抄録
Supercooling point, inoculative freezing point, sugar content and frost resistance of four beetles were studied in winter to understand the overwintering strategies of soil insects. Adult Gastrophysa atrocyanea (Chrysomelidae) showed a weak frost resistance, with lower lethal temperature at about -10°C. In Agriotes fusicicollis (Elateridae) adults supercooled down to -20°C, but larvae only to -8.4°C, and both died from freezing. Larvae of Anomala testaceipes and Popillia japonica (both Scarabaeidae) were also freezing susceptible with supercooling points only at about -7°C. These scarabaeids and also larvae of Ag.fuscicollis descend to deeper soil layers in winter to avoid coldness. The overwintering strategies of the studied beetles thus can be classified into three types : frost resistant, supercooling, and cold avoidance.
