Seasonal variation of Drosophilidae communities in viticultural landscapes

Abstract

Studies at the landscape scale are important to understand insect population and community dynamics. Despite numerous studies on the effects of landscape context on phytophagous insect communities, few studies were conducted on fruit flies and the seasonal variation in the effects of landscape context remains poorly explored. Here, we investigate how landscape composition affects Drosophilidae communities in vineyards and how these effects vary over time. To do this, we sampled Drosophilidae communities in 20 vineyards selected along a gradient of proportion cover of semi-natural habitats in the landscape over a whole year in southwestern France. We found an overall positive effect of increasing proportion of semi-natural habitats in the landscape on abundance of drosophilid species but not on the rarefied species richness. We also found strong seasonal changes in community composition with a major temporal differentiation between the two dominant species of the community, Drosophila subobscura and Drosophila suzukii. Our study revealed that the composition of the Drosophilidae communities in vineyards is strongly influenced by the proportion of semi-natural habitats and the time of year. Our results suggest that the variation in space and time of key resources such as host plants or overwintering habitats in the landscape is a key factor affecting community composition of Drosophilidae in crops.