Synergism between chemical attractants and visual cues influencing oviposition of the mosquito,Culex quinquefasciatus (Diptera: Culicidae).

Physical factors, such as the color of the oviposition substrate, have seldom been compared with chemical cues in their ability to elicit oviposition behavior in mosquitoes. The role of dyed oviposition waters in attracting ovipositingCulex quinquefasciatus was examined in laboratory experiments. Oviposition waters dyed with ink were found to be significantly attractive to ovipositingCx. quinquefasciatus when compared to distilled water controls. Experiments demonstrated that the mosquitoes were responding to the increased optical density of the dyed oviposition water rather than volatile components of the dye. Ink was also considered in combination with chemical oviposition cues. No comparative data exist on the effect of physical and chemical factors presented together on the oviposition behavior ofCx. quinquefasciatus. Waters dyed with ink acted synergistically with a five-component chemical attractant mixture (3-methylindole, indole, 4-methylphenol, 4-ethylphenol, and phenol) in inducing oviposition in a 2×2 factorial experiment.