Distribution and molecular detection of Theileria and Babesia in questing ticks from northern Spain

Abstract.  A total of 562 questing adult ixodid ticks, collected during 2003−05 in 10 recreational mountain areas in northern Spain, were analysed for piroplasm infection. Reverse line blot (RLB) analysis using a panel of probes for 23 piroplasm species identified 16 different piroplasms, with an overall prevalence of 9.3%. Most were Theileria spp.-positive (7.7%), 3.0% were positive for Babesia spp. and 1.4% of ticks harboured both genera. Ixodes ricinus (Linnaeus, 1758), the most abundant tick in the vegetation, ranked third with regard to piroplasm infection prevalence (11.4%) after Rhipicephalus bursa (Canestrini & Fanzago, 1878) (16.0%) and Haemaphysalis punctata (Canestrini & Fanzago, 1878) (13.5%). Infection was detected in 6.2% of Dermacentor reticulatus (Fabricius, 1794) and in 1.1% of Haemaphysalis inermis (Birula, 1895), but was absent from Haemaphysalis concinna (Koch, 1844). Ixodes ricinus carried more piroplasm species (13), followed by H. punctata (10), D. reticulatus (8), R. bursa (3) and H. inermis (1). Although most of the positive ticks harboured a single infection (76.9%), mixed infections with two or three different piroplasm species were also detected (23.1%). The various tick−pathogen associations found are discussed and prevalences of infection in ticks are compared with previous results on piroplasms infecting animals in the same region.     

Species composition, distribution, and ecological preferences of the ticks of grazing sheep in north-central Spain

The distribution and ecological preferences of tick (Acari: Ixodidae) parasites of grazing sheep in the region of Aragón (north-central Spain) were surveyed on flocks four times a year and mapped into a 5 x 5 km grid. Nine tick species were found. These were species of the Rhipicephalus sanguineus group (about 95% of them Rhipicephalus turanicus Pomerantsev, in 91% of cells of the grid), Rhipicephalus bursa Canestrini & Fanzago (79% of cells), Dermacentor marginatus (Sulzer) (58% of cells), Haemaphysalis punctata Canestrini & Fanzago (74% of cells) and Ixodes ricinus (Linnaeus) 14% of cells. Other species weakly represented in the surveys were Dermacentor reticulatus (Fabricius), Haemaphysalis sulcata Canestrini & Fanzago and Hyalomma m. marginatum Koch. Data on temperature, Normalized Difference Vegetation index (NDVI), topography, vegetation categories and plant productivity were used to build models of distribution and abundance of D. marginatus, H. punctata, R. bursa and R. turanicus. The occurrence models largely incorporated climatic variables and had good discrimination ability (P < 0.0001 for every modelled species, correct classification rate or sensitivity within 0.89 and 0.99), whereas the abundance models had a lower explanatory power. These models are relevant in the understanding of the variables composing the main distribution patterns, but they are unable adequately to predict the density. Abundance models produce good predictions in cells with low tick density, whereas poor correlation is observed in sites with high tick abundance. Several causes may be responsible for this low predictive power of the abundance models. Model output might be sensible to host density, to local farming practices, or to the size of the grid used to refer the results of the survey. In the latter case, small patches may support locally important populations of ticks, influencing largely the results of the survey. These patches of particular abiotic conditions, or supporting large host densities, may have been undetected at the resolution of the survey, thus obscuring the impact of the predictive variables.     

An updated list of the ticks of Ghana and an assessment of the distribution of the ticks of Ghanaian wild mammals in different vegetation zones

Twenty one species of ticks belonging to five genera of the family Ixodidae (Order Acari, sub-order Ixodida) - Amblyomma, Haemaphysalis, Hyalomma, Ixodes and Rhipicephalus (including the sub-genus Rhipicephalus (Boophilus)) - were collected from 1260 mammals, representing 29 species, 14 families and 6 orders, in four vegetation zones in Ghana during the period 1971-1978. Four other species were collected from humans in 1977. In all, eight species appeared to be new records for Ghana: Amblyomma tholloni Neumann; Dermacentor circumguttatus Neumann; Haemaphysalis houyi Nuttall & Warburton; Ixodes loveridgei Arthur; Ixodes oldi Nuttall; Ixodes vanidicus Schultze; Rhipicephalus complanatus Neumann; Rhipicephalus cuspidatus Neumann. The updated list of tick species in Ghana given here includes 41 species of ixodid ticks and four species of argasid ticks. Most species have been found in neighbouring regions of West Africa but 56 of the 121 different combinations of ixodid tick species and host species found in the collection described here have not apparently been reported before. The new combinations recorded here bring the total number of different combinations of ixodid tick species and mammalian host species now reported in Ghana to 151. The tick species found on wild mammals in Ghana mostly differed from those reported from domestic stock by other authors. The data showed that different tick species occurred in different vegetation zones and that most species displayed a pronounced preference for certain groups of related host species. Some tick species were found in the savanna feeding mainly on large bovids and/or suids; others were found in forests feeding mainly on small bovids, large rodents or small carnivores.     

Comments on controversial tick (Acari: Ixodida) species names and species described or resurrected from 2003 to 2008

There are numerous discrepancies in recent published lists of the ticks of the world. Here we review the controversial names, presenting evidence for or against their validity and excluding some altogether. We also address spelling errors and present a list of 17 species described or resurrected during the years 2003–2008. We consider the following 35 tick species names to be invalid: Argas fischeri Audouin, 1826, Ornithodoros boliviensis Kohls and Clifford, 1964, Ornithodoros steini (Schulze, 1935), Amblyomma acutangulatum Neumann, 1899, Amblyomma arianae Keirans and Garris, 1986, Amblyomma bibroni (Gervais, 1842), Amblyomma colasbelcouri (Santos Dias, 1958), Amblyomma concolor Neumann, 1899, Amblyomma cooperi Nuttall and Warburton, 1908, Amblyomma curruca Schulze, 1936, Amblyomma cyprium Neumann, 1899, Amblyomma decorosum (Koch, 1867), Amblyomma nocens Robinson, 1912, Amblyomma perpunctatum (Packard, 1869), Amblyomma striatum Koch, 1844, Amblyomma superbum Santos Dias, 1953, Amblyomma testudinis (Conil, 1877), Amblyomma trinitatis Turk, 1948, Dermacentor confractus (Schulze 1933), Dermacentor daghestanicus Olenev, 1928, Haemaphysalis himalaya Hoogstraal, 1966, Haemaphysalis vietnamensis Hoogstraal and Wilson, 1966, Hyalomma detritum Schulze, 1919, Ixodes apteridis Maskell, 1897, Ixodes donarthuri Santos Dias, 1980, Ixodes kempi Nuttall, 1913, Ixodes neotomae Cooley, 1944, Ixodes rangtangensis Teng, 1973, Ixodes robertsi Camicas, Hervy, Adam and Morel, 1998, Ixodes serrafreirei Amorim, Gazetta, Bossi and Linhares, 2003, Ixodes tertiarius Scudder, 1885, Ixodes uruguayensis Kohls and Clifford, 1967, Ixodes zealandicus Dumbleton, 1961, Ixodes zumpti Arthur, 1960 and Rhipicephalus camelopardalis Walker and Wiley, 1959. We consider the following 40 names valid: Argas delicatus Neumann, 1910, Argas vulgaris Filippova, 1961, Ornithodoros aragaoi Fonseca, 1960, Ornithodoros dugesi Mazzoti, 1943, Ornithodoros knoxjonesi Jones and Clifford, 1972, Ornithodoros marocanus Velu, 1919, Ornithodoros nattereri Warburton, 1927, Amblyomma beaurepairei Vogelsang and Santos Dias, 1953, Amblyomma crassipes (Neumann, 1901), Amblyomma echidnae Roberts, 1953, Amblyomma fuscum Neumann, 1907, Amblyomma orlovi (Kolonin, 1995), Amblyomma parkeri Fonseca and Arag?o, 1952, Amblyomma pseudoconcolor Arag?o, 1908, Bothriocroton oudemansi (Neumann, 1910), Bothriocroton tachyglossi (Roberts, 1953), Dermacentor abaensis Teng, 1963, Dermacentor confragus (Schulze 1933), Dermacentor ushakovae Filippova and Panova, 1987, Haemaphysalis anomaloceraea Teng, 1984, Haemaphysalis filippovae Bolotin, 1979, Haemaphysalis pavlovskyi Pospelova-Shtrom, 1935, Hyalomma excavatum Koch, 1844, Hyalomma isaaci Sharif, 1928, Hyalomma rufipes Koch, 1844, Hyalomma turanicum Pomerantzev, 1946, Ixodes arabukiensis Arthur, 1959, Ixodes boliviensis Neumann, 1904, Ixodes columnae Takada and Fujita, 1992, Ixodes maslovi Emel′yanova and Kozlovskaya, 1967, Ixodes sachalinensis Filippova, 1971, Ixodes siamensis Kitaoka and Suzuki, 1983, Ixodes sigelos Keirans, Clifford and Corwin, 1976, Ixodes succineus Weidner, 1964, Rhipicephalus aurantiacus Neumann, 1907, Rhipicephalus cliffordi Morel, 1965, Rhipicephalus pilans Schulze, 1935, Rhipicephalus pseudolongus Santos Dias, 1953, Rhipicephalus serranoi Santos Dias, 1950 and Rhipicephalus tetracornus Kitaoka and Suzuki, 1983.     

Ixodid ticks (Acari: Ixodidae) infesting humans in Tokat Province of Turkey: species diversity and seasonal activity

Ixodid ticks (Acari: Ixodidae) are the major vectors of pathogens threatening animal and human health. Tokat Province, Turkey, is a suitable habitat for extended tick activity with its moderate climate and vegetation. In the present study, we surveyed humans visiting health centers to determine the species diversity, geographical distribution, and seasonal activity of ixodid ticks infesting them. Out of 5,999 adult ticks collected from humans from April to September, 2008, 800 ticks were identified to species, while the remaining were identified to genus according to their distinct morphological characteristics. Hyalomma marginatum, Hyalomma detritum, Rhipicephalus bursa, Rhipicephalus (Boophilus) annulatus, Haemaphysalis punctata, Dermacentor marginatus, and Ixodes laguri were the most prevalent tick species among 24 ixodid tick species infesting humans in the region. One of these tick species, Hyalomma isacii was identified as a new record for the ixodid tick fauna of Turkey. Hyalomma species were the most abundant in summer, while Dermacentor and Ixodes species displayed the lowest frequency. Hyalomma aegyptium infestation was very common on humans in the province. Results indicated that a variety of ixodid tick species infest humans depending on the season in the target area. It is possible that a variety of ixodid tick species may contribute to the spread of tick‐borne diseases such as Crimean‐Congo haemorrhagic fever virus (CCHFV), which is endemic in the region.     

The ixodid tick species attaching to domestic dogs and cats in Great Britain and Ireland

The species of ixodid ticks, attached to dogs and cats presented to veterinary practices in Great Britain and Ireland were identified. Most host animals carried only one tick species with Ixodes ricinus Linné (Acari: Ixodidae) being the most common, identified on 52% of animals, Ixodes hexagonus Leach (Acari: Ixodidae) the second most common (on 39%) and Ixodes canisuga Johnston (Acari: Ixodidae) the third most common (on 11%). A significantly higher proportion of dogs than cats carried I. ricinus, while I. hexagonus was more frequently carried by cats. One animal carried a single specimen of Haemaphysalis punctata Canestrini & Fanzago (Acari: Ixodidae), one carried a Dermacentor reticulatus Fabricius (Acari: Ixodidae) but none carried Rhipicephalus sanguineus Latreille (Acari: Ixodidae). This indicates that the latter two species, vectors of 'exotic' tick-borne diseases, remain at low densities in Great Britain and Ireland. Retrospective information on exposure of the animals to different habitats and geographic regions was collected by questionnaire and subject to contingency table and logistic regression analysis. Woodlands and moorlands were habitats significantly associated with I. ricinus attachment. Exposure to urban parks was significantly associated with I. hexagonus attachment and exposure to boarding kennels and catteries was significantly associated with I. canisuga attachment. Ixodes hexagonus, rather than I. ricinus, was the ixodid tick species most likely to be encountered by urban populations of dogs and cats and, by inference, possibly also humans. The implications of these findings, for the transmission of tick-borne pathogens to dogs, cats and humans are discussed.     

Risk factors associated with ixodid tick species distributions in the Basque region in Spain

Ixodid tick abundance was investigated in the Basque region in Spain in two 1-year longitudinal studies, in 1992-1993 and 2003-2004. Forty zones were visited monthly and 162 672 ticks (87% larvae, 12% nymphs and 1% adults) were collected by blanket dragging. Eleven tick species belonging to the genera Ixodes, Haemaphysalis, Rhipicephalus and Dermacentor were identified including Haemaphysalis concinna Koch, which had not previously been reported in Spain. Tick species abundance differed between zones, studies and seasons. In 1992-1993, Haemaphysalis punctata Canestrini & Fanzago was the predominant species and distinct spring-summer and autumn-early winter peaks of activity were observed. In 2003-2004, Ixodes ricinus (Linneaus) was the most common species and was active throughout the winter. Larval and nymph seasonal activity patterns coincided in both 1993 and 2003 and this could facilitate co-feeding transmission of pathogens. Higher tick abundance was associated with increased livestock abundance in 1992-1993 and milder winter temperatures in 2003-2004. Tick collection rates in areas with moderate and high tick density were positively associated with the interaction between ambient temperature at sampling and rainfall 7 days prior to sampling. Collection rates were also significantly higher at medium rather than higher altitude, in forested areas than in open grasslands and lower in recreational areas frequented by people and with wet vegetation at sampling.     

Prevalence of ixodid ticks on cattle in Mazandaran province, Iran

A survey was carried out to investigate the prevalence of hard tick species (Acari: Ixodidae) on cattle in Mazandaran province, Iran. A total of 953 ticks were collected from 86 infested cattle during activating seasons of ticks during 2004-2005. Nine species were identified: Boophilus annulatus (51.3%), Rhipicephalus bursa (16.8%), Haemaphysalis punctata (6.3%), Ixodes ricinus (6.8%), Hyalomma marginatum (12.5%), Hyalomma anatolicum excavatum (5.2%), Hyalomma asiaticum (0.6%), Hyalomma detritum (0.2 %), and Dermacentor spp. (0.1%). The results show that Boophilus annulatus, Rhipicephalus bursa, and Hyalomma species are dominant tick species in the surveyed area.     

Ticks infesting domestic animals in Italy: current acarological studies carried out in Sardinia and Basilicata regions

The note reviews published and unpublished data on acaralogical studies carried out by different parasitologists' groups in Sardinia and Basilicata regions. In Sardinia 72 collecting sites were investigated and a total of 4,086 ticks were collected from hosts (cattle, sheep, goats and pigs) and from soil. So far 2,413 ticks belonging to six genera have been identified: Rhipicephalus (67.2%), Haemaphysalis (24.1%), Hyalomma (2.7%), Boophilus (0.7%), Dermacentor (4.9%), Ixodes (0.3%). Host-associated ticks were collected from 50 out of 200 selected farms in Basilicata. About 4,000 tick specimens were collected and 1,794 ticks have been identified (of which 1,215 were adults, 6 larvae and 573 nymphs). The following genera were identified: Ixodes (20%), Rhipicephalus (27%), Hyalomma (31%), Haemaphysalis (18%), Dermacentor (6%). The seasonal distribution of the species identified in the two regions studies is discussed from a geographical and climatic point of view.     

Ixodid ticks in Bosnia and Herzegovina

Ticks of the Ixodidae family represent an enormous threat to human and animal health. From January to December 2004, a total of 10,050 ixodid ticks were collected from 26 areas in Bosnia and Herzegovina and determined to the species level. Ticks were collected from dogs, sheep, cows, goats, rodents, humans and plants. Ixodes ricinus was the most prevalent species, followed by Dermacentor marginatus marginatus, Rhipicephalus bursa, Hyalomma marginatum marginatum, Rhipicephalus sanguineus, Haemaphysalis punctata, Dermacentor reticulatus and Ixodes hexagonus.     

Shifts in the distribution of ixodid ticks parasitizing cattle in Zimbabwe

In an attempt to update information on the ecological distribution of ixodid ticks (Ixodida: Ixodidae) in Zimbabwe, a cross‐sectional survey was carried out between September 2013 and May 2015 at 322 dip tanks. A total of 15 tick species were collected, namely: Amblyomma hebraeum Koch (65.2%, n = 210/322), Amblyomma variegatum Fabricius (14.9%, n = 48/322), Hyalomma rufipes Koch (62.4%, n = 201/322), Hyalomma truncatum Koch (37.9%, n = 122/322), Rhipicephalus appendiculatus Neumann (60.6%, n = 195/322), Rhipicephalus compositus Neumann (0.3%, n = 1/322,), Rhipicephalus decoloratus Koch (61.8%, n = 199/322), Rhipicephalus evertsi evertsi Neumann (65.2%, n = 210/322), Rhipicephalus lunulatus Neumann (4%, n = 13/322), Rhipicephalus microplus Canestrini (32%, n = 103/322), Rhipicephalus near punctatus Walker and Horak (7.1%, n = 23/322), Rhipicephalus simus Koch (5.6%, n = 18/322) and Rhipicephalus cf. turanicus Pomerantsev (3.4%, n = 11/322). Compared with previous surveys, changes in the distribution of A. hebraeum, A. variegatum and R. microplus were recorded. The distributions of other tick species have largely remained unchanged. Factors which might have influenced these changes and the possible impacts on the epidemiology of tick‐borne diseases are discussed.     

General review of tick species present in Portugal

At present, 24 species are known to occur in Portugal: Argas vespertilionis, Ornithodoros maritimus and Ornithodoros erraticus in Argasidae; Ixodes acuminatus, Ixodes bivari, Ixodes canisuga, Ixodes frontalis, Ixodes hexagonus, Ixodes ricinus, Ixodes simplex simplex, Ixodes ventalloi, Ixodes vespertilionis, Dermacentor marginatus, Dermacentor pictus', Haemaphysalis hispanica, Haemaphysalis inermis, Haemaphysalis punctata, Rhipicephalus bursa, Rhipicephalus pusillus, Rhipicephalus sanguineus, Rhipicephalus turanicus, Hyalomma lusitanicum, Hyalomma marginatum marginatum and Boophilus annulatus in Ixodidae. The more relevant diseases transmitted to cattle by ticks, particulary in Ribatejo and Alentejo regions, are the babesiosis due to Babesia bigemina and Babesia bovis, the theileriosis by Theileria annulata and the anaplasmosis due to Anaplasma marginale; the theileriosis by Theileria mutans2 may not be considered significant. The sheep and goats parasitoses transmitted by ticks are of less importance than the cattle diseases. However the babesiosis due to Babesia motasi and Babesia ovis and also theileriosis by Theileria hirci3 are present in some districts of the country.     

New faunal and biological observations on ticks in Abruzzo]

Ticks collected during the years 1975-76 in Abruzzo (Prov. l'Aquila and Chieti) Italy are reported. The following species have been identified: Ixodes canisuga, Ixodes frontalis, Ixodes hexagonus, Ixodes ricinus, Dermacentor marginatus, Haemaphysalis sulcata, Rhipicephalus bursa, Rhipicephalus sanguineus, Hyalomma marginatum. New hosts are: Felis catus for Ixodes canisuga; Scolopax rusticola, Motacilla flava, Corvus cornix for Ixodes frontalis; Sciurus vulgaris for Haemaphysalis punctata; Garrulus glandarius for Haemaphysalis sulcata. For Italy the following records are new: hosts: Corvus frugilegus for Ixodes frontalis; Coturnix coturnix and Alauda arvensis for Haemaphysalis sulcata; immature stages: Ixodes canisuga on Vulpes vulpes; Ixodes frontalis on Turdus merula; Haemaphysalis punctata on Coturnix coturnix, Phasianus colchicus, Erinaceus europaeus, Lepus europaeus; Accordingly numerous species, hosts and seasonal records are new for Abruzzo.     

Potential tick vectors for Theileria equi in Israel

Theileria equi Mehlhorn and Schein, 1998 (Piroplasmida: Babesiidae) is an important tick-borne pathogen of horses that is highly endemic in many parts of the world, including Israel. The present study evaluated the potential roles of five hard tick species [Hyalomma excavatum Koch, 1844; Hyalomma marginatum Koch, 1844; Rhipicephalus turanicus Pomerantsev 1936; Rhipicephalus annulatus Say, 1821; Haemaphysalis parva (Neumann, 1897) (all: Ixodida: Ixodidae)], previously found to infest horses in Israel, in acting as vectors for piroplasmosis. For this, DNA was extracted from whole ticks and, when possible, from the salivary glands in each species (n = 10–59). Polymerase chain reaction amplification and sequencing of the 18S rRNA gene were used to detect T. equi in 48 of the 127 ticks (37.8%) and in 21 of the 90 extracted salivary glands (23.3%) in all five species. All but two sequences were classified as T. equi genotype A; the remaining two were classified as genotype D. The findings of this study point to Ha. parva and R. annulatus as potential novel vectors of T. equi, and suggest that parasite genotype selection occurs within the tick vector.     

Ectoparasite ticks and chewing lice of red-legged partridge,Alectoris rufa,in Spain

During the 1992-1993 and 1993-1994 shooting seasons, 212 wild red-legged partridge, Alectoris rufa (Galliformes: Phaisanide) were captured in 18 Spanish provinces and examined for chewing lice and ticks. Three tick species and six species of chewing lice were found. Ticks (Acari: Ixodidae) Haemaphysalis punctata Canestrini & Fanzago, Hyalomma lusitanicum Koch and Ixodes frontalis Panzer were found at the lowest prevalence (1.4% overall tick prevalence). The louse (Mallophaga) species, Goniodes dispar Burmeister (Goniodidae) (52.8%) and Cuclotogaster obscurior Hopkins (Philopteridae) (28.8%) were the most prevalent, while Goniocotes obscurus Giebel (Philopteridae) (10.8%), Menopon pallens Clay (Menoponidae) (7.5%) and Menacanthus lyali Rodriguez et al. (Menoponidae) (3.3%) were found at medium to low prevalence. Columbicola columbae columbae Linnaeus (Philopteridae) was found at the lowest prevalence (0.5%). The intensity of C. obscurior and overall intensity of all lice species were directly related to the environmental mean temperature and the Normalized Difference Vegetation Index (NDVI), whereas intensity of G. dispar was directly related to NDVI only. The intensity of G. dispar, C. obscurior, all louse intensity, and louse species richness were higher in male than female birds. Intensity of each louse species, all louse intensity and louse species richness were inversely associated with the nutritional index. No relationship was observed between bird age and louse intensity or species richness.     

The intraspecific taxonomic structure and identification of closely related species of ixodid ticks (Ixodidae)

Two variants of intraspecific morphological differentiation of 7 palearctic species of Ixodidae and respectively two variants of their intraspecific taxonomic pattern have been revealed on the basis of the study of geographic variation of each species. Three species--Ixodes pavlovskyi Pom., 1946, Haemaphysalis erinacei Pavesi, 1884, Hyalomma asiaticum Sch. et Schl., 1929, are subdivided into subspecies, and four ones--I. ricinus (L., 1758), I. persulcatus Sch., 1930, I. crenulatus Koch, 1844, Dermacentor marginatus (Sulzer, 1776),--into morphotypes by the degree of distinction of the whole complex of active stages in ontogenesis. Acknowledging the conventional character of the categories of subspecies and morphotype their criteria have been formulated for ixodid ticks. Paleogeographic and ecological grounds are given. Some data of geographic variation of immature stages favour the identification of closely related species in concrete localities.     

Effect of of methoprene and retinoic acid on characteristics of Haller's organ regeneration in the tick Haemaphysalis longicornis (Acari, Ixodidae)

The results of experiments on regeneration of the Haller's sensory organ in the metastriate ixodid tick Haemaphysalis longicornis Neumann in the presence of the juvenoid methoprene and retinoic acid and of studies of its structural changes by SEM confirmed the similarity of prostriate and metastriate ixodids as concerns the juvenalizing effect of the above morphogens on regenerative processes during nymphal-imaginal metamorphosis. However, the metastriate ticks (Haemaphysalis and earlier studied Hyalomma) are well behind the prostriate ticks (Ixodes) as concerns the extent of changes induced by juvenoids and retinoids in the sensillar sets of Haller's organ regenerates.     

Influence of biotope on the distribution and peak activity of questing ixodid ticks in Hungary

Abstract In order to update the occurrence of hard tick species in Hungary, 3442 questing ticks were collected from the vegetation by the dragging/flagging method in 37 different places in the country, between March and June of 2007. Ixodes ricinus (L.) turned out to be ubiquitous. Dermacentor marginatus (Schulzer) was absent from sampling sites in the southwestern part of the country, but in most places was concomitant and contemporaneous with Dermacentor reticulatus (Fabricius). These two species, as well as I. ricinus, occurred up to an altitude of 900–1000 m a.s.l. Haemaphysalis inermis (Birula) and Haemaphysalis concinna (Koch) were not confined to any parts of the country, unlike Haemaphysalis punctata (Canestrini & Fanzago) which was found in only one region. The local prevalence of the latter species was also significantly lower than those of the former two in the same habitat (fringes of meadows, paths in forests). Dermacentor spp. and H. inermis were represented only by adults. In most species females were collected more frequently than males, except in H. concinna and H. punctata. Temporal differences between the peak activity of I. ricinus and Dermacentor spp. on dry pastures appeared to equalize on meadows in mountain forests, and a similar phenomenon was observed for the three Haemaphysalis spp. when collected along forest paths with fresh, green vegetation.     

Resistance and cross-resistance in guinea-pigs and rabbits to immature stages of ixodid ticks

Infestation of guinea-pigs and rabbits with larvae of any one of five species of ticks, Rhipicephalus appendiculatus Neumann, Rhipicephalus evertsi evertsi Neumann, Amblyomma hebrauem Koch, Amblyomma variegatum Fabricius and Ixodes ricinus L., conferred resistance in the animals when exposed to subsequent infestations with the same tick species. Resistance to infestations by other tick species was not observed.     

Mapping and monitoring tick (Acari,Ixodida) distribution,seasonality, and host associations in the United Kingdom between 2017 and 2020

Tick-borne disease risk is intrinsically linked to the distribution of tick vector species. To assess risk and anticipate disease emergence, an understanding of tick distribution, host associations, and seasonality is needed. This can be achieved, to some extent, using passive surveillance supported by engagement with the public, animal health, and public health experts. The Tick Surveillance Scheme (TSS) collects data and maps tick distribution across the United Kingdom (UK). Between 2017 and 2020, 3720 tick records were received and 39 tick species were detected. Most records were acquired in the UK, with a subset associated with recent overseas travel. The dominant UK acquired species was Ixodes ricinus (Ixodida: Ixodidae, Linnaeus), the main vector of Lyme borreliosis. Records peaked during May and June, highlighting a key risk period for tick bites. Other key UK species were detected, including Dermacentor reticulatus (Ixodida: Ixodidae, Fabricius) and Haemaphysalis punctata (Ixodida: Ixodidae, Canestrini & Fanzago) as well as several rarer species that may present novel tick-borne disease risk to humans and other animals. Updated tick distribution maps highlight areas in the UK where tick exposure has occurred. There is evidence of increasing human tick exposure over time, including during the COVID-19 pandemic, but seasonal patterns remain unchanged.