Deployment of aggregation-sex pheromones of longhorned beetles (Coleoptera: Cerambycidae) facilitates the discovery and identification of their parasitoids

Authors: JOHNSON, TODD - University Of Illinois; Buffington, Matthew; Gates, Michael; Kula, Robert; TALAMAS, E.T. - Florida State University

Submitted to: Journal of Chemical Ecology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/5/2020
Publication Date: 1/6/2021
Citation: Johnson, T.D., Buffington, M.L., Gates, M.W., Kula, R.R., Talamas, E. 2021. Deployment of aggregation-sex pheromones of longhorned beetles (Coleoptera: Cerambycidae) facilitates the discovery and identification of their parasitoids. Journal of Chemical Ecology. 47:28042. https://doi.org/10.1007/s10886-020-01238-7.
DOI: https://doi.org/10.1007/s10886-020-01238-7

Interpretive Summary: Parasitic wasps attack plant-feeding insects that cause billions of dollars in damage to forests annually. The wasps treated in this paper attack plant-feeding insects in U.S. forests, including longhorned beetles with wood boring larvae that can severely damage or kill trees. This research used sticky traps baited with different longhorned beetle pheromones to determine how attractive certain pheromones are to parasitic wasps. The utility of pheromones to help determine wasp-host associations and identify wasps potentially useful for biocontrol of longhorned beetles was assessed. This paper will be useful to scientists conducting research on longhorned beetles and their parasitoids, personnel responsible for controlling and regulating longhorned beetles, and personnel generally involved in forest management.

Technical Abstract: Longhorned beetles (Coleoptera: Cerambycidae) include many species that are among the most damaging pests of managed and natural forest ecosystems worldwide. Many species of cerambycids use volatile chemical signals (i.e., pheromones) to locate mates. Pheromones are often used by natural enemies, including parasitoids, to locate hosts and therefore can be useful tools for identifying host-parasitoid relationships. In two field experiments, we baited linear transects of sticky traps with pheromones of cerambycid beetles in the subfamily Cerambycinae. Enantiomeric mixtures of four linear alkanes or four linear alkanes and a ketol were tested separately to evaluate their attractiveness to hymenopteran parasitoids. We hypothesized that parasitoids would be attracted to these pheromones. Significant treatment effects were found for 10 species of parasitoids. Notably, Wroughtonia ligator (Say) (Hymenoptera: Braconidae) was attracted to syn-hexanediols, the pheromone constituents of its host, Neoclytus acuminatus acuminatus (F.) (Coleoptera: Cerambycidae). Location and time of sampling also significantly affected responses for multiple species of parasitoids. These findings contribute to the basic understanding of cues that parasitoids use to locate hosts and suggest that pheromones can be used to hypothesize host relationships between some species of cerambycids and their parasitoids. Future work should evaluate response by known species of parasitoids to the complete blends of pheromones used by the cerambycids they attack, as well as other odors that are associated with hosts of cerambycids.