**Preface to "Forest Pathology and Entomology"**

Forest ecosystems are vital to life on Earth since they provide a multitude of benefits in terms of water and air purification, nutrient recycling, soil erosion prevention, and carbon storage, as well as habitat, food, and fibers to human populations and wildlife. These irreplaceable products and services are today in increasing danger due to multiple natural and anthropogenic disturbances. Global climate change and trade in particular, besides destabilizing forest ecosystems, offer new chances of survival, reproduction, and spread to both native and introduced forest pathogens and pests. Outbreaks of pathogens and pests have in fact dramatically increased in number and impact in the last few decades, causing loss of significant forest areas worldwide. In this context, studies on forest health have become increasingly prominent and topical, making forest pathology and entomology forefront disciplines to tackle this emerging global threat. A special research effort is aimed at tackling the problem of invasive alien species. The timely identification of new introductions and follow up monitoring of non-native pathogens and pests is of critical importance so that prompt eradication and other control measures can be implemented. At the same time, native pathogens and pests need to be more deeply investigated, since climate change and the consequent environmental stress are causing a resurgence of their attacks in endemic areas and their range expansion in previously free areas. Effective disease and pest management requires reliable information on the life strategies of harmful parasites, from their biology to their ecology and distribution, including the impact on forest ecosystems and possible control strategies.

The 22 papers that make up this Special Issue deal with different aspects of the above subjects, from the diagnosis to the surveillance of causative agents, from the study of parasites' biological, epidemiological and ecological traits to their correct taxonomic positioning and classification, and from disease and pest monitoring to sustainable control strategies. All the authors have invested significant time and energy in writing their papers. The editors of this Special Issue are grateful to all of them for their dedication. The editors also hope that the readers will find this book a useful point of reference and they can gain insights for their own research on the same or related topics.

### **Salvatore Moricca, Tiziana Panzavolta** *Editors*
