Abstract
Studies were conducted to investigate the adaptations of the wood centipede, Lithobius forficatus, to winter conditions. During winter centipedes were freeze tolerant. However, inoculative freezing initiated from external ice was required for survival of freezing. Because the lower lethal temperature (after 24 hr exposure) was only β6Β°C, it appears that the insulation provided by the overwintering microhabitat under large logs is important for survival. Freezing proved lethal to summer animals.
Inoculative freezing points of live specimens remained steady at approximately β1Β°C throughout the year, as did the melting points of hemolymph. Although the supercooling points of the hemolymph stayed roughly constant at β7 to β9Β°C, those of live animals rose in winter and decreased in summer, suggesting the presence of nonhemolymph ice nucleators in winter. However, inoculative freezing was still essential for freeze tolerance. Centipedes did not accumulate carbohydrates or polyols in winter.
Winter hemolymph showed marked recrystallization inhibition activity, indicating the presence of thermal hysteresis proteins, but summer hemolymph did not. However, only occasional individuals had measurable thermal hysteresis activity in winter, indicating that the hemolymph concentration of thermal hysteresis proteins is low. Β© 1994 WileyβLiss, Inc.