Studies on autogeny in Culex tarsalis: 1. Selection and genetic experiments.

Autogenous and anautogenous strains were selected from a laboratory colony of Culex tarsalis established from a foothill environment in Kern County, California. An autogenous strain also was selected from immatures collected at the Kern River. Autogenous and anautogenous strains remained heterogeneous and did not consistently exhibit 100 or 0% autogeny, respectively, despite continual selection pressure and inbreeding. Autogeny rates did not increase when sublines selected from the anautogenous strains were outcrossed within single female lines; however, autogeny rates increased when crosses were made between single female lines. Crosses and backcrosses between the autogenous and anautogenous strains indicated that autogeny was controlled by a dominant, autosomal gene(s). The persistence of heterogeneity during selection and the decrease in autogeny rates among the female progeny of crosses where autogeny was inherited through the male indicated that the genetics of autogeny may be polyfactorial and/or phenotypic expression compromised by sex.