Mark-release-recapture studies with Culex mosquitoes (Diptera: Culicidae) in Southern California

Cohorts of Culex adults were marked uniquely with date- and site-specific fluorescent dust colors and were released at centrally located residences and at peripheral breeding sources to study population dispersal, size, additions, and deletions. The recapture rate of Cx. quinquefasciatus females was higher and the mean distance dispersed was lower in residential than in agricultural or park habitats. Dispersal was associated with host-seeking activity and ranged from 0.6 to 1.0 km/d. Survivorship ranged from 0.65 to 0.84 per day, and population density ranged from 36,612 to 671,634 females per km2. The sampling efficiency of CO2-baited traps in residential habitats increased coincidentally with increasing population density. Gravid traps were most effective in residential habitats where there were few competitive oviposition sites. Teneral Cx. stigmatosoma were extremely dispersive, and few marked females were recaptured. Unmarked females were more abundant at CO2-baited traps in residential habitats than at traps near productive peripheral breeding sources. Few Cx. tarsalis were released, and the recapture rate in residential habitats was low when compared with rural sites.