A pest risk analysis of the importation of the mango stone weevil (Sternochetus mangiferae ) from Ghana into Mainland USA

Abstract

Recent Ghana government policy on export diversification has made mangoes and other tropical fruit crops important non-traditional export crops. Up to now the main export market has been the European market. However, in order to benefit from the recent trade liberalization policies of the USA, under the African Growth and Opportunities Act (AGOA) and to access the fast growing `niche market` for tropical fruits, it is necessary to meet quarantine requirements for the export of produce into the USA market. We conducted studies on the distribution, ecology and control of the mango stone weevil (Strernochetus mangiferae) in Southern Ghana with the aim of undertaking pest risk assessment and developing risk mitigation scenarios to meet USA requirements. Except for Hawaii, S. mangiferae is absent from mango cultivation areas in mainland USA, but is endemic in the coastal savanna and forest areas of Ghana. If introduced it is likely to follow the risk pathway in the form of immature larvae, pupae or mature adult weevils in fruits. The risk analysis is based on a pathway initiated qualitative risk analysis. The analysis recommends that to mitigate the risk, prospective Ghanaian mango exporters should obtain their fruits outside the current domain outside the current domain of the stone weevil. They should use cold chains for export or radiate (gamma radiation) to kill the developing larvae, pupae and adults. Integrated pest management strategies such as the use of neem extracts and other botanical pesticides and treatment of tree trunks with pesticides to kill off ovipositing and hibernating adults as well as the destruction of dropped and discarded fruits would reduce fruit infestation levels significantly. In addition to these strict quarantine measures, there is also the need to enforce other measures. Such measures ensure that the pest is not moved from its current domain into the areas where it is absent so that exporters can obtain fruits from pest free areas