D3374: Advances in the semiochemistry of North American click beetles (Coleoptera: Elateridae)

The click beetles (Coleoptera: Elateridae) comprise a large family with more than 10,000 described species, several of which are important agricultural pests on cereal crops and root vegetables. Prior to 2018, relatively few click beetle pheromones or pheromone candidates had been identified, and most were from European species in the subfamily Elaterinae. Although the existing published data was not extensive, patterns of conservation of pheromone structures within closely related taxa were beginning to emerge. We describe how this conservation of structures was exploited as a mechanism to identify possible pheromone components for North American species. We synthesized and field tested a library of known elaterid pheromones and their structural analogues across the United States, which resulted in the identification of pheromones or likely pheromones for several species across multiple genera. In parallel, we were able to identify novel pheromone structures from various species across multiple subfamilies. The structural differences of some pheromones and putative pheromones, however, may lead to some discussion about taxonomic relationships within some click beetle tribes and genera. Overall the results of this project have demonstrated that traps baited with pheromones from some click beetle species can jump start  pheromone identifications of related species and be useful for surveying elaterid diversity. Additionally, we have also provided strong leads for follow-up work to formally identify the pheromones of several North American species.