Olfactory responses of female Culex quinquefasciatus Say (Diptera : Culicidae) in a dual-choice olfactometer

Olfactory responses of individual female (n=1010) Culex quinquefasciatus Sa y (Diptera: Culicidae) to various odor stimuli were studied in a dual-choic e olfactometer. Responses (i.e., the number of mosquitoes entering either o f both olfactometer ports) were studied towards clean conditioned air (cont rol), human foot skin emanations (collected on worn stockings), carbon diox ide (4.5% in clean air), moistened air, and various combinations thereof. S kin emanations were significantly more attractive (chi(2) = 23.0, p<0.001) than clean stockings (control). The mosquito was also significantly more at tracted (chi(2) = 7.7, p<0.01) to Skin emanations than to a clean stocking to which water tan equivalent of that absorbed by a worn stocking) was adde d. A moistened (1 g H2O) clean stocking, however, was slightly more attract ive than a dry stocking (chi(2) = 6, p<0.025). Carbon dioxide (4.5%) did no t elicit higher responses than clean air, and no synergistic effect was obs erved in combination with skin emanations. With the aim of developing an od or-baited trap, our results indicate that Cx. quinquefasciatus responds wel l to human body odors which can be collected on polyamide materials.