Species-dependent captures of three Limonius pest click beetle (Coleoptera: Elateridae) species in western North America with aerial and ground traps

Authors: VAN HERK, WILLEM - Agriculture And Agri-Food Canada; CATTON, HALEY - Agriculture And Agri-Food Canada; WANNER, KEVIN - Montana State University; LEMKE, EMILY - Agriculture And Agri-Food Canada; Serrano, Jacqueline

Submitted to: Environmental Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/4/2025
Publication Date: 9/10/2025
Citation: Van Herk, W.G., Catton, H.A., Wanner, K., Lemke, E., Serrano, J.M. 2025. Species-dependent captures of three Limonius pest click beetle (Coleoptera: Elateridae) species in western North America with aerial and ground traps. Environmental Entomology. https://doi.org/10.1093/ee/nvaf078.
DOI: https://doi.org/10.1093/ee/nvaf078

Interpretive Summary: Wireworms, the larvae of click beetles, are insect pests that inhabit the soil and feed on many staple crops such as cereals and root vegetables. In recent years, these pests have become increasingly problematic in the Pacific Northwest states and western Canadian providences in part due to the lack of effective management strategies. There are three species of Limonius wireworms that co-occur on farmland, and previous research demonstrated that the click beetle adult males respond to the same sex attractant. An international team of researchers that included researchers at the USDA-ARS in Wapato, WA investigated different trapping methods to determine optimal trapping parameters for adult beetles across several regions in North America. In a field study that compared different pheromone lure types, we determined that a commercial lure is the best overall for trapping the three species . In a separate field study that compared trap type and placement, we determined that traps placed at ground level are best for capturing two of the Limonius species, however aerially-suspended traps were better for one species. The results from this study will aid with future work to conduct areawide surveys and integrative management techniques.

Technical Abstract: In western North America, 3 pest wireworms in the genus Limonius co-occur on farmland, and the click beetle adult males respond to the same single-component sex attractant, limoniic acid. While divergence in seasonal occurrence may provide a means of separating sexual communication for Limonius canus (LeConte) and Limonius californicus (Mann.), both species overlap temporally with Limonius infuscatus (Mots.), suggesting the existence of additional reproductive isolating mechanisms. To determine the effect of trap height on the relative captures of these species, we deployed ground-based Vernon Pitfall Traps and aerially suspended Japanese Beetle traps baited with limoniic acid dispensed from rubber septa or plastic capsules, in British Columbia, Alberta, Washington state, and Montana. The proportion collected of each species differed among study locations, but our data indicate species differ in trap preference, with L. infuscatus and L. californicus preferring ground traps, and L. canus preferring aerial traps. This possibly reflects preferences in where species locate mates, and therefore another separation mechanism. Lure type also had a significant effect on captures in most studies, with generally more L. californicus and/or L. infuscatus collected if capsule dispensers, and more L. canus if septa dispensers were used. Implications for monitoring these species with these trap and dispenser combinations are discussed.