Female calling behaviour in the Asian longhorned beetle (Coleoptera: Cerambycidae)

Female Asian longhorned beetles, Anoplophora glabripennis (Motschulsky) (Coleoptera: Cerambycidae), were observed rhythmically extruding their genitalia, resembling the calling behaviour observed in other species of Cerambycidae. We demonstrate that only female A. glabripennis adults perform this behaviour, which lasts up to nearly six minutes and typically includes two types: (1) extrusion of only the tip of genitalia and (2) genitalia fully extruded and deflexed. The frequency and duration of this behaviour are affected by temperature and posteclosion feeding experience, but do not vary with the female age. Anoplophora glabripennis adult males were observed flexing their abdomen downward while extruding their genitalia but only when exposed to the odour of live females with host twigs. In Y-tube olfactometer assays, the volatiles from live females or female genital extracts both attracted more males than the volatiles from live males, male genital extracts, or solvent controls, all in the presence of host-plant volatiles. These findings indicate that A. glabripennis females may produce volatile sexual attractants in association with genital extrusion.