The southern part of Europe is one of the most species-rich regions from the point of view of the genus and subgenus Ixodes . However, numerous unresolved or questionably interpreted issues exist in the context of tick species indigenous to Mediterranean countries, such as the validity of Ixodes festai , synonymy of Ixodes tatei with Ixodes eldaricus (never tested molecularly) or the haplotype heterogeneity of Ixodes gibbosus . In this study, 21 specimens of six tick species from the subgenus Ixodes were compared morphologically with high resolution digital microscopy and also analyzed with molecular-phylogenetic methods based on two mitochondrial genetic markers. The nymphs of I. eldaricus and I. tatei showed differences in the morphology of the scutum and basis capituli. Both the nymph and the females of I. festai could be distinguished from those of I. eldaricus , I. ventalloi and I. acuminatus . A female tick resembled I. gibbosus but was also different from this species, based on its descriptions. Analysis of phylogenetic relationships confirmed with moderate to strong support that all six species examined in this study represent different taxa of the subgenus Ixodes , including a previously unknown sister species to I. gibbosus . The latter is recognized and described here as a new species, Ixodes paragibbosus Hornok and Kontschán, sp. nov. Based on findings of this study, the tick species I. tatei Arthur, 1959 should be resurrected and reestablished. Morphological and phylogenetic comparisons performed here (including the first barcoding sequences of I. eldaricus and I. festai) confirm that the latter is a valid species, distinct from both I. eldaricus and I. ventalloi . For the differential diagnosis of the above species, the results highlight the importance of observing (among other structures) the auriculae, the internal spur of coxa I and the hypostome.

Ixodes arboricola and Ixodes lividus are ornithophilic tick species. The former is typically associated with tree-hole dwelling birds, while the latter is a host-specific parasite of sand martins (Riparia riparia). These two tick species share important morphological characters that make them difficult to identify when they are collected from atypical hosts, such as birds of prey. Despite this, high resolution digital pictures have not been reported to compare I. arboricola and I. lividus, nor was their complete mitogenome reported. The aim of this study was to compensate for this lack of illustrations and sequence data. Nymphs and females of I. arboricola and I. lividus were used for morphological comparison, and one specimen of each species to generate mitogenome sequences. The results showed that females of these two species are different in the shape of their scutum, porose areas, the length of basis capituli, palps, coxae, genital pore, anal groove and tarsus I. On the other hand, nymphs of I. arboricola and I. lividus can be distinguished according to their cervical grooves, cornuae, auricular ridges and spiracular plates. The mitochondrial genome size was 14,539 and 14,536 bp, for I. arboricola and I. lividus, respectively. The mitogenome sequences of I. arboricola and I. lividus were 91.1% identical to each other. Phylogenetic analysis of Ixodes species showed that I. arboricola and I. lividus are sister species, and cluster together with Ixodes crenulatus/canisuga under strong support. In conclusion, results of this study confirmed that the front of the basis capituli is crucial in distinguishing Ixodes species, especially in the subgenus Pholeoixodes where these two species are phylogenetically closest related to I. canisuga. Another phylogenetically relevant morphological character is the scutal surface which is wrinkled (rugose) as a common feature of Pholeoixodes species in the clade of I. arboricola and I. lividus (including I. canisuga, I. rugicollis and I. ariadnae). Although the host ranges of I. arboricola and I. lividus do not substantially overlap, they may transmit some of the shared pathogens. Relevant data indicate that the eco-epidemiological significance of the two ornithophilic tick species studied here may in part be similar and they may play a role in the transmission of rickettsiae, borreliae and viruses of which birds act as reservoirs.

Tick infestation of songbirds has been extensively studied at global and regional scales but relevant data on birds of prey remain scarce and fragmentary. Raptors are of particular epidemiological relevance because their large size, wide-ranging movements and nesting habits may facilitate long-distance dispersal of ticks, and endophilic tick species (e.g. from prey animals) may even persist in their re-used nests. In this study, we aimed to compensate for the lack of comprehensive data in this context. First, more than 1800 birds of prey were examined at 61 sites in Central and South-Eastern Europe, encompassing both continental and Mediterranean climatic regions. Ticks (n = 839) were obtained from 98 birds representing 13 raptor species from three avian orders. Twelve tick species were identified, the most abundant being Rhipicephalus turanicus, Haemaphysalis concinna and Ixodes ricinus. Several previously unknown tick–host associations were revealed. Molecular-phylogenetic analysis showed that sequences of Ixodes arboricola from Tawny Owls (Strix aluco) clustered separately from other conspecific sequences, raising the possibility that Ixodes strigicola Schulze and Schlottke, 1929 is a valid species. Owls proved to be the most heavily tick-infested, particularly Eurasian Eagle-Owl (Bubo bubo) nestlings. Endophilic and rodent-associated tick species were significantly more common on owls and on bird species nesting in cavities or buildings, whereas diurnal raptors were predominantly infested by generalist and exophilic ticks. These patterns highlight the importance of nesting ecology and prey composition in shaping tick assemblages on raptors. The results provide novel insights into tick–raptor associations, contribute new records of tick species from birds of prey, and improve our understanding of the role of raptors in tick maintenance and dispersal which appears to be particularly important in the case of cavity-nesting species. In addition to field sampling, a comprehensive database from nearly 150 published sources revealed that 32 tick species have been reported from birds of prey in the Western Palearctic to date.

The present study was initiated to analyze ticks collected periodically from the vegetation in an urban marshy biotope of central Europe. During the one-year-long study period, 1960 ticks were found, including Ixodes ricinus (n = 1037), Dermacentor reticulatus (n = 610) and Haemaphysalis concinna (n = 313). DNA was extracted from 199 Dermacentor reticulatus and 47 Ixodes ricinus, selected from the beginning of their questing period. Molecular analysis of the cytochrome c oxidase subunit I (cox1) barcoding gene with the classical Folmer primers revealed that among 37 D. reticulatus all except two ticks had serial mutations along a 129-bp-long part of the gene. The majority of these ticks were young, freshly molted adults. However, when the complete mitogenome was sequenced from two such "aberrant" ticks, these serial mutations were absent. In D. reticulatus, host DNA was detected from four synanthropic bird species, the dog, the red fox, the bank vole, the Eurasian shrew and the wild boar. Besides long-known endemic tick-borne pathogens, specimens of D. reticulatus and I. ricinus were shown to contain the DNA of Ehrlichia muris. Babesia microti had very high, 36% prevalence in I. ricinus. In conclusion, mutations in the cox1 fragment amplified with the Folmer primers were not present in the complete mitochondrial genome of D. reticulatus, indicating that probably nuclear mitochondrial DNA (NUMT) was amplified with the first method. To our knowledge, similarly high local prevalence of B. microti was only reported in ticks in North America, where this piroplasm is responsible for most cases of human babesiosis (unlike in Europe).