Intra-annual variation and landscape composition interactively affect aphid community composition

Agricultural intensification impacts local arthropod communities. The temporal and spatial variation of agricultural environments can have a significant impact on insect pest populations, yet little work has been done to date on the effect of intra-annual variation (within season) or spatiotemporal effects on arthropod functional community composition. The aim of this research was to evaluate the effects of intra-annual variation and landscape composition on the aphid community. To that end, we investigated the following research question: How do intra-annual variation and landscape composition affect aphid abun- dance, species richness, and functional community composition? In this study, we quantified landscape com- position as percent cropland, intra-annual variation as sampling week measured throughout the growing season, and aphid functional community composition as crop virus transmission—or vectoring—ability. We collected data in two agricultural regions: a diversified agricultural region in New York State (NY) and an agriculturally intense potato-growing region in Wisconsin (WI). We found that the interactive effect of land- scape composition and intra-annual variation significantly affected aphid abundance and species richness in both study regions, and functional community composition in NY. These results indicate that spatiotempo- ral shifts in agroecosystems have significant implications for aphid functional community composition.