Analyses of essential and edible oils, and constituents therein, as candidate repellents for the yellow fever mosquito Aedes aegypti L. (Diptera: Culicidae)

Some plant essential and edible oils repel mosquitoes but often quantitatively minor repellent constituents therein remain unknown. In gas chromatographic-electroantennographic detection (GC-EAD) analyses of catnip, cinnamon, citronella, cumin, eucalyptus, geranium, ginger, melissa, peppermint, rosemary, and thyme essential oils, 43 constituents elicited responses from antennae of female yellow fever mosquitoes, Aedes aegypti L. (Diptera: Culicidae). GC-EAD analyses of soybean oil (active ingredient of BiteBlocker™) were inconclusive. In GC-EAD analyses of garlic oil, 10 constituents and 4 thermal degradation components stimulated antennae. Dual-port olfactometer and screened-cage experiments failed to reveal any repellent effect associated with soybean oil. Diallyl trisulfide and diallyl tetrasulfide as EAD-active constituents of garlic oil were significantly more repellent to female Ae. aegypti than control stimuli. I conclude that GC-EAD screening of plant essential oils and other sources is a viable technology to detect new quantitatively minor constituents that could be potent repellents when tested at an appropriate dose.