Susceptibility of the stone leek leafminer Liriomyza chinensis (Diptera: Agromyzidae) to insecticides

Abstract

The stone leek leafminer, Liriomyza chinensis (Kato), has become a serious pest on onion in the whole Vietnam, and it was controlled by a wide range of conventional insecticides. Because there is no recommendation on insecticide application, growers continue to use whatever is available without considering the effectiveness. The susceptibility of larva and adult L. chinensis to several insecticides currently and potentially used for the management of leafminers was investigated in the laboratory. Among 10 insecticides available in Vietnam, dimethoate, phenthoate, permethrin, and cartap were highly or moderately effective on either larvae or adults of L. chinensis, but ethofenprox was ineffective. Of the seven insecticides labeled for leafminer control in Japan, cyromazine, emamectin benzoate, cartap, and spinosad were highly effective, but thiamethoxam, flufenoxuron, and chlothianidin were less or no effective on L. chinensis at their field recommended dilutions. While dimethoate was effective on both the larvae and adults, cyromazine was only highly effective on the larvae and spinosad, and phenthoate were only found highly effective on the adults. These results suggest that dimethoate, cyromazine, spinosad, phenthoate, and cartap can be rotationally used for L. chinensis control.