The observed link between urbanization and invasion can depend on how invasion is measured

Aim Cities are thought to promote biological invasions because invasive species are more often introduced in urban areas and because they are more successful in disturbed environments. However, the association is not as strongly supported by the literature as is generally assumed and might depend on how urbanization and invasion are measured. In this study, we test if the type of data used to assess the link between urbanization and invasion can affect a study's conclusions. Location Europe and middle Rhône valley (~5000 km2 in south-eastern France). Method We studied the spatial distribution of the invasive garden ant Lasius neglectus in its current introduced range in Europe and tested its association with urbanization using three measures of invasion (presence-only, presence–absence and population area) and two measures of urbanization (urban/nonurban land cover classification and proportion of impervious surfaces (buildings, road) per spatial unit). Results Based on presence-only data across Europe, L. neglectus occurred in urban areas 10 times more often than expected from a random geographical distribution. However, when controlling for spatial bias in sampling effort with presence–absence data (1870 sampling locations in the middle Rhône valley, France), the occurrence of the species was independent of urbanization. Moreover, the surface occupied by L. neglectus populations was negatively correlated with urbanization. Main conclusions These findings show that the type of occurrence data used to test the link between urbanization and invasion can strongly affect the conclusion of a study. This is particularly concerning because invasion studies often use presence-only data that are likely biased towards cities. Future urban invasions studies must be carefully designed to avoid this pitfall.Peer reviewe

Land-cover and climate factors contribute to the prevalence of the ectoparasitic fungus Laboulbenia formicarum in its invasive ant host Lasius neglectus

International audienceUnderstanding the distribution of parasites is crucial for biodiversity conservation. Here, we studied the distribution of the ectoparasitic fungus Laboulbenia formicarum in native and invasive Lasius ants in a 2000 km2 area. We screened over 16,000 ant workers in 478 colonies of five different species. We found that Lab. formicarum was rare in native Lasius species but infected 58% of the colonies of the invasive species Las. neglectus. At landscape scale, Lab. formicarum presence could not be explained by geographic and genetic distances between Las. neglectus colonies but was associated with hotter and dryer climatic conditions and its prevalence in colonies increased with urbanization. Within infected colonies, fungal prevalence varied from 0 to 100 percent within meters and was negatively correlated with impervious ground cover. In a changing world, our findings emphasize the importance of land-use and climatic factors in shaping the distribution and prevalence of fungal parasites

Etude du mutualisme entre un champignon phytopathogène Botrytis cinerea et un ravageur de la vigne Lobesia botrana : recherche de nouvelles méthodes de lutte

*INRA. Centre de Recherche de Bordeaux. Unité de Recherches Intégrées sur la Vigne Diffusion du document : INRA. Centre de Recherche de Bordeaux. Unité de Recherches Intégrées sur la Vigne Diplôme : Dr. d'Universit

Mey – villa « 6 rue des Jardins » et lotissement Coteau du Soleil

International audienc

Les thermes de la villa gallo-romaine de Damblain (Vosges)

International audienc

Feeding insects with a phytopathogenic fungus influences their diapause and population dynamics

International audienc

Effet de l'ingestion d'extraits de Serratula tinctoria contenant des phytoecdysteroïdes sur le développement de Lobesia botrana

National audienc

Relations inter-organismes et recherches de nouvelles méthodes de lutte : union à bénéfice réciproque entre un insecte ravageur du vignoble (Lobesia botrana) et un champignon phytopathogène (Botrytis cinerea)

National audienc

Les thermes de la villa gallo-romaine de Damblain (Vosges)

La fouille préventive réalisée par l’Inrap en 2008 et 2009 à Damblain, commune localisée à l’extrême sud de la Lorraine, a notamment permis de mettre au jour les thermes d’une importante villa gallo-romaine occupée du ier au iiie siècle. Le vestiaire et le frigidarium avec son bain froid sont les deux principales pièces ayant livré des enduits peints. La première était décorée de bandes linéaires contenant des compositions à réseau différentes, dont l’emplacement sur les murs pose bien des questions. Le comblement du frigidarium et de son bassin froid conservait également de nombreux éléments d’architecture permettant de reconstituer son élévation et sa voûte.During 2008 and 2009 a rescue excavation at Damblain (in the extreme south of Lorraine), conducted by the Institut national de recherches archéologiques preventives (Inrap), allowed the baths of a large Gallo-Roman villa to be brought to light. The villa was occupied from the 1st to the 3rd centuries. The apoditerium and the frigidarium were the two major rooms retaining vestiges of wall paintings. The first was decorated with linear bands containing different repeated patterns, though their arrangement on the walls remains hypothetical. The filling of the frigidarium and its cold water pool also conserved numerous architectural elements that allowed its elevation and vault to be surmised.Eine in den Jahren 2008 und 2009 vom Institut national de recherches archéologiques préventives (Inrap) in Damblain (Department Vosges, France) durchgeführte Rettungsgrabung führte zu Freilegung einer bemerkenswerten römischen Villenanlage, die vom 1. bis zum 3. Jahrhundert n. Chr. existierte. Zwei Räume der Badeanlage der villa, das apoditerium und das frigidarium, waren die einzigen Räume, bei denen Wandmalereien erhalten waren. Der erste Raum war mit linearen Bändern in unterschiedlichen Kompositionen und Arrangements verziert, jedoch bleibt ihre genaue Anordnung an den Wänden hypothetisch. Die Verfüllung des frigidarium und des in diesem Raum befindlichen Kaltwasserbeckens lieferte dagegen zahlreiche Architekturelemente, die es erlaubten, die ehemalige Innenraumgestaltung und die vorhandenen Gewölbe zu rekonstruieren. (Trad. Julian Wiethold