Nectar-related olfactory and visual attractants for mosquitoes.

Mosquitoes commonly feed on plant nectar and other sugar sources, which they locate chiefly by visual and chemical cues. A summary of current evidence indicates that nectar sources are not as attractive as blood sources at specific times in a mosquito's life but that sugar feeding is usually necessary and more frequent than bloodfeeding. Plant attractants used in traps would have the advantage of being effective for both sexes, starting soon after emergence, and for blood-digesting, gravid, and gonoinactive females. Field studies suggest that mosquitoes are most attracted to light-colored flowers, but the independence of appearance from fragrance has not been firmly established. Volatile components of flowers and honey have been proven to be attractive, but in a preliminary field trial honey extract was less attractive than some blood-host kairomones. Terpenoids and aromatics provide many of the distinctive and dominant volatiles of flowers; they elicit both chemosensory and behavioral responses in mosquitoes.