Evaluation of control effect of insecticides on a leaf beetle, Demotina fasciculata Baly, that damages young bud of tea plants.

Abstract

Laboratory and field experiments were conducted to evaluate effects of insecticides on a leaf beetle, Demotina fasciulata Baly (Coleoptera: Chrysomelidae), of which adults damage young buds of tea plant. In the laboratory, fluxaemetamide, thiamethoxam, spinosad, spinetoram, dinotefuran and clothianidin showed 100 % mortality of D. fasciculata adults within one to four days after treatment, among 13 insecticides examined. In the field, significant reduction was observed in damage on buds and young leaves by D. fasciculata when tea plants were treated with fluxaemetamide, clothianidin, dinotefuran, acetamiprid, spinosad and chlorfenapyr. Control of D. fasciculata by using insecticide and/or the other methods is discussed for better organic farming of tea plant.