Meeting Abstract

44.6  Saturday, Jan. 5  Body size affects the expression of seasonal phenotypic plasticity: thresholds, diapause length, and over winter survival in big and little flesh flies. HAHN, D.A.*; BUSKIRK, M.C.; University of Florida; University of Florida dahahn@ufl.edu

Body size is a critical determinant of organismal life histories and physiology affecting a wide range of traits including reproduction, development, survival, and metabolism. Many organisms have evolved a facultative developmentally-programmed dormancy during some part of their lifecycle to mitigate the effects of seasonally-predictable stressors. Large individuals have been shown to have greater overwintering survival during dormancy (diapause) in many insects. However, how size affects entry into dormancy and the length and depth of dormancy is unknown. By quantitatively manipulating the body size of pupae programmed to enter diapause, we show that there is no minimum size threshold for diapause entry in the flesh fly, Sarcophaga crassipalpis. We show that size affects overwintering survival under ecologically-relevant, non-developmentally permissive temperatures. Size also affects the duration of dormancy under developmentally-permissive temperatures. Although large individuals survive long overwintering periods better, surprisingly, smaller individuals have a longer dormancy under developmentally-permissive conditions.