Attraction of <scp> <i>Phoracantha mastersi</i> </scp> (Coloeptera: Cerambycidae) to copulation‐associated olfactory stimuli

Abstract Infestations by the Australian longicorn beetle genus Phoracantha Newman (Coleoptera: Cerambycidae) are an established problem in extralimital eucalypt plantations, and these insects are emergent actors in native forest decline. While olfactory attractants have been successfully applied in control‐oriented trapping of other cerambycids, lures have not been identified for Phoracantha beetles. We investigated behavioural responses of Phoracantha mastersi Pascoe—an irruptive species associated with sub‐alpine Eucalyptus pauciflora woodland decline in southeast Australia—to a small suite of commercial semiochemicals. Drawing upon field‐based observations of male sexual aggregation, we also evaluated responses of male beetles to conspecifics engaged in active copulation. Tests were conducted using a Y‐maze within which treatment‐related visual cues were eliminated. Although we did not detect a significant behavioural response to semiochemicals, we report significant bias in male response to copulating conspecifics that is suggestive of a pheromone. Although research is constrained by the long larval stage of P. mastersi , the results reported here suggest a potential avenue may exist for exploring pheromones of commercially relevant congenerics.