Recent baculovirus and cabbage host plant resistance studies for the management of diamondback moth in Georgia

This project's goal was to mitigate the effects of insecticide resistance in diamondback moth (DBM) populations in commercial Cole cropping systems through the use alternative pest management options. The two tactics we evaluated in 2021-2022 were 1) the use of an alternative biocontrol agent Lepigen, active ingredient: Autographa californica Multiple Nucleopolyhedrovirus, in collaboration with AgBiTech, to control insecticide resistant DBM larvae and 2) to evaluate potential DBM-resistant cabbage cultivars for reducing the impact of DBM infestations in the field. In a spring 2022 field test, the most efficacious insecticide treatments for DBM control were a Proclaim 5%WDG plus a Radiant 1SC 2-wk rotation, a Spear-Lep + Xentari plus a Radiant 1SC 2-wk rotation, a Radiant 1SC + Lepigen combination, a Lannate 2.4LV + Lepigen combination and a Avaunt 30DG + Lepigen combination. The result of the spring cabbage host plant resistance experiments was to show that the cabbage cultivars, Green Challenger and Cairo, appeared to provide mature plant resistance to DBM, but did not affect larvae on young plants. Alternative control options to reduce the frequency of insecticide resistance in DBM populations are discussed.