Exploration for natural enemies of the cassava mealybug,Phenacoccus manihoti(Homoptera: Pseudococcidae), in South America for the biological control of this introduced pest in Africa

Abstract

AbstractAreas in Argentina, Bolivia, Brazil and Paraguay were searched for the cassava mealybug,Phenacoccus manihotiMatile-Ferrero. The mealybug was located in the Paraguay River basin in the Santa Cruz de la Sierra area of eastern Bolivia, the Mato Grosso do Sul state in South-Western Brazil and in Paraguay east of the Paraguay River. Mealybug populations were extremely low in all areas but there was a period of increase from August to December. Eighteen species of natural enemies were found attackingP. manihoti: the most abundant and also most important were a solitary, internal parasitoid,Epidinocarsis lopezi(DeSantis) (Hymenoptera: Encyrtidae),Hyperaspis notataMulsant andDiomusspp. (Coleoptera: Coccinellidae), andOcyptamusspp. (Diptera: Syrphidae). Collections of a closely related mealybug,Phenacoccus herreniCox & Williams yielded two additional encyrtid parasitoids,Epidinocarsis diversicornis(Howard) andAenasiussp. nrvexansKerrich, but they did not survive onP. manihoti.Four parasitoids (E. lopezi, E. diversicornis, Parapyrus manihotiNoyes andAllotropasp.) and four predators (H. notata, Diomussp.,Sympherobius maculipennisKimmins, andExochomussp.) were sent for quarantine. With the exception ofParapyrus manihoti, all mentioned natural enemy species were forwarded to the International Institute of Tropical Agriculture at Ibadan, Nigeria for mass rearing and subsequent release.