Parasitoid Wasp Acerophagus papayae: A Promising Solution for the Control of Papaya Mealybug Paracoccus marginatus in Cassava Fields in Vietnam

SIMPLE SUMMARY: This study examined the occurrence, biological characteristics, and effectiveness of the parasitoid wasp Acerophagus papayae Noyes and Schauff in controlling the papaya mealybug Paracoccus marginatus Williams and Granara de Willink, a major pest of cassava crops in Vietnam. The results showed that A. papayae naturally occurred more frequently than other species of parasitoid wasps. The honey solution was found to be important for increasing the lifespan of A. papayae in the absence of hosts. The second instar of the mealybug was found to be the most suitable host stage for parasitism by A. papayae. Female wasps can produce a large number of eggs during their entire lives. These findings suggest that A. papayae could be an effective agent for controlling P. marginatus and improving crop pest management not only in Vietnam, but in other regions as well. ABSTRACT: Cassava is a valuable export commodity crop that is often attacked by pests, causing economic losses for this crop. The papaya mealybug Paracoccus marginatus has become a major pest of cassava in Vietnam. The parasitoid wasp Acerophagus papayae has been demonstrated to be the most efficient parasitoid wasp for controlling P. marginatus in many regions. We observed the occurrence of A. papayae in Vietnam, studied the biological characteristics of A. papayae, and investigated its parasitic activity on P. marginatus. The results showed that A. papayae occurred more frequently than Anagyrus loecki, another known parasitoid of P. marginatus. The lifespan of A. papayae was approximately 16 days. In the absence of hosts, a 50% honey solution was an essential diet to increase the longevity of both female and male of A. papayae. The second instar of P. marginatus was a suitable host stage for parasitism by A. papayae. Female A. papayae laid approximately 60.8 eggs within 17 days, mostly during the first 6 to 7 days. These findings suggest that A. papayae has the potential to control P. marginatus, and could inform the development of more effective pest management strategies for cassava crops in Vietnam and other regions affected by this pest.