Early detection of hitchhiking pests requires the identification of strategic entry points via transport. We propose a framework for achieving this in Europe using the Japanese beetle ( Popillia japonica ) as a case study. Human-mediated dispersal has been responsible for its introduction into several continents over the last century, including Europe where it is listed as a priority pest. Furthermore, interceptions far from the infested area confirm the risk of unintentional transport within continental Europe. Here, we analyse how three modes of transport - air, rail and road - connect the infested area to the rest of Europe. We ranked all European regions from most to least reachable from the infested area. We identified border regions and distant major cities that are readily reachable and observed differences between modes. We propose a composite reachability index combining the three modes, which provides a valuable tool for designing a continental surveillance strategy and prioritising highly reachable regions, as demonstrated by recent interceptions. Significance statement Species can be moved long distances by unintentional human transport. Such events can lead to their introduction into non-native areas where they can cause biological invasions. Using the case study of the Japanese beetle, a hitchhiker invasive insect, we propose a framework for identifying entry points for human-transported pests within Europe. We consider how the European infested area is connected to the rest of the continent by three modes of transport: air, rail and road. We propose a methodology that considers the three modes to identify potential entry points. This framework could assist authorities in designing surveillance strategies to achieve early detection of pests in Europe.

The Japanese beetle (Popillia japonica) has been listed as a priority pest in the EU since its introduction and gradual spread over the past decade. Our study presents a species distribution model that incorporates environmental factors relevant to the beetle's biology. Presence-only data from both native and long-invaded ranges (Japan, North America, and the Azores - Portugal) were used to train the model. These data were collected from both citizen-science platforms and standardised surveys. We adapted standard machine-learning techniques to account for the sampling bias inherent in opportunistic data. Suitability maps produced for the Northern Hemisphere show good agreement with actual beetle presence, especially in North America. They also show that Central Europe is generally suitable, while Northern European countries are at lower risk. A large cluster of high suitability is located in the currently invaded region, further confirming the robustness of our predictions, and extends eastwards towards the Balkans. Other clusters of moderate suitability are scattered across the central part of the continent, embedded in a matrix of low suitability. This picture highlights the importance of designing surveillance strategies considering both active insect dispersal and the possibility of hitchhiking to reach distant areas, and advocates for contingency planning at continental level.

The assessment of population vulnerability under climate change is crucial for planning conservation as well as for ensuring food security. Coffea canephora is, in its native habitat, an understorey tree that is mainly distributed in the lowland rainforests of tropical Africa. Also known as Robusta, its commercial value constitutes a significant revenue for many human populations in tropical countries. Comparing ecological and genomic vulnerabilities within the species' native range can provide valuable insights about habitat loss and the species' adaptive potential, allowing to identify genotypes that may act as a resource for varietal improvement. By applying species distribution models, we assessed ecological vulnerability as the decrease in climatic suitability under future climatic conditions from 492 occurrences. We then quantified genomic vulnerability (or risk of maladaptation) as the allelic composition change required to keep pace with predicted climate change. Genomic vulnerability was estimated from genomic environmental correlations throughout the native range. Suitable habitat was predicted to diminish to half its size by 2050, with populations near coastlines and around the Congo River being the most vulnerable. Whole-genome sequencing revealed 165 candidate SNPs associated with climatic adaptation in C. canephora, which were located in genes involved in plant response to biotic and abiotic stressors. Genomic vulnerability was higher for populations in West Africa and in the region at the border between DRC and Uganda. Despite an overall low correlation between genomic and ecological vulnerability at broad scale, these two components of vulnerability overlap spatially in ways that may become damaging. Genomic vulnerability was estimated to be 23% higher in populations where habitat will be lost in 2050 compared to regions where habitat will remain suitable. These results highlight how ecological and genomic vulnerabilities are relevant when planning on how to cope with climate change regarding an economically important species.

Alors que de nombreux animaux fréquentent l’espace aérien, les activités humaines occupent également sensiblement cette strate. Dans cet article nous prenons l’exemple de quatre types d’obstacles – les aéronefs, le bâti, les éoliennes et les lignes électriques – afin d’illustrer leurs impacts sur trois groupes d’espèces volantes en particulier, les Oiseaux, les Chauves-souris et les Insectes. Nous montrons que, d’après la littérature existante, ces obstacles aériens sont clairement une source de mortalité par collision, électrocution ou barotraumatisme, en plus de générer des nuisances, une perte et une fragmentation des habitats. Cependant, la quantification de ces problèmes reste très variable en fonction des obstacles et des espèces et en France elle est globalement mal connue (à l’exception des aéronefs et, dans une moindre mesure, des éoliennes). Nous présentons ensuite différentes mesures de gestion qui sont d’ores et déjà mises en œuvre ou testées pour diminuer ces impacts. Mais il ressort aussi que leur déploiement est très variable selon les obstacles (par exemple, la gestion du risque aviaire sur les aéroports bénéficie de plusieurs décennies d’expériences alors que l’impact du bâti n’est quasiment pas pris en compte) et que la plupart du temps ces mesures sont sectorielles et plus ou moins efficaces à ce jour (certaines restant au stade de la recherche et du développement). Nous soulignons alors l’intérêt d’une démarche globale, via l’approche par trames, afin d’approfondir ces problématiques, et proposons plusieurs pistes pour mettre en œuvre cette « Trame aérienne ».

The quantification of bird mortality due to collision with power lines is complicated by the heterogeneity of survey methods used and the bias related to searching for carcasses on the ground (e.g., carcass persistence and imperfect detection by observers). To estimate the bias associated with ground search surveys, we conducted three 30-d trials to test carcass persistence by placing and monitoring carcasses of red-legged partridges (Alectoris rufa) and common pheasants (Phasianus colchicus) below power lines at 14 sites. We also conducted two detection experiments, testing the ability of 19 observers to detect bird carcasses. We used survival analysis and generalized linear mixed-effects models to investigate the effects of site, habitat, carcass size, and survey period on both carcass persistence and detection. We also investigated the effect of carcass age on carcass persistence and the effect of the observer on carcass detection. Our findings show significant variations in carcass persistence between sites and survey periods, as well as significant interaction between these variables. The daily carcass persistence probability was highly variable between sites, with an up to eightfold variation. Carcass detection increased with increasing carcass size and was significantly affected by the microhabitat surrounding the carcass; it also varied between observers. These findings suggest that both carcass persistence and detection vary strongly and unpredictably at a small scale. As a result, conservation managers should be encouraged to conduct carcass persistence and detection experiments on sites where they aim to produce unbiased estimates of bird mortality below power lines, and these trials should be carried out in conditions similar to the mortality survey. A large-scale, unbiased, and accurate estimate of bird collision mortality due to power lines may require substantial field effort, with a survey frequency of more than once a week.