Lipid composition of the pea aphid, Acyrthosiphon pisum (Harris) (homoptera: Aphididae), reared on host plant and on artificial media

Abstract

Polar and neutral lipids and their constitutive fatty acids were quantified in the pea aphid, Acyrthosiphon pisum (Harris), grown on host plant or on a lipid free artificial diet. The results were compared to determine if lipids were involved in the suitability of the diet for continuous rearing of this A. pisum biotype. For apterous adults grown on plants, the lipids were characterized by a low amount of neutral lipids (2.5% weighvfresh weight) almost entirely (96.4%) composed of hexanoyl and sorboyl dimyristin. These storage lipids were higher in the alatae (3.8%), probably correlated with potential flight activity. The phospholipid amounts were identical in these two morphs (1.3-1.4% weightlfresh weight), comprised mainly of phosphatidylethanolamines (52%) and phosphatidylcholines (40.6%). These phospholipids contained a still unidentified fatty acid, with a retention time close to that of linolenic acid and synthesized by the aphid or its bacterial symbiont5 (not found in plants). The apterous adult aphids reared on an artificial diet showed an accumulation of neutral lipids (8.9% for the first generation); this increase was shown to be slightly greater for the hexanoyl and sorboyl triglycerides. In contrast, the phospholipids decreased in aphids reared on an artificial diet (1.1 % and 0.9%, respectively, for first and second generation), correlated with a phospholipid fatty acid profile significantly deficient in C18:3 and in the unidentified peculiar fatty acid. These phospholipids are essential components of biological membranes and a diet-driven deficient synthesis in some of their components may result in the observed symptoms. 01992 WiIey-Liss, Inc.

A novel fatty acid binding protein produced by teratocytes of the aphid parasitoid Aphidius ervi

“…Ae ‐FABP may well play this transport role; its high abundance in the host haemolymph when increased lipid amounts become available (Pennacchio et al ., 1995), and its considerably higher affinity for some of the FAs more abundantly present in Ac. pisum acylglycerols (Febvay et al ., 1992; Rahbé et al ., 1994) appear to corroborate this hypothesis.…”

“…Ae-FABP may well play this transport role; its high abundance in the host haemolymph when increased lipid amounts become available (Pennacchio et al, 1995), and its considerably higher affinity for some of the FAs more abundantly present in Ac. pisum acylglycerols (Febvay et al, 1992;Rahbé et al, 1994) appear to corroborate this hypothesis. This parasitoid-driven lipid mobilization pathway is in tune with a rather general parasitic strategy of host exploitation, based on the disruption of the host's major metabolic sinks and the redirection of its metabolism in favour of the developing parasitoid larva Vinson et al, 2001).…”

Egg cannibalism by ladybird larvae is less frequent than expected from the nutritional benefit accrued to cannibals

“…This result may be due to the fact that eggs are four times richer in lipids than A. pisum (Febvay et al. ; Sloggett and Lorenz ). Thus, it is not surprising that conspecific eggs appear to be high‐value food for late instar larvae.…”

“…We also noticed that larvae lost less mass during the pupal stage if they previously ate a pure diet of conspecific eggs or a mixed diet of eggs and aphids rather than only aphids. This result may be due to the fact that eggs are four times richer in lipids than A. pisum (Febvay et al 1992;Sloggett and Lorenz 2008). Thus, it is not surprising that conspecific eggs appear to be high-value food for late instar larvae.…”

Changes in the lipid and fatty acid composition of hemolymph and ovaries during the reproductive cycle of Labidura riparia

“…2002) and many dipterans are characterized by having a high proportion of 16:1 (Fast 1970; Thompson 1973). Among the homopterans, aphids are characterized by having very high proportions of 14:0 (Fast 1970; Febvay et al . 1992).…”