The threats posed by the pet trade in alien terrestrial invertebrates in South Africa

Abstract

The pet trade has been a major pathway for the introduction of vertebrate invaders, but little is known about its role in invertebrate invasions. Here we assess the trade in terrestrial invertebrates (excluding spiders) in South Africa and the potential of this trade to result in biological invasions and impacts. Pet stores, websites, and expositions were visited, and a list of the taxa traded was compiled. DNA barcoding was used to determine if the species were correctly identified in the trade. Information on invasion history and impact elsewhere was used to assess the potential for species to become invasive and have impact in South Africa. We found 53 alien terrestrial invertebrate taxa that were traded, although only 36 of these matched a valid species name. Of 11 species tested using DNA barcoding nine were correctly identified. Species accumulation curves were produced, but did not reach an asymptote, suggesting there are many species in the trade that were not recorded. The most common species were used as food for pets, rather than as pets themselves. None of the species were reported to be invasive elsewhere, and few had records of causing negative impacts (the exception being moderate impacts to human health caused by venomous scorpions). Therefore, there is little evidence that the invertebrates traded pose a significant threat to South Africa. However, given uncertainties in which taxa are traded and the lack of data on invasiveness and impact, there might be a significant invasion debt. We recommend continued monitoring and engagement with the industry.