DEVELOPMENT OF A LABORATORY STRAIN OF THE TOBACCO BUDWORMRESISTANT TO DENIM~R AND A FIELD KIT FOR RESISTANCE MONITORING

摘要

A laboratory strain of the tobacco budworm, Heliothis virescens, was selected every generation by larval dip using Denim~R(emamectin benzoate). A moderate level of resistance was detected after selection for seven successive generations. The LC50for the parental strain by dip was 0.8 PPM while that for the selected strain (generation 8) was 6.1 PPM, a resistance ratio of7.6-fold. Using this resistant strain, we developed a feeding disruption assay for the diagnosis of Denim~R resistance inneonates of the tobacco budworm. The presence of blue feces on a white background is a marker for resistance. The kit is inthe commercialization phase of development.