Seasonal changes in the fatty acid composition of Argentine stem weevil,Hyperodes bonariensis(Coleoptera: Curculionidae)

Publisher Website
Google Scholar
Abstract
The fatty acids of the Argentine stem weevil were examined by gas-liquid chromatography. Peaks were attributed to myristic (14:0), palmitic (16:0), palmitoleic (16:1), stearic (18:0), oleic (18:1), linoleic (18:2), linolenic (18:3), and small amounts of 20-carbon fatty acids. During diapause the major fatty acids were oleic (42%) and palmitic (29%), and it is suggested that the majority of oleic acid originated from bacterial (Enterobacter sp.) biohydrogenation of linoleic acid, which constituted 72% of the fatty acids in the ryegrass diet. Relative to the diapausing weevils, the reproductive population showed a marked increase (12%) in palmitic acid and 32% less oleic acid. Furthermore, only 43% of the fatty acids from reproductive weevils were unsaturated, as against 63% in diapausing weevils. The reasons for these dramatic differences are unclear. However, preferential oxidation of oleic acid during periods of high metabolic activity may account for much of the change in fatty acid composition.