Arthropods and associated pathogens from native and introduced rodents in Northeastern Italy.

Introduced Siberian chipmunks Eutamias sibiricus have been reported to be important reservoirs for human Lyme disease, as they may host high numbers of hard ticks carrying Borrelia spp. and other pathogens. In the present study, we assessed the prevalence of Borrelia spp. and other pathogenic bacteria in ectoparasite arthropod species infesting Siberian chipmunks and coexisting native small rodents. Small rodents were trapped with Sherman traps in Veneto (NE Italy), where the largest Italian populations of chipmunks occur. A total of 14 individual ticks were found on 223 rodents, with 6 more ticks obtained from stored dead chipmunks from the same study area. Ectoparasites were screened for pathogens by molecular analyses including species-specific PCR amplifications. Rickettsia monacensis, Borrelia lusitaniae, and Anaplasma platys were present in the parasites of both native rodents and introduced chipmunks. The present findings suggest a role for the invasive species E. sibiricus in the maintenance of the Ixodes ricinus life cycle, which may result in the modification of the transmission dynamics of tick-borne pathogens. Moreover, the presence of Rickettsia in urban populations of chipmunks may represent a serious risk for human health and should be investigated further.

Spatial behaviour of an overlooked alien squirrel: The case of Siberian chipmunks Eutamias sibiricus.

Alien species of concern within the European Union have been recently listed and their populations need to be monitored, to plan addressed eradication or control programs. Therefore, the assessment of their presence should be rapidly carried out, particularly for elusive species or for those living at low densities. The Siberian chipmunk Eutamias sibiricus is a ground-dwelling squirrel, naturally distributed in northern and eastern Asia. Many introduced populations occur in Europe and Italy too. This species has been listed within the invasive species concern within the European Union and, thus, monitoring is mandatory to manage its potential range expansion. We carried out a hair-tube survey on 31 wood patches in northern and central Italy, where reproductive populations of Siberian chipmunk have been recorded. Hair tubes provided reliable data in assessing the presence of the Siberian chipmunk, with only 1% pseudo-absence and a high detection probability. The occurrence of Siberian chipmunk was positively influenced by study site and by the distance from release site, confirming low dispersal abilities by this species. Dense understorey also affected the presence of chipmunks, preventing them to search for food on the ground and to dig burrows.