Fatty acid compositions of phospholipids and triacylglycerols of selected tissues, and fatty acid biosynthesis in adult periodical cicadas, Magicicada septendecim

Fatty acid compositions of phospholipids and triacylglycerols prepared from selected body segments (head/thorax and abdomen) and tissues (fat body, al imentary canal, gonads, head and thoracic muscles) of adults of the periodi cal cicada, Magicicada septendecim, were determined. Adult males and female s yielded similar fatty acid profiles. Saturated and unsaturated C16 and C1 8 fatty acids were the predominant components, which varied slightly among tissues. The eicosanoid-precursor polyunsaturated fatty acid, 20:4n-6, was present in very low quantities, which varied among tissue sources. Adult pe riodical cicadas were competent to biosynthesize fatty acids from radioacti ve acetate. Compared to males, females incorporated just over five times mo re radioactivity into fatty acids. The radioactive components were incorpor ated into complex lipids in the fat body and gonads. In the fat body and ov aries, most radioactivity was incorporated into neutral lipid fractions, wh ile in testes most radioactivity was incorporated into phospholipids. These data indicate that even though periodical cicadas have evolved very unusua l life history patterns, fatty acid metabolism and composition in adults is similar to patterns seen in many terrestrial insect species. (C) 1999 Else vier Science Inc. All rights reserved.