Free amino acids in wild-caught Phlebotomus perniciosus and P. perfiliewi (Diptera: Psychodidae)

Free amino acids occurring in wild Phlebotomus perniciosus and P. perfiliewi were analyzed using high performance liquid chromatography. For both species the total concentration of amino acids, per unit weight, is over three times greater in females than in males. Qualitative inter-sex differences in amino acid compositions were also discovered: the most significant involving higher proportions of taurine and gamma-aminobutyric acid in females and higher proportions of arginine and glutamic acid in males. Although amino acid composition is consistent between females of both species, there are significant differences between males. The most important difference between males is an increase in tyrosine levels, at the expense of taurine, in P. perniciosus (as compared with P. perfiliewi). It is suggested that the intra- and inter-specific variation in amino acid composition identified in these studies could be due to ecological factors, such as differences in the sandflies natural amino acid sources (honeydew and/or plants), although a physiological explanation is not ruled out.