Terrestrial flatworms are a group of successful carnivorous invaders that have been introduced to many regions outside their native range. In France, six different species have been recorded in significant numbers over the past 20 years, with a recent increase in observations. These include predators of earthworms, gastropods and soil arthropods. Their presence raises concerns about their potential to disturb communities of soil-dwelling organisms. Here, we aimed to describe patterns of co-occurrence between these species in France, using a national inventory of alien flatworms coupled with estimates of potential co-occurrence derived from ecological niche models trained at the global scale. We showed that, although alien predatory flatworms are relatively widespread in France, they co-occur less frequently than expected simply based on each species’ respective environmental suitability, i.e., they tend to be found alone and not in association with other alien flatworm species. However, ecological niche models indicate a high potential for more frequent co-occurrences in the future. We hypothesize that their limited dispersal ability and their relatively recent introduction has confined most species close to their introduction sites. However, if they eventually fill out their potential range, predators of different taxonomic groups will co-occur more frequently, leading to greater predation pressure in invaded ecosystems. Our conclusions shed light on the current and future co-occurrence patterns of alien predatory flatworms in France. Understanding how they translate in the field in terms of predation and competitive interactions will be crucial for predicting the impact of flatworm invasion on soil ecosystems.

Un stage de niveau Master 2 (6 mois à partir de début 2026) est ouvert au sein du laboratoire iEES-Paris, et sera basé à l'Université Paris-Est Créteil. Le·la stagiaire explorera comment les propriét...

Un contrat d’un an de post-doctorat est proposé à iEES-Paris dans l’équipe i-SOL sur le site de Créteil à l’UPEC pour réaliser une étude de génomique du paysage sur un couple papillon- parasitoïde. Le...

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Soil plays a critical role in ecosystem functioning and on the provision of ecosystem services. The soil fauna, especially earthworms, contributes to these processes through their action on the physic...

Do beetles indicate more predators and fewer pests in Lao PDR organic farms?

Fine-scale temporal monitoring of the invasive land flatworm Obama nungara was obtained during a 4-year survey of a French private garden, where up to 1585 O. nungara were recorded in 1 month. Popula...

📢 PhD position in ecology ❗ Last days to apply ! ❗ We have a 3-year PhD position available at iEES Paris to investigate ecological connectivity in relation…