The distribution of Hyalomma spp. ticks from domestic ruminants in Iran

The distribution of Hyalomma species on domestic animals was studied in four zoogeoghraphical zones. Nine hundred and ninety-two Hyalomma ticks were collected from sheep, goats, cattle and camels. A total of seven tick species consisting of: Hyalomma anatolicum Koch, 1844 (28.93%), H. excavatum Koch, 1844 (12.5%), H. asiaticum Schulze & Schlottke, 1930 (13.5%), H. marginatum Koch, 1844 (27.01%), H. detritum Schulze, 1919 (9.67%), H. schulzei Olenev, 1931 (4.03%) and H. dromedary Koch, 1844 (4.33%) were recorded. The results indicated that H. anatolicum, H. asiaticum, H. marginatum and H. detritum were present in all zones whereas H. excavatum was absent in Zone I. The result also showed that H. dromedari was presented in Zones III and IV whereas H. schulzei was present in Zones II and III. During this study, the tick species collected are candidates for investigation as vectors of pathogenic organisms in Iran.     

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.     

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.     

Prototypes of Hyalomma scupense Schulze, 1918 and H. detritum Schulze, 1919 (Acari: Ixodidae) in connection with microevolution within the genus

Type series of two species of the genus Hyalomma Koch, 1844 deposited in the Museum of Zoology in Berlin have been examined. Examination of the H. detritum Schulze, 1919 holotype has shown that this name is actually a junior synonym (syn. nov.) of H. marginatum turanicum Pomerantsev, 1946. At the same time it was also found out that the paratypes of H. detritum are conspecific to the syntypes of H. scupense Schulze, 1818, among which the lectotype has been designated. Taxonomic errors of Schulze and other authors, which had led to a worldwide use in acorological literature the name H. detritum instead of the valid name H. scupense, are discussed. It is suggested that the reasons of microevolution within the polymorphic species H. scupense could be explained by unequal climatic conditions. Microevolutionary process in this species is most well expressed in a tendency to reduce the number of contacts with a host during the life cycle. It has resulted in the reformation of the two-host cycle into the one-host cycle.     

Experimental transmission of Crimean-Congo hemorrhagic fever virus: role of 3 vector species in the maintenance and transmission cycles in Senegal

In this article, we published the role of three species of ticks Amblyomma variegatum (Fabricius, 1974), Hyalomma marginatum rufipes (Koch, 1844) and Hyalomma truncatum (Koch, 1844) in the maintenance and transmission of the CCHF virus. The imagos of these species were infected by intracoelomic route. Vertical transmission (transtasial and transovarial) and horizontal transmission for different stases were studied by isolation on newborn mice, polymerase chain reaction, indirect immunofluorescence and ELISA. Our results proved that 15 days after inoculation, infection rates of 100% were noted with Hyalomma marginatum rufipes and Hyalomma truncatum. This rate is about 60% for Amblyomma variegatum. The imagos of the three species infected have transmitted the virus to their host during blood feeding (100%). A high transovarial transmission for Hyalomma marginatum rufipes and Hyalomma truncatum were observed (respectively 53 and 50%). This rate is about 12% for Amblyomma variegatum. The tick infection does not persist up to the first generation for the three species studied. Ticks are temporary reservoirs vectors but not permanent reservoirs of CCHF virus.     

Sense organs in post-embryonic stages of Hyalomma marginatum marginatum Koch, 1844 (Acari: Ixodida: Ixodidae). I. Tarsal sensory system.

Light and scanning electron microscopic studies showed the differences in morphology and in size of Haller's organ in larvae, nymphs and adults (females and males) of Hyalomma marginatum marginatum Koch, 1844. The length of the anterior pit setae increases during post-embryonic development. The localization of these setae is the same in all stages. Six setae (one porose seta, two grooved setae, two fine setae, one conical seta) contain anterior pit of various developmental stages. In nymphs and adults more numerous pores appear on the wall surface of porose seta than in the larval stage. The structure of the capsule roof also differs in various developmental stages. Haller's organ of Hyalomma m. marginatum shows great degree of morphological development which is connected with the complicated life cycle and feeding behaviour of this tick species.     

The hard-tick fauna of mainland Portugal (Acari: Ixodidae): an update on geographical distribution and known associations with hosts and pathogens

This work is an updated revision of the available information on Portuguese ixodid tick species. It includes data on tick biology, ecology, taxonomy and host/pathogen-associations. The current list of Portuguese ixodid ticks comprises twenty species: Dermacentor marginatus (Sulzer, 1776), Dermacentor reticulatus (Fabricius, 1794), Haemaphysalis hispanica Gil Collado, 1938, Haemaphysalis inermis Birula, 1895, Haemaphysalis punctata Canestrini & Fanzago, 1878, Hyalomma lusitanicum Koch, 1844, Hyalomma marginatum Koch, 1844, Ixodes acuminatus Neumann, 1901, Ixodes bivari Dias, 1990, Ixodes canisuga Johnston, 1849, Ixodes frontalis (Panzer, 1798), Ixodes hexagonus Leach, 1815, Ixodes ricinus (Linnaeus, 1758), Ixodes simplex Neumann, 1906, Ixodes ventalloi Gil Collado, 1936, Ixodes vespertilionis Koch, 1844, Rhipicephalus (Boophilus) annulatus (Say, 1821), Rhipicephalus bursa Canestrini & Fanzago, 1878, Rhipicephalus pusillus Gil Collado, 1938, and Rhipicephalus sanguineus (Latreille, 1806).     

The manifestation of sexual dimorphism in the preimago phases of 2 species of the genus Hyalomma (Ixodoidea, Ixodidae)

Experiments on laboratory cultures of Hyalomma asiaticum and H. anatolicum have shown that at the nymphal phase sexual dimorphism manifests itself in statistically reliable differences between general sizes and mass of the body of male and female individuals. Larger nymphs moult mostly into females, small ones mostly into males. Reliable differences have been noted in the sizes of scutum, gnathosoma and its appendages in male and female nymphs of both species. At the larval phase sexual dimorphism does not manifest itself in the sizes of individuals.     

Sense organs in post-embryonic stages of Hyalomma marginatum marginatum Koch, 1844 (Acari: Ixodida: Ixodidae). II. Palpal organ.

Light microscopy and scanning electron microscopy (SEM) studies show the differences in structure, number and topography of terminal setae in the palpal organ in different stages of Hyalomma marginatum marginatum Koch, 1844. The palpal organ contains eight terminal setae in larvae and nymphs, and ten setae in adults. The length of these setae increases in the course of post-embryonic development. Other setae on palpal segments also undergo quantitative and morphological changes.     

Distribution and ecology of ticks (Acari: Ixodidae) infesting livestock in Tunisia: an overview of eighth years field collections

Ticks (Ixodidae) play a significant role as vectors of pathogens of domestic animals in Tunisia. The major losses caused by ticks are related to transmission of protozoan parasites. These include agents of tropical theileriosis and babesiosis in ruminants. Since 1991, we conducted research studies on tick population of livestock in Tunisia. This overview reports a synthesis on tick distribution, their biology and their role as vectors of pathogens in domestic animals, particularly cattle. During the whole period of the study about 15,000 tick specimens were collected from different zones of the country. A total of 14 species were identified. Hyalomma detritum detritum was the most abundant and important (vector of Theileria annulata) species infesting cattle. Hyalomma dromedarii and Hyalomma impeltatum were collected on domestic ruminants in the arid and desertic zones. Hyalomma marginatum marginatum and Hyalomma anatolicum excavatum were widespread and found on livestock hosts. Ixodes ricinus, vector of Babesia divergens and Borrelia burgdorferi sl, colonises mainly the humid zone. Boophilus annulatus and Rhipicephalus bursa infesting cattle, sheep and goats were found in the sub-humid and semi-arid zones. Haemaphysalis sulcata and Hae. punctata were collected in humid and sub-humid zones on cattle and sheep. Rhipicephalus turanicus were collected in different regions, on different animal species. Rhipicephalus sanguineus, tick of dogs, were often collected on livestock. Only few specimens of Hyalomma marginatum rufipes and Hyalomma franchinii were collected.     

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.     

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.     

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.     

Hyalomma (Hyalommina) arabica: nymphal and larval identity and spiny mouse hosts in Saudi Arabia (Acarina: Ixodoidea: Ixodidae)

Nymphal and larval Hyalomma (Hyalommina) arabica Pegram, Hoogstraal, and Wassef, 1982, described herein, closely resemble those of Hyalomma (Hyalommina) rhipicephaloides Neumann, differing chiefly in body size (both stages), nymphal basis capituli and scutal proportional dimensions, and distinctness of larval coxal spurs. Females of these species are also structurally similar but males differ in major critical characters. Nymphs and larvae of both species parasitize the spiny mouse (Acomys spp.), but immatures of the third African- Arabian species of this subgenus, Hyalomma (Hyalommina) punt Hoogstraal, Kaiser, and Pedersen, are unknown. Hyalomma (Hyalommina) arabica occurs in valleys and hills of western Saudi Arabia and western Yemen; H. (H.) rhipicephaloides in the Red Sea and Dead Sea areas; and H. (H.) punt in northeastern Somalia and eastern Ethiopia. The ibex (Capra ibex nubiana Cuvier) is probably the original host of adult H. (H.) arabica and H. (H.) rhipicephaloides; the related domestic goat is an important host of adults of the 3 species, which also parasitize domestic sheep. Gazelles are recorded hosts of adults of H. (H.) rhipicephaloides and H. (H.) punt and the latter is also recorded from goats, sheep, camels and cattle.     

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.     

Transstadial transmission of Theileria annulata through common ixodid ticks infesting Indian cattle.

Transstadial transmission of Theileria annulata with Hyalomma anatolicum anatolicum, H. dromedarii and H. marginatum isaaci, and Haemaphysalis bispinosa, Rhipicephalus haemaphysaloides haemaphysaloides and Boophilus microplus was determined. It was found that the infection was successfully transmitted by H. a. anatolicum from larva to nymph and nymph to adult in all attempts. When larvae were fed on an infected calf the succeeding adults transmitted the infection when the intervening nymphs fed on a rabbit (non-susceptible host) but not when fed on a calf (susceptible host). Infective adult ticks transmitted the parasite during the first 24 h of feeding on a calf. When the feeding was interrupted after 24 h, and the tick transferred to another calf, the infection was transmitted to the latter as well. H. dromedarii successfully transmitted the infection from larva to nymph and from nymph to adult. Larvae of H. marginatum isaaci did not feed on calves but the infection was successfully transmitted from nymph to adult. Haemaphysalis bispinosa, Rhipicephalus h. haemaphysaloides and Boophilus microplus did not transmit Th. annulata from larva to nymph to adult.     

Experimental infection of ixodid ticks with Karshi virus

The ixodid ticks Hyalomma asiaticum, H. anatolicum, Dermacentor niveus were infected experimentally with Karsha virus. The virus replication has been proved to occur in the tick's organism. The titre of the virus grows gradually in infected ticks. Entering the tick's gut during its feeding virus particles penetrate into the gut walls where primary multiplication and accumulation of the virus take place.     

Tick-borne bacteria in mouflons and their ectoparasites in Cyprus

The Cypriot mouflon (Ovis orientalis ophion), a once almost extirpated species of wild sheep, is under strict surveillance because it can be threatened by likely transmission of pathogenic bacteria, such as Anaplasma spp., Rickettsia spp., and Coxiella burnetii, primarily from domestic ungulates. We collected 77 blood samples from Cypriot mouflons and 663 of their ectoparasites (Rhipicephalus turanicus, Rhipicephalus sanguineus, Rhipicephalus bursa, Hyalomma anatolicum excavatum, Hyalomma marginatum, Haemaphysalis punctata, Haemaphysalis sulcata, and Ixodes gibossus) and tested them by polymerase chain reaction and sequencing. Twenty-three mouflon blood samples (30%) were positive for C. burnetii, 23 (30%) for Rickettsia spp., and 8 (10%) for Anaplasma ovis. Of 109 pools of ectoparasites, 32.1% were positive for C. burnetii, 28.4% for Rickettsia spp., and 10.9% for A. ovis; 11.9% were positive for both C. burnetii and Rickettsia spp., 6.4% for both Rickettsia spp. and A. ovis, and 2.8% for all three pathogens. This is the first survey that records the presence of tick-borne pathogens, both in the Cypriot mouflon and in ticks parasitizing it.