Meeting Abstract

P3.209  Sunday, Jan. 6  Seasonal and altitudinal variation in fatty acid composition of native bees GIRI, S.*; DILLON, M.E.; Univ. of Wyoming, Laramie; Univ. of Wyoming, Laramie sgiri@uwyo.edu

Lipids are critical for organism physiology, both as key energy storage molecules (fatty acids), and as fundamental components of cell membranes (phospholipids and sterols). The quantity and quality of fat (the most important energy resource) stored strongly affects survival & fitness in many organisms. However, the structure and physiological functions of key lipid components (fatty acids) are strongly affected by temperature. In particular, low temperatures compromise the mobilization of energy from stored fats and reduce the fluidity of phospholipid cell membranes. In response to changing temperatures, organisms may also alter lipid and hence fatty acid composition to maintain fluidity, a hypothesis termed “homeoviscous adaptation”. Small ectotherms like insects may be particularly susceptible to temperature induced shifts in lipid physiology but the homeoviscous adaptation hypothesis has rarely been tested in terrestrial insects, except in the context of diapause. We tested whether lipid content and fatty acid composition vary with seasonal (May to September) and altitudinal (2241 – 3151 m) variation in environmental temperature among eight species of native bees. We measured total lipid content and fatty acid composition using a vanillin assay and gas chromatography coupled with a flame ionization detector (GC-FID). Here, we discuss how fat physiology varies seasonally and with altitude among a diverse array of native bee species.