Growers will begin planting fall melon crops within the next week or so and PCAs are likely to encounter a number of insects that have the potential to cause serious economic losses to seedling crops during stand establishment. These include flea beetles, crickets (sometimes grasshoppers), darkling and rove beetles, and saltmarsh caterpillars. Seedling crops at the cotyledon stage are most susceptible to these pests, where feeding by large numbers can devour much of the cotyledons or outright kill the small plants. If left uncontrolled, larger seedling plants (2-4 leaf stage) can sustain significant feeding damage on the newly emerged leaves. Not only can this feeding stunt plant growth, but can result in lack of uniformity and maturity at harvest. Host sources of flea beetle, cricket and "wooly worm" infestations include numerous weeds (e.g., purslane, sudangrass, cotton and alfalfa). Experience suggests that melon fields planted adjacent to these crops are at risk from these seedling pest, and particularly flea beetles. As these summer host plants 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 chemigation (i.e., pyrethroids) or foliar sprays (i.e., Lannate, neonicotinoids) that can cost-effectively minimize their abundance and damage to emerging melons crops. For more information on insect pests of leafy vegetables and melons at stand establishment go to: Insect Management on Desert Melons.

Insect Pests at Stand Establishment

To contact John Palumbo go to: jpalumbo@ag.arizona.edu

For questions or comments on any of the topics please contact Marco Pena at the Yuma Agricultural Center.
College of Agriculture, The University of Arizona, Tucson, AZ.