The invasive mealybug species Paracoccus marginatus has caused severe damage to the papaya industry and the agricultural sector as a whole, since it was first reported in Ghana in 2009. It is now spreading to other African countries. In search of a sustainable and environment friendly control option against this pest, field survey and laboratory studies were undertaken in three districts in the Eastern region of Ghana to identify possible natural enemies against this pest. Fruit and leaf samples containing over 100,000 samples of P. marginatus, Pseudococcus longispinus (Targioni Tozzetti), as well as larvae of other insect species were incubated under controlled conditions. Various sampling techniques were used to sample parasitic wasps and predators in the field. A total of 25 different species of natural enemies of a number of papaya pests including 15 species of parasitoids were found, with four of these collected from P. marginatus incubated leaf and fruit samples. However, none of the parasitoids had the potential as biocontrol agent against P. marginatus as indicated by further studies. The carnivorous butterfly Spalgis epius (Westwood) was recorded for the first time in Africa as a potential biocontrol agent against P. marginatus as indicated by both field and laboratory studies. It should thus be considered for incorporation into P. marginatus biocontrol programmes. Other mealybug predators including the coleopteran Crytolaemus montrouzieri Mulsant, lacewings (Hemerobius and Chrysoperla sp.), Syrphid larvae and unidentified predatory Noctuid were also found to contribute in curbing the population of P. marginatus and can thus also play a role in its management.
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