Prospects for management of whitefly using plant semiochemicals, compared with related pests

Whitefly (Hemiptera: Sternorrhyncha: Aleyrodidae) pests are economically important in agriculture, including the tobacco whitefly, Bemisia tabaci, and the greenhouse whitefly, Trialeurodes vaporariorum. Whiteflies are mainly controlled by synthetic insecticides but resistance to these insecticides is rapidly evolving. A semiochemical-based management strategy could provide an alternative to the use of insecticides, by exploiting natural volatile signalling processes to manipulate insect behaviour. Whitefly behaviour is affected by differences in plant odour blends. Selected compounds have been suggested as putative semiochemicals, but in only a few studies, potential volatiles were eventually characterised by electrophysiology or olfactometry. The application of antennal preparation methods from the closely related families, the aphids (Hemiptera: Aphididae) and psyllids (Hemiptera: Psyllidae), may help to facilitate whitefly electroantennography. Behavioural bioassays are essential to identify the repellent or attractant effect of each semiochemical. The relevance of the semiochemicals in whitefly management needs to be evaluated in the respective cultivation system. Although the value of semiochemicals has not been demonstrated in the field against whiteflies, there is an emerging range of possible field applications and some promising prospects. Overall, the olfactory system of whiteflies needs to be elucidated in more detail.