Current status and potential future impact of invasive vespid wasps(Vespula germanica and Polistes dominulus) in South Africa

Abstract: Two social vespid wasps, Vespula germanica and Polistes dominulus, have nowbecome naturalised in the Western Cape Province of South Africa, adding to the number of exoticsocial insects that now occur in the Fynbos biome. Although both species are known to beinvasive in other countries, up untill now the rate of spread of both species has been rather slow.Previous work in matching V. germanica’s climatic suitability within South Africa, revealed itscurrent extent occurs in marginal habitat. However the Coastal Belt of South Africa starting fromabout George is much more suitable and could provide a route of invasion into Eastern seaboardof Africa. Based on the invasive record of both species in other countries, they are bothcandidates for eradication. Before the feasibility of eradication can be determined, detailedcurrent distribution records are required. Here we report on available data on the past and currentdistribution of both vespid species, mostly derived from museum records. We also comment onthe likely impact of both species if they were to realize their potential range in South Africa.