LIPID AND FATTY-ACID COMPOSITION OF THE FAT-BODY DURING THE FEMALE REPRODUCTIVE-CYCLE OF LABIDURA-RIPARIA (INSECTA DERMAPTERA)

During the reproductive cycle of the female Introduction Labidura ripa ria, cytological observations show cyclical modifications of lipid dro plets in the periovarian adipocyte. Fat body lipids and their constitu tive fatty acids are analyzed. The lipids are predominantly triacylgly cerols, which increase after adult ecdysis during vitellogenic and non -vitellogenic periods. Small amounts of diacylglycerols and phospholip ids are found. Diacylglycerols increase during vitellogenesis and decr ease during the non-vitellogenic period. Cytological modifications of lipid droplets are probably related to diacylglycerol fluctuations. Ga s-liquid chromatography of fatty acid methyl esters shows oleic acid t o be the predominant fatty acid in total lipids and triacylglycerols; unsaturated acids are approximately twice as abundant as saturated aci ds all along the reproductive cycle. Fatty acid composition of diacylg lycerols and phospholipids differs from triacylglycerols and total lip ids composition Palmitic, stearic, oleic and linoleic acids represent the major fatty acids; their relative amounts vary during the differen t periods of the reproductive cycle. The correlations between fat body lipid changes and ovarian development were discussed and compared wit h observations made on other insect species.