Influence of dietary lipids upon lipids in larvae and adults of the dried-fruit moth

Abstract

The dried-fruit moth was reared on three diets differing in quantity and types of fatty acids. Triacylglycerols (TAG) were the major lipid present in both larvae and adults and their fatty acid compositions reflected dietary fatty acids to some extent. However, larval and adult contained relatively high levels of 16:0, 16:1, and 18:1 even when these acids were not predominant in the dietary lipid. Diacylglycerols were present in larvae and adults at lower levels than TAG and their fatty acid compositions were similar to those of the corresponding TAG. Adults contained more phospholipid (PL) and cholesterol than larvae regardless of diet employed. Phosphatidyl-ethanolamine and phosphatidyl-choline were the major PL present with appreciable levels of diphosphatidyl-glycerol and lesser amounts of lysophosphatidyl-ethanolamine and choline, sphingomyelin, phosphatidyl-serine, and inositol being present. The higher level of PL noted in the adults were due to a general increase in all of the individual phospholipids and not to any specific PL. Dietary fatty acids did influence fatty acid compositions of larval and adult PL. However, there appeared to be compensations in the proportions of other fatty acids in the PL in that high 18:1 was accompanied by lowered levels of 18:2 and high 18:2 was accompanied by lowered levels of saturated fatty acids. In every case adult PL contained more polyenoic fatty acids than did larval PL. There were no apparent compensations in other fatty acids accompanying these changes.