TEMPORAL VARIATION IN MORPHOLOGICAL AND GENETIC-CHARACTERISTICS WITHIN A HYBRID POPULATION OF CULEX-PIPIENS (DIPTERA, CULICIDAE)

Samples of mosquitoes in the Culex pipiens L. complex from Memphis, Tenn., were collected from June to November 1985 and examined in regard to allozyme frequencies and ratios of the two arms of the phallosome of the male genitalia (DV/D). The dominant allozymes of hexokinase (Hk(A)) and 6-phosphogluconate dehydrogenase (Pgd(F)) significantly increased in frequency during this period as did the mean DV/D ratio. An analysis of gene frequencies by species group designated by DV/D ratios revealed no significant differences among Cx. pipiens, Cx. quinquefasciatus Say, and intermediates. The lack of association of gene frequencies with the taxa determined by the DV/D ratio indicated that although allozyme frequencies were correlated temporally with the DV/D ratio in the population, they were not associated with subspecies. These results are consistent with previous work that has shown latitudinal association and thermal stability differences in the major allozymes of these enzymes in the Cx. pipiens complex.