Are Native Predators Likely to Influence the Establishment and Persistence ofAnthonomus santacruzi(Curculionidae), a Biological Control Agent ofSolanum mauritianum(Solanaceae) in South Africa?

Abstract

Solanum mauritianum Scop. (bugweed, woolly nightshade, Solanaceae), a perennial small tree that is native to South America, threatens several commercial and conservation activities in the eastern higher rainfall regions of South Africa and has thus been targeted for biological control (see review by Olckers 2011). The flowerbud-feeding weevil Anthonomus santacruzi Hustache (Coleoptera: Curculionidae), which has the potential to reduce the weed's excessive fruit set, was first released in South Africa in late 2008 (Olckers 2003, 2008) and is currently the subject of extensive release efforts to promote its establishment and distribution. Mass-rearing by the South African Sugarcane Research Institute since 2011 has so far facilitated the release of several thousand weevils in the province of KwaZulu-Natal (D. Gillespie, pers. comm.).