Potential distribution of Acerophagus papayae, a parasitoid of the papaya mealybug (Paracoccus marginatus), across Africa

Abstract

The papaya mealybug, Paracoccus marginatus, is a highly polyphagous invasive pest that affects at least 133 economically important crops, and causes economic losses worldwide. Acerophagus papayae (Noyes and Schauff), a parasitic wasp, has proven to be a successful biocontrol agent, but its use in Africa is limited. Here, we use a predictive correlative model to explore the potential distribution of A. papayae and relate it to data showing the potential distribution of P. marginatus, to highlight potentially suitable areas for biological control of P. marginatus, for its current distribution, as well as its potential future distribution.

The resulting model performed well with a test AUC of 0.89. Areas that were highly suitable for P. marginatus and were also suitable for A. papayae were highest across West Africa. Whilst there were areas which were suitable for both species in both East Africa and Central Africa, there were large areas of cropping land which were highly suitable for P. marginatus although not suitable for A. papayae. Across Northern and Southern Africa, there were limited cropping areas which were suitable for P. marginatus and where there was suitability, it was only moderate. Across these areas, there was limited suitability for A. papayae.

Our results offer refined information on the potential suitability for A. papayae across Africa with the aim to help guide decisions on the areas where use of A. papayae could be used effectively as a part of an integrated pest management programme against P. marginatus.