First evidence of established populations of the taiga tick Ixodes persulcatus (Acari: Ixodidae) in Sweden

Abstract

BackgroundThe tick species Ixodes ricinus and I. persulcatus are of exceptional medical importance in the western and eastern parts, respectively, of the Palaearctic region. In Russia and Finland the range of I. persulcatus has recently increased. In Finland the first records of I. persulcatus are from 2004. The apparent expansion of its range in Finland prompted us to investigate if I. persulcatus also occurs in Sweden.MethodsDog owners and hunters in the coastal areas of northern Sweden provided information about localities where ticks could be present. In May-August 2015 we used the cloth-dragging method in 36 localities potentially harbouring ticks in the Bothnian Bay area, province Norrbotten (NB) of northern Sweden. Further to the south in the provinces Västerbotten (VB) and Uppland (UP) eight localities were similarly investigated.Results Ixodes persulcatus was detected in 9 of 36 field localities in the Bothnian Bay area. Nymphs, adult males and adult females (n = 46 ticks) of I. persulcatus were present mainly in Alnus incana - Sorbus aucuparia - Picea abies - Pinus sylvestris vegetation communities on islands in the Bothnian Bay. Some of these I. persulcatus populations seem to be the most northerly populations so far recorded of this species. Dog owners asserted that their dogs became tick-infested on these islands for the first time 7–8 years ago. Moose (Alces alces), hares (Lepus timidus), domestic dogs (Canis lupus familiaris) and ground-feeding birds are the most likely carriers dispersing I. persulcatus in this area. All ticks (n = 124) from the more southern provinces of VB and UP were identified as I. ricinus.ConclusionsThe geographical range of the taiga tick has recently expanded into northern Sweden. Increased information about prophylactic, anti-tick measures should be directed to people living in or visiting the coastal areas and islands of the Baltic Bay.Electronic supplementary materialThe online version of this article (doi:10.1186/s13071-016-1658-3) contains supplementary material, which is available to authorized users.

Limited consequences of infestation with a blood‐feeding ectoparasite for the nestlings of two North Pacific seabirds

“…Recent studies suggest that the seabird tick may be expanding its range poleward (Coulson et al ), and that infestation rates (Descamps ) and the period of time over which the ticks are active each year (Benoit et al ) are both on the increase. Similar tendencies have been documented in other species of ticks (Jaenson et al ), and typify the types of changes to host‐parasite relationships that are widely expected to result from global warming (Harvell et al , Dantas‐Torres ).…”

“…These ectoparasites can affect the fitness of hosts through direct mechanisms, i.e., by causing the deaths of adults (Gaston et al , Devevey and Christe ) and juveniles (Hawlena et al , Hillegass et al ); and through indirect mechanisms, such as retarding the rate at which offspring develop (Moss and Camin , Merino and Potti ). The severity of the infestation with ectoparasites, the intensity of the host's responses, and the consequences for fitness all can vary with environmental conditions (de Lope et al , McCoy et al , Jones et al ).…”

Tick saliva and its role in pathogen transmission

“…This review focuses on pathogens transmitted by I. ricinus, the vector of numerous human pathogens, most notably TBE virus and certain species of the Borrelia burgdorferi sensu lato (s. l.) complex that cause Lyme borreliosis [31,32]. Evidence of SAT is also considered involving the sympatric and parapatric species, I. persulcatus (found in parts of northern Europe and northern to north-eastern Asia), and the allopatric species of North America, I. scapularis [33][34][35][36][37].…”

First evidence of Ixodiphagus hookeri (Hymenoptera: Encyrtidae) parasitization in Finnish castor bean ticks (Ixodes ricinus)

“…In addition, their abundance seems to be increasing, particularly in the more southern parts of this region (Jaenson et al 2012;Sormunen et al 2016b). Likewise, I. persulcatus has recently been found across Estonia and Finland, and in 2016 the species was reported for the first time from Sweden as well (Geller et al 2012;Jaenson et al 2016;Laaksonen et al 2017).…”