TEMPERATURE AND DIEL CATCHES OF TRIALEURODES-VAPORARIORUM AND BEMISIA-TABACI (HOMOPTERA, ALEYRODIDAE) ADULTS ON STICKY TRAPS IN THE GREENHOUSE

Patterns of diel flight activity of the greenhouse whitefly, Trialeuro des vaporariorum (Westwood), and sweetpotato whitefly, Bemisia tabaci (Gennadius), were investigated on poinsettia, Euphorbia pulcherrima Wi lld., and gerbera daisy, Gerbera jamesonii H. Bolus, under greenhouse and environmentally controlled conditions. Adult flight activity was m onitored at 2-h intervals (from 0700 to 2100 h EST) at various heights using yellow sticky traps. Traps placed 5 cm above the top of the pla nt canopy caught more adults of both species than traps placed higher. The daily patterns of catches of T. vaporariorum and B. tabaci adults in the greenhouse were similar and were unimodal with peak catches oc curring between 0900-1300 h. Numbers of adults caught on the sticky tr aps in the greenhouse were correlated with temperature and relative hu midity for T. vaporariorum, but not for B. tabaci. Few adults were cau ght during the dark hours (from 2100 to 0700 h). Under constant temper atures of 20-degrees, 25-degrees, and 30-degrees-C, the flight activit y patterns of both whitefly species were unimodal, with peak catches o f T. vaporariorum and B. tabaci occurring in the morning and afternoon , respectively. Differences in temperature did not significantly alter the pattern of catches of adults on sticky traps. The lowest temperat ure for initiation of whitefly flight was 16-17-degrees-C for T. vapor ariorum, and 17-18-degrees-C for B. tabaci.