Larvae of the goldenrod gall moth, Epiblema scudderiana (Clemens) utilize a freeze-avoidance strategy for winter survival. Cold-hardiness adaptations of an outdoor population of the species were profiled over the 1984-1985 winter. Over the autumn months supercooling points of the larvae dropped from -13.9±2.3°C to -37.8±2.8°C (the lowest winter temperature recorded was -26°C), water content of the larvae decreased from 57.2±1.2 to 24.8±1.6% of fresh weight, and glycerol content of the larvae rose to an average of 2030 μmol/g wet weight or 18.7% of fresh weight. All parameters stabilized over the mid-winter months. Glycerol production was largely accounted for by the loss of stored glycogen while lipid and protein reserves remained nearly constant over the winter months. Supercooling-point depression and glycerol systhesis both appeared to be initiated after the first overnight exposures to subzero temperatures. Highest rates of glycerol production, about 60 μmol g-1 d-1, were achieved with mean daily temperatures of about 0°C and subzero nights. Glycerol content was rapidly cleared in the spring but only 20% of the resulting carbon was restored as glycogen.

cold hardiness adaptations, cryoprotectants, Epiblema scudderiana, freeze avoidance, insect overwintering, supercooling point
Journal of Insect Physiology
Department of Biology

Rickards, J. (Julian), Kelleher, M.J. (Mary Jane), & Storey, K. (1987). Strategies of freeze avoidance in larvae of the goldenrod gall moth, Epiblema scudderiana: Winter profiles of a natural population. Journal of Insect Physiology, 33(6), 443–450. doi:10.1016/0022-1910(87)90024-2