Sexually differentiated functions of female-produced pheromone of theblack chafer Holotrichia loochooana loochooana (Sawada) (Coleoptera:Scarabaeidae)

Summary. Both male and female Holotrichia loochooanaloochooana (Sawada) (Coleoptera: Scarabaeidae) wereattracted with female-produced pheromone, anthranilic acid(2-aminobenzoic acid), in the field. Male chafers wereobserved to apparently directly locate cotton balls impregnatedwith 1 to 10 mg of pheromone. In contrast, females neverdirectly oriented to the treated balls but landed 0.2-1.5 maway and exposed their abdominal glands in a calling posture,which occasionally resulted in aggregation of both femalesand males. This suggested the mating aggregation of thisspecies could be primarily induced by pheromone released byfemales. A hypothesis for adaptability of female aggregationis proposed and discussed.