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.

Description and characterization of questing hard tick, Dermacentor steini (Acari: Ixodidae) in Malaysia based on phenotypic and genotypic traits

Identifying certain species of Dermacentor ticks in Malaysia is challenging as there is no comprehensive work on their systematics and lack of specific taxonomic keys. In this study, we described and characterized D. steini ticks collected from a forest reserve in the vicinity of the Forest Research Institute of Malaysia using integrated phenotypic and genotypic traits. In total two males and three females of questing D. steini ticks were morphologically identified using specific illustrated taxonomic keys based on their special characters. Further confirmation and characterization of the tick species were then examined using PCR, followed by sequencing partial mitochondrial 16S rDNA gene (mt-rrs). Clustering analysis based on mt-rrs was carried out by constructing neighbor-joining tree topology to clarify the genetic variation of local D. steini. Based on external morphological characterizations, all ticks were successfully identified down to the species as adult D. steini. The molecular traits based on phylogenetic tree provide very strong support for the monophyletic clade of D. steini including high percentages of similarity (97-100%) with available sequences in GenBank. Furthermore, a low intraspecific variation (4%) among the species of D. steini was observed but it was genetically different from other Dermacentor species with high interspecific value (8-15%). These findings produced the first genotypic data of D. steini using 16S rDNA gene which confirmed the presence of this species in Malaysia. Moreover, this study supports the taxonomic status of local D. steini and adds to the knowledge of accurate identification of ticks.

Ticks (Acari: Ixodidae) infesting dogs in Nigeria: epidemiological and public health implications

Ticks are haematophagous arthropods that exert direct and indirect effects on their hosts. Their global importance as reservoirs and vectors of diseases of veterinary and public health importance is well recognized. However, the level of understanding of their role in disease epidemiology varies from one country to the other based on available data. Information on ticks infesting dogs across Nigeria and the public health significance is scarce. Therefore, this study aimed to provide information on ixodid ticks infesting dogs in Nigeria. Ticks were collected from 608 owned dogs presented to veterinary clinics and hospitals in 10 out of 36 states of Nigeria over a 14-month period and identified using taxonomic descriptions and morphological keys. In all, 1196 ticks belonging to three genera were identified. Rhipicephalus (including the subgenus Boophilus) ticks were collected from dogs from all the states surveyed and accounted for 95.2% of the ticks collected, followed by Haemaphysalis (3.7%) and Amblyomma species (1.2%). The brown dog tick, Rhipicephalus sanguineus sensu lato was the only tick identified in all the climatic zones of Nigeria. There is a statistically significant association between tick infection rate and rainy season, female animals, local and cross breed against exotic animals, total lack of control practice by dog owners, frequency of the control and with traditional methods of tick control but not the age of the dogs. The epidemiological and public health implications of these findings were discussed.

Morphological and molecular identification of Rhipicephalus (Boophilus) microplus in Nigeria, West Africa: a threat to livestock health

The cattle tick Rhipicephalus (Boophilus) microplus was first reported in West Africa in Ivory Coast, in 2007. Since then it has made an aggressive eastward advancement having been reported in four other West African countries: Mali, Burkina Faso, Togo and Benin. We herein report the first molecular identification of this tick species in Nigeria, West Africa, and highlight the threat it poses to livestock health. A nation-wide tick survey was conducted in 12 out of 36 states across the various agro ecological zones of Nigeria over a 1 year period (April 2014-March 2015). In total 1498 ticks belonging to three genera collected from cattle were morphologically identified. Overall, Amblyomma species constituted the highest percentage of sampled ticks, 50.2% (752/1498), followed by Rhipicephalus (including the subgenus Boophilus) species, 29.4% (440/1498) and Hyalomma species, 20.4% (306/1498). The presence of Rh. (B.) microplus was identified morphologically from four out of the 12 states. This finding was confirmed for the first time in Nigeria using a molecular method targeting the ITS-2 region of the ticks in three of the 12 states. This study ascertained the presence of Rh. (B.) microplus in Nigeria in addition to a broad variety of cattle tick species, most of which are of veterinary importance. The implication of this finding is that there may be additional economic burden to livestock farmers due to increased cost of tick control occasioned by the acaricide resistance by this tick species widely reported from different climes. Additionally, there may be a potential upsurge in incidence of hemoparasitic infections in cattle leading to increased morbidity, cost of treatment and mortalities.

Lifecycle of Rhipicephalus haemaphysaloides under laboratory conditions

Rhipicephalus haemaphysaloides Supino, 1897 (Ixodida: Ixodidae) is a three-host hard tick widely distributed in Sri Lanka. The lifecycle of the R. haemaphysaloides population in Sri Lanka was studied under laboratory conditions using fully engorged females collected from dogs. Larvae, nymphs and adults were reared on New Zealand rabbits. Engorged females weighed a mean ± standard deviation (SD) of 470.1 ± 106.5 mg and laid a mean ± SD of 4067.4 ± 3136.2 eggs within 16.1 ± 3.7 days. The mean ± SD preoviposition period was 6.5 ± 1.1 days. The mean ± SD reproductive efficiency index was 8.5 ± 4.1, and was higher in heavier females (Pearson correlation, r = 0.8; P = 0.001). The incubation period of eggs was shorter at higher temperatures. The majority (86.9%) of larvae successfully moulted after a mean ± SD premoulting period of 7.9 ± 0.7 days following a parasitic period of 3.2 ± 0.5 days. Unfed larvae survived a mean ± SD of 103.4 ± 19.8 days. Nymphs completed the bloodmeal after 3.7 ± 0.9 days, weighed 5.7 ± 1.7 mg and demonstrated a premoulting period of 15.1 ± 1.9 days. Unfed nymphs survived a mean ± SD of 45.8 ± 3.8 days. Heavier nymphs moulted into females, whereas lighter nymphs moulted into males (two-sample t-test, P < 0.001). The bodyweight of adult females increased more than 100-fold after feeding. The lifecycle of R. haemaphysaloides was successfully completed on rabbits within a mean of 91.3 days (range: 69-117 days) under laboratory conditions.

Redescription of Amblyomma integrum adults and immature stages

Amblyomma integrum Karsch, 1879 (Acari: Ixodidae) is one of four Amblyomma Koch, 1844 species with eyes found in southern India and Sri Lanka. The immature stages of this species were poorly described. Therefore, accurate identification is difficult. Here we re-describe the male, female, nymph and larva of A. integrum and illustrate all the stages in greater detail for the first time. A set of diagnostic morphological characters is defined to distinguish this species from other sympatric species of eyed Amblyomma in any parasitic stage of development. Adults of A. integrum parasitize mostly various larger mammals whereas nymphs and larvae use mostly larger and medium mammals. Amblyomma integrum is recorded from India (Andhra Pradesh, Goa, Karnataka, Orissa and Tamil Nadu States) and throughout Sri Lanka.

Diversity and distribution of tick species (Acari: Ixodidae) associated with human otoacariasis and socio-ecological risk factors of tick infestations in Sri Lanka

Tick infestation in humans is a major public health concern. The diversity and distribution of tick species associated with human otoacariasis was studied in five districts: Anuradhapura, Kandy, Kurunegala, Nuwara Eliya and Ratnapura in the main agro-climatic zones of Sri Lanka. Ticks from patients attending the ear, nose and throat clinics of the General Hospitals were collected during a 3 year period. In total 426 ticks were collected. Most human otoacariasis cases were reported from Kandy (33.8 %) and the fewest from Nuwara Eliya (8.2 %). Of the five tick species identified, nymphs of Dermacentor auratus constituted 90.6 % of the collection. Rhipicephalus sanguineus, Hyalomma isaaci, Haemaphysalis bispinosa and Otobius megnini were found rarely infesting humans possibly as an accidental host; H. bispinosa and O. megnini in the human ear canal were first time records in Sri Lanka. Females and children under 10 years were identified as risk groups of human otoacariasis. Subsequently, a field study was carried out to determine socio-ecological risk factors of human tick infestations in the five districts. Based on hospital data, eight villages with high prevalence of otoacariasis were selected from each district. A total 40 villages were visited and 1674 household members were interviewed. Involvement in outdoor activities, presence of wild animals around the house, location of the house in close proximity to a forest and occupation were identified as major risk factors.

Life cycle of Amblyomma integrum (Acari: Ixodidae) under laboratory conditions

Amblyomma integrum is a hard tick infesting mainly buffalo and cattle and has been identified as an agent of human otoacariasis in Sri Lanka. Data on the life cycle pattern of A. integrum were collected by experimental infestation on New Zealand white rabbits under laboratory conditions. Wild-caught females laid 55-7389 eggs for 2-35 days after spending a latent period of 10-25 days. Egg incubation period was 31-105 days and the newly emerged larvae started feeding after 4-11 days. Larvae dropped off after feeding and they moulted into nymphs after 10-16 days. Nymphs actively fed on rabbits for 4-8 days and dropped off. Engorged nymphs took 11-25 days for moulting before emerging as adults. The male:female sex ratio of the adults moulted under laboratory conditions was 11:9. All the stages showed periodicity in engorgement and dropping off. The three-host life cycle was completed within 74-245 days with an average of 152.9 days. The mean Reproductive Efficiency Index (REI) and Reproductive Aptitude Index (RAI) were 3.6 and 1.1, respectively. Females hatched in the laboratory did not successfully feed on New Zealand white rabbits. The wild-caught females which fed on buffaloes had prolonged pre-oviposition and oviposition periods, low REI, low RAI and low eclosion under controlled laboratory conditions compared to other tick species. Although larva and nymphs of A. integrum successfully fed on New Zealand white rabbits under laboratory conditions, full life cycle was not completed because the adult females did not feed on rabbits.

Life cycle of Nosomma monstrosum (Acari: Ixodidae) under laboratory conditions

Nosomma monstrosum (Nuttall & Warburton) is a hard tick infesting mainly buffalo and cattle in Sri Lanka. Biological data on the life cycle pattern of N. monstrosum were collected using experimental infestation on New Zealand white rabbits under laboratory conditions. The three-host life cycle was completed within 64-102 days. Eggs hatched after 20-29 days of incubation and the larvae hatched out started feeding which lasted for 2-4 days. After a moulting period of 8-11 days nymphs emerge and they actively fed for 2-4 days. Subsequently the nymphs took 15-18 days for moulting before emerging as adults. Freshly moulted females fed for 7-8 days and remained latent for 4-5 days before starting the oviposition. Females laid 3864-12,520 eggs for 11-17 days. The male: female sex ratio was 8:3 in the adults which were moulted under laboratory conditions. Strong positive correlations were found in female weight with number of eggs laid and REI. Females raised from the first generation of eggs had higher oviposition periods, higher REI, laid ten times more eggs, and lower pre-oviposition periods compared to those collected from the wild. When a suitable host is given, N. monstrosum could successfully complete its three-host life cycle under laboratory conditions.

Ectoparasite fauna of rodents collected from two wildlife research centres in Saudi Arabia with discussion on the implications for disease transmission

The majority of human pathogens are zoonotic and rodents play an important role as reservoirs of many of these infectious agents. In the case of vector-borne pathogens, rodent reservoirs not only act as a source of infection for vectors but also serve as hosts for the vectors themselves, supporting their populations. Current data on rodent-ectoparasite relationships is limited in Saudi Arabia, however, this is needed to assess disease risk and the relative importance of different hosts for the maintenance of vector-borne pathogen cycles. In order to provide baseline data for the region that could be used to assess zoonotic disease risk, we collected and identified 771 ectoparasite specimens (ticks, fleas and mites) from 161 rodents at two wildlife research centres in Saudi Arabia and discuss our results in the context of possible zoonotic disease risk based on the hosts and vectors present.

Molecular detection of Rickettsia aeschlimannii in Hyalomma spp. ticks from camels (Camelus dromedarius) in Nigeria, West Africa

Several species of the spotted fever group rickettsiae have been identified as emerging pathogens throughout the world, including in Africa. In this study, 197 Hyalomma ticks (Ixodida: Ixodidae) collected from 51 camels (Camelus dromedarius) in Kano, northern Nigeria, were screened by amplification and sequencing of the citrate synthase (gltA), outer membrane protein A (ompA) and 17-kDa antigen gene fragments. Rickettsia sp. gltA fragments were detected in 43.3% (42/97) of the tick pools tested. Rickettsial ompA gene fragments (189 bp and 630 bp) were detected in 64.3% (n = 27) and 23.8% (n = 10) of the gltA-positive tick pools by real-time and conventional polymerase chain reaction (PCR), respectively. The amplicons were 99-100% identical to Rickettsia aeschlimannii TR/Orkun-H and R. aeschlimannii strain EgyRickHimp-El-Arish in GenBank. Furthermore, 17-kDa antigen gene fragments of 214 bp and 265 bp were detected in 59.5% (n = 25) and 38.1% (n = 16), respectively, of tick pools, and sequences were identical to one another and 99-100% identical to those of the R. aeschlimannii strain Ibadan A1 in GenBank. None of the Hyalomma impressum ticks collected were positive for Rickettsia sp. DNA. Rickettsia sp. gltA fragments (133 bp) were detected in 18.8% of camel blood samples, but all samples were negative for the other genes targeted. This is the first report to describe the molecular detection of R. aeschlimannii in Hyalomma spp. ticks from camels in Nigeria.

Arthropod symbiotes of Laonastes aenigmamus (Rodentia:Diatomyidae)

Arthropod symbiotes of the Laotian rock-rat, Laonastes aenigmamus (Rodentia:Diatomyidae), from Laos are examined. This host is a member of Diatomyidae previously thought to have gone extinct >10 million yr ago. Permanent symbiotes are represented by 2 species, a new species of sucking louse, Polyplax sp., near rhizomydis (Phthiraptera:Polyplacidae), and a new species of fur mite, Afrolistrophorus sp., near maculatus (Acariformes:Listrophoridae). The temporary parasites are represented by 18 species, i.e., 1 mesostigmatan species, i.e., a new species of Androlaelaps near casalis (Parasitiformes:Laelapidae); immature stages of 2 tick species, Ixodes granulatus and Haemaphysalis sp. (Parasitiformes:Ixodidae); and a rich fauna of chiggers (Acariformes:Trombiculidae) comprising 8 genera and 15 species. It is hypothesized that this host completely lost its initial fauna of ectosymbiotes and that ancestors of the recorded symbiotes switched to this host from rodents of the superfamily Muroidea.

[Larval identification of species and subspecies of the genus Hyalomma (Acari: Ixodidae) from Russia and neighbouring territories]

The following species and subspecies of Hyalomma Koch, 1844 are recorded from Russia and neighbouring territories, including those involved in natural foci of tick-borne diseases: H. (Hyalomma) aegyptium (Linnaeus, 1758), H. (Euhyalomma) dromedarii Koch, 1844, H. (Euh.) asiaticum asiaticum Schulze et Schlottke, 1930, H. (Euh.) asiaticum caucasicum Pomerantzev, 1940, H. (Euh.) asiaticum kozlovi Olenev, 1931, H. (Euh.) anatolicum Koch, 1844, H. (Euh.) excavatum Koch, 1844, H. scupense Schulze, 1918, H. (Euh.) marginatum marginatum Koch, 1844, H. (Euh.) marginatum turanicum Pomerantzev, 1946, and H. (Euh.) marginatum rufipes Koch, 1844. The geographic distribution and host-parasite relationships of each taxon are discussed. Species characters of the larval stage, that can be distinguished using light microscopy, are found to be very few. These characters include shape of scutum, shape and rate of hypostome denticulation, shape and rate of the development of spurs on coxae I to III. Measurements of some morphological structure and their rations show statistically significant differences between some closely related species, even if qualitative discriminating characters are unknown. Only measurements and their ratios can be used for the discrimination of larval H. anatolicum from larval H. excavatum, because qualitative discriminating features have not been found for these species. The complex structure of the subspecific morhological differentiation of all parasitic stages in the polymorphic species H. asiaticum and H. marginatum is revealed. This structure probably reflects some peculiarities of the microevolutionary processes. Identification key for the larval stage of seven Hyalomma species is provided.

The genus Hyalomma Koch, 1844. i. reinstatement of Hyalomma (euhyalomma) glabrum Delpy, 1949 (Acari, Ixodidae) as a valid species with a redescription of the adults, the first description of its immature stages and notes on its biology

For nearly 50 years the ixodid tick Hyalomma marginatum turanicum, reputedly introduced into South Africa on imported Persian sheep, has been considered identical to the Asian Hyalomma (Euhyalomma) marginatum turanicum Pomerantzev, 1946. Comparisons of this tick with the Asian H. (E.) m. turanicum and other subspecies of Hyalomma (Euhyalomma) marginatum, however, reveal that it is an old taxon, namely Hyalomma rufipes glabrum Delpy, 1949. It is hereby reinstated as Hyalomma (Euhyalomma) glabrum, and its adults are redescribed and its immature stages described for the first time. The preferred hosts of its adults are large herbivores such as zebras, gemsbok and eland, on which it occurs during summer. The preferred hosts of its immature stages are scrub hares and ground-frequenting birds, on which it is present during autumn and winter. Data on its distribution and possible disease relationships are also provided.

[Host-parasite relationships of the genus Hyalomma Koch, 1844 (Acari, Ixodidae) and their connection with microevolutionary process]

Host-parasite relationships of Hyalomma species of the world fauna are analyzed. The majority of species infests predominately various mammals. Birds and reptiles are used as preferred hosts by several Hyalomma species, and only on certain stage: adults of H. aegyptium parasitize tortoises; immature stages of H. marginatum parasitize birds. It is hypothesized that relationships of H. aegyptium adults (subgenus Hyalomma s. str.) with reptiles are secondarily in origin. Immature stages of H. aegyptium retain the primary wide diapason of hosts, which are various small mammals, birds and reptiles. The life cycle of this species is the three-host type that is considered as a primary type in ixodid ticks. A typical scheme of relationships with their hosts in all well-examined Hyalommina species has following features: the adult stage parasitize large and medium sized mammals, immature stages parasitize small mammals, three-host life cycle. A variety of preferred hosts and types of life cycle is observed in the subgenus Euhyalomma. All species of this subgenus can be arranged into two groups. In the first group, the immature stages infest only small mammals and birds, and the adults parasitize large mammals; this type of host preferences is probably primary host-parasite relationships of Hyalomma. This group includes: H. albiparmatum, H. asiaticum, H. excavatum, H. franchinii, H. impeltatum, H. impressum, H. lusitanicum, H. marginatum, H. nitidum, H. schulzei, and H. truncatum. Hyalomma marginatum and H. schulzei are two-host species; H. excavatum is two- or three-host tick. All the remaining species (except H. albiparmatum, which life cycle is unknown) are three-host ticks. In the second group, the immature stages as well as the adult stage parasitize large mammals. This group includes: H. dromedarii, H. anatolicum, and H. scupense. These species are two- or one-host ticks.

[Discrimination of subspecies in a polymorphic species Hyalomma marginatum (Acari, Ixodidae) based on adult stage]

Morphological characteristics allowing discriminating adult stages of four subspecies of Hyalomma marginatum (H. m. marginatum, H. m. turanicum, H. m. rufipes and H. m. isaaci) are displayed. The subspecies status of all named forms is confirmed. The main discriminating characters for adults of these subspecies are peculiarities of scutal or conscutal punctations and a shape of the dorsal tale of spiracular plates (Fig. 1, 1-4; 2, 4-7; 4, 1, 2; 5, 1, 2, 6, 5-8). Nevertheless, there are a number of facts, which support only the subspecific rank of these taxa. In Turkmenistan, there is a zone inhabited by forms, adult stages of which are morphologically intermedial between H. m. marginatum and H. m. turanicum. A zone of intermedial forms between H. m. turanicum and H. m. rufipes exists in Arabian Peninsula (Hoogstraal e. a., 1981). An absence of clear discriminative characters between immatures of H. m. marginatum, H. m. turanicum and H. m. rufipes also confirms the subspecies level of these taxa. H. m. isaaci is the most differentiated subspecies. It is difficult to estimate relationships between the latter subspecies and H. m. turanicum because of a deficit of materials. However, clear morphological differences of H. m. isaaci immature stages from other subspecies were noticed (Apanaskevich, 2003). Therefore, it is quite probable that H. m. isaaci might deserve the species rank. Further analysis of relationships between subspecies of H. marginatum needs additional materials represented by all stages from zones containing intermedial forms between recently recognized subspecies.

[Differentiation of subspecies of the polymorphic species Hyalomma marginatum (Acari: Ixodidae) based on immature stages]

Study of morphological characters to identify the subspecies of Hyalomma marginatum immature stages is based on material collected throughout all the geographical range of the species. As it was found, the discrimination of subspecies of H. marginatum immature stages needs a complex use of structural and morphometrical characters. Only H. m. marginatum larvae and H. m. isaaci nymphs may be easily differentiated from other subspecies based on the structural (qualitative) characters. Besides, morphometric (quantitative) characters should be used only in combinations for identification of the subspecies. In regard to structural characters of larvae, it was found that the shape and size of coxal spurs of H. marginatum allow differentiating this subspecies from the others (Fig. 3, 5, 6). Based on morphometrical characters of larvae, the following characteristic features of subspecies have been found: in H. m. marginatum, the capitulum is wide, the palpi, hypostome and genua I are short and narrow; in H. m. turanicum, the capitulum is narrow, the palpi are short and narrow, the hypostome is short and wide, the genua I are long and narrow; in H. m. rufipes, the scutum is large, the capitulum is wide, the palpi are long and narrow, the hypostome and genua I are long and wide; in H. m. isaaci, the scutum is small, the capitulum is narrow, the palpi and hypostome are long and narrow, the genua I are short and narrow. Among structural characters of nymph, several discriminative features of subspecies have been found. The shape of the scutum in H. m. isaaci (Fig. 2, 2) clearly differentiates this subspecies from the others (Fig. 2, 1). In H. m. marginatum, the setae of alloscutum as a rule have bluntly rounded apices (Fig. 1, 2), while in the other subspecies these setae are more tapering apically (Fig. 1, 1). The shape of spiracular plates is rather variable within the species, but in H. m. marginatum and H. m. isaaci (Fig. 1, 3) the plates are larger and more perforated than in H. m. rufipes and H. m. turanicum (Fig. 1, 4). In H. m. isaaci, the spurs of coxae I are narrower than in other subspecies (Fig. 1, 8). Based on morphometrical characters of nymphs, the following discriminative features of subspecies have been found: in H. m. marginatum, the capitulum is wide, the palpi are short and wide; in H. m. turanicum, the capitulum is narrow, the palpi are long and narrow; in H. m. rufipes, the scutum is wide, the capitulum is narrow, the palpi are long and narrow, the hypostome is long; in H. m. isaaci, the scutum is long and narrow, the capitulum is wide, the palpi are short and wide, the hypostome is short.

[Differentiation of closely related species Hyalomma anatolicum and H. excavatum (Acari: Ixodidae) based on a study of all life cycle stages, throughout entire geographical range]

Species status is stated for Hyalomma anatolicum and H. excavatum, based on numerous material from the territory of their distribution. The differentiation of species is recovered for all stages of the life cycle. Diagnosis of Hyalomma anatolicum. Female: small tick--length of scutum commonly less than 2 mm; width of scutum commonly less than 1.9 mm; color of scutum, gnathosoma and coxae light, yellowish- or reddish-brown; whitish enameled pigment on scutum absent; posterolateral ledges of scutum weakly expressed or absent; cervical and lateral grooves more shallow (than in H. excavatum) (fig. 1); setae of scutum, alloscutum, sternal setae and ventromedian setae of second article of palpae more tapering to the apex, narrow rounded or acute (fig. 2, 1, 2, 5, 8). Male: small tick--length of conscutum, as a rule, less than 4 mm; width of scutum, as a rule, less than 2.3 mm; shape of conscutum marrow oval (fig. 3), widest in the midlevel; color of conscutum, anal shields, gnathosoma and coxae light, yellowish- or reddish-brown; whitish enameled pigment on conscutum absent; caudal depression with less dense and more large punctuations (than in H. excavatum); ridges lateral to caudal field less high and sharp (than in H. excavatum); posteromedian groove separated from parma by contiguous punctuations or smooth non high area; setae of conscutum conus-like, more sharpening (fig. 4, 1-3); posterior dorsal margin of gnathosoma straight or slightly concave (fig. 4, 8); segments of leg IV not swallowed. Nymph: large tick (see description). Scutum more narrow. Dorsal tale of spiracular plates clear expressed, marginal perforations distant from margin of spiracular plates at the base of tale (fig. 5, 3); anterolateral side of basis capituli approximately equal to half of gnathosoma width; ventrally lateral projections of gnathosoma situated in posterior half of capitulum base (fig. 5, 4, 5). Hypostome more longer and narrow (fig. 5, 5). Larva: large tick (see description). Diagnosis of Hyalomma excavatum. Female: large tick--length of scutum commonly more than 2 mm; width of scutum commonly more than 1.9 mm; color of scutum, gnathosoma and coxae dark, reddish- or black-brown; whitish enameled pigment commonly present; posterolateral ledges of scutum clearly expressed; cervical and lateral grooves more dipper (than in H. anatolicum) (fig. 7). Setae of scutum, alloscutum, sternal setae and ventromedian setae of second article of palpae more stick-like, more widely obtuse (fig. 8, 1-5). Male: large tick--length of conscutum more than 4 mm; width of scutum more than 2.3 mm; shape of conscutum wide oval (fig. 9), widest in posterior half of length; color of conscutum, anal shields, gnathosoma and coxae dark, reddish- or black-brown; whitish enameled pigment often present; caudal depression with more dense and more small punctuations (than in H. anatolicum); ridges lateral to caudal field more high and sharp (than in H. anatolicum); posteromedian groove separated from parma by strong elevations fused with paraparmal festoons; setae of conscutum more obtuse, often stick-like (fig. 10, 1, 2); posterior dorsal margin of gnathosoma straight or lightly concave. (fig. 10, 3); segments of leg IV swallowed. Nymph: small tick (see description). Scutum more wide. Dorsal tale of spiracular plates weakly expressed, marginal perforations not distant from margin of spiracular plates at the base of tale (fig. 11, 3); anterolateral side of basis capituli clearly shorter than half of gnathosoma width; ventrally lateral projections situated in the middle of or anterior half of capitulum base (fig. 11, 4, 5). Hypostome more shorter and wider (fig. 5, 5). Larva: small tick (see description). Established taxonomical independence of H. anatolicum and H. excavatum is confirmed by several criteria: external morphology (see diagnoses); morphometrical data (see diagnoses and fig. 12, 13); size inversion: larva and nymph of H. anatolicum are large, but females and males are small; while H. excavatum vise versa--larva and nymph are small, but adults--large; host specialization of immature stages: larvae and nymphs of H. anatolicum, as rule, parasitize larger mammals (cattle, camels), while immature stages of H. excavatum parasitize smaller mammals (rodents, hares); presence of sympatry areas: almost entire area of H. excavatum include in area of H. anatolicum and cattle help to mix its populations.

[Towards a diagnostic view of Hyalomma (Hyalomma) aegyptium (Acari, Ixodidae)]

The diagnostic characters of larval, nymphal and adult Hyalomma aegyptium (L., 1758) based on specimens from the territory of most part of the area are given. In the diagnoses of immature stages, was used the characters, which were formerly tested by the author for diagnostics of other Hyalomma species occurring in the former USSR. Commonly used characters and those which were revealed by the author as useful for the majority of Euhyalomma Filippova, 1984 and Hyalommina Schulze, 1919 species, have been used in the diagnoses of male and female. Differential diagnosis of Hyalomma aegyptium. Female: genital orifice as wide arch with straight posterior margin (fig. 2, 5); vestibular part of vagina funnel-like, greatly swollen (fig. 2, 5); setae of alloscutum stick-like, tapering in apical one (figs 2, 3, 4); second segment of palps with proximal narrowing (figs 3, 1, 2); spurs of coxae I widely separated, triangular, wide, subequal in size (fig. 3, 5). Male: any grooves of conscutum absent, except short and pit-like cervical ones (fig. 4); punctation sparce and impressive (fig. 4); adenal shields short and wide, without inner branch, posterior part widened, anteromedian margin straight (fig. 5, 4); spurs of coxae I widely separated, triangular, wide, subequal in size (fig. 6, 5). Nymph: posteromedian setae of alloscutum stick-like and, as a rule, with indented apices (fig. 7, 2); spurs of coxae I large, median spur as equilateral triangle and shorter than lateral one (fig. 7, 8); spurs of coxae II-IV well developed, with acute apices (fig. 7, 8). Larva: posterior part of scutum (behind the eyes) heavy elongated, its apex straight, postero-lateral incisions weakly developed (fig. 8, 1); spurs of coxae I as equilateral triangle in shape and with rounded apices, spurs of coxae II-III very large (fig. 8, 5).

[Identification of species of Hyalomma asiaticum group (Ixodidae) in areas of their sympatry based on immature stages]

Morphological characters of immature stages of three closely related tick species, Hyalomma asiaticum Schulze et Schlottke, 1929, H. dromedarii Koch, 1844 and H. schulzei Olenev, 1931, collected mainly in areas of their sympatry (Fig. 1) were investigated. The larvae and nymphs of these three species were collected in Egypt, Iran, Turkmenistan, Uzbekistan, Afghanistan and Tadjikistan: 159 larvae and 137 nymphs of H. asiaticum from 12 localities; 78 larvae and 167 nymphs of H. dromedarii from 5 localities; 30 larvae and 6 nymphs of H. schulzei from one locality. Both qualitative morphological features and measured character (in mkm) were used to discriminate these species. Main discriminant characters for larvae. H. asiaticum (Fig. 3). Scutum: length < 246, width < 389; base of capitulum: width < 158, dorsally hexagonal, apices of lateral projections directed forward; palpae (II and III segments): length < 106, width < 42; hypostome: length < 87, width < 25; the spur of coxa I small, equilateral triangular; patella: length < 154. H. dromedarii (Fig. 4). Scutum: length > 236, width > 379; base of capitulum: width > 158, dorsally almost triangular, apices of lateral projections directed laterally or backward; palpae: length > 110, width < 46; hypostome: length > 87, width < 26; the spur of coxa I large, isosceles triangular; patella: length > 115. H. schulzei (Fig. 5). Scutum: length > 249, width > 407; base of capitulum: width > 162, dorsally hexagonal, apices of lateral projections directed forward; palpae: length > 114, width > 44; hypostome: length > 89, width > 28; the spur of coxa I large, isosceles triangular; patella: length > 164. Main discriminant characters for nymphs: H. asiaticum (Fig. 3). Scutum: small, width < 650, length and width subequal, posterior margin widely rounded, lateral incisions weakly developed; spiracular plates with distinct, pointed dorsal projection, marginal row of perforations distant from the base of dorsal projection, submarginal row with a gap; base of capitulum: lateral projections situated in posterior half of capitulum; palpae (II segment) short and narrow; hypostome short and narrow, width < 69; pore of coxae I-III present. H. dromedarii (Fig. 4). Scutum: large, width > 650, length shorter than width, posterior margin widely rounded, lateral incisions moderately developed; spiracular plates: with distinct and wide dorsal projection, marginal row of perforations distant from the base of dorsal projection, submarginal row present, without gap; base of capitulum: lateral projections situated in the middle part of capitulum; palpae long and narrow; hypostome long and wide, width > 69; coxal pore lacking. H. schulzei (Fig. 5). Scutum: small, width < 630, length larger than width, posterior margin narrow rounded, lateral incisions weakly developed; spiracular plates: with weakly developed dorsal projections, marginal row of perforation situated just behind the base of dorsal projection, submarginal row with a gap; base capitulum: lateral projections situated in posterior half of capitulum; palpae short and wide; hypostome long and narrow, width < 73; coxal pore lacking.