Freezing and Survival of Insects at Low Temperatures

摘要: The literature on the general subject of freezing and survival both in plants animals is briefly reviewed a bibliography given. Insects representing three ecological groups, (1) oak borers—exposed to temperature extremes normally; (2) stored-products insects supposedly tropical or subtropical group, and, (3) aquatic never exposed temperatures lower than 0°C., were chosen for this study. Determinations undercooling points made during yearly cycle. Both studied showed no periodicity undercooling. borers marked periodicity. freezing-point varies directly with moisture content. Cold-hardiness was produced experimentally by, exposure low by dehydration. Loss cold-hardiness combinations high temperature, food, relative humidity. ordinarily found corresponds that blood. Repeated freezings same insect tissue hysteresis. There exists certain secondary below found. Oak summer condition die at first freezing-point; fully hardened they freezingpoint.