Abstract
The haemolymph of eight ages during larval development of the two female castes of the honeybee, Apis mellifera L., were examined for free amino acids. Twenty-seven identified free amino acids and three unidentified ninhydrin-positive compounds were detected in both castes by the technique of thin-layer chromatography described. The amino acids identified were aspartic acid, cystine, glutamic acid, asparagine, glycine, serine, taurine, ornithine, threonine, lysine, alanine, arginine, histidine, gtutamine. β-alanine, hydroxyproline, proline, methionine, methionine sulphone and (or) sulphoxide, α-amino-n-butyric acid, γ-amino-n-butyric acid, tyrosine, tryptophan, valine, phenylalanine, leucine, and isoleucine.The general trend in both castes was for the total amino acid concentration first to increase and then, around the third day in workers and the fourth day in queens, to undergo a steady decrease with age.Aspartic acid concentration varied so greatly between the two castes that it is suggested as a criterion of dimorphism.The significance of these results is discussed in relation to female dimorphism.