Ixodes ariadnae is a tick species of bats so far reported only in Central 
Europe, with its description based on the female and nymph. This study describes 
the male and larva in order to complete the description of the species. Male 
ticks collected from cave walls in Hungary showed a different morphology from 
those of I. vespertilionis and I. simplex. Molecular analysis of the cytochrome 
oxidase subunit I (COI) gene of these ticks verified them as conspecific to I. 
ariadnae. In addition, a larva of I. ariadnae was removed from a Daubenton's bat 
(Myotis daubentonii Kuhl, 1817). The male of I. ariadnae is characterized by 
long legs (7-8mm; I. vespertilionis: 8-10mm; I. simplex: 2-2.2mm), relatively 
short palpal setae (30-100μm; I. vespertilionis: 100-200μm; I. simplex: 20-50μm) 
and straight lateral edge of palps, the genital aperture (enclosed by a line of 
sclerotization) situated anteriorly to second intercoxal space and rounded 
coxae. The larva of I. ariadnae has long legs (2-2.2mm; I. vespertilionis: 
1.6-1.8mm; I. simplex: 1mm), broad palps (length×width: 200×90μm; I. 
vespertilionis: 200×70μm; I. simplex: 140×60μm), pentagonal and posteriorly 
reverse bell-shaped scutum. These features allow to distinguish the male and the 
larva of I. ariadnae from those of I. vespertilionis (of which the male has 
longer palpal setae and curved lateral edge of palps, the genital aperture is 
situated posterior to the second intercoxal space, and the second coxae are 
squared; the larva of I. vespertilionis has narrower palps and posteriorly 
triangular scutum) and I. simplex (of which the male and the larva have 
considerably shorter legs, palps).