Using Species Distribution Models (SDMs) to Estimate the Suitability of European Mediterranean Non-Native Area for the Establishment of Toumeyella Parvicornis (Hemiptera: Coccidae)

Simple Summary Predicting species distribution is a fundamental step for setting up opportune control actions. The suitability of the environment for the establishment of the species is even more important in case of invasive insects, such as Toumeyella parvicornis (Hemiptera, Coccidae). This species is a soft scale insect native to North America recently introduced in Italy and in France, where it established and spread, causing harmful infestations on stone pine (Pinus pinea L.) plants. Some aspects of its biology, such as the several overlapped generations and the high fecundity, may contribute to make it a successful invasive species when in a suitable environment. This is supported by the observations carried out in Central Italy, where the climate and environmental conditions seem suitable for the species to develop. To prevent further spread across the Mediterranean basin, it would be helpful to identify the most suitable areas by considering bioclimatic variables, as is commonly carried out in case of invasive species. We prepared potential pest distribution maps of European areas by utilizing Species Distribution Models. This information adds further detail to the report recently published by the European Food Safety Authority (EFSA). The areas with the highest suitability for the species are located along the coasts, where most Mediterranean pines occur. This correspondence suggests a high risk of widespread dispersal and provides useful information for implementing management strategies of this damaging pest. The pine tortoise scale, Toumeyella parvicornis, is an insect native to the Nearctic region that is able to infest several Pinus species. It can cause weakening, defoliation and, at high infestation levels, tree death. After its first report in Italy in 2015, the pest spread rapidly over the surrounding areas and was reported in France in 2021. Due to the threat that this pest poses to pine trees, the suitability of European Mediterranean basin areas for T. parvicornis at different spatial scales was estimated by constructing species distribution models (SDMs) using bioclimatic variables. Our results showed that several coastal areas of the Mediterranean basin area could be suitable for T. parvicornis. Based on performance assessment, all the SDMs tested provided a good representation of the suitability of European Mediterranean non-native area for T. parvicornis at different spatial scales. In particular, most of the areas with a medium or high level of suitability corresponded to the geographical range of distribution of different Pinus spp. in Europe. Predicting the suitability of European Mediterranean areas for T. parvicornis provides a fundamental tool for early detection and management of the spread of this pest in Europe.