Sex pheromones and sex attractants of species within the genera Idolus Desbrochers des Loges and Dalopius Eschscholtz (Coleoptera: Elateridae) in the western United States

Authors: SERRANO, JACQUELINE; LANDOLT, PETER - US Department Of Agriculture (USDA); REYES CORRAL, CESAR - Washington State University; MILLAR, JOCELYN - University Of California

Submitted to: Agricultural and Forest Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/9/2022
Publication Date: 2/24/2022
Citation: Serrano, J.M., Landolt, P.J., Reyes Corral, C.A., Millar, J.G. 2022. Sex pheromones and sex attractants of species within the genera Idolus Desbrochers des Loges and Dalopius Eschscholtz (Coleoptera: Elateridae) in the western United States. Agricultural and Forest Entomology. 24(3):301-309. https://doi.org/10.1111/afe.12494.
DOI: https://doi.org/10.1111/afe.12494

Interpretive Summary: Wireworms, the juvenile stages of click beetles, are serious pests of many globally important crops such as cereals and root vegetables. Identification of click beetle pheromones has led to improved integrated pest management practices in Europe and Japan. A research team that included researchers at the USDA-ARS in Wapato, WA, University of California Riverside, and Washington State University, tested whether pheromones of European click beetles are also attractive to North America click beetles. They found that some pheromones of European click beetles were highly attractive to the several North American click beetles. This discovery allowed the researchers to rapidly identify the exact pheromone from one North American Idolus species and will likely lead to others. This study provides a novel strategy for rapid identification of pest pheromone attractants, which can be used to improve monitoring of pests or to develop mass-trapping approaches for pest management

Technical Abstract: Most known click beetle (Coleoptera: Elateridae) sex pheromones have been identified from economically important European species. We hypothesized that pheromone components might be conserved between New and Old World species, and so tested blends of known pheromones in California and Washington states. Males of the endemic species Idolus californicus and I. columbianus (subfamily Elaterinae) were attracted to blends of neryl esters, many of which are known pheromones of related European species. Electroantennogram (EAG) assays determined that antennae of male beetles responded strongly to two neryl esters, and in field bioassays, males of both species were specifically attracted to neryl hexanoate. Female I. californicus were found to produce both neryl hexanoate and neryl octanoate, and lures that contained neryl hexanoate alone or in blends attracted male beetles. Neryl octanoate was not attractive, and neither synergized nor antagonized attraction to neryl hexanoate. Males of Dalopius spp. also were captured in traps baited with lures containing neryl octanoate. Our results support the hypothesis that the neryl ester pheromone motif is conserved among taxonomically related European and North American elaterids in the tribe Elaterinae, which should aid in the identification of pheromones of pest species within the tribe.