REPRODUCTIVE-BIOLOGY OF THE YELLOW-SPOTTED LONGICORN BEETLE, PSACOTHEA-HILARIS (PASCOE) (COLEOPTERA, CERAMBYCIDAE) .2. EVIDENCE FOR 2 FEMALE PHEROMONE COMPONENTS WITH DIFFERENT FUNCTIONS

Behavioral responses of males of the yellow-spotted longicorn beetle, Psacothea hilaris (PASCOE), to female extracts were analyzed using a g elatin capsule as an; artificial female model. Males showed dash (DS) and/or abdominal bending (AB) behaviors when exposed to a capsule coat ed with female extracts. When exposed to the body extracts, both DS an d AB responses increased depending on the extract dose from 2(-6) FE ( female equivalent)/capsule, and the AB response decreased at high dose s (1 and 2 FE/capsule). When exposed to elytra extracts, however, the AB response increased from 2(-1) FE/capsule level but the DS response was observed only at 2 FE/capsule. These data indicate the presence of two different pheromone components: one which induces a DS response a nd another which induces an AB response. In follow-up experiments, the component inducing the DS response was demonstrated to be localized m ainly on the prothorax surface but that inducing the AB response was d istributed on the entire body surface.