Meeting Abstract

48.1  Jan. 6  Overwintering Physiology of the Beetle Cucujus clavipes: Roles of Antifreeze Proteins, Polyols, and Dehydration SFORMO, T*; BENNETT , VA; WALTERS , K; JEANNET, K; BARNES, B; DUMAN, J; Institute of Arctic Biology, University of Alaska, Fairbanks; Department of Biology Clarion University; Department of Biological Sciences, University of Notre Dame, Notre Dame; Institute of Arctic Biology, University of Alaska, Fairbanks; Institute of Arctic Biology, University of Alaska, Fairbanks; Department of Biological Sciences, University of Notre Dame, Notre Dame rfts@uaf.edu

Insects that overwinter at high latitudes and under extreme environmental conditions should require, in comparison to populations from lower latitudes, tolerance to exceptionally low temperatures. The freeze-avoiding larvae of the coleopteran Cucujus clavipes found in sub-arctic and arctic Alaska (64 � 67 �N latitude) populations produce antifreeze protein in August and may be cued by decreases in photoperiod, whereas polyol production (predominately glycerol) appears to be cued by decreases in temperature (~0 �C). Alaska larvae undergo extreme dehydration from 63 � 65 % body water (1.7 � 1.8 g H2O g-1 dry weight) in summer to 28 � 40 % body water (0.40 � 0.68 g H2O g -1 dry weight) in winter. While the 2.5 � 4.6 fold reduction in body water and the increase in antifreeze and glycerol allow Alaska C. clavipes to supercool in winter between -35 to -42 �C, we also present evidence that some Alaska larvae in winter do not freeze even when cooled to -80 �C.