CLASSICAL BIOLOGICAL CONTROL OF THE PAPAYA MEALYBUG, PARACOCCUS MARGINATUS (HEMIPTERA: PSEUDOCOCCIDAE) IN THE REPUBLIC OF PALAU

The papaya mealybug (PM), Paracoccus marginatus Williams and Granara de Willink (Hemiptera: Pseudococcidae), a pest in Central America and the Caribbean, was noted to have established on Palau in March 2003 and was causing serious damage to papaya, plumeria, hibiscus, and other plants. The parasitoids Anagyrus loecki Noyes, Pseudleptomastix mexicana Noyes and Schauff, and Acerophagus papayae Noyes and Schauff (Hymenoptera: Encyrtidae) totaling 24,586 were imported from Puerto Rico and field released in Palau from August 2003 to June 2004. Anagyrus loecki and A. papayae appear to be promising biological control agents of PM in Palau. No field recovery of P. mexicana was made in spite of several field releases. The reduction of the papaya mealybug population density levels below detectable levels was observed in a six-month period following the introduction of these exotic parasitoids. Following the successful implementation of a classical biological control program, the risk of this mealybug spreading to other islands in the Republic of Palau and to neighboring Micronesian Islands has been considerably reduced.