Role of environmental thermal fluctuation in seasonal variation of fatty acid composition of total lipid in fatbody of the cockroach, Periplaneta americana (Linn.)

Abstract

1. 1. The fatty acid composition of total lipid in the fatbody of male, female and nymphal cockroach, Periplaneta americana (Linn.), changes in response to seasonal alterations in environmental temperature. 2. 2. The compensatory mechanisms employed in cold adaptation, either in winter-acclimatized insects or 16°C-acclimated summer roaches, include an increase in the level of unsaturated fatty acids and a decrease in the level of saturated fatty acids. In the warm, either during the summer or during the 32°C acclimation of winter insects, the content of unsaturated fatty acids fell and the level of satured fatty acids rose. Thus temperature seems to play an important role in seasonal variation of lipid metabolism in the fatbody of cockroach. 3. 3. A sexual dimorphism is also discerbible in this insect with respect to the fatty acid composition of total lipid of fatbody either during seasonal acclimatization in nature or during thermal acclimation under laboratory conditions.