Dietary history of click beetles and wireworms in the genus Limonius Eschscholtz (Coleoptera: Elateridae) revealed by molecular gut content analysis

Authors: Serrano, Jacqueline; Cook, Rachel; Headrick, Heather; Cooper, William - Rodney

Submitted to: Environmental Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/4/2023
Publication Date: 12/4/2023
Citation: Serrano, J.M., Cook, R.E., Headrick, H.L., Cooper, W.R. 2023. Dietary history of click beetles and wireworms in the genus Limonius Eschscholtz (Coleoptera: Elateridae) revealed by molecular gut content analysis. Environmental Entomology. https://doi.org/10.1093/ee/nvad114.
DOI: https://doi.org/10.1093/ee/nvad114

Interpretive Summary: Wireworms, larvae of click beetles, are pests of many staple crops and are capable of feeding and developing upon a wide range of crop and non-crop hosts. The management of wireworms is challenging in part because of incomplete knowledge of adult click beetle biology, including their ability to feed and the identification of their host plants. Therefore studies were needed to determine the feeding and landscape ecology of click beetles. Researchers at the USDA Agricultural Research Service laboratory in Wapato, WA used a novel technique called molecular gut content analysis to provide evidence that adult click beetles do in fact feed on weeds and crops in Washington State. These data can help infer landscape-level movements of click beetles and provides researchers the identity of crop and non-crop plants that serve as food sources of click beetle and wireworm pests that colonize crops.

Technical Abstract: Wireworms, the larval stage of pest click beetle species (Coleoptera: Elateridae), are pests of many crops in North America including root vegetables and cereals. There is cause for concern amongst growers who are facing pressure from wireworms because there are a decreasing number of effective pesticides that can be used for wireworm management. Most research on pest elaterids has focused on the wireworm stage, which is the damage causing life stage. Recently, the focus in elaterid research has shifted to the adult click beetle stage, including identification of semiochemicals and development of effective traps. However, there is still a lot to be discovered about the basic biology of click beetles, including their feeding ecology. In an effort to understand the feeding ecology of click beetles, we investigated the presence of plant DNA in the digestive tracts of Limonius californicus (Mann.), L. canus (LeConte), and L. infuscatus (Mots.) beetles collected in three different locations within central Washington. To examine dietary histories of beetles and wireworms, specimens were collected from natural habitats and high-throughput sequencing of the plant genes trnF and ITS was used to identify their dietary history. Results revealed that click beetles do feed on a large variety of plants, which included a large quantity of brassicaceous plants commonly found in areas surrounding wireworm infested plots. The identification of the dietary history of the click beetles allowed us to infer their landscape-scale movements thus providing a means to better understand their behavior.