Macroparasites of introduced parakeets in Italy: a possible role for parasite-mediated competition

Alien species are considered a cause of biodiversity loss throughout the world. An important but often overlooked

form of competition with native species is the parasite-mediated one. Introduced species may bring their own parasites

from their native ranges (spillover) or get native parasites from native species, thus increasing the parasites’ spread and

transmission risk (spillback). Thus, a complete knowledge of parasites hosted by introduced species is important to assess

and to possibly prevent impacts. Ring-necked and monk parakeets have been introduced in many European countries,

where they established a number of alien reproductive populations. We sampled 21 ring-necked parakeets and 7 monk

parakeets from Italy and identified 35 arthropod ectoparasites belonging to five species. Amongst those, one species was

native to India (Neopsittaconirmus lybartota), where alien populations of ring-necked parakeet may have been originated,

and one species from South America (Paragoniocotes fulvofasciatus), which is typically found of the monk parakeet

in its native range. The other three species of arthropod parasites were native to Italy and commonly found on native species,

suggesting the possibility of spillback processes.