Low-temperature tolerance of the vegetable weevil, Listroderes costirostris Schönherr (Coleoptera: Curculionidae).

The vegetable weevil, Listroderes costirostris SCHONHERR, hibernates in a non-diapause state in winter and can survive in northern Japan despite regional low temperatures. For these reasons, the low-temperature tolerance of larvae and adults was determined. The supercooling points of the adults and last-instar larvae were -9.0°C and -6.7°C, respectively. All adults and 50% of tested larvae could not tolerate -10°C for 3 hours. As air temperature decreases, adults and larvae move beneath the bottom leaves in contact with the ground surface or around the stalks where temperatures are higher than in aerial parts. Their behavior for avoiding freezing temperatures may enable them to survive winter in northern Japan, although their low-temperature tolerance is poor.