ACCUMULATION OF DENDROBIUM-SUPERBUM (ORCHIDACEAE) FRAGRANCE IN THE RECTAL GLANDS BY MALES OF THE MELON FLY, DACUS-CUCURBITAE

4-(4-Hydroxyphenyl)-2-butanone was characterized from flowers of the o rchid Dendrobium superbum as a specific attractant factor for the male melon fly, Dacus cucurbitae. The male flies compulsively licked the f lower surface and sequestered the compound in significant quantities i n their rectal glands. The compound was detected within 6 hr after ing estion and was retained for more than six days in the rectal gland sac s.