REPRODUCTIVE-BIOLOGY OF THE YELLOW-SPOTTED LONGICORN BEETLE, PSACOTHEA-HILARIS (PASCOE) (COLEOPTERA, CERAMBYCIDAE) .5. MALE MATING RESPONSES TO MALE EXTRACT

Male mating behavior elicited by solvent extracts of males in the yell ow-spotted longicorn beetle, Psacothea hilaris (PASCOE), was examined. When a gelatin capsule was coated with the extract of male elytra or elytra-removed body, male responses were similar to those elicited by female extracts, although less intense. These pheromonal activities we re observed at more than 2(-5) male equivalent/capsule but decreased a t higher doses. Among the different body parts of males, male 'dash' t oward the treated capsule was elicited most strongly by prothorax extr acts. Abdominal bending response was released by all the extracts exce pt for those from the antenna and head. The distribution of active sub stances on the male body was similar to that of the female pheromone. When prothorax extract was mixed with other body extracts, male respon se was reduced, which suggested the presence of a masking substance.