D3127: Life cycle of squash bugs in cucumber greenhouses in Québec, Canada

Squash bugs Anasa tristis and A. armigera (Heteroptera: Coreidae) are sporadic pests in Québec (Canada) cucumber greenhouses. They can cause significant cucumber damages, and the only control method is the manual removal of individuals. This project aims: 1) to determine their life cycle in a greenhouse, 2) to identify possible natural enemies and 3) to determine their diurnal activity to optimize detection strategy. Observations in three greenhouses per year have been done weekly between June and September 2019 and 2020. Different traps and squash plants have been installed in the greenhouses and observed weekly. Around each station, ten cucumber plants have been observed to count eggs, nymphs, adults of squash bugs and predators. Specimens were captured and kept in the laboratory for parasitism evaluation. Evaluation of the diurnal activity was done using large cages with five plants of cucumbers or squash per cages. Five marked individuals were introduced in cages for each species and observed each 2h for 8h. Presence on soil, stems, leaves or cages has been noted. Anasa armigera was dominant in greenhouses both years. No predation or parasitism has been noted. The diurnal activity of both species on cucumber and squash was different between species and crops, while variable between the two years of study. Better knowledge of the life cycle of squash bugs in cucumber greenhouse will help to develop IPM strategy against those pests.