REMATING INHIBITION IN THE MELON FLY, BACTROCERA-(=DACUS)-CUCURBITAE (DIPTERA, TEPHRITIDAE) - COPULATION WITH SPERMLESS MALES INHIBITS FEMALE REMATING

Eight hour copulation of the melon fly, Bactrocera cucurbitae, which u sually mates at dusk and finishes copulation at dawn, inhibited female remating, while 3 h copulation did not. Copulation of females with ei ther normal or virgin sterile males inhibited female remating. Sperm-d epleted sterile males inhibited female remating at the same rate as no rmal males when the copulation duration was 8 h, indicating that exist ence or amount of sperm in females' spermathecae is not important in r emating inhibition. Females of a wild strain remated later than female s of a mass-reared strain, irrespective of strains of lst and 2nd male s. This suggests that the females may control their own remating, or t hat there is a difference between wild and mass-reared strains in thei r sensitivity to a male substance that inhibits females' receptivity.