Geographical Distribution, Host Associations, and Vector Roles of Ticks (Acari: Ixodidae, Argasidae) in Sweden

Abstract

This review covers the geographic distribution and host relationships of the tick species in Sweden. Ixodes uriae White, I. caledonicus Nuttall, I. unicavatus Neumann, I. arboricola Schulze & Schlottke, and I. lividus Koch are ornithophagous species. I. trianguliceps Birula, I. canisuga Johnston, I. hexagonus Leach, and Argas vespertilionis (Latreille) are mammalophagous. I. ricinus (L.) and Haemaphysalis punctata Canestrini & Fanzago feed on both birds and mammals. All these tick species may be considered to be permanently present in Sweden. I. persulcatus Schulze, Hyalomma marginatum Koch, and the brown dog tick, Rhipicephalus sanguineus (Latreille), may be regarded as not indigenous to Sweden although they may be regularly introduced by spring-migrating birds or imported dogs, respectively. The first European record of the American dog tick, Dermacentor variabilis (Say), is reported. There are several records of Hyalomma aegyptium (L.) from imported tortoises in Sweden. Excluding other ticks imported on exotic pets and zoo animals, another 13 tick species are listed that may occur, at least occasionally, in Sweden. Because of its wide geographic distribution, great abundance, and wide host range, I. ricinus is medically the most important arthropod in northern Europe. I. ricinus is common in southern and south-central Sweden and along the coast of northern Sweden and has been recorded from 29 mammal species, 56 bird species, and two species of lizards in Sweden alone. The potential introduction to Sweden of exotic pathogens with infected ticks (e.g., I. persulcatus and H. marginatum on birds or Dermacentor spp. and R. sanguineus on mammals) is evident.

Climate and Tickborne Encephalitis

“…Changes in the macro-and microclimate may influence transmission of Lyme disease and TBE through impact on the life cycle dynamics of the tick, the tick habitat, and the host animals, as well as through changes in human behavior and human-vector-host animal interactions (Cederlund 1981, Dobson and Carper 1993, Jaenson et al 1994, Kaiser 1995, Lindsay et al 1995 (Fig. 1).…”

Species Composition and Abundance of Ixodid Ticks (Acari: Ixodidae) in the City of Petrozavodsk, Republic of Karelia, Russia

“…Имеется в виду, с одной стороны, более высокая численность I. persulcatus по сравнению с I. ricinus, наблюдаемая в Каре-лии в районах совместной встречаемости этих видов Бугмырин и др., 2014]. С другой стороны, на городских терри-ториях возможны одиночные находки адвен-тивных видов клещей (Dermacentor marginatus), которые можно объяснить их случайным заносом [Jaenson et al, 1994;Котовский, Буг-мырин, 2013].…”

The wild life of tick-borne pathogens

“…The life cycle of I. ricinus consists of three active life stages, larva, nymph and adult, which all need a bloodmeal from a vertebrate host in order to moult to the next stage or to lay eggs, and all stages feed from a large array of host species 36,37 (Figure 1.1). Ixodes ricinus is sensitive to desiccation and is mostly found in forested areas throughout Europe 36 .…”

“…Both I. ricinus and B. burgdorferi are considered generalist parasites, as they utilize a multitude of host species 37,46 . These host species differ considerably in the numbers of ticks they feed, which differs between the different life stages of the tick 36,64 .…”