Salzburg study finds urbanity has limited impact on aphid‑parasitoid communities

A research project examined how urban environments affect aphid‑parasitoid interactions across the city of Salzburg, Austria. The study counted aphids on four host plants—Sambucus nigra, Cornus sanguinea, Sonchus oleraceus and Aegopodium podagraria—and collected parasitised aphids to identify emerging parasitoids. Multiple metrics of urbanity and vegetation were incorporated as explanatory variables.

Results showed that aphid abundance varied among host‑plant species, but no measurable effect of urbanity was detected on species richness, parasitoid abundance, parasitism rates or overall community composition. Parasitoids were observed only on Sonchus oleraceus, and most aphid and parasitoid species were generalists, contrasting with specialists found on woody plants. The findings suggest that parasitoids may be less sensitive to urbanisation than predators at comparable trophic levels.