The Occurrence and Characteristics of Imbrasia belina (Westwood, 1849) in the Subtropical Region of KwaZulu-Natal Province, South Africa

Abstract

Mopane worm is the edible larva of Imbrasia (Gonimbrasia) belina (Westwood, 1894), a species of emperor moth that is generally found in central and southern African tropical regions. Both over-harvesting of larvae and the destruction of the mopane woodlands are threatening its biodiversity. An insect with a description matching that of I. belina was observed in the northern coastal region of KwaZulu-Natal, a subtropical biota. The aim of this study was to gain insight into the potential of the northern coastal region of KwaZulu-Natal as a sanctuary for I. belina. The presence of I. belina in the subtropical biota of the coastal region of KwaZulu-Natal was confirmed through mitochondrion CO1 gene sequences, this being so far its southernmost occurrence. Field surveys revealed the occurrence of four morphologically distinct variants within the uMkhanyakude District, inclusive of the protected iSimangaliso Wetland Park and Hluhluwe Game Reserve from the beginning of September to early November as do most of the populations in the mopane woodlands but differs from them by having one outbreak per season instead of two. Imbrasia belina is polyphagous and feeds off hosts including marula (Sclerocarya birrea [(A. Rich.) Hochst.] [Anacardiaceae]) and seven other tree species. There is therefore scope to use the northern KwaZulu-Natal coastal region as a sanctuary for biodiversity conservation of I. belina. There are initiatives to cultivate marula for its fruit in the region, which further increases the potential of the area as a sanctuary for I. belina by farming marula for both its fruit and I. belina. The protected nature reserves present in the region will ensure areas of controlled use by humans.