Climate change, particularly extreme weather events, can directly affect forest pests and the damage they cause by influencing the pests’ development, survival, reproduction and spread and by altering host defences and susceptibility. Basic knowledge of the identity, origin, pathway, and time of introduction of invasive species is essential for assessing the threats. Warming is expected to force species to shift their distributions by expanding into new climatic areas. Several projects have shown that genotypes have increasingly migrated to the north in the last decade, mainly caused by climate change. Records of changes as a result of pest-host-climate change interaction, including possible reasons for changes, are a crucial point of forest monitoring which forms the basis for control strategies and forest management decisions. We will build case studies to represent a specific pest-host-climate change interaction model: native and potentially invasive: i) from one isolated population to other population, (Gypsy Moth); ii) from one climate/geographic region to another (Abraxas pantaria) and non-native potentially invasive in a new climate/geographic region (Cydalima perspectalis).

The study presents an extensive research on targeted insect pests in Croatia, taking into account the biology of the pest and host plants and all aspects of the bioecology of the species like genetic constitution and origin, thermal requirements, possible host plants, palatability, antagonists etc.) that influence its spread in a novel environment influenced by climate change. All the gained data could be used for predictive pest risk analysis models for the researched species, as well as for other native and non-native invasive species that could become a serious threat to Croatian forest ecosystems in changed climate conditions in the near future.