Invasive occurrence and abundance changes of Armadillidium vulgare (Latreille, 1804) in Hungarian roadside verges

Background and purpose: The impact of invasive species in ecosystems is an important problem worldwide and the spreading of invader species are affected exceedingly by linear infrastructure. Primarily the aim of our investigation was to studied how the invasion of the species impacts the isopod diversity of roadside verges. Secondly, we determined what attributes of linear infrastructure affect on mass occurrence by the species. Materials and methods: Double-glass pitfall traps were established a total of 37 localities along highways and mainroads in Hungary between 2011 and 2015. To studied what attributes of roads affect the abundance of A. vulgare we considered seasons, adjacent areas, road edge proximity, leaf-litter depth, highway age, vegetation and mowing. Results: We collected a total of 18 isopod species. The A. vulgare was the most abundant and frequently encountered species in both road types, which represented 89% of the total isopod catches. The high abundance of the species negatively correlated with isopod diversity. The invasive nature of this species is promoted by summer conditions, proximity of arable fields, intermediate distance from the road, leaf-litter at a depth of 3 cm and the youthfullness of the sampling sites. On mainroad verges the highest abundance was in the non-mown sections of the arid grassland sites. Conclusions: Our results suggest that this species is likely to adversely impact ecosystem function of roadside verges in Hungary. Different land use, water supply, surrounding landscapes, habitat structure, vegetation, biogeographical context and human activities along road verges influence the invasiveness of A. vulgare.