Three members of the subgenus Pholeoixodes
Three members of the subgenus Pholeoixodes, i.e., Ixodes canisuga, Ixodes hexagonus and Ixodes kaiseri are frequently collected from carnivorous/insectivorous hosts in Europe.
While a pictorial identification key has been reported for female Pholeoixodes ticks, a similar work has not been done on their male, nymphal and larval specimens.
The study clarifies those morphological characters of these three members of the subgenus Pholeoixodes, which can be used easily to identify/distinguish them.
In larvae the aims included finding alternatives to chaetotaxy, which is difficult to observe and its usefulness is also affected by uncertainties in literature data.
For this, 609 Pholeoixodes ticks (males, nymphs and larvae) were collected from carnivores, hedgehogs and their environment in six European countries (representing Western, Central and Southeastern Europe), followed by detailed morphological examination and/or molecular analyses to confirm the identity of their species.
In Central Europe, all three species were collected, the largest number of specimens represented by I. hexagonus.
On the other hand, in Southeastern Europe I. kaiseri had the highest abundance.
In conclusion, the morphology of spur on the first coxae is to recognize males but is less informative in nymphs and larvae.
The latter can be identified more properly by observing the morphology of basis capituli. In particular, nymphs and larvae of I. canisuga have anteriorly flattened basis capituli, forming a plateau that surrounds the base of the hypostome.