Intra-specific trait variation is receiving renewed interest as a factor affecting the structure of multi-species communities within and across trophic levels. One pervasive form of intra-specific trait variation is sexual dimorphism in animals and plants, which might exert large effects particularly on the communities of host-associated organisms, but the extent of these effects is not well understood. We investigated whether host-associated microbial communities developed differently in the floral nectar of female and male individuals of...