Both climate change and global trade are important drivers of changes in the abundance and distribution of insect pests. Whiteflies (Homoptera: Aleyrodidae) are important plant pests and virus vectors in many agricultural systems worldwide. Among them, the sweet potato whitefly, Bemisia tabaci (Gennadius) is considered the most devastating pest of vegetables, ornamentals, and agronomic crops throughout the tropical and subtropical regions of the world, because it can transmit over 200 species of plant viruses. Previous distributions of the species were limited to regions between the 30th latitudes but in the past two decades, it has invaded every continent in the world except Antarctica. Based on climate models, B. tabaci populations are expected to expand to regions where increasing temperatures will eliminate frosts, allowing year round breeding. Due to the extreme polyphagy of the species, the effects of such changes will probably be profound and may lead to substantial ecosystem-wide changes. Many arthropods host one or more inherited bacterial symbionts, the phenotypes of which have important implications for ecologically based pest management strategies. The overall goal of this proposal is to develop novel strategies for reducing the direct and indirect damage inflicted by B. tabaci. It aims to predict the evolution of B. tabaci populations around the Mediterranean, from which diagnostic and preventive measures can be derived. To achieve these goals the following objectives have been set: 1) Determine the geographic distribution of B. tabaci biotypes, their population genetic structure and symbiotic complement around the Mediterranean basin in light of climatic changes; 2) Determine B. tabaci invasion routes within the Mediterranean basin; 3) Determine the respective influence of nuclear and symbiotic variations on stress resistance in B. tabaci; 4) Model the influence of climate change on B. tabaci biotype/population outbreaks; 5) Establish a network of researchers. The research conducted will involve the use of diverse methods including field studies, molecular biology, bioinformatics, analyses of international data bases and advanced computer programs. In order to begin preparing now for the upcoming challenges of our changing environment, we will combine established research expertise in climate change assessment and environmental system modelling with insects and symbionts ecology, behaviour and population genetics for allowing the necessary incorporation of pest risk assessment and simulation models into comprehensive management planning systems of both natural and agricultural ecosystems.

PESTOLIVE aims at producing knowledge and tools for a new and efficient management of plant-parasitic nematodes (PPN) and plant-pathogenic fungi (PPF) in olive (Olea europea L.) cropping systems and nurseries, while reducing the use of pesticides. Because of the anthropic continuum from Olea post-glacial refuges to oleasters (domestication) and then to olive-trees (breeding and cropping), the fragmentation of the PPN and PPF communities and of their natural enemies could explain the scattered diversity of the control techniques (especially resistance rootstocks, biocontrol, cropping strategies) developed and applied all around the Mediterranean basin. The novelty of PESTOLIVE is based on i) the analysis and the management of the parasite diversity (ecology of communities) instead of controlling emblematic species (population approach) and ii) the involvement of knowledge about the historical co-adaptation of soil-borne parasite and natural enemies communities to olive-tree domestication (origins and past assemblages) and breeding that follows the history of O. europea around the Mediterranean basin. PESTOLIVE is breakdown in four scientific work-packages. In WP1 (olive domestication and breeding), the analysis of the wild and cropped olive diversity (phylogeography and population genetics) all around the Mediterranean basin associated with domestication history and breeding is a prerequisite to understand co-evolutionary patterns between pathogens and the olive tree. In WP2 (response of soil-borne organisms to domestication and breeding), the spatial distribution of PPN, PPF and associated antagonists is explored to investigate i) co-phylogeographic correspondences between plant and parasite diversities and ii) life-strait genetic variation involved in community assemblages forced by anthropisation. In WP3 (response of soil-borne organisms to plant-resistance (ancestral & cultivars)), resistance against PPN and PPF is tackled in order to look for new resistance sources and to assess the durability of the resistance in terms of time remanence and of parasite diversity conservation. In WP4 (response of soil-borne organisms to cropping systems (low vs high inputs)), the capacity to manage PPN and PPF communities in a soil diversity conservation approach is assessed considering the very large range of olive production systems in the Mediterranean countries. PESTOLIVE is managed and coordinated in a specific work-package (WP0_project management). It involves 18 research and teaching organisations from seven Mediterranean countries in order to promote international multidisciplinary collaboration, training co-supervision and shared technical platforms within the consortium. Attachments with national and international councils (e.g. IOC) will guaranty communication with local producer organisations in order to fit with olive and oil production constraints vs to implement production strategies with innovative methods for soil-borne pest management.