|CHOATE, BETH - Allegheny College|
Submitted to: Crop Protection
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/24/2015
Publication Date: 8/16/2015
Citation: Choate, B.A., Lundgren, J.G. 2015. Invertebrate communities in spring wheat and the identification of cereal aphid predators through molecular gut content analysis. Crop Protection. 77:110-118.
Interpretive Summary: A frequent pest of wheat worldwide are cereal aphids, but in the US farmers seldom have to treat for these pests. Predators of aphids may be one explanation for this. In this study, we surveyed the aphid and insect communities present in spring wheat fields of eastern SD, measured how well aphids performed on wheat plants in the presence and absence of predators, and used molecular tools to examine predator stomachs for aphid DNA (gut content analysis). Our study revealed a diverse insect community in wheat comprised of at least 103 different arthropod taxa and dozens of predator species. Aphids were rapidly consumed by a suite of predators in wheat fields, such that nearly all aphids were removed from wheat within a few days of them being placed. Predators help reduce this pest populations and thus save farmers money. As farming practices and the environment change, comprehensive bioinventories within agroecosystems will be important resources for promoting species conservation.
Technical Abstract: Cereal aphid complexes are responsible for reducing wheat production worldwide; however, management against these species is rare in North America. Generalist predators may contribute to reducing cereal aphid numbers and preventing significant damage to crops. A two-year survey identifying the arthropod community on wheat vegetation, at the soil surface and within the soil of wheat fields was conducted to better guide conservation efforts. Sentinel Rhopalosiphum padi L. (bird cherry-oat aphid, BCOA) were placed on wheat plants and predator gut-content analysis employed to identify specific species actively consuming cereal aphids. The arthropod complex in wheat was diverse with 103 taxa identified. The soil-dwelling arthropod community had the greatest abundance and diversity when compared with the foliar-dwelling community. Twenty five percent of collected predators tested positive for R. padi DNA in their guts. The diverse and abundant predatory arthropod community prevented establishment of cereal aphids throughout the duration of the study, with pest species identified at extremely low densities.