D3372: Ovicidal effects of various groups of insecticides on the eggs of Bemisia tabaci MED (Gennadius)

Bemisia tabaci is a species complex composed of several cryptic species due to its global distribution and high genetic diversity. In Korea, B. tabaci MED is the major cryptic species and infests various horticultural crops. Over the years, insecticide resistance has developed due to the overuse of insecticides, but there is a lack of research on the resistance rate to each insecticide. In this study, the ovicidal rate of eight groups of insecticides (acetamiprid, flupyradifurone, spinetoram, emamectin benzoate, pyrifluquinazon, pyraidaben, spiromesifen, and cyantraniliprole) with a different mode of actions were analyzed against B. tabaci MED eggs using a leaf-dipping assay. When the insecticides were treated on 2, 6, or 9-day-old eggs of the lab colony, the highest ovicidal activity was obtained with acetamiprid (50-90%), followed by flupyradifurone (40-50%), but the rest were below 20%. When analyzing the mortality of the larvae that hatched from insecticide-treated eggs, the mortality of spinetoram, emamectin benzoate, pyrifluquinazon, and cyantranilliprole was 60-70%, while that of other insecticides was 30% or less. These findings provide important information for predicting insecticide resistance of B. tabaci MED in the field.