text: Aug 7, 2024Protecting Crops at Stand Establishment (2024)
  Fall melon production is underway and transplanting/direct seeding of produce crops is close behind. PCAs will soon be faced with several important insect management decisions. As crops begin to emerge, you can expect to encounter several insect species that can potentially cause serious economic losses to crop stands. These seedling pests include flea beetles, crickets, grasshoppers, darkling beetles, earwigs, and saltmarsh caterpillars (‘woolly worms’). These insects all have chewing mouthparts, and most are capable of consuming large amounts of leaf tissue in a short period of time. Seedling crops at the cotyledon stage are most susceptible; these pests can devour entire cotyledons or outright kill small seedlings. If left unprotected, transplants and larger seedling plants can sustain significant feeding damage on the terminal growing points or newly emerged leaves. Not only can this feeding stunt plant growth but can result in lack of stand uniformity and ultimately, lack of uniform maturity at harvest. Host crop sources for flea beetle, crickets and "woolly worm" infestations include several summer crops (e.g., Sudan grass, cotton, and alfalfa), volunteer melons, and weeds (e.g., purslane, pigweed).
  Flea beetles are notorious for building up on weeds, particularly purslane, and alfalfa this time of the year. Fortunately, growers have been vigilant about field sanitation, and weeds are few and far between throughout the valleys. Be aware of beetle migration from recently harvested hay adjacent to your germinating crops. Crickets have also been especially abundant this summer, so keep a sharp eye for them, particularly under sprinkler pipe. Also be on the lookout of grasshoppers this fall. They can easily sneak up on you especially if we have an active monsoon. Salt marsh caterpillars have not been seen in years but are known to disperse from alfalfa and Pima cotton (non-Bt). Experience suggests that melon fields planted next to these crops and weedy areas are at a high risk from these seedling pests, particularly flea beetles. As cotton and Sudan grass are harvested or terminated during the next several weeks, these seedling pests typically move to the next available host crop; lettuce, cole crops and melons.
  Fortunately, there are many registered insecticide alternatives available that can be applied via sprinkler chemigation (i.e., pyrethroids) or foliar sprays (i.e., pyrethroids, methomyl, neonicotinoids) that can cost-effectively reduce their abundance and damage to susceptible produce and melon seedlings. Additionally, insecticide seed treatments are available for lettuce and broccoli that will protect stands from flea beetles and bagrada bug (i.e., Nipsit) for 14–21 days. For more information on insect pests of leafy vegetables and melons at stand establishment please see:
  1) Management of Insect Pests at Stand Establishment on Desert Produce and Melons
  2) Palestriped Flea Beetles in Leafy Vegetables and Cole CropsTo contact John Palumbo go to: firstname.lastname@example.org