AUTOGENY AND BLOOD-FEEDING BY CULEX TARSALIS (DIPTERA: CULICIDAE) AND THE INTERVAL BETWEEN OVIPOSITION AND FEEDING

Abstract

Female Culex tarsalis Coquillett trapped in CO₂-baited light traps or reared from field-collected pupae were marked with fluorescent dust, released, and recaptured in traps baited with CO₂ with or without light. Recaptures of trapped females peaked on the first night of recapture collections. Recaptures of reared females peaked on the first or second night when autogeny rates were low (25–44%) but 2-4 nights later when rates were high (86–88%). It was concluded that autogenous females did not seek blood until after they had oviposited, and that autogenously induced delays in feeding probably influence the extent of virus transmission by C. tarsalis.Stretched follicular tubes indicating recent oviposition were found in 23.4% and 5.2% of empty parous females from shelters and CO₂-baited traps, respectively, and in 2.3% of freshly engorged parous females from shelters. Females often failed to blood-feed until at least the second night after oviposition.