Influence of the amino acid balance on the improvement of an artificial diet for a biotype of <i>Acyrthosiphon pisum</i> (Homoptera: Aphididae)

Abstract

A green biotype of the pea aphid, A. pisum, from Lusignan (France), showed very poor performance on the standard Akey and Beck diet. Significant improvement occurred after reduction of the osmotic pressure of the diet and modification of the amino acid component, according to the results of carcass analysis. A further improvement was obtained through an optimalization of the aromatic amino acid level: the tyrosine deficiency induced by its poor solubility was overcome by an excess of phenylalanine and the inclusion of a soluble tyrosine compound, β-alanyltyrosine. A new diet was therefore formulated for this biotype, on which adults were more than twice as heavy as on the standard diet.