Identification of Aggregation-Sex Pheromone Components for a “Living Fossil”, the False Click Beetle, Palaeoxenus dohrni Horn (Coleoptera: Eucnemidae)
Insect pheromones have rarely been exploited in surveys or studies of rare and endangered species, despite their potential as effective and highly selective attractants for target species. Here, we report the identification, synthesis, and field bioassays of a male-produced aggregation-sex pheromone blend of a rare false click beetle species endemic to southern California, Dohrn’s elegant eucnemid beetle, Palaeoxenus dohrni Horn (Coleoptera: Eucnemidae). This species is the only extant species in its genus and subfamily. Analyses of extracts of headspace volatiles collected from adult beetles revealed several male-specific compounds. Two of these compounds, identified as (E)-2-nonen-4-one and (R)-2-nonanol, elicited electroantennographic responses from antennae of beetles of both sexes. In field bioassays, a blend of the two compounds attracted both sexes, whereas the individual compounds were not attractive. The identification of an attractant pheromone should provide a useful tool for bioconservation and ecological studies of this iconic species.
KeywordsEucnemidae Aggregation-sex pheromone (E)-2-Nonen-4-one (R)-2-Nonanol False click beetle Saproxylic
We thank Stacy Hishinuma for providing access to field sites, and Sean Halloran for assistance with field work. We also thank Ian Wright for assistance with specimen photography. This work was funded in part by Hatch Act grant #CA-R*-5181-H to JGM and Robert van den Bosch scholarship to JMS.
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