Abstract
The oviposition responses of Culex tarsalis and C. pipiens quinquefasciatus females to 2 organic infusions have been studied in the laboratory. A 1% lab chow infusion was significantly repellent to ovipositing C. tarsalis and C. p. quinquefasciatus females when tested in both one liter choice bioassay units and screen cage choice tests. C. p. quinquefasciatus females were attracted to a 1% chicken manure infusion while C. tarsalis females were repelled by this infusion when both were tested in one-liter units. These infusions were quite stable when stored at –20°C and remained active for 10 wk. Biological parameters including interval between blood feeding and oviposition, parity, and prior exposure to test infusions in bioassays did not affect the responses to the 1% lab chow infusion. Microorganisms were found to be involved in the responses to both infusions.