Control of the Silverleaf Whitefly (SW) on Poinsettia Under Greenhouse Conditions, Fall 1993

Poin settias obtained as rooted cuttings were potted in 15 cm pots. Plants were allowed 4 wk growth (25-30 cm tall) before use in trials. Leaves were counted from the top (leaf of >2 cm2) down. Twenty SW adults were clip-caged (2.5 cm diam) on the adaxial surface of leaf no. 5 for 24 h to obtain a moderate no. of eggs/leaf. Ten days later the no. of nymphs were counted as a pre-treatment count (0 DAT). Plants were assigned to treatments to obtain an equal no. of immatures/treatment. Five plants/treatment were arranged in a randomized block design on a greenhouse bench. Ten treatments and a water treated control were applied by hand sprayer at 45 psi. Post-treatment counts were made at 7 DAT and 14 DAT.