Predicting the spread of an invasive tree pest: the pine wood nematode in Southern Europe

1. Invasive tree pests are increasingly threatening forest ecosystems. Understanding and controlling their spread presents a major challenge for managers, researchers, and policy makers. In 1999, the pine wood nematode Bursaphelenchus xylophilus, causal agent of pine wilt disease and native to North America, was first detected in Europe, more precisely in south western Portugal. Since then, it has spread to more than 30% of the country, producing large-scale damages in Portuguese forests. 2. We applied a new spatio-temporal network-based model to predict, at yearly intervals, the natural spread of the pine wood nematode on the Iberian Peninsula, as dispersed by the longhorn beetle Monochamus galloprovincialis, its only known vector in Europe. We compared the model predictions with independent observations of the natural spread of pine wilt disease in Portugal between 2005 and 2015. We simulated the effect of potential containment measures on the disease spread. 3. The model predicted ...