Threatened or threatening? Evidence for independent introductions of Macrothele calpeiana (Walckenaer, 1805) (Araneae: Hexathelidae) and first observation of reproduction outside its natural distribution range

摘要

Despite being endemic to the south of the Iberian Peninsula, Macrothele calpeiana has been repeatedly reported far from its native range (e.g. northern Italy, Switzerland, Belgium, Holland). Here, we confirm, using DNA barcode data, that the specimenscollected in northern Catalonia, Majorca, and northern Italy are indeed recent introductions. Additionally, our data suggest that they originated from different source populations, and corroborate former suggestions that the recent expansion of Macrothele may be linked to the commercial transport of olive trees. Former species distribution modelling studies have revealed that the exotic localities reported are far from the ecological optimum of the species and hence that introduced specimens have slimchances of survival. However, a recent finding of several individuals of different sex and stages in a coastal town in northern Catalonia (northeastern Iberian Peninsula) suggests that M. calpeiana is able to reproduce outside its native range and that microclimate conditions may allow establishment of accidentally introduced populations.