Suppression of Bemisia tabaci (Homoptera: Aleyrodidae) infestations in cantaloupe and cotton with sprinkler irrigation

A series of field experiments were conducted to evaluate Bemisia tabaci (Genn.) infestations in both sprinkler and furrow irrigated cantaloupe and cotton plots under conditions of intense whitefly pressure in Imperial Valley, CA. Various fungal pathogen and insecticide treatments also were compared within each irrigation regime. A consistent finding throughout all experiments was that densities of immature whiteflies were significantly reduced in sprinkler irrigated plots. This was most evident in sprinkler irrigated cantaloupe plots treated with the insecticide imidacloprid, as plants survived whitefly infestations to produce marketable fruit in these plots only; Similarly, whitefly densities in imidacloprid- treated/sprinkler-irrigated cotton were significantly lower than all other treatments. Spray applications of insect fungal pathogens were for the most part indistinguishable from the untreated control in terms of densities of whiteflies. Results from the first cantaloupe trial indicate that sprinkler irrigation on a daily schedule resulted in consistently lower whitefly infestations compared to a biweekly schedule. Published by Elsevier Science Ltd