Alocasia odoraC. Koch, a hermaphroditic understory clonal herb, showed endogenous heat production during its blooming sequence. The first heat production cycle was associated with the initiation of the female phase and the third or the fourth cycle was associated with the male phase. Two flower-breeding flies,Colocasiomyia alocasiae(Okada) andC. xenalocasiae(Okada) (Diptera: Drosophilidae), were attracted by the strong odor that emanated fromA. odora. The flies carried pollen from other inflorescences thus affecting the reproductive success of the female phase of the hermaphroditic host. The flies stayed within the flowers, eating pollen during the subsequent male phase, then exited the inflorescence carrying pollen to other inflorescences, thus affecting reproductive success of the male phase. These flower-breeding flies increased the efficiency of the alternating reproductive tactics of the protogynous host plant. The special odor that emanated from the host during heat production may serve as an important stimulus for the two pollinator species to locate their host inflorescences.