Leaf trichome and insecticide interactions relative to Bemisia tabaci (Hemiptera: Aleyrodidae) management in a cotton-cucurbit strip cropping arrangement

Host plant resistance (HPR) has shown potential for suppressing sweetpotato whitefly, Bemisia tabaci Gennadius (Hemiptera: Aleyrodidae), in smooth (glabrous) crop varieties lacking leaf trichomes. The objective of this study was to investigate the interaction between HPR and insecticidal control, aiming to enhance their collective efficacy in whitefly management. Field trials were conducted in cotton and cantaloupe planted as strip crops at 2 locations in southern Georgia, United States: Tifton and Camilla. Treatments comprised 2 insecticides, based on the active ingredients pyriproxyfen and cyantraniliprole, with 2 different trichome conditions: pubescent (hairy), or smooth varieties. During the crop growing season, B. tabaci adult, egg, and nymph populations were monitored, and whitefly preferences were evaluated. Results indicate a preference of whiteflies for cotton and cantaloupe pubescent varieties, largely attributed to the presence of leaf trichomes. Pyriproxyfen predominantly reduced nymph populations, while cyantraniliprole was effective against both immatures and adults. Significant interactions among crop type, trichome presence, and insecticide application in determining B. tabaci abundance were measured. The glabrous cotton variety demonstrated greater whitefly suppression compared to glabrous melon, and cyantraniliprole exhibited a heightened initial mortality in pubescent cultivars. The study underscores the importance of selecting smooth leaf crop varieties in integrated B. tabaci management strategies. The results illuminate the need for developing real-world testing models with compatible strategies of integrated pest management (IPM) programs for B. tabaci and provide a wide-ranging insight into the interactive effects and dependency of multiple components involved in whitefly control in multicropping systems.