Olfaction in Asian tiger mosquito Aedes albopictus: flight orientation response to certain saturated carboxylic acids in human skin emanations

The flight orientation response of nonblood-fed and hungry Aedes albopictus females was studied in a Y-tube olfactometer at 10(-6) to 10(-2) g odor plumes of saturated carboxylic acids (C-1-C-20), in which C-2-C-18 were the main constituents of human skin emanations. Thirteen acids viz C-1, C-2, C-3, C-5, C-6, C-8 C-9, C-10, C-12, C-14, C-16, C-18, and C-20 showed attractance at odor plumes ranging from 10(-5) to 10(-3) g doses, while five acids viz C-4, C-7, C-11, C-15, and C-19 showed repellence at 10(-4) to 10(-2) g to test mosquitoes. Tridecanoic acid (C-13) showed attractance only at 10(-4) g dose while higher doses caused repellence. Dose-dependent reversal of orientation behavior from attractance to repellence was observed at 10(-2) g plumes of C-5, C-9, C-10, C-13, C-17, C-19, and C-20 acids. The outcome of the study will help in the identification of odoriferous acids as potential attractants, repellents, or attraction inhibitors, which may find their application in the repellent formulations and odor-baited traps for surveillance and control of mosquitoes.