Flower- and Water-Dwelling Yeasts Influence Nectar-Seeking and Oviposition Behavior in the Asian Tiger Mosquito with...

Volatile organic compounds (VOCs) emitted by flowers and aquatic microorganisms influence mosquito behavior, but the role of water- and nectar-dwelling yeasts remains underexplored. In Aedes albopictus, we characterized yeast communities from visited and non-visited flowers, and from colonized and non-colonized breeding-site waters in urban community gardens. Mint flowers were preferentially visited, and the yeasts Metschnikowia reukaufii and Aureobasidium pullulans, present at higher densities in this plant, strongly attracted adult males and females, respectively. GC-MS analysis showed that M. reukaufii emitted a greater diversity of VOCs than A. pullulans, including specific compounds (3-methylbutyl acetate, 2-methylbutyl acetate, ethyl acetate, and ethyl hexanoate) and higher concentrations of shared ones (3-methylbutan-1-ol, ethanol, 2-methylbutan-1-ol, 2-methylpropan-1-ol). For aquatic yeasts, Rhodotorula mucilaginosa and Cystobasidium slooffiae attracted gravid females, whereas Hanseniaspora uvarum, Torulaspora delbrueckii, Pichia kluyveri, and Papiliotrema laurentii repelled them, when present at higher cell densities. Repellent yeasts emitted a greater VOC diversity, including specific compounds such as ethanol, 3-methylbutyl acetate, ethyl acetate, pentyl propanoate, and ethyl propanoate, and higher concentrations of two shared compounds with attractive yeasts (3-methylbutan-1-ol, 2-methylbutan-1-ol). Further studies are needed to identify which compounds and concentrations mediate these effects and whether nectar-dwelling yeast attraction is linked to nectar feeding and mosquito fitness.