Monitoring for insecticide resistance of melon fly populations in the field of Southern China

Objective To identify the insecticide resistance of melon fly, Bactrocera cucurbitae, to the commonly used pesticides, and to provide a scientific basis for prevention and resistance management of melon fly populations.

Method The melon fly populations were collected from Guangzhou, Zhanjiang, Maoming, Qingyuan, Nanning, Changsha, Wuxi from June to October in 2013. The insecticide resistances of melon fly to six different types of pesticides (trichlorphon, cyhalothrin, cypermethrin, emamectin benzoate, abamectin, spinosad) were tested with residual film method.

Result and conclusion The insecticide resistance ratios of melon fly population from Guangzhou and Wuxi to trichlorphon were 2.03 and 2.14 respectively. The resistance ratio of population from Zhanjiang to emamectin benzoate was 2.69. The above resistance ratios indicate that these populations are still susceptible. The populations collected from other areas show low-level or intermediate-level resistance to those six types of insecticides.