Prospects for biological control of the invasive moth catcher vine, Araujia sericifera (Apocynaceae), in South Africa

Biological control (biocontrol) has been identified as a promising strategy for managing the invasive moth catcher vine, Araujia sericifera Brotero (Apocynaceae) in South Africa. The release of the leaf-feeding beetle, Freudeita cf. cupripennis Lefèvre (Coleoptera: Chrysomelidae) in New Zealand and completion of the host-specificity testing on the fruit fly, Anastrepha nigrotaenia (Enderlein) (Diptera: Tephritidae) provides South African Ar. sericifera control efforts with two potentially effective and host-specific agents. However, studies of Ar. sericifera in New Zealand and South America indicate that the vine’s taxonomy remains unresolved, with morphological, climatic, and biogeographical differences between plant populations in its native range suggesting potential species differences that may have implications for the efficacy of biocontrol agent(s) in South Africa. In addition, climatic differences between South Africa, New Zealand and South America have not been evaluated for their effects on potential agent establishment. This study compared the nuclear ribosomal internal transcribed spacer (nrITS) regions of Ar. sericifera individuals from South Africa, New Zealand and Uruguay, revealing no genetic variation between sampled populations. To evaluate the climatic suitability of F. cf. cupripennis and An. nigrotaenia for South Africa, climate comparisons between South Africa and the agents’ native (South American) and introduced (New Zealand) ranges were conducted, providing candidate regions for agent establishment along South Africa’s coast. Given the lack of genetic differences between populations and the potential climatic suitability of the agents, biocontrol remains a promising management strategy for Ar. sericifera in South Africa.