Control of the Sweetpotato Whitefly on Poinsettia, 1992

Poinsettias obtained as rooted cuttings were potted in 15 cm pots. Plants were allowed 4 wk growth (25-30 cm tall) before use in trials. Six plants/treatment were arranged in a RCB design on a raised greenhouse bench. Poinsettia leaves were numbered from the top (first leaf of 1 cm2) down. Twenty adult SWF were clip-caged (2.5 cm diam.) on leaf no. 5 for 48 h to obtain a moderate no. of eggs/leaf. After egg eclosion (10 d) the no. of nymphs were counted as a pre-treatment count on day 0. Treatments began on the same day and continued weekly for 3 wk with a hand sprayer at 40 psi to runoff. Three post-treatment counts of all immature stages and emerged whiteflies were made 16, 20, and 28 DAT.