QUANTITATIVE-DETERMINATION OF FREE AMINO-ACIDS IN THE HEMOLYMPH OF AUTOGENOUS AND ANAUTOGENOUS STRAINS OF CULEX TARSALIS (DIPTERA, CULICIDAE)

Autogenous and anautogenous strains were selected from the egg rafts o f Culex tarsalis Coquillett collected from Coachella Valley, Californi a. In autogenous (21-25 generations) and anautogenous (0-4 generations ) strains used for hemolymph free amino acid analysis, the autogenous oviposition rates were 73.6-83.6% and 2.7-3.9%, the proportions of fem ales undergoing autogenous ovarian development 120 h postemergence wer e 75.6 and 8.9%, respectively. To study the presence and quantities of free amino acids and explore their relationship to autogenous ovarian development, the 6 legs of females from both autogenous and anautogen ous strains were removed at the coxo-femoral joints, and hemolymph was collected by centrifuging the bodies of 50-100 females. Proteins in t he hemolymph were precipitated with 10% sulphosalicylic acid. On days 1, 4, 7, and 10 postemergence, a total of 17 free amino acids was foun d in females from the autogenous strain, and a total of 16 was found i n females from the anautogenous strain in which asparagine (Asn) was a bsent. Comparisons of free amino acid concentrations between these 2 s trains indicated that there were significant differences in total free amino acids and 13 individual free amino acids except Glu, Gln, Pro, and Met on day 1, total free amino acids and 14 individual free amino acids except Gln, Pro, and Met on day 4, and total free amino acids an d 12 individual free amino acids except Asp, Glu, Gln, Pro, and Met on day 7 postemergence. There were no significant differences in the con centrations of individual and total free amino acids on day 10 posteme rgence. Female age affected free amino acid content in the autogenous strain, where total free amino acids and 14 individual free amino acid s increased from day 1, peaked on day 4, declined on day 7, and declin ed further on day 10 postemergence. In the anautogenous strain, only t otal free amino acids and Ser, Gly, Ala, and Leu exhibited age-depende nt changes in concentration, and tile magnitude of changes in concentr ation was less than that in autogenous strain. Conclusively, autogenou s ovarian development was the major reason for the changes in hemolymp h free amino acid concentration postemergence. The current and previou s findings indicate that the free amino acids, Arg, Gly, Ile, Leu, Lys , Phe, Ser, Thr, and Val putatively may be essential for vitellogenesi s in mosquitoes.