Redescription of adults and first description of the larva of Haemaphysalis (Rhipistoma) adleri Feldman-Muhsam, 1951 (Acari: Ixodidae), parasite of carnivorans in Western Asia.

The adults of Haemaphysalis (Rhipistoma) adleri Feldman-Muhsam, 1951 (Acari: Ixodidae) are redescribed and the larva of this species is described for the first time here. The adults of H. adleri that we studied were collected from various canid, felid and hyaenid carnivorans (Carnivora: Canidae, Felidae, Hyaenidae) as well as a hedgehog (Erinaceomorpha: Erinaceidae) in Iraq, Israel and West Bank. The males, females and larvae of H. adleri can be differentiated from Haemaphysalis (Rhipistoma) species occurring in the Palearctic portion of West Asia and Egypt as well those in the H. asiatica subgroup by the length of idiosomal setae, development and size of spurs on palpi, dental formula on the hypostome and size of spur on coxae. A lectotype of H. adleri has been designated and the geographic distribution and hosts of this tick species are discussed.

Description of a new species of Amblyomma Koch, 1844 (Acari: Ixodidae), parasite of deer (Artiodactyla: Cervidae) and wild pigs (Artiodactyla: Suidae) in the Philippines.

Amblyomma anicornuta n. sp. (Acari: Ixodidae) is described based on adults and nymphs ex deer (Artiodactyla: Cervidae) and wild pigs (Artiodactyla: Suidae) from Luzon, Philippines. Adults of A. anicornuta n. sp. are similar to those of several Asian and Australasian species of Amblyomma Koch, 1844 with a 4/4 dental formula on the hypostome but can be distinguished by the colouration and pattern of punctations on the conscutum in the male and scutum in the female, the absence of a marginal groove on the conscutum in the male, the possession of long, thick, prominent setae on the alloscutum in the female, projections on anal valves and sclerotised ring around them in the male, a large median sclerite ventrally in the male, as well by the shape of the genital aperture in the female and the size and shape of spurs on coxae I-IV in both sexes. The nymph of A. anicornuta n. sp. is somewhat similar to that of A. babirussae Schulze, 1933 and A. geoemydae (Cantor, 1847) but can be distinguished by the colouration pattern on the scutum, the presence of dorsal cornua and the size of the spurs on coxae I-IV.

Inhibition of the classical pathway of the complement system by saliva of Amblyomma cajennense (Acari: Ixodidae).

Inhibition of the complement system during and after haematophagy is of utmost importance for tick success in feeding and tick development. The role of such inhibition is to minimise damage to the intestinal epithelium as well as avoiding inflammation and opsonisation of salivary molecules at the bite site. Despite its importance, the salivary anti-complement activity has been characterised only in species belonging to the Ixodes ricinus complex which saliva is able to inhibit the alternative and lectin pathways. Little is known about this activity in other species of the Ixodidae family. Thus, the aim of this study was to describe the inhibition of the classical pathway of the complement system by the saliva of Amblyomma cajennense at different stages of the haematophagy. The A. cajennense saliva and salivary gland extract (SGE) were able to inhibit the complement classical pathway through haemolytic assays with higher activity observed when saliva was used. The anti-complement activity is present in the salivary glands of starving females and also in females throughout the whole feeding process, with significant higher activity soon after tick detachment. The SGE activity from both females fed on mice or horses had no significant correlation (p > 0.05) with tick body weight. The pH found in the intestinal lumen of A. cajennense was 8.04 ± 0.08 and haemolytic assays performed at pH 8.0 showed activation of the classical pathway similarly to what occurs at pH 7.4. Consequently, inhibition could be necessary to protect the tick enterocytes. Indeed, the inhibition observed by SGE was higher in pH 8.0 in comparison to pH 7.4 reinforcing the role of saliva in protecting the intestinal cells. Further studies should be carried out in order to identify the inhibitor molecule and characterise its inhibition mechanism.

Antiplatelet-derived growth factor (PDGF) activity in the saliva of ixodid ticks is linked with their long mouthparts.

The saliva of blood-feeding arthropods modulates their vertebrate hosts' haemostatic, inflammatory and immune responses to facilitate blood feeding. In a previous study, we showed that salivary gland products from ixodid tick species also manipulate the wound-healing response by targeting at least four different mammalian growth factors: transforming growth factor ß1, hepatocyte growth factor, fibroblast growth factor 2 and platelet-derived growth factor (PDGF). In addition, species that showed PDGF-binding activity also inhibited cell proliferation in vitro and induced changes in cell morphology accompanied by disruption of the actin cytoskeleton. Here, we show a correlation between the length of the tick hypostome, the sclerotized feeding tube of the mouthparts inserted into the host's skin and anti-PDGF activity. This apparent link between hypostome length, and hence the potential depth of skin damage, and PDGF-binding activity was not apparent for the other growth factors or for other cytokines important in wound healing (keratinocyte growth factor, interleukin 6 and stromal cell-derived factor 1). However, PDGF-binding activity was no longer correlated with anti-cell activities, indicating that an additional as yet unidentified activity in tick saliva may affect cellular changes in wound repair.

Amblyomma hadanii n. sp. (Acari: Ixodidae), a tick from northwestern Argentina previously confused with Amblyomma coelebs Neumann, 1899.

All stages of Amblyomma hadanii n. sp. (Acari: Ixodidae) are described from northwestern Argentina. The diagnostic characters for males are a combination of the pattern of scutal ornamentation, basis capituli dorsally rectangular with cornua, coxa I with two subequal spurs (the internal wider, the external longer), coxae II-III with a single spur, coxa IV with a single spur not reaching level of anus, ventral plates irregular in shape (larger and sometimes with a small incision on festoons 4, 5 and 6) and hypostome spatulate with dental formula 3/3 in 7-8 rows. The diagnostic characters for the females are a combination of scutal ornamentation, postero-lateral margins of scutum slightly convex, coxa I with two subequal spurs (the internal wider, the external longer), basis capituli dorsally rectangular, porose areas rounded, genital aperture U-shaped, and hypostome spatulate with dental formula 3/3 in 7-8 rows. Diagnosis of nymphs can be performed by a combination of basis capituli rectangular, scutum with large punctations in the lateral fields and small punctations in the central field, and cervical groove short and ending as a small shallow depression at the eye level. Larvae are diagnosed by the shape of basis capituli, scutum with with posterior margin slightly convex, and legs with coxa I with 2 triangular spur (the external longer than the internal), and with coxae II and III each with 1 triangular spur. The hosts recorded for this new tick species are Tapirus terrestris (Linnaeus), horse, cattle, dog and humans. Analyses of a 410 bp fragment of the mitochondrial 16S rRNA gene and the complete sequence of the nuclear 18S rRNA gene supported the description of A. hadanii as a new species.

Scanning electron microscopy and morphometrics of nymph and larva of the tick Hyalomma impressum (Acari: Ixodidae).

Nymphs and larvae of ixodid ticks play an important role on the distribution of ticks and transmission of pathogens. They almost infest small mammals and birds which either move from place to place as rodents or migrate across different countries as migratory birds. The morphological descriptions of nymph and larva of the tick Hyalomma impressum were firstly studied in details by scanning electron microscopy and morphometric analysis. The distinguished characters of H. impressum nymph are as follows: dorsal idiosoma (excluding scutum) with 26-27 pairs of setae, posterior margin of scutum is narrowly rounded, posterolateral margins of scutum is straight, cervical grooves on the scutum extend to the midlength, coxa I with two large spurs, coxae (II-IV) with one small spur for each, spiracle is an egg shape with a numerous pores, palpus does not project beyond the hypostome, with nine setae dorsally and six setae ventrally, hypostome has cylindrical shape, dental formula 2/2, teeth number per file is eight in the outer file and seven in the inner file, basis capitulum has triangular shape without setae dorsally and tetragonal shape with three pairs of setae ventrally. The distinctive characters of H. impressum larva are as follows: idiosoma with 13 pairs of setae for each dorsal (including scutal setae) and ventral (excluding coxal setae), scutum with cervical grooves is narrow and shallow extending about one third of the scutal length, posterior margin of scutum is broadly rounded, posterolateral margins of scutum is straight, fold-like indistinctive spurs on coxae II and III, palpus with eight setae dorsally, three setae ventrally and one seta apically, hypostome with dental formula 2/2, teeth number per file (excluding small basal and apical teeth) is seven in the outer file and six in the inner file, basis capitulum without setae dorsally and with three pairs of setae ventrally.

Elemental Enrichment of the Exoskeleton in Three Species of Tick (Arachnida: Ixodidae).

Three species of adult hard tick (Ixodidae) were examined with scanning electron microscopy-energy dispersive X-ray spectroscopy to obtain elemental profiles of their exoskeletons and determine the presence of trace elements. The scutum, tarsal claws, chelicerae, and hypostome were examined on females and males of Amblyomma americanum, Dermacentor variabilis, and Ixodes scapularis. The only trace elements present included chlorine, calcium, and sodium. Chlorine was the most abundant trace element and occurred in all examined regions. The chelicerae generally possessed the highest weight percentages of Cl (up to 11.32 ± 1.36%) across all 3 species, although high weight percentages of Cl (up to 8.78 ± 2.77%) were also present in the hypostome teeth of most specimens. All 3 trace elements were present in the hypostome of A. americanum and I. scapularis, but Ca and Na appear to be absent from the teeth of D. variabilis. In general, there were few differences in the elemental profiles of the exoskeletons between the sexes of any species. This study confirms the presence of alkali metals (Na) and alkaline earth metals (Ca) in adult ticks, which are also common in other arachnids; however, the absence of transition metals such as zinc from the exoskeletons of ticks is uncommon and only shared with species of Ricinulei and Opiliones.

Amblyomma boeroi n. sp. (Acari: Ixodidae), a parasite of the Chacoan peccary Catagonus wagneri (Rusconi) (Artiodactyla: Tayassuidae) in Argentina.

All parasitic stages of Amblyomma boeroi n. sp. (Acari: Ixodidae) are described here from Catagonus wagneri (Rusconi) in Argentina. The diagnostic characters for the male are a combination of orbited eyes, a 2/2 dental formula, coxa IV considerably larger than coxae I-III and with a long, sickle-shaped, medially directed spur arising from its internal margin, a scutum which is light grey to very pale ivory in colour, and the absence of a postanal groove. The diagnostic characters for the females are a combination of orbited eyes, a central pair and two marginal pairs of short, coarse notal setae, a 2/2 dental formula, and the absence of a postanal groove. The nymph has short palpi and a 2/2 dental formula arranged in 6 rows, its eyes are convex and orbited, and it has no postanal groove. The dorsally rectangular basis capituli of the larva, its bulging eyes and slightly sinuous posterior scutal margin all serve to distinguish it from the larva of other species of the genus. The principal host for all parasitic stages is C. wagneri (Artiodactyla: Tayassuidae). Phylogenetically A. boeroi appears to represent an independent lineage within Amblyomma Koch, 1844.

Two new species of African Haemaphysalis ticks (Acari: Ixodidae), carnivore parasites of the H. (Rhipistoma) leachi group.

Two new tick species belonging to the African Haemaphysalis (Rhipistoma) leachi subgroup, namely H. (R.) colesbergensis n. sp. and H. (R.) oliveri n. sp., are described. Haemaphysalis (R.) colesbergensis adults are easily differentiated from the other species of the H. (R.) leachi subgroup, including H. (R.) oliveri, by the spur on coxa IV, which is considerably longer than that on coxa III. The adults of the 2 new species are equal in size, but the dental formula of the hypostome of H. (R.) colesbergensis is 4/4 compared to 5/5 for H. (R.) oliveri. The dental formula of H. (R.) oliveri also distinguishes it from other ticks in the subgroup, namely H. (R.) leachi, H. (R.) elliptica, H. (R.) moreli, and H. (R.) punctaleachi (4/4 in these species), but not from H. (R.) paraleachi, which has a 5/5 dental arrangement. However, the average total length and width of H. (R.) oliveri males (2.47 x 1.20 mm) are considerably shorter and narrower than those of H. (R.) paraleachi males (3.81 x 1.79 mm). Similar differences in size apply to the females. Nymphs and larvae of H. (R.) colesbergensis and H. (R.) oliveri can be distinguished from those of other members of the H. (R.) leachi subgroup, as well as from each other, by a combination of the following characters: size and measurement ratios, length of posterodorsal and posteroventral spurs on palpal segment II, and number of denticles per file on the hypostome. Haemaphysalis (R.) colesbergensis is known only from South Africa, where it has been collected from domestic cats and dogs and medium-sized wild felids. Haemaphysalis (R.) oliveri is recorded only from Sudan, where it has been collected from small- to medium-sized wild felids and canids and an antelope. The hosts of the immature stages of H. (R.) colesbergensis are unknown, while nymphs of H. (R.) oliveri have been collected from rodents.

Redescription of the adult stages of Ixodes (Afrixodes) rasus Neumann 1899, with notes on its phylogenetic position within the genus Ixodes.

The tick subgenus Afrixodes Morel 1966 (Ixodidae) is distributed in sub-Saharan Africa. It consists of about 60 species which are described based on a few specimens and/or only some developmental stages, mostly adults. Because of this, the diagnosis of the African species of Ixodes is in many aspects complicated. Ixodes rasus Neumann 1899 is a common species, widely distributed in tropical and subtropical moist broadleaved forests in central Africa, whose morphology remains poorly described. We redescribe the adults of the species and provide molecular data for 16S rDNA based on three questing females and one male collected in the Central African Republic. Both sexes have an anal groove rounded and closed. The female has syncoxae on coxae I to III, a dental formula of 2/2, and long, curved auriculae. The male has moderate syncoxae on coxae I-III, coxae I-II carry one single internal spur each: coxae III and IV unarmed. The cornua are absent in the male, and the auriculae are small lobes. The male pregenital plate is longer than broad, with an anterior margin widely rounded; the median plate is large and clearly divergent posteriorly, with adanal plates fused posteriorly to the anus, and a dental formula of 4/4 (one row of 5/5). The molecular features of 16S rDNA place I. rasus near I. aulacodi (the only other Afrixodes species for which 16S rDNA is available) and near I. turdus and I. frontalis; two species of ticks of the Palearctic region, which commonly infest birds. The paucity of data regarding the subgenus Afrixodes makes it necessary to provide reliable and comparable re-descriptions of several species, as well as description of the immature stages for many of the currently known taxa.

[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.

Structural characterization of tick cement cones collected from in vivo and artificial membrane blood-fed Lone Star ticks (Amblyomma americanum).

The Lone Star tick, Amblyomma americanum, is endemic to the southeastern United States and capable of transmitting pathogenic diseases and causing non-pathogenic conditions. To remain firmly attached to the host, the tick secretes a proteinaceous matrix termed the cement cone which hardens around the tick's mouthparts to assist in the attachment of the tick as well as to protect the mouthparts from the host immune system. Cement cones collected from ticks on a host are commonly contaminated with host skin and hair making analysis of the cone difficult. To reduce the contamination found in the cement cone, we have adapted an artificial membrane feeding system used to feed long mouthpart ticks. Cones collected from in vivo and membrane fed ticks are analyzed to determine changes in the cone morphology. Comparisons of the cement cones using light microscopy shows similar structures and color however using scanning electron microscopy the cones have drastically different structures. The in vivo cones contain fibrils, sheets, and are heavily textured whereas cones from membrane fed ticks are remarkably smooth with no distinct structures. Analysis of the secondary protein structures using FTIR-ATR show both in vivo and membrane fed cement cones contain ß sheets but only in vivo cement cones contain helical protein structures. Additionally, proteomic analysis using LC-MS/MS identifies many proteins including glycine rich proteins, metalloproteases, and protease inhibitors. Proteomic analysis of the cones identified both secreted and non-secreted tick proteins. Artificial membrane feeding is a suitable model for increased collection of cement cones for proteomic analysis however, structurally there are significant differences.

Failure of ticks to transmit Scopulariopsis brevicaulis (Deuteromycota), a common filamentous fungal commensal of ticks.

The capacity of ticks to transmit a fungus was examined by analyzing tick saliva, host tissue from feeding sites, and host blood for presence of Scopulariopsis brevicaulis (Sacc.) Bainier, an internal mycosymbiont of the American dog tick, Dermacentor variabilis (Say), and lone star tick, Amnblyomma americanum (L.). Although >85% of ticks were infected with S. brevicaulis, conidia presence was low (0-5% of samples) in microscopic observations and mycological culturing of saliva expressed from larvae, nymphs, and adults. Additionally, the recovery of S. brevicaulis from blood and tissue feeding sites from a rabbit where S. brevicaulis-positive adult ticks had attached and fed was not increased compared with control tissue where no feeding occurred, indicating that transmission does not occur by the blood-feeding route. Tick mouthparts were found to contain S. brevicaulis in addition to Penicillium glabrum (Wehmer) Westling, but these agents were sparse in isolations from the feeding sites, which makes it unlikely that ticks act frequently as a mechanical fungal vector.

Redescription of Amblyomma varium Koch, 1844 (Acari: Ixodidae) based on light and scanning electron microscopy.

Amblyomma varium Koch, 1844 is a Neotropical tick, known as the 'sloth's giant tick', with records from southern Central America to Argentina. It is found almost exclusively on mammals of the families Bradypodidae and Magalonychidae (Xenarthra). Differences exist in discussions with regard to the dentition of the female hypostome being either 3/3 or 4/4. The male was also originally described as having a short spur on coxa IV, but some specimens recently collected from different Brazilian localities have this spur three times longer. These differences beg the question of whether there is more than one species included under this taxon. In order to answer this question and to clarify the taxonomic characters of this species, 258 adult specimens were examined, and a redescription of male and female based on light and scanning electron microscopy is provided. In addition, DNA was extracted from males with either a long or a short spur on coxa IV to help settle this question for future investigations on their taxonomy. The morphological study showed that the dental formula pattern for males and females is 3/3 and 4/4, respectively. When sequenced, the 12 S rDNA genes of both A. varium males with long and short spurs on coxa IV were found to be identical, indicating that the length of the spurs on coxa IV is likely to be an intraspecifically polymorphic character of this species.