Response of Bollworm and Predaceous Arthropod Populations to Aldicarb Treatments in Cotton

Populations of Heliothis zea (Boddie), and 10 predaceous arthropods were sampled in irrigated and dryland cotton fields following infurrow and sidedress applications of the systemic insecticide aldicarb. The numbers of bollworm larvae were much greater in aldicarb-treated, cotton than in untreated cotton. Several applications of insecticide were applied to suppress the bollworm population in irrigated cotton which had received a sidedness application of aldicarb. Little difference was noted in the average number of predaceous arthropods present in aldicarb-treated and untreated cotton before foliar applications of insecticide were required to suppress bollworms in some aldicarb-treated fields. However, samples taken during the single period of greatest bollworm activity indicated that the predaceous insects Geocoris sp., Nabis sp., Hippodomia sp. and Chrysapa sp., as well as spiders, were more abundant in untreated irrigated cotton than in aldicarb-treated irrigated cotton.