Identification of sex pheromone components for the click beetles Melanotus piceatus Blatchley and Melanotus insipiens (Say) (Coleoptera: Elateridae)

Authors: Williams Iii, Livy; HALLORAN, SEAN - University Of California, Riverside; BAKER, PAUL - College Of Agriculture; ETZLER, FRANK - Montana Department Of Agriculture; MILLAR, JOCELYN - University Of California, Riverside

Submitted to: Journal of Chemical Ecology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/27/2026
Publication Date: 3/9/2026
Citation: Williams Iii, L.H., Halloran, S.T., Baker, P.D., Etzler, F.E., Millar, J.G. 2026. Identification of sex pheromone components for the click beetles Melanotus piceatus Blatchley and Melanotus insipiens (Say) (Coleoptera: Elateridae). Journal of Chemical Ecology. https://doi.org/10.1007/s10886-026-01702-w.
DOI: https://doi.org/10.1007/s10886-026-01702-w

Interpretive Summary: The reproductive behavior of many insects is mediated by chemicals produced by one sex that attracts members of the opposite sex for mating. These species-specific behavior-modifying chemicals have been used for more than 50 years for monitoring and management of insect pests of agriculture and human health. Recent work on these chemicals has focused on click beetles, many of which are important pests in the U.S. We used chemical, electrophysiological, and behavioral studies to identify, synthesize, and field test the sex attractants of female-produced sex attractant pheromones of two North American click beetle species. Our results indicated that male beetles of each species were strongly attracted to a single chemical compound, and that the chemicals were species-specific, i.e., there was no cross-attraction between the species. In both species, male beetle flight activity occurred from May through June. Identification of the sex attractants of these species will provide useful tools to study their biology and management, while further expanding our knowledge of the types of compounds to be expected in the sex pheromones of related species.

Technical Abstract: Little is known about the semiochemicals that mediate the reproductive behavior of click beetles, the Elateridae. Research over the past two decades has begun to fill this gap, with: 1) the discovery of sex attractants for a number of pest and non-pest species, and 2) subsequent studies toward development of semiochemically-based pest management approaches and conservation initiatives for pests and non-pests, respectively. We used chemical, electrophysiological, and behavioral studies to identify, synthesize, and field test female-produced sex attractant pheromones of two North American elaterid species, Melanotus piceatus and M. insipiens. In coupled gas chromatography-mass spectrometry analyses of extracts of ovipositors of females, two possible pheromone components were identified for each species; (2Z,6E)- and (2E,6E)-farnesyl acetate for M. piceatus, and decyl octanoate and decyl butanoate for M. insipiens. Subsequent coupled gas chromatography-electroantennogram detection analyses indicated that antennae of males were responsive to only one of the two compounds for each species: (2Z,6E)-farnesyl acetate for M. piceatus, and decyl butanoate for M. insipiens. In field trials, (2Z,6E)-farnesyl acetate and decyl butanoate as single components attracted males of M. piceatus and M. insipiens, respectively. In both species, most male beetle flight activity occurred from May through June. Identification of the sex pheromones of these species will provide useful tools to study their biology, while further expanding our knowledge of the types of compounds to be expected in the sex pheromones of related species.