IDENTIFICATION AND FIELD-EVALUATION OF ANOMALA-OCTIESCOSTATA (COLEOPTERA, SCARABAEIDAE) SEX-PHEROMONE

Using GC-EAD, the sex pheromone of the scarab beetle Anomola octiescostata was identified to be a 8:2 binary mixture of (R,Z)-5-(-)-(oct-1-enyl)oxacyclopentan-2-one and (R,Z)-5-(-)-(dec-l-enyl)oxacyclopentan-2-one. These semiochemicals have been also reported as sex pheromone constituents of other Anomala species, either geographically or seasonally isolated from A. octiescostata. Synthetic sex pheromone was highly attractive in the field; 0.1 mg captured significantly more males than two virgin females. Buried traps were significantly more attractive than those positioned at 30, 90, and 150 cm above the ground. In a dose-response test (0.1-100 mg), no saturation due to overdose of pheromone was observed, but in most cases, two dosages differing by 10-fold were not significantly different. Response of males to traps baited with different ratios of the two components was tested in two experiments with randomized blocks and Latin-square designs. Deviation from the natural ratio (8: 2) of sex pheromone did not significantly diminish the response of males. Peak flight activity of beetle was recorded at 9:00-10:00 AM JST on sunny days in the end of April 1993.