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.

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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