Insectivorous birds disrupt biological control of cereal aphids. Issue 6 (11th May 2017)

• Record Type: Journal Article
• Authors: Grass, Ingo; Lehmann, Katrin; Thies, Carsten; Tscharntke, Teja
• Is Part Of: Ecology. Volume 98:Issue 6(2017)
• Page Start: 1583
• Page End: 1590
• Publication Date: 2017-05-11
• Subjects: aphids -- biological control -- cascade effects -- cereals -- food webs -- hoverflies -- intraguild predation -- ladybird beetles -- mesopredators -- Passer montanus -- Sparrows -- trophic interactions; Ecology -- Periodicals; Ecology -- Periodicals; Écologie -- Périodiques; Ecologie; Écologie; Écologie animale; Écologie végétale; Ecology; Periodicals; 577.05
• DOI: 10.1002/ecy.1814
• Languages: English
• ISSNs: 0012-9658

Abstract

Abstract: Insect‐feeding birds may interfere with trophic interactions in plant–insect food webs, which may be particularly important in agroecosystems. Here, we studied how Eurasian Tree Sparrows ( Passer montanus ) affect aphids and their predators in cereal fields using bird exclusion experiments. The Tree Sparrows fed their nestlings with aphid antagonists. Hoverflies and ladybird beetles accounted for 77% of the food for the nestlings during peak aphid density. When birds were excluded, densities of hoverfly larvae, which were the most abundant aphid predator group in the cereals, were 4% higher in wheat and 45% higher in oat, while aphid densities were 24% lower in wheat and 26% lower in oat. The demonstrated disruption of biological control by mesopredators through bird predation may be a common phenomenon in cropping systems characterized by small‐sized and abundant pest species. Management of biotic interactions such as biological control needs a broad food‐web perspective, even in simplified agroecosystems.