Effects of rearing temperature on cuticle permeability and epicuticular lipid composition in Drosophila pseudoobscura

TLDR: High transcuticular water loss rates were correlated with higher proportions of relatively short-chain, methyl-branched alkanes and alkadienes, and high proportions of longer chain lengths of both branched alkenes and alkADienes were associated with lower cuticular permeabilities.

Abstract: The effects of larval and pupal thermal regime on adult transcuticular water loss rates and epicuticular hydrocarbon composition in Drosophila pseudoobscura were determined. Temperatures encountered by the larval stage had no effect, but flies emerging from pupae maintained at 24°C exhibited significantly lower cuticular permeabilities than those emerging from pupae maintained at 17°C. More than 50% of the variance in cuticular permeability was accounted for by variation in the proportion of n-pentacosadiene in the epicuticular hydrocarbons. High transcuticular water loss rates were correlated with higher proportions of relatively short-chain, methyl-branched alkanes and alkadienes. High proportions of longer chain lengths of both branched alkanes and alkadienes were associated with lower cuticular permeabilities. The molecular basis for these findings is discussed.