Responses of Whitefly and Poinsettias to Insecticidal Controlled Atmospheres

Eggs, larvae, pupae, and adult stages of greenhouse whitefly ( Trialeurodes vaporarium Westwood) and silverleaf whitefly ( Bemisia argentifolii Bellows & Perring) were exposed to insecticidal controlled atmospheres at 20 °C or 30 °C. Mortality data were calculated for each stage and results demonstrated that reduced-O 2 atmospheres (an O 2 level of 90% of adults, larvae, and eggs and pupae was 2, 4, and 8 hours, respectively. Increasing the treatment temperature from 20 to 30 °C reduced the treatment time to one-half that of 20 °C. Treatment time required to achieve complete elimination of the insects also caused phytotoxicity symptoms on poinsettias ( Euphorbia pulcherrima Willd. ex Klotzsch), thus, limiting use of insecticidal controlled atmospheres as the sole means for managing whitefly.