title: Differences in extent of genetic introgression between sympatric Culex pipiens and Culex quinquefasciatus (Diptera: Culicidae) in California and South Africa.
abstract: Comparisons of five morphological characters, 12 enzyme electrophoresis profiles, and Wolbachia pipientis infection rates were used to characterize populations of members of the Culex pipiens L. complex in California and South Africa. In South Africa, male phallosome DV/D ratio, male maxillary palp index, branching of siphonal seta 1a, the enzyme locus Mdhp-1, and W. pipientis infection rates proved highly diagnostic for separating Culex quinquefasciatus from Cx. pipiens phenotypes. In Johannesburg, where sympatric members of the Cx. pipiens complex were analyzed as one population, a significant Wahlund Effect was observed in the enzyme loci such as Ao, 6-Pgdh, Mdh-2, and Pgm. In California, all populations of the Cx. pipiens complex were in Hardy Weinberg equilibrium at all polymorphic enzyme loci examined. Additionally, in California, all populations had similar W. pipientis infection rates and appeared morphologically identical (except for DV/D ratio, in extreme north and south). These findings indicate that in South Africa, Cx. pipiens and Cx. quinquefasciatus remain as genetically distinct populations and behave as separate species. Conversely, in California, there is considerable genetic introgression between Cx. pipiens and Cx. quinquefasciatus, and they behave as a single species.
authors.affiliation: Department of Entomology, University of California at Davis, Mosquito Control Research Laboratory, Parlier, CA 93648, USA.
authors.forename: Anthony J
authors.initials: AJ
authors.lastname: Cornel
authors.forename: Rory D
authors.initials: RD
authors.lastname: McAbee
authors.forename: Jason
authors.initials: J
authors.lastname: Rasgon
authors.forename: Matthew A
authors.initials: MA
authors.lastname: Stanich
authors.forename: Thomas W
authors.initials: TW
authors.lastname: Scott
authors.forename: Maureen
authors.initials: M
authors.lastname: Coetzee
mesh_terms: D000818:Animals; D001483:Base Sequence; D002140:California; D003465:Culex / Q000145:classification* / Q000235:genetics* / Q000382:microbiology / Q000502:physiology; D017931:DNA Primers; D005260:Female; D014644:Genetic Variation; D005837:Genitalia, Male / Q000033:anatomy & histology; D005843:Geography; D008297:Male; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012098:Reproduction; D012744:Sex Ratio; D013019:South Africa; D020577:Wolbachia / Q000472:pathogenicity
chemical_list: D017931:DNA Primers; D012336:RNA, Ribosomal, 16S