication of a recent introduction or not. The case of New Caledonia, where the species was found in many localities after a coordinated participative survey was initiated, and, on the contrary, the case of Guam, for which we have no report for the last decade, show that land planarians are detected and reported only when an appropriate survey is undertaken. It is obvious that land planarians in Solomon Islands, a country with low income and expensive internet access, are less often photographed by amateur photographers who post their findings on the internet than they are in the US or Singapore. 
 
 Figure 7 shows all available records of P. manokwari in the world. The spread of the species mainly concerns countries and territories in the Pacific Area; Florida and Puerto Rico are the first records in the Americas. The record in Florida is the first on the American mainland. 

 Why are Earthworms Important 
 
 Only a few decades ago, the predominating thought was that earthworms were not very important for agriculture. Emphasis was placed on physical and chemical aspects of plant growth while biological aspects were neglected. We are now realizing how interactions between crops, climate, soil, and living organisms play important roles in sustaining our agriculture. Earthworms are among the most visible of soil organisms and have received considerable attention. They play a pivotal role in maintaining the productivity of our soils. This makes understanding these lowly animals and finding ways to make them thrive very important. 
 
 Benefits of Earthworms 
 
 The burrowing and feeding activity of earthworms have numerous beneficial effects on overall soil quality for crop production. The following soil properties can be improved by earthworms. 
 
 Water infiltration 
 
 Some earthworm species create vertical burrows, whereas other species live in horizontal burrows in the soil. The vertical burrows are typically open, although the worms cap the top with residue and excrement. The vertical burrows are very important points of entry for quick water infiltration into the soil, especially in no-till systems. 
 
 Soil aeration 
 
 Air-filled porosity is critical in helping plant roots to thrive. Roots need oxygen for their growth, whereas they produce carbon dioxide that needs to leave the soil. Because earthworms improve soil porosity, they improve the exchange of these gases with the atmosphere. Earthworms increase porosity by two mechanisms: (1) by creating permanent burrows, and (2) by improving soil aggregation. Aggregation is improved by the mixing of soil and organic matter in the earthworms’ guts. These highly stable aggregates are deposited by some earthworms in their burrows, and by others at the surface of the soil. In one pasture study, earthworms consumed between 20 and 40 tons of soil per acre per year. In another study, earthworms were estimated to consume 4 to 10 percent of the top 6 inches of the soil annually. This only goes to show the enormous amounts of soil that can be processed by earthworms. 
 
 Soil compaction and soil tilth 
 
 Soil compaction reduces the porosity of the soil. Because earthworms increase porosity, they reduce the effects of compaction. In addition, the excrement of earthworms has a very stable structure, which makes the soil more resistant to compaction and improves its tilth. 
 
 Soil organic matter 
 
 Typical earthworm populations can easily consume 2 tons of dry matter per acre per year, partly digesting and mixing it with soil. The importance of earthworms to mix surface residue with soil becomes very clear in soils that do not have any earthworms. Most of our Pennsylvania soils have at least some earthworms and the effect of their complete absence therefore cannot be noted. In the Netherlands, some soils reclaimed from the sea at first did not have any earthworms. In these soils the formation of topsoil with reasonable organic matter content did not take place, resulting in poor crop growth. Once the cause was established, the government of the Netherlands started a campaign to introduce earthworms. After the introduction of the earthworms, a dark topsoil layer was formed, and crop growth increased substantially. 
 
 Plant available nutrients 
 
 Earthworm casts have higher available nitrogen, phosphorus, potassium, and calcium contents than surrounding soil, as well as a higher cation-exchange capacity. Some micronutrients, such as zinc and boron, are more available in the excrement of earthworms through chelation of the micronutrients. 
 
 Soil pH 
 
 Soil passed through the gut of earthworms has a neutral pH. This is probably due to the pH buffering action of organic molecules produced in the gut of worms. 
 
 Beneficial microbes 
 
 Earthworms excrete material that has high concen- trations of beneficial microbes that help decompose crop residue. 
 
 Nematode control 
 
 Some earthworms eat harmful nematodes, thus decreasing the concentration of these harmful organisms in soil. 
 
 Types of Earthworms 
 
 There are more than 1,000 different earthworm species, but they can be placed into one of three groups (Fig. 1): 
 
 Litter dwellers or epigeic species live in crop or forest litter. They are not common in most agricultural soils. These species do not ingest large amounts of soil. The manure or red worm, Eisenia foetida, is an example of a litter dweller. Topsoil dwellers or endogeic species live in the upper 2 to 3 inches of the soil. They live primarily from partially decomposed organic matter that is already incorporated in the soil. They eat their way through the soil, creating horizontal burrows that they fill with their excrement. These species ingest large amounts of soil that they mix with digested crop residue in their guts. Subsoil dwellers or anecic species live in permanent vertical burrows that can be 5 or 6 feet deep. These earthworms need surface crop residue to live. Their burrows remain open, although they cap the top with crop residue that they pull to the entrance. These species ingest substantial amounts of soil that they mix with digested residue in their guts. Their excrement is primarily deposited at the surface of the soil. The nightcrawler Lumbricus terrestris is the most prominent member of this group. 
 
 
 
 Figure 1. Three major groups of earthworms are: litter dwellers, topsoil dwellers, and subsoil dwellers. 
 
 Earthworm Biology 
 
 Earthworms are invertebrates composed of many segments (Fig. 1). They don’t have bones and move by contracting and relaxing the body segments in sequence. They also have little bristlelike organs that help them cling to slippery surfaces. Most earthworms have both male and female organs. Typically, however, they still need a partner to reproduce. When earthworms mate, they lay side by side in reverse position. At that moment they exchange sperm. The sperm of the partner is stored in little chambers called spermathecal apertures. These are positioned in front of the egg-producing organs. After mating, the swollen external gland, called clitellum, produces egg cases called cocoons. A cocoon case slides slowly forward, picking up eggs and sperm as it moves over the head of the earthworm. From 3 to 1,000 cocoons can be produced per year, depending on species and environmental conditions. Typically, an earthworm will produce 20 to 30 cocoons per year, with each cocoon containing 1 to 10 eggs. Peak cocoon production is in the spring or early summer. The eggs in the cocoons hatch when conditions are right. Under ideal conditions, it may take from 1 to 5 months for the eggs to hatch. It may then take from 3 to 12 months before these worms are sexually mature. Worms typically live only a few months because of the many environmental threats they face. They have been observed to live for 10 years in a protected environment. In a favorable environment previously without earthworms, earthworm populations increased 80-fold in 4 years after introduction. 
 
 Environmental Effects on Earthworms 
 
 The burrowing and feeding activity of earthworms, as well as their overall population, are affected by the soil environment in which they live. Some of the properties important to earthworms include the following. 
 
 Moisture 
 
 Earthworms absorb and lose moisture through their skin. If soils are dry, earthworms may move to deeper soil layers, die, or revert to a hibernation condition called diapause. Earthworms in diapause are tied up in a knot in a little hole that is lined with a slimy substance to avoid moisture loss. Eggs in cocoons survive prolonged drought, allowing earthworm populations to survive drought periods. Because of dry conditions, earthworm populations in Pennsylvania are low in the summer. Earthworms can live under submerged conditions if the oxygen content of the water is high enough. In most cases, however, earthworms will die when exposed to excessive waterlogging. They move to the surface when the soil is saturated to avoid suffocation. 
 
 Temperature 
 
 Most earthworms don’t tolerate temperatures below freezing, nor do they tolerate high temperatures. Prolonged exposure to temperatures above 95°F kills them. They can move down into the soil to escape these adverse temperatures. Optimum temperatures are between 50 and 60°F. 
 
 pH 
 
 Earthworms commonly found in agricultural fields thrive at neutral pH, but can tolerate a pH from 5.0 to 8.0. 
 
 Soil texture 
 
 Earthworms prefer soils with loamy texture. Coarse sand can be a negative factor either because the abrasive action of sand grains damages their skin, or because these soils dry out more easily. In some studies, clay soils had fewer earthworms than lighter-textured soils. The reason for this phenomenon is not clear. 
 
 Food supply 
 
 Quantity, quality, and placement of food influence earthworm populations. Earthworms eat organic residue that needs to be present in sufficient quantity. The quality of residue is also important. Residue with a high carbon to nitrogen (C:N) ratio is not very palatable for earthworms. Manure can help make it more palatable. Packed manure is an excellent food source for earthworms. In some cases, residue has to undergo some weathering before earthworms are able to digest it. Topsoil dwellers need smaller particles than subsoil dwellers, which can use large leaves, for example. The placement of food becomes a critical issue for some earthworm species. Topsoil dwellers prefer small organic residue particles incorporated into the soil, but subsurface dwellers need residue at the surface of the soil. 
 
 Management Effects on Earthworms 
 
 Soil and crop management practices can influence many soil properties that affect earthworms (Fig. 2). Some practices can have immediate effects on earthworms, whereas others may gradually change earthworm population and activities over several years. So when you are considering management options, you should also think about their effects on earthworms. Some of the more important management effects on earthworms are described below. 
 
 
 
 Figure 2. Management practices favoring/hurting earthworms. 
 
 Tillage 
 
 Soil tillage greatly affects earthworms (Table 1). The burial of crop residue and manure by tillage favors topsoil dwellers over subsoil dwellers. In long-term clean-tilled fields, nightcrawlers are scarce. Tillage also stimulates drying the surface soil and wide day/night temperature fluctuations. This is another reason earthworms are less numerous in clean-tilled fields compared to no-tilled fields. Tillage brings earthworms to the surface where they are subject to predators such as birds. Total earthworm populations in long-term no-tilled fields are typically at least twice those of clean-tilled fields. 
 
 Table 1. Earthworm Populations as Affected by Management Tillage Management Earthworms/Acre From Earthworms and Crop Management by E. J. Kladivko, 1993. Purdue University Cooperative Extension Service Agronomy Guide AY-279. Crop and management systems had been continuous for at least 10 years. Continuous corn Plow 39,000 Continuous corn No-till 78,000 Continuous soybean Plow 235,000 Continuous soybean No-till 549,000 Bluegrass-clover Alleyway 1,568,000 Dairy pasture Manure 1,333,000 Dairy pasture Manure (heavy) 5,097,000 
 
 Crop rotation 
 
 Providing earthworms with a diverse diet is important. Crop residue of leguminous species (low C:N ratio) is more palatable to earthworms than that of mature grass and grain species (high C:N ratio). However, a legume such as soybean produces very little crop residue, which limits the quantity of food available to earthworms. Earthworms thrive in grasslands and alfalfa. In one grassland study, 70 earthworms were counted per square foot (more than 3 million earthworms per acre). 
 
 Crop residue 
 
 If crop residue is removed, earthworms lose their food source. Use of a cover crop that is left in the field or removal of only part of the crop are ways to feed earthworms. 
 
 Manure 
 
 Manure is a food source for earthworms. It also makes crop residue with a high C:N ratio more palatable to earthworms. Manure stimulates crop residue production because of its fertilizing effect, increasing the food supply for earthworms. Liquid manure can have a temporary depressing effect on earthworms due to its ammonia and salt content. After this effect has subsided, however, earthworm populations tend to increase. 
 
 Organic amendments 
 
 Sludge and compost can greatly stimulate earthworm populations by providing a quality feedstock for them. 
 
 Fertilizer and lime 
 
 There is good evidence that most inorganic fertilizers favor the buildup of large numbers of earthworms, probably due to the increased amounts of crop residues being returned to the soil. Anhydrous ammonia and ammonium sulfate have been found to have negative effects on earthworms. This may be due to the acidifying effect of this fertilizer, but also due to the toxic effect of ammonia. Liming to neutralize acidity stimulates earthworm activity. 
 
 Pesticides 
 
 The effects of pesticides on earthworms depend on the type of pesticide and its rate of application, earthworm species and age, and environmental conditions. Appendix 1 gives test results of pesticide toxicity on earthworms. The studies simulated normal exposure rates of pesticides commonly used in field crops. The table summarizes a great number of different studies that used widely varying methods of evaluation and should therefore be used with caution. 
 
 Most inorganic chemicals tested are no longer in use as pesticides. Based on the limited amount of information available, these chemicals do not seem to be very toxic to earthworms, except when they accumulate in soil over a long period of time. Organochlorine insecticides were extensively used from the 1950s to the 1970s, but are not used in large quantities today. Endosulfan and lindane are moderately toxic and probably toxic at normal exposure rates, respectively. Some organophosphate insecticides, such as acephate, azinphos methyl, chlorpyrifos, ethoprophos, ethyl- parathion, and phorate are very toxic to earthworms. The other organophosphate insecticides listed are nontoxic to moderately toxic to earthworms. Carbamate insecticides and fungicides are very toxic to earthworms. Carbaryl and carbofuran, both commonly used in field crop production, are extremely toxic to earthworms. Pyrethroid insecticides, on the other hand, have not been found to be toxic to earthworms. Most contact fumigant nematicides/fungicides are broad-spectrum biocides that will kill most earthworms, even those living deep in the soil. Of the other fungicides tested, none were found to be toxic to earthworms except carbamate fungicides such as benomyl and carbendazim (not listed). Most herbicides are nontoxic to earthworms, although some, such as 2,4-D, pendimethalin, and simazine, are toxic at high exposure rates. 
 
 Similar to that of humans, pesticide health risks to earthworms depend not only on the toxicity of the chemical but also on the exposure to it. On the other hand, earthworms that crawl on the soil surface (such as nightcrawlers) have a higher exposure to surface- applied pesticides than those feeding and burrowing below the soil surface. On the other hand, pesticides injected in a small slot in the soil (such as the seed slot) may not come in contact with many earthworms and therefore will not pose a significant threat for the population at large. Remember that earthworms are most active in the spring and fall under favorable temperature and moisture conditions. Pesticide application during these periods is most likely to pose a threat to earthworms. If the soil is moist, earthworms will be more active and therefore more likely to come into contact with pesticides. The effects of pesticides on earthworms also depend on age of the earthworms. Juvenile earthworms are more sensitive to pesticides than adults because they move slower and are not able to burrow away deep into the soil. 
 
 Appendix. Summary of Lab and Field Data on Toxicity of Chemicals to Earthworms Chemical Trade name Relative 
 
 toxicity* Comments * 0 = Nontoxic, 1 = slightly toxic, 2 = moderately toxic, 3 = very toxic, 4 = extremely toxic, ND = not enough data to categorize Sources: Biology and Ecology of Earthworms by C. A. Edwards and P. J. Bohlen, 1996 (Chapman & Hall, London, UK) and The farmer’s earthworm handbook, by David Ernst, 1995 (Lessiter Publications, Inc., Brookfield, Wis.). Thanks to Dennis Calvin, William Curran, Erick de Wolf and Eileen Kladivko for their help with this fact sheet. Inorganic chemical Copper sulfate 
 
 Mastercop 
 
 Ramenox P.B. 0 Persistent, toxic at high rates 
 
 Sulfur Kumulus 2 
 
 Biological agents Enterobacterin 
 
 0 
 
 
 
 Mowrah meal 
 
 0 Expels earthworms from soil Rotenone Nicouline 
 
 Tubatoxin 0 Expels earthworms from soil Mustard 
 
 ND Probably nontoxic Aromatic and organochlorine insecticides Endosulfan 
 
 Thiodan 
 
 Phaser 2 
 
 
 
 Lindane 
 
 
 
 ND 
 
 Probably toxic 
 
 Organophosphate insecticides Acephate 
 
 Orthene ND 
 
 Probably toxic Azinphos methyl 
 
 Guthion 
 
 Sniper ND 
 
 Probably toxic Chlorpyrifos 
 
 Lorsban 3 
 
 
 
 Chlorpyrifos-methyl Reldan ND 
 
 Probably nontoxic Diazinon 
 
 Diazinon 1 
 
 
 
 Dimethoate 
 
 Cygon 
 
 Dimethoate 1 
 
 
 
 Disulfoton 
 
 Disyston 1 
 
 
 
 Ethoprophos 
 
 Mocap 3 
 
 
 
 Ethyl-parathion 
 
 
 
 3 
 
 
 
 Fonofos Dyfonate 2 
 
 Malathion 
 
 Cythion 
 
 Malathion 1 
 
 
 
 Methyl-parathion 
 
 Penn Cap ND 
 
 Probably nontoxic Phorate 
 
 Thimet 4 
 
 
 
 Terbufos 
 
 Counter 2 
 
 
 
 Carbamate insecticides Carbaryl 
 
 Sevin 4 
 
 
 
 Carbofuran 
 
 Furadan 3 
 
 
 
 Methomyl 
 
 Lannate 4 
 
 
 
 Synthetic pyrethroids and chitin inhibitors Alphamethrin 
 
 Ammo 
 
 Cymbush ND Probably nontoxic Diflubenzuron 
 
 Dimilin 0 
 
 
 
 Es Fenvalerate 
 
 Asana 0 
 
 
 
 Permethrin 
 
 Ambush 
 
 Pounce ND Probably nontoxic Pyrethrins (unspecified) 
 
 
 
 ND Probably nontoxic Fungicides Captan 
 
 Captan 
 
 Rival 1 
 
 Seed treatment 
 
 Chlorthalonil 
 
 Bravo 2 
 
 Foliar 
 
 Imazalil 
 
 Double R 
 
 Double RII ND Seed treatment, probably toxic 
 
 Mancozeb 
 
 Manzate 
 
 Penncozeb 
 
 Dithane 0 
 
 Foliar 
 
 Maneb 
 
 DB-Green 
 
 Enhance Plus ND Foliar, probably nontoxic 
 
 Propiconazole 
 
 Tilt ND Foliar, probably toxic 
 
 Thiabendazole 
 
 RTU 3 
 
 Seed treatment Thiram 
 
 Thiram 
 
 Vitavax 200 
 
 Agrosol T 
 
 Stiletto 
 
 RTU 0 
 
 Seed treatment Herbicides Atrazine 
 
 Aatrex 
 
 Basis Gold 0 
 
 
 
 Bromacil 
 
 Hyvar 0 
 
 
 
 2,4-D 
 
 Butoxone 
 
 Weedone 1 
 
 Toxic at high exposure rates 
 
 Dicamba 
 
 Banvel 
 
 Trooper ND Probably nontoxic Diquat 
 
 Weedtrine 
 
 Reglone 
 
 Reglox ND Probably nontoxic Diuron 
 
 Karmex 0 
 
 
 
 Glyphosate 
 
 Roundup 0 
 
 
 
 Hexazinone 
 
 Velpar ND Probably nontoxic Linuron 
 
 Lorox 
 
 Linuron 0 
 
 Probably slightly toxic 
 
 Maleic hydrazide 
 
 Regulox 
 
 Stunt Man 0 
 
 Probably slightly toxic MCPA 
 
 MCPA 0 
 
 Probably slightly toxic MCPB 
 
 Butoxone 
 
 M40 ND Probably nontoxic Mecoprop CMPP ND Probably nontoxic Metribuzin Lexone 
 
 Sencor 
 
 Axiom ND Probably nontoxic Paraquat Gramoxone 0 Probably nontoxic Pendimethalin Prowl 
 
 Pendulum ND Probably toxic Simazine Princep 2 
 
 Terbacil Sinbar 0 
 
 Triclopyr Turflon ND Probably nontoxic Trifluralin Treflan 
 
 Tri-4 
 
 Trust 0 
 
 
 
 Conclusion 
 
 Earthworms are an important part of the soil ecosystem. They help improve soil structure and soil chemical and biological properties. They are especially important in no-till, helping to stimulate air and water movement in soil. Earthworms tend to thrive most without tillage, if sufficient crop residue is left on the soil surface. Crop rotations, cover crops, manure, fertilizer and lime applications all affect earthworm populations. Some pesticides, especially organophosphates and carbamates, are toxic to earthworms. Most herbicides do not pose a threat to earthworms. 
 
 Prepared by Sjoerd Duiker, associate professor of soil management and applied soil physics, and Richard Stehouwer, associate professor of environmental soil science.
– It's considered one of the "world's worst invasive alien species," sucks snails into a ravenous mouth located in the middle of its belly, and has now invaded US shores for the first time. "It" is the New Guinea flatworm, and researchers are afraid that now that their study in PeerJ has shown the worm is in Florida, the slimy species could spread to the rest of the mainland and put the country's entire snail population on the run, the Washington Post reports. And the gastropods would literally have to learn to run, because Platydemus manokwari is so persistent it will chase the future escargots up trees to retrieve them, the paper notes. How the two-inch worm chows down on a snail once it does catch it, per LiveScience: It wraps itself around its prey, then "ingests them with a mouthlike structure on its underside." The flatworm is usually found in the Pacific region and most recently has terrorized France, the study notes. An expert with France's National Museum of Natural History told the Guardian last year that "all snails in Europe could be wiped out," adding that "it's worth pointing out the effect that this will have on French cooking." It takes the worms awhile to move into a new habitat—they've got to be accidentally carried in in soil or plants, the Post notes—but once they infiltrate, they can wreak havoc on a region's ecosystem by taking snails out of the food chain and removing earthworms (another of their preferred meals) from their job of maintaining our soils and other needed agricultural tasks. (Another invasive creature that has ecologists worried: a "walking" fish that can choke birds that try to eat it.)