Abstract
Plant-reared, apterous adult Myzus persicae were allowed to feed on synthetic diets with and without 0.01% aureomycin, and their progenies raised on antibiotic-free diets from which single amino acids were omitted. The individual omission of all 10 “essential” amino acids from diets fed to larvae derived from the antibiotic-treated mothers resulted in a considerable reduction in larval growth. Larvae derived from mothers fed an antibiotic-free diet exhibited such a reduction only when fed histidine-, isoleucine-, or methionine-free diets. In contrast, the individual omission of the “nonessential” amino acids did not affect the growth of larvae whether they were derived from mothers fed antibiotic-free diet or from mothers fed the diet containing aureomycin. The results suggest that the symbiotes of M. persicae supply the aphid with most of the essential amino acids in amounts sufficient for growth, when these nutrients are inadequately or not available to the aphids in their food. No improvement in the growth of larvae from antibiotic-treated mothers was obtained by incorporating lipid extracts of aphids or cholesterol into “complete” diets, in attempts to supply the aphids with dietary sterol.