Year: 1972
Type: dissertation
Abstract: In contrast to many other insects whose characteristic fatty acid compositions are influenced to a limited extent by dietary fats, the fatty acid composition of the total lipid of hymenopterous parasitoids of the family Ichneumonidae is very similar to that of their diet, that is, the hosts on which they are reared.In cases where such parasites were reared on two different species of host with very different fatty acid patterns, the parasitoids, Exeristes comstockii and Itoplectis conquisitor retained no characteristic fatty acid composition of their own.In contrast, the hosts Lucilia sericata and Galleria mellonella, are influenced very little by dietary fats.This lack of control over pool size of fatty acids was characteristic of, but not exclusive to, all the ichneumonids examined in these studies.Isolated cases were found in other families analyzed, which included the Aphidiidae, Brachonidae, Pteromalidae and Eulophidae.More detailed analyses demonstrated that although the parasitoid I. conquisitor appears to have little qualitative or quantitative control over the fatty acid composition of its neutral lipids, it does exert some quantitative control over that in its phospholipids.Although the fatty acid composition of the phospholipids varied considerably, and adopted many of the characteristics of the composition of the phospholipids of the host, consistent ratios of the fatty acid classes were maintained, thus the physical nature of the phospholipids, would be maintained.Radioisotope studies demonstrated that the fatty acid pattern of the parasitoid, -E.comstockii is maintained by active metabolic processes, and that the fractional turnover rates of the individual fatty acids are iiimuch g r e a t e r t h a n t h o s e i n e i t h e r of t h e h o s t s , 4. s e r i c a t a and 2. mellone l l a .The p a t t e r n was a l s o shown t o b e maintained p a r t i a l l y by d i r e c t i n c o r p o r a t i o n of h o s t f a t s . . . . . . . . . . . . . . . . . . . . . . . . . . .
Source: Summit (Simon Fraser University)
Author: S. N. Thompson
Language: English
Subfield: Biochemistry
Domain: Life Sciences
Open Access status: green
OpenAlex ID: W2299080634