Where and how Argentine ant (Linepithema humile) spreads in Corsica?

The Argentine ant, Linepithema humile (Dolichoderinae), is one of the most widespread invasive ant species in the world. When established in optimal habitat, this species usually excludes most other local ants and can heavily impact other arthropods as well. Although Argentine ants have been present in southern Europe for more than 100 years, they were first noted in Corsica, a French Mediterranean island, in 1957 in only one urban station. In this study, we aimed to map precisely their geographical distribution in Corsica and to quantify their presence by using an infestation index. We recorded changes in the distribution of Argentine ants in Corsica over the past decade. Argentine ants appeared to be well established within their introduced range and spreading along the Corsican coasts principally through Human-mediated jump-dispersal but not homogenously.

Consequences of the cessation of 3000 years of grazing on dry Mediterranean grassland ground-active beetle assemblages.

Due to extensive grazing regimes over a long period of time, the Plain of Crau, the unique steppe of France, is a particularly suitable model to study the role of sheep grazing on beetle (Coleoptera) assemblages and their response to grazing abandonment. After four years of abandonment, beetle assemblages first only undergo a decrease in the abundance of a few species and then a gradual and slight change in species composition. Later, there is a change in the structure of assemblages, which increases with increasing time since abandonment. After 23 years of grazing abandonment, there is no significant loss of species.