An Unstable Monoterpene Alcohol as a Pheromone Component of the Longhorned Beetle Paranoplium gracile (Coleoptera: Cerambycidae)
We report the identification of p-mentha-1,3-dien-8-ol, an unstable monoterpene alcohol, as a male-produced aggregation-sex pheromone component of the cerambycid beetle Paranoplium gracile (Leconte) (subfamily Cerambycinae, tribe Oemini), a species endemic to California. Headspace volatiles from live males contained a blend of nine cyclic terpenoids that were not detected in analogous samples from females. Volatiles produced by male Eudistenia costipennis Fall, also in the tribe Oemini, contained the same suite of nine compounds. Four compounds, dehydro-p-cymene, p-mentha-1,3-dien-8-ol, p,α,α-trimethylbenzyl alcohol, and an unidentified compound were found to elicit responses from antennae of P. gracile females in coupled gas chromatography-electroantennogram detection (GC-EAD) assays, whereas only p-mentha-1,3-dien-8-ol elicited responses from antennae of males. In field assays, p-mentha-1,3-dien-8-ol stabilized with the antioxidant butylated hydroxytoluene (BHT) attracted P. gracile of both sexes, indicating it functions as an aggregation-sex pheromone, as with other pheromones identified from its subfamily, the Cerambycinae. Adding four of the other compounds found in headspace samples to the dienol lure had no effect on attraction. Because of the instability of p-mentha-1,3-dien-8-ol, it seems likely that at least some of the compounds seen in the extracts of volatiles from both species are artefacts, rather than being components of the pheromone.
KeywordsCerambycidae Aggregation-sex pheromone Male-produced pheromone Terpenoid p-Mentha-1,3-dien-8-ol α,α,4-Trimethyl-1,3-cyclohexadiene-1-methanol
We thank Sue Lee and Robert Bonnett for permission to conduct the field experiments at UCR Agricultural Operations, and Dr. Ken Halama for permission to conduct experiments at Emerson Oaks Nature Reserve. We thank Ian Swift for consultation regarding cerambycid biology. We also gratefully acknowledge the financial support for this research provided by the USDA-AFRI-NIFA Predoctoral Fellowship Program to RMC (2016-67011-25097).
- Linsley EG (1962) Cerambycidae of North America, Part III. Taxonomy and classification of the subfamily Cerambycinae, tribes Opsimini through Megaderini. Univ Calif Pub Entomol 20:1–188Google Scholar
- Mitchell RF, Ray AM, Hanks LM, Millar JG (2018) The common natural products (S)-α-terpineol and (E)-2-hexenol are important pheromone components of Megacyllene antennata (Coleoptera:Cerambycidae). Environ Entomol 47:1547–1552Google Scholar
- R Core Team (2017) R: a language and environment for statistical computing. R Foundation for Statistical Computing, Vienna, Austria. https://www.R-project.org/
- Roy A, Gurudutt KN, Rao S (1995) Base-catalyzed rearrangement of p-menth-1-en-4(8)-oxide. Ind J Chem 34B:636–638Google Scholar
- Venables WN, Ripley BD (2002) Modern applied statistics with S. Fourth Edition. Springer, New YorkGoogle Scholar
- Wickham JD, Lu W, Zhang L, Chen Y, Zou Y, Hanks LM, Millar JG (2016) Likely aggregation-sex pheromones for the invasive beetle Callidiellum villosulum, and the related Asian species Allotraeus asiaticus, Semanotus bifasciatus, and Xylotrechus buqueti (Coleoptera: Cerambycidae). J Econ Entomol 109:2243–2246CrossRefGoogle Scholar
- Xu T, Yasui H, Teale SA, Fujiwara-Tsujii N, Wickham JD, Fukaya M, Hansen L, Kiriyama S, Hao D, Nakano A, Zhang L, Watanabe T, Tokoro M, Millar JG (2017) Identification of a male-produced sex-aggregation pheromone for a highly invasive cerambycid beetle, Aromia bungii. Sci Rep 7:7330. https://doi.org/10.1038/s41598-017-07520-1 CrossRefGoogle Scholar