Studies on freezing injuries in Eleodes blanchardi beetles

Abstract

1. 1. Cold-acclimated tenebrionid beetles of the species Eleodes blunchardi tolerated freezing at −6 to −8°C. whereas beetles kept at room temperature for 2 weeks were seriously injured by freezing at these temperatures. 2. 2. The cold-acclimated beetles tolerated the freezing of a higher percentage of their body water than did the warm-acclimated beetles, indicating that the difference in cold tolerance is not due to a colligative cryoprotective mechanism. 3. 3. Immediately after freezing, both groups of beetles had a markedly elevated oxygen consumption, most pronounced in the warm-acclimated group. After 20 hr at room temperature, the oxygen consumption had returned to normal level, even in those beetles which were seemingly dead The normal oxygen consumption indicates that most of the cells were still intact after the freezing. 4. 4. It is proposed that the freezing injury might occur in nervous tissues, and that the difference in cold tolerance might be due to acclimation in these tissues.