Invasive insects and their costs for biodiversity, economy and human health – InvaCosts

Global environmental changes are among the most important threats for human society, both directly and indirectly. In particular, climate change and human-assisted introductions of invasive alien species are both expected to become major causes of biodiversity loss and ecosystem functioning disruption in the near future. They are also expected to incur major economic and sanitary impacts, although these have not been quantitatively estimated. In addition, synergies between climate change and biological invasions are considered a likely driver of exacerbation of alien species invasions for many species among the most problematic. Should climate change exacerbate biological invasions, as suggested by numerous studies, their economic impacts could be vastly amplified. In particular, invasive insects could invade new regions following the lift of thermal barriers, causing in some cases important impacts on biodiversity, ecosystem functions, ecosystem services, economy and/or human health. Predictions are thus crucial to alert society of the potential future risks. However, few studies take into account both components, despite the likelihood they will interact and worsen overall impacts.

The aim of the InvaCosts programme is to characterise and quantify the worldwide impacts of invasive species following climate change. These impacts will be considered sensu lato, including biodiversity losses, disruption of ecosystem functioning and loss of ecosystem services, economic costs (on agriculture, forestry, real estate and infrastructures) and damages to public health (sanitary impacts and associated secondary costs for the society). This project focuses on insects, a taxonomic group of major importance for the target environmental and societal categories, and whose ectothermic nature makes them especially sensitive to climate variables.

InvaCosts brings together 3 leading research teams in 3 key disciplines of this project, ecology of invasive species, environmental economics and economy of public health. This interdisciplinary, collaborative work will lead to the development of distribution models for a large number of invasive insects at a macro-ecological scale, both under current and future environmental conditions (climate, land use, human density, etc.), according to different climate change and socio-economic scenarios. These probabilistic maps will be associated to our estimates of the economic costs from different types of impacts by invasive species and to the number of people whose health will be affected by some of these species (allergies, attacks, disease vectors) in order to estimate global and spatial costs. These estimates will then be projected in different time horizons according to the evolution of climatic, habitat and human-related variables, in order to estimate the economic and social costs associated to these changes following the modifications of suitability areas of these invasive species. We selected 20 of the worst insect species (drivers of biodiversity loss, pest for agriculture or forestry, vectors of human diseases, …) in order to provide a quantitative assessment of their global impacts and costs in the context of a changing climate.

We aim to bring the first robust estimations of suitability areas for invasion of some of the most problematic insect species worldwide, and of the associated environmental, economical and health costs that they can incur both currently and following climate change. In addition, we aspire to provide some of the first rigorous assessments on the impact of invasive species for our societies through the first estimations of a unique (monetary) value that would regroup all accessible types of impacts.