Exotic arthropods in the Kruger National Park, South Africa: modes of entry and population status.
At least 21 species of exotic arthropods have successfully established breeding populations in the Kruger National Park, South Africa. Of these, 7 species were intentionally introduced as biological control agents of alien weeds (Lantana camara, Eichhornia crassipes, Salvinia molesta, Sesbania punicea, Pistia stratiotes, Opuntia stricta), 4 species (Dermacentor rhinocerinus, Rhipicephalus maculatus, Gyrostigma rhinocerontis, Rhinomusca dutoiti) inadvertently accompanied vertebrate hosts (e.g. rhinoceroses, Ceratotherium simum and Diceros bicornis) during game translocation, and the remainder are presumed to have gained entry through packing crates, human activities or natural dispersal in some instances. Information on 28 species, including phytophagous, haematophagous, synanthropic and ectoparasitic arthropods, is tabulated. The modes of entry of exotic species are discussed and, where known, the time of first appearance in the Kruger National Park recorded. The rapidly escalating practice of wildlife translocation within and between countries is discussed in relation to passive transfer of diseases and parasites, and reasons are listed why routine precautionary steps should be instituted to avoid transfer of non-target organisms during translocation operations.