Free amino acid composition of the ageing female mosquito Aedes aegypti as determined by automatic ion-exchange chromatography

Abstract

The free amino acids of the adult female mosquito, Aedes aegypti (L.), were investigated at seven different ages after emergence in insects maintained on two different dietary regimens (sucrose, and sucrose and blood). The qualitative and quantitative determination of free amino acids was carried out by automatic ion-exchange chromatography. Sixteen amino acids were consistently found: α-alanine, aspartic acid, glutamic acid, glycine, serine, threonine, proline, valine, methionine, isoleucine, leucine, tyrosine, phenylalanine, lysine, histidine, and arginine. Four other amino acids found but in rather low concentrations included β-alanine, taurine, cysteic acid, and methionine sulphoxide. Throughout the 45-day experimental period the concentrations of free amino acids in mosquitoes given sucrose and blood were consistently higher than in those individuals given only sucrose as adults. α-Alanine was found in highest concentration in mosquitoes from both dietary regimens, comprising from 34 to 52 per cent of the total amino acid load. Total amino acid concentration was found to be highest at 30 days of age. Statistical procedures applied to the data indicated diet alone had less effect on individual amino acids than it did when time (age) was considered, or diet was primarily significant when time was included.