Management of whiteflies using a behavior-based push-pull system in organic squash

Florida is one the biggest producers of squash, Cucurbita pepo L. (Cucurbitaceae), accounting for over 19% of all U.S. squash production in 2021. The greatest threat to squash production in Florida is the sweetpotato whitefly, Bemisia tabaci MEAM1 Gennadius (Hemiptera: Aleyrodidae), which damages squash through a physiological disorder and the transmission of viruses. Management of this pest involves the regular application of insecticides, but overuse has led to the development of resistances to the most commonly used insecticide classes. Alternative strategies based on exploiting the host-finding behaviors of whiteflies were tested in a 2020 field study in organic squash. Mass-trapping yellow sticky rolls were used to exploit whitefly visual attraction to the color yellow and foliar applications of a repellent solution made of kaolin clay (Surround® WP) and limonene, a constituent of citrus peel oil, were used to disrupt whitefly olfaction and host acceptance. These two treatments were tested alone and together as part of a push-pull system. The repellent spray was as effective as M-Pede®, a standard insecticide in organic squash, in reducing whitefly and aphid populations and in improving marketable yields. The yellow sticky roll was as effective as M-Pede® in reducing whitefly populations but led to an increase in aphid populations. Combining both the yellow sticky rolls and repellent spray in a push-pull system provided stronger control of whitefly populations than either treatment individually. No effects on key natural enemy groups were seen for any treatment type.