Inferring the invasive stage of Eurasian spider Myrmarachne formicaria in North America using species distribution models

Introduced to North America sometime before 2001, Myrmarachne formicaria's potential for expansion and its current invasion stage are yet to be estimated.MaxEnt species distribution models (SDMs) for this species were developed with open-source data to predict suitable regions in North America and globally.Comparisons of SDM predictions across global, native, and invasive occurrences were made to hypothesize the invasion stage for North American populations.Suitable habitats were identified from the east coast of North America, extending west to Indiana and Michigan, and south to southern Appalachia.Additionally, regions of South America, Africa, Australia, and New Zealand, fall within its fundamental climate niche.Predictions show invasive M. formicaria populations occupy stabilized and colonizing habitats, suggesting an ongoing colonizing phase with high risk for further spread.All SDMs showed a high sensitivity to temperature variables, with the invasive SDM uniquely sensitive to precipitation.The prevalence of stabilized invasive populations implies niche conservation and suggests that niche differences more likely reflect specialization rather than a niche shift.Overall, findings indicate that M. formicaria has extensive climatically suitable habitat both within and outside of North America.Further research and the development of targeted mitigation strategies are imperative to prevent its spread to these environments.