Populations of Arthropod Predators and Heliothis Spp. After Applications of Systemic Insecticides to Cotton123

Abstract

Populations of arthropod predators, certain groups of hymenopterous insects, and Heliothis spp. including the bollworm,Heliothis zea (Boddie), and the tobacco budworm, Heliothis virescens (F.), were sampled in experiments following in-furrow applications of disulfoton and Temik^®, a 10% formulation of UC-21149 (2-methyl-2-(methylthio)propionaldehyde ^O-(methylcarbamoyl)oxime); sidedress soil applications of phorate, American Cyanamid CL-47031 (cyclic ethylene (diethoxyphosphinyl)dithioimidocarbonate), and Temik; stem applications of Azodrin^® (3-hydroxy-N-methyl-^cis-crotonamide dimethyl phosphate) and CL-47031; and foliar applications of toxaphene plus DDT. Results indicated that populations of certain predators, particularly those belonging to the order Hemiptera, may be reduced by applications of systemic insecticides. Spiders (order Araneida and certain groups of hymenopterous insects (families Braconidae and lchneumonidae) Were less affected. In 2 experiments, the number of eggs and larvae of Heliothis spp. increased as the population of predators decreased. These results demonstrated the importance of natural populations of predators in regulating populations of Heliothis spp.