The efficacy of insecticides against eggs and nymphs of Aleyrodes proletella (Hemiptera: Aleyrodidae) under laboratory conditions

The importance of Aleyrodes proletella (L.) (Hemiptera: Aleyrodidae) as a pest of cruciferous crops is rising. Concurrently, there is insufficient know-how for successful and efficient control of this pest. The aim of this study was to compare the efficacies of 21 commonly used insecticides in order to search for the most suitable chemical control of this pest. Insecticides were sprayed on the leaves of Brassica oleracea var. gongylodes L. cv. Luna with laid eggs and nymphs of A. proletella at the concentrations recommended by the manufacturers. Treating eggs and nymphs with insecticides significantly increased their mortality compared to the control, but the effects of particular insecticides varied. The overall efficacy was lower in case of nymphs than for eggs. Many of the selected insecticides were effective against one stage only. Egg mortality was highest after treatment with spirotetramat, cyantraniliprole, spinosad, diflubenzuron, pyridaben, imidacloprid and thiacloprid. The most efficient active ingredients against nymphs were spirotetramat, cyantraniliprole, pyridaben and rapeseed oil. Thus, spirotetramat, cyantraniliprole and pyridaben were the most effective active ingredients against immature stages of A. proletella in this study, and so further confirmatory studies in the field are recommended.