Cotes-Perdomo et al.
First report of the Taiga Tick, Ixodes persulcatus, in Norway.Ticks Tick Borne Dis. Published online June 24, 2025. doi:10.1016/j.ttbdis.2025.102508
The main vector of the European subtype of the TBE virus is the castor bean tick, Ixodes ricinus. The primary vector of the Siberian subtype is the taiga tick, I. persulcatus. This species is widely distributed in Russia but has been spreading westward (see, e.g., Snapshot week 7/2025) and has expanded its range into Latvia, Estonia, Sweden, and Finland (see, e.g., Snapshot week 28/2025). This expansion suggests that I. persulcatus may also become established in northern Norway.
A study was conducted to screen for I. persulcatus by dragging a flannel cloth in nine different locations in the northern regions of Norway (northeast of Brønnøysund). Of the 62 ticks collected, 58 were identified as I. ricinus, while 4 (1 nymph and 3 adults) were morphologically and genetically identified as I. persulcatus.
This is the first report of I. persulcatus in Norway. The finding is concerning, as I. persulcatus is the primary vector of the Siberian subtype of the TBE virus, which is associated with more severe neurological symptoms than the European subtype.