Survival of cabbage looper, Trichoplusia ni (Lepidoptera: Noctuidae), through winter cleanups of commercial vegetable greenhouses: Implications for insecticide resistance management

► Cabbage loopers do not survive overwinter outside greenhouses in BC. ► Cabbage loopers can survive cleanup procedures inside unheated greenhouses. ► Insecticides used in winter cleanups do not kill cabbage looper pupae. ► Initial infestations in greenhouses are due to carryover from one season to the next.