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In this work, the update of the taxonomic composition in Mexico of two genera belonging to the Ixodidae family is presented: Ixodes and Amblyomma. For this, a bibliographic search was carried out in electronic databases such as: BiDi-UNAM, Biological Sciences, Google Scholar and Zoological Record between 2007 and 2023. From this, 80 publications carried out in the last 16 years were obtained, and with these we integrated a list that represents the current state of knowledge of both genera. In this way, we can point out that a total of 28 species of the genus Ixodes and 25 species of the genus Amblyomma are distributed in Mexico, finding that in this period three species of Ixodes were recorded and one was eliminated from the list (Ixodes loricatus Neumann, 1899). In the case of Amblyomma, one species less is counted than in previous counts, since Amblyomma elaphense Price, 1959 was transferred to the genus Robertsicus. Regarding their host spectrum, Ixodes species are mainly associated with mammals (15 families) and birds (seven families), while those of Amblyomma have been found parasitizing 13 families of amphibians and reptiles, seven of birds and 21 of mammals. From a geographical point of view, 13 of the species included in Ixodes are distributed in the Neotropical region, 11 in the Nearctic, and only four in both regions; On the other hand, nine species of Amblyomma have been collected in the Neotropical region, one in the Nearctic, and 11 in both regions. Robertsicus elaphense (Price, 1959) has only been found in association with one Nearctic reptile species. Ticks are one of the most studied groups within the Acari subclass; however, it must continue to achieve a full understanding of its classification, geographic and host distribution, as well as its phylogenetic relationships. [ABSTRACT FROM AUTHOR]

Tapirs are common hosts of ticks and an individual can be infested by up to seven different tick species. We explored the parasitic tick fauna associated with wild Baird's tapirs (Tapirus bairdii) from the Yucatan Peninsula. A total of 326 ticks of 10 species of the Family Ixodidae were collected from 15 tapirs. We found a range of one to six tick species per host, but most of the tapirs were parasitized by two or three tick species. We tested the relationship between body condition, sex, and age classes of the tapirs versus the number of tick species on each host. The most common tick species was Amblyomma mixtum found on 93% of the hosts. Amblyomma pecarium, Amblyomma tenellum, Ixodes affinis and Rhipicephalus sanguineus sensu lato were recorded for the first-time parasitizing Baird's tapirs. We did not find a relationship between body condition, sex, and age classes of tapirs versus the number of parasitizing tick species. Our finding demonstrates that the richness of ticks parasitizing tapirs does not depend on the biological characteristics and health status of the host, but could be determined by other factors such as habitat use and the rate of contact with domestic animals. [ABSTRACT FROM AUTHOR]

The genetic population structure relationships of Hyalomma (Euhyalomma) lusitanicum in Andalusia (the south of the Iberian Peninsula) were examined using mtDNA sequence data from 887 bp of cytochrome oxidase subunit I (COI) gene. The sequence for the COI region was determined for 84 individuals collected in several localities of Andalusia, and 10 for other localities (i.e., five from Toledo, central Iberian Peninsula, four from Sicily (Italy) and one from Canary Island). Seventeen haplotypes were detected, including 27 polymorphic sites. The number of amino acid substitutions per site from mean diversity calculations for the entire population was 0.017. AMOVA analysis revealed a low gene flow that characterises the genetic population structure of this species in South Iberian Peninsula, with a haplotype diversity (h) value of 0.815. No geographically induced differentiation was observed, and separate evolutionary units were not detected. Our results indicate low genetic diversity across the geographical range of H. lusitanicum tick in Andalusia. Our data do not show any genetic discontinuity between the tick populations studied, including specimens from Canary Island and Sicily (Italy). [ABSTRACT FROM AUTHOR]

Some specific features of the fauna of ticks Ixodidae Murr 1890, their landscape distribution and ecology. Total found 18 species ticks belonging to 6 genera: Ixodes, Haemaphysalis, Boophilus, Dermacentor, Rhipicephalus, Hyalomma, families - Ixodidae. Determined the habitat distribution of ticks community and seasonal reproductive dynamics in domestic, wild, game animals and birds. [ABSTRACT FROM AUTHOR]

This research reports ticks on wild raptors in Brazil. Between the years 1936 and 2019, 127 larvae, 230 nymphs and 34 adult ticks were collected on 92 raptors (among 27 different species) from 35 localities in distinct Brazilian biomes. Additionally, an extensive literature review on ticks on wild raptors has been carried out, demonstrating that from 1993 to 2016, 29 larvae, 81 nymphs, 29 adults and 186 indeterminate immature ticks (larvae or nymphs) were collected on 41 raptors (16 different species) in 17 distinct localities in the Brazilian territory. The following tick species were identified on wild raptors in the country: Amblyomma aureolatum (Pallas, 1772), Amblyomma auricularium (Conil, 1878), Amblyomma brasiliense Aragão, 1908, Amblyomma cajennense (Fabricius, 1787) sensu stricto, Amblyomma calcaratum Neumann, 1899, Amblyomma coelebs Neumann, 1899, Amblyomma dubitatum Neumann, 1899, Amblyomma longirostre (Koch, 1844), Amblyomma nodosum Neumann, 1899, Amblyomma ovale Koch, 1844, Amblyomma parkeri Fonseca & Aragão, 1952, Amblyomma sculptum Berlese, 1888, Haemaphysalis juxtakochi Cooley, 1946, Rhipicephalus microplus (Canestrini, 1888), and Rhipicephalus sanguineus (Latreille, 1806) sensu lato. This study is therefore a significant contribution to our knowledge of the ticks associated with Brazilian raptors. [ABSTRACT FROM AUTHOR]

The tick Amblyomma humerale is endemic to South America, where its adult stage has been reportedmostly from terrestrial tortoises, whereas larvae and nymphs have been reported on various species of reptiles, birds, and mammals. Herein, we evaluated for the first time the life cycle of A. humerale in the laboratory. For this purpose, larvae and nymphs were exposed to feed on six host species: Gallus gallus, Mesocricetus auratus, Calomys callosus, Chelonoidis carbonaria, Salvator merianae, and Trachemys scripta. Adult ticks were exposed to feed on T. scripta. The life-cycle of A. humerale in the laboratory could be completed in an average period of ca. 200 days, considering prefeeding periods of 25 days for each of the parasitic stages. One bird species (G. gallus), one small mammal (C. callosus) and one reptile species (C. carbonaria) were the most suitable hosts for larvae; however, chickens (G. gallus) were the most suitable host for nymphs, whereas a turtle species (T. scripta) was highly suitable for adult ticks. These results corroborate field observations that indicated that the immature stages of A. humerale have a low host specificity, being able to feed successfully on reptiles, birds, and mammals, whereas reptiles are important hosts for the adult stage. [ABSTRACT FROM AUTHOR]

Ectoparasites of bats (Chiroptera: Pteropodidae), with a description of three species of of which two belong to order Mesostigmata (family: Ameroseiidae and Macronyssidae) and one belong to order Ixodida (family: Ixodidae), from northeastern India are discussed. The present study was carried out for six months (January–June 2014) to identify the various ectoparasites of the Short-nosed Fruit Bat Cynopterus sphinx in Cachar District of Assam, northeastern India. A total of 12 individuals of C. sphinx was captured using mist nets from eight different localities of the study area. During the study, a total of 125 parasites was collected from C. sphinx. The identified parasites were Dermacentor sp. Indet., Ameroseius sp. Indet., and Steatonyssus sp. Indet. and falls under the class Arachnida. [ABSTRACT FROM AUTHOR]

Ticks significantly affect the health of humans and animals in Japan. However, no complete checklist has been produced for the Japanese tick fauna in English, and even recent checklists in Japanese do not include all presently known tick species found on the Japanese islands. Here, a complete species list of all tick taxa known to occur within Japan is presented. The status of several controversial Japanese tick species is also discussed. [ABSTRACT FROM AUTHOR]

A tick survey was conducted to document tick-host associations with Florida (USA) wildlife, and to determine the relative abundance and distribution of ixodid ticks throughout the state. The survey was conducted using collection kits distributed to licensed Florida hunters as well as the examination of archived specimens from ongoing state wildlife research programs. Collected tick samples were obtained from 66% of Florida counties and were collected from nine wildlife hosts, including black bear, bobcat, coyote, deer, gray fox, Florida panther, raccoon, swine, and wild turkey. In total, 4176 ticks were identified, of which 75% were Amblyomma americanum, 14% Ixodes scapularis, 8% A. maculatum, 3% Dermacentor variabilis, and < 1% were I. affinis and I. texanus. americanum, D. variabilis, and I. scapularis had the broadest host range, while A. maculatum, D. variabilis, and I. scapularis had the widest geographic distribution. While the survey data contribute to an understanding of tick-host associations in Florida, they also provide insight into the seasonal and geographic distribution of several important vector species in the southeastern USA. [ABSTRACT FROM AUTHOR]

The Australian paralysis ticks ( Ixodes: Sternalixodes) are of considerable medical and veterinary importance within Australia. This is because of their ability to cause paralysis but also their capacity to transmit pathogens and induce allergic reactions. The available keys for the identification of the group ( Ixodes holocyclus Neumann, Ixodes cornuatus Roberts, and Ixodes hirsti Hassall) are ambiguous and contain errors, making accurate identification of the group difficult. Illustrations of varying quality and accuracy of these species have been published in the past; however, they have never been collectively treated using scanning electron microscopy (SEM). Female Australian paralysis ticks are here examined using SEM, and the first pictorial key for this group is presented along with an accurate text key. [ABSTRACT FROM AUTHOR]

. 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. [ABSTRACT FROM AUTHOR]

Ticks are blood-feeding arthropods and can harbor several bacteria, including the worldwide zoonotic disease Q-fever agent Coxiella burnetii. Recent studies have reported a distinct group of Coxiella mostly associated with Ixodidae ticks, including the primary endosymbionts of Amblyomma americanum. In the present work, a screening for Coxiella infection was performed by 16S ribosomal DNA (rDNA) gene analyses in 293 tick samples of 15 different species sampled worldwide, including Brazil, Colombia, Kenya, and China. Different Coxiella phylotypes were identified, and these putative symbiotic bacteria were detected in ten different Amblyomma tick species. Approximately 61 % of Rhipicephalus sanguineus and ∼37 % of Rhipicephalus microplus DNA samples were positive for Coxiella. Sequence analysis and phylogenetic reconstruction grouped all the detected Coxiella with Coxiella-like symbionts from different Ixodidae ticks. This well-defined clade clearly excludes known phylotypes of C. burnetii pathogens and other Coxiella spp. detected in different environmental samples and other invertebrate hosts. [ABSTRACT FROM AUTHOR]

We investigated intra-annual variability in acarine parasite load (species richness, prevalence and abundance) and spleen mass in populations of leaf-nosed bats in highly seasonal tropical and subtropical climates: one population of California leaf-nosed bat ( Macrotus californicus) in a subtropical thorn forest, one population of Waterhouse's leaf-nosed bat ( M. waterhousii) in a subtropical desert, and one population of Waterhouse's leaf-nosed bat in a tropical deciduous forest. We tested the hypothesis that hosts in highly seasonal tropical and subtropical climates exhibit significant seasonal changes in immune response and parasite load. Prevalence was 100% in most populations examined, except in the subtropical population of M. waterhousii in the rainy season. The tropical population had the highest parasite richness in both seasons and presented species belonging to the four acarine orders examined: Mesostigmata, Ixodidae, Trombidiformes, and Sarcoptiformes. Abundance values of Trombidiformes in M. californicus, and of Ixodida and Sarcoptiformes in the tropical M. waterhousii population were higher in the rainy than in the dry season. Spleen mass was larger in the tropical population in the rainy season and in the subtropical population in the dry season. Spleen mass was not related to abundance of any of the acarine orders (Mesostigmata, Ixodidae, Trombidiformes, and Sarcoptiformes) analyzed. Our findings suggest that bats in highly seasonal tropical and subtropical environments experience significant seasonal changes in parasite burden and in immune response. [ABSTRACT FROM AUTHOR]

The recent invasion of the hard tick Ixodes affinis, a sylvatic vector of Borrelia burgdorferi, into the Mid-Atlantic region of the United States has prompted questions as to the origin of these ticks, and the possibility of connectivity with presumed ancestral populations in Central and South America. To assess connectivity and ancestry of I. affinis throughout its range, a fragment of the 16S mitochondrial rRNA gene was sequenced from seven adult I. affinis ticks collected in Colon, Panama, and compared to 19 previously published 16S haplotypes in two clades from the US, seven previously published haplotypes from Belize, and one previously published haplotype from Colombia. This study did not find any overlapping haplotypes between the US, Panama, Belize, and Colombia, showing no evidence for connectivity between North, Central, and South American populations of I. affinis. Two new I. affinis clades associated with ticks from Panama and Belize were also identified. The node that gave rise to the Panama clade of I. affinis was more basal than the nodes leading to the clades containing the majority of ticks from Belize and the United States, and ticks from Belize were more closely related to US ticks than Panama ticks. Several possible competing migration pathways were identified, where ticks may have been introduced to the northern US from Belize, or to the southern US from Panama. Star clusters present in each clade suggest rapid mutation rates after arrival in new areas, and may be associated with the success of I. affinis in invading northern climates. This study provides preliminary evidence for the spread of I. affinis from Central America into the US, and serves as a first step in investigating the possibility of connectivity between Central and North America tick populations. [ABSTRACT FROM AUTHOR]

Background: Recently, a new rickettsia named 'Candidatus Rickettsia vini' belonging to the spotted fever group has been molecularly detected in Ixodes arboricola ticks in Spain, the Czech Republic, Slovakia and Turkey, with prevalence reaching up to 100 %. The aim of this study was to isolate this rickettsia in pure culture, and to describe it as a new Rickettsia species. Methods: A total of 148 ornitophilic nidicolous ticks Ixodes arboricola were collected in a forest near Breclav (Czech Republic) and examined for rickettsiae. Shell vial technique was applied to isolate rickettsiae in Vero cells. Rickettsial isolation was confirmed by optical microscopy and sequencing of partial sequences of the rickettsial genes gltA, ompA, ompB, and htrA. Laboratory guinea pigs and chickens were used for experimental infestations and infections. Animal blood sera were tested by immunofluorescence assay employing crude antigens of various rickettsiae. Results: Rickettsia vini n. sp. was successfully isolated from three males of I. arboricola. Phylogenetic analysis of fragments of 1092, 590, 800, and 497 nucleotides of the gltA, ompA, ompB, and htrA genes, respectively, showed closest proximity of R. vini n. sp. to Rickettsia japonica and Rickettsia heilongjiangensis belonging to the spotted fever group. Experimental infection of guinea pigs and chickens with R. vini led to various levels of cross-reactions of R. vini-homologous antibodies with Rickettsia rickettsii, Rickettsia parkeri, 'Candidatus Rickettsia amblyommii', Rickettsia rhipicephali, Rickettsia bellii, and Rickettsia felis. Laboratory infestations by R. vini-infected I. arboricola larvae on chickens led to no seroconversion to R. vini n. sp., nor cross-reactions with R. rickettsii, R. parkeri, 'Ca. R. amblyommii', R. rhipicephali, R. bellii or R. felis. Conclusions: Our results suggest that R. vini n. sp. is possibly a tick endosymbiont, not pathogenic for guinea pigs and chickens. Regarding specific phenotypic characters and significant differences of DNA sequences in comparison to the most closely related species (R. japonica and R. heilongjiangensis), we propose to classify the isolate as a new species, Rickettsia vini. [ABSTRACT FROM AUTHOR]

The life cycle of Ixodes persulcatus lasts 3 years in the conditions of the Leningrad province (North-West Russia), the development of each phase taking a year. The normal age of the taiga tick is 3 years. The calendar age of larvae and nymphs reaches 11-12 months under favorable abiotic and biotic factors, while the calendar age of adults does not exceed 11 months. At the preimaginal phases of development the ticks that breed in August can feed before or after winter. However, their metamorphosis begins and reaches completion within the same timeframes (from late June to early August) and lasts for about 30-50 (60) days. The survival rate of hungry and engorged larvae and nymphs after wintering is quite high (88.6-100 %). We explain the low activity of larvae and nymphs in late summer and autumn by incomplete development. Morphogenetic diapause of engorged larvae and nymphs interrupts digestion but not metamorphosis which starts only in late June and July after the complete absorption of blood from the gut cavity. [ABSTRACT FROM AUTHOR]

Knowledge about soft ticks (Ixodida: Argasidae) in Sardinia is incomplete and distribution data need to be updated. This work studies soft ticks on the island focusing on two species, Argas reflexus and Ornithodoros maritimus, both recently recorded. A total number of 12 specimens of these species of interest were collected between 2004 and 2015. This study reports for the first time the presence of O. maritimus in a coastal area in Italy, and more generally in a coastal area rather than small islands near the coastline, confirming the presence of this species on the island 20 years after its last recording. Moreover we confirm the presence of A. reflexus on the island, in the town of Cagliari and, for the first time, in the town of Quartu Sant'Elena. At the present state of knowledge, in Sardinia, Ornithodoros erraticus, which was actively looked for within the surveillance for African swine fever, an endemic disease since 1978 on the island, is not present. The presence of another species reported only once in Sardinia, Argas vespertilionis, needs further confirmation. [ABSTRACT FROM AUTHOR]

Hard ticks are the vectors of many pathogens including tick-borne encephalitis virus and the Lyme disease agent Borrelia burgdorferi sensu lato. In Eastern Siberia, Ixodes persulcatus, Dermacentor nuttalli, Dermacentor silvarum and Haemaphysalis concinna are regarded as aggressive to humans. Recently, significant changes in world tick fauna have been reported and this affects the spread of tick-borne pathogens. We studied the current species diversity, population structure and prevalence of tick-borne pathogens of hard ticks (Acari: Ixodidae) that attacked humans in Eastern Siberia (Irkutsk region, Russia). In total, 31,892 individual ticks were identified and analysed during the years 2007-2014. The majority (85.4 %) of victims was bitten by I. persulcatus, 14.55 % of attacks on humans were caused by D. nuttalli and D. silvarum, whereas H. concinna was documented only in 15 cases (0.05 %). The seasonal activity and the age/gender structure of the tick population were studied as well. Among all the studied ticks, three unconventional species, i.e. Rhipicephalus sanguineus, Dermacentor reticulatus and Amblyomma americanum, were identified. Analysis of tick bite histories indicates at least three events of invasion of non-endemic ticks into the ecosystems of northern Eurasia with harsh continental climates. Invading ticks are able to reach the adult life stage and are aggressive to the local human population. Phylogenetic analysis of mt 16S rRNA gene fragments suggests multiple independent routes of tick migration to Eastern Siberia. Possible implications to human health and epidemiology of tick-borne infections are discussed. [ABSTRACT FROM AUTHOR]

Seventeen Myodes gapperi (Vigors) (Rodentia: Cricetidae), 13 Peromyscus maniculatus (Wagner) (Rodentia: Cricetidae), 12 Microtus pennsylvanicus (Ord) (Rodentia: Cricetidae), four Zapus princeps Allen (Rodentia: Cricetidae), three Ictidomys tridecemlineatus (Mitchill) (Rodentia: Sciuridae), and eight shrews (Soricomorpha: Soricidae) collected at Blackstrap Lake (BL), and 48 P. maniculatus, 15 Z. princeps, 15 M. pennsylvanicus, and one Sorex monticolus Merriam (Soricomorpha: Soricidae) collected at Saskatchewan Landing Provincial Park (SLPP), in southern Saskatchewan, Canada were examined for ticks. Although no adult ticks were detected on small mammals at either locality, Dermacentor variabilis (Say) (Acari: Ixodidae) larvae (n=144) and nymphs (n=7) were found on four species of small mammal at BL. At SLPP, both D. variabilis larvae (n=71) and nymphs (n=6), and Dermacentor andersoni Stiles (Acari: Ixodidae) nymphs (n=9) were collected from small mammals. Both tick species were present on P. maniculatus and M. pennsylvanicus at SLPP, indicating an overlap in their host range and, hence, the potential for transmission of microorganisms between tick species at sites where they coexist. However, the results of polymerase chain reaction assays used to detect bacteria of the genus Rickettsia da Rocha-Lima (Rickettsiaceae) in ticks, revealed that R. peacockii Niebylski et al. only occurred in nymphs of D. andersoni, whereas no Rickettsia were present in the larvae and nymphs of D. variabilis. [ABSTRACT FROM PUBLISHER]

• Nymphs, followed by females and males were more frequent parasitizing humans. • The Atlantic Forest was the most frequent biome in human parasitism records but that doesn't mean it favors it. • The species with the highest number of records of human parasitism were Amblyomma sculptum, Amblyomma coelebs, Amblyomma cajennense sensu stricto and Amblyomma brasiliense. • Environmental change will favor the geographic expansion of ticks and the increase of human parasitism. Records of accidental parasitism by ticks in humans from Brazil are scarce, with most being reported by researchers who are parasitized during their research and by professionals who work with animals. In order to compile these records, an extensive literature review was carried out. Our revision includes studies published between 1909 and 2022, including nine species of the Argasidae family and 32 species of the Ixodidae family that were reported biting humans in the six biomes of the Brazilian territory. The species with the highest number of records of human parasitism was Amblyomma sculptum , followed by Amblyomma coelebs, Amblyomma cajennense sensu stricto, and Amblyomma brasiliense. The Atlantic Forest was the most frequent biome where human parasitism occurred, probably due to the greater number of inhabitants, universities, and researchers in the region; however, this does not mean that this biome is more conducive to the development of ticks and their parasitism in humans. In addition to Amblyomma ovale , a vector of Rickettsia parkeri in the country , two of the main species that act as vectors of Rickettsia rickettsii, A. sculptum , and Amblyomma aureolatum , have been reported, which is quite worrying considering that the wide distribution of the species and life stages most frequently mentioned in parasitism (i.e., nymphs and adults) are the ones that favour pathogen transmission. This research provides a significant contribution to the knowledge of tick species associated with human parasitism in Brazil; however, due to environmental change potentiated by deforestation and fires, it is expected that there will be a geographic expansion of some tick species and the pathogens that use them as a vector and an increase in human parasitism. [Display omitted] [ABSTRACT FROM AUTHOR]

Background: Amblyomma variegatum and A. hebraeum are two ticks of veterinary and human health importance in south-east Africa. In Zimbabwe they occupy parapatric (marginally overlapping and juxtaposed) distributions. Understanding the mechanisms behind this parapatry is essential for predicting the spatio-temporal dynamics of Amblyomma spp. and the impacts of associated diseases. It has been hypothesized that exclusive competition between these species results from competition at the levels of male signal reception (attraction-aggregation-attachment pheromones) or sexual competition for mates. This hypothesis predicts that the parapatry described in Zimbabwe could also be present in other countries in the region. Methods: To explore this competitive exclusion hypothesis we conducted field surveys at the two species' range limits in Mozambique to identify areas of sympatry (overlapping areas) and to study potential interactions (communicative and reproductive interference effects) in those areas. At sympatric sites, hetero-specific mating pairs were collected and inter-specific attractiveness/repellent effects acting at long and short distances were assessed by analyzing species co-occurrences on co-infested herds and co-infested hosts. Results: Co-occurrences of both species at sampling sites were infrequent and localized in areas where both tick and host densities were low. At sympatric sites, high percentages of individuals of both species shared attachment sites on hosts and inter-specific mating rates were high. Although cross-mating rates were not significantly different for A. variegatum and A. hebraeum females, attraction towards hetero-specific males was greater for A. hebraeum females than for A. variegatum females and we observed small asymmetrical repellent effects between males at attachment sites. Conclusions: Our observations suggest near-symmetrical reproductive interference between A. variegatum and A. hebraeum, despite between-species differences in the strength of reproductive isolation barriers acting at the aggregation, fixation and partner contact levels. Theoretical models predict that sexual competition coupled with hybrid inviability, greatly reduces the probability of one species becoming established in an otherwise suitable location when the other species is already established. This mechanism can explain why the parapatric boundary in Mozambique has formed within an area of low tick densities and relatively infrequent host-mediated dispersal events. [ABSTRACT FROM AUTHOR]

In order to study homology among the major lineages of the mite (super)order Parasitiformes, developmental patterns in Opilioacarida are documented, emphasizing morphology of the earliest, post-embryonic instars. Developmental patterns are summarized for all external body structures, based on examination of material in four different genera. Development includes an egg, a 6-legged prelarva and larva, three 8-legged nymphal instars, and the adults, for the most complete ontogenetic sequence in Parasitiformes. The prelarva and larva appear to be non-feeding. Examination of cuticular structures over ontogeny allows development of an updated model for body segmentation and sensillar distribution patterns in Opilioacarida. This model includes a body made up of a well-developed ocular segment plus at most 17 additional segments. In the larvae and protonymphs each segment may carry up to six pairs of sensilla (setae or lyrifissures) arranged is distinct series ( J, Z, S, Sv, Zv, Jv). The post-protonymphal instars add two more series ( R and Rv) but no extra segments. This basic model is compatible with sensillar patterns in other Parasitiformes, leading to the hypothesis that all taxa in that (super)order may have the same segmental ground plan. The substantial segmental distortion implied in the model can be explained using a single process involving differential growth in the coxal regions of all appendage-bearing segments. [ABSTRACT FROM AUTHOR]

Haemaphysalis bispinosa Neumann has been considered to exist in China, especially in the southern part of the country. However, H. bispinosa referred to in many Chinese research papers may in fact be H. longicornis, which is widely distributed in most regions of China. In order to clarify the occurrence of H. bispinosa, Haemaphysalis ticks collected from 18 of 23 provinces of China (Hebei, Henan, Hubei, Guangxi, Gansu, Yunnan, Xinjiang, Anhui, Zhejiang, Shannxi, Guizhou, Sichuan, Shanxi, Shandong, Ningxia, Fujian, Qinghai and Jiangxi) were examined based on morphological and molecular characteristics. We found no evidence of H. bispinosa being present in China. Our results indicate that all of the so called ' H. bispinosa' ticks reported in China are in fact H. longicornis. [ABSTRACT FROM AUTHOR]

Infestation by the nest-dwelling Ixodes hexagonus Leach and the exophilic Ixodes ricinus ( Linnaeus) (Ixodida: Ixodidae) on the Northern white-breasted hedgehog, Erinaceus roumanicus (Erinaceomorpha: Erinaceidae), was investigated during a 4-year study in residential areas of the city of Poznań, west-central Poland. Of 341 hedgehogs, 303 (88.9%) hosted 10 061 Ixodes spp. ticks encompassing all parasitic life stages (larvae, nymphs, females). Ixodes hexagonus accounted for 73% and I. ricinus for 27% of the collected ticks. Male hedgehogs carried significantly higher tick burdens than females. Analyses of seasonal prevalence and abundance of I. hexagonus revealed relatively stable levels of infestation of all parasitic stages, with a modest summer peak in tick abundance noted only on male hosts. By contrast, I. ricinus females and nymphs peaked in spring and declined steadily thereafter in summer and autumn, whereas the less abundant larvae peaked in summer. This is the first longterm study to evaluate the seasonal dynamics of both tick species on populations of wild hedgehogs inhabiting urban residential areas. [ABSTRACT FROM AUTHOR]

The Pantanal in Brazil is the largest floodplain of the world. This ecosystem, rich in wildlife, has a large feral pig population. Such a large host biomass must have a strong influence on the parasite fauna. In this work, we evaluated the role of feral pigs in the maintenance of Amblyomma sculptum (formerly Amblyomma cajennense), the most prevalent tick species in the Pantanal. Tick infestations were evaluated on 243 feral pigs and their environment. The suitability of domestic pigs, representing their feral relatives, to A. sculptum adults and nymphs was assessed experimentally. Tick infestation of feral pigs was strongly associated with that of the environment: 96 and 97 % of the ticks, respectively, were A. sculptum. The infestation prevalence on this host species was close to 90 % in the dry season and 100 % in the wet season and mean infestation intensity was above 30 ticks in both seasons. Suitability of pigs as hosts for A. sculptum was shown by the high proportion of nymphs and female ticks found engorging on captured feral pigs and adequate biological parameters displayed by ticks from experimental infestations of domestic pigs. Other tick species on feral pigs, albeit in much lower numbers, were Amblyomma parvum and Ornithodorus rostratus. Results show that feral pigs feed a high proportion of the A. sculptum adults and nymphs in their territories and should be a target for tick-borne diseases studies. This is particularly relevant to public health because all the main tick species found on feral pigs are aggressive to humans as well. [ABSTRACT FROM AUTHOR]

Host specificity of Neotropical hard ticks (Acari: Ixodidae) was analyzed by using the number of hosts species for each tick species and the index of host specificity STD*, which integrates phylogenetic and ecological information. The analyses were based on 4172 records of hard ticks collected from wild and domestic tetrapods. Most tick species included in this study were associated with three to 20 host species. No tick species has been associated either with a single species or with a single genus of host. It was found that the number of host species is sensitive to sampling effort, but not the STD*. The most frequent values of STD* were between 2.5 and 3.5, which shows that the host species more frequently used by Neotropical hard tick species belong to different families or different orders. Immature stages tend to use a broader taxonomic range of hosts than adults, and the interpretation of both measures of host specificity used in this study led to the conclusion that the impact of non-endemic hosts does not alter the patterns of host specificity in Neotropical hard ticks. The index STD* showed that a high proportion of tick species has phylogenetically unrelated species as principal hosts. The conclusion reached in this work indicates that strict host specificity is not common among Neotropical hard ticks and suggests that the influence of tick ecology and evolution of habitat specificity, tick generation time, phenology, time spent off the host and the type of life-cycle could be more important than hosts species. [ABSTRACT FROM PUBLISHER]

Traditional systems account for 95 % of the livestock produced in Burkina Faso. Tick infestation hampers livestock productivity in this area. However, little information exists on tick-control practices used by livestock farmers. We interviewed 60 stockbreeders working in traditional farming systems to obtain the first data on tick-control practices. Sixteen farmers (27 %) did not use conventional practices: seven removed ticks by hand or plastered cattle with dung or engine oil; nine farmers treated cattle with crop pesticides. Forty-four farmers (73 %) used mainly synthetic pyrethroids (SP; either alphacypermethrin or deltamethrin in 20 and 18 farms, respectively) and occasionally amitraz (N = 6). Intervals between treatments varied significantly depending on the chemical used: most farmers using crop pesticides (100 %), amitraz (100 %) or alphacypermethrin (80 %) adjusted tick-control to tick-burden, whereas farmers using deltamethrin tended more to follow a tick-control schedule. Perception of tick-control effectiveness significantly varied among practices: tick-control failures were more frequently reported by farmers using alphacypermethrin (55 %) than by those using either other conventional acaricides (17 %) or crop pesticides (0 %). We investigated whether this could indicate actual development of SP-resistance in cattle ticks. First, using the larval packet test technique, we confirmed that the computation of LC and LC was repeatable and remained stable across generations of the Rhipicephalus (Boophilus) geigyi Houndé laboratory strain. We then collected from the field fully-engorged female R. geigyi to evaluate the SP-resistance relative to the Houndé reference strain. We did not detect any case of SP-resistance in the field-derived R. geigyi ticks. [ABSTRACT FROM AUTHOR]

Foci of tick species occur at large spatial scales. They are intrinsically difficult to detect because the effect of geographical factors affecting conceptual influence of climate gradients. Here we use a large dataset of occurrences of ticks in the Afrotropical region to outline the main associations of those tick species with the climate space. Using a principal components reduction of monthly temperature and rainfall values over the Afrotropical region, we describe and compare the climate spaces of ticks in a gridded climate space. The dendrogram of distances among taxa according to occurrences in the climate niche is used to draw functional groups, or clusters of species with similar occurrences in the climate space, as different from morphologically derived (taxonomical) groups. We aim to further define the drivers of species richness and endemism at such a grid as well as niche similarities (climate space overlap) among species. Groups of species, as defined from morphological traits alone, are uncorrelated with functional clusters. Taxonomically related species occur separately in the climate gradients. Species belonging to the same functional group share more niche among them than with species in other functional groups. However, niche equivalency is also low for species within the same taxonomic cluster. Thus, taxa evolving from the same lineage tend to maximize the occupancy of the climate space and avoid overlaps with other species of the same taxonomic group. Richness values are drawn across the gradient of seasonal variation of temperature, higher values observed in a portion of the climate space with low thermal seasonality. Richness and endemism values are weakly correlated with mean values of temperature and rainfall. The most parsimonious explanation for the different taxonomic groups that exhibit common patterns of climate space subdivision is that they have a shared biogeographic history acting over a group of ancestrally co-distributed organisms. [ABSTRACT FROM AUTHOR]

Scanning electron microscopes (SEM), which image sample surfaces by scanning with an electron beam, are widely used for steric observations of resting samples in basic and applied biology. Various conventional methods exist for SEM sample preparation. However, conventional SEM is not a good tool to observe living organisms because of the associated exposure to high vacuum pressure and electron beam radiation. Here we attempted SEM observations of live ticks. During 1.5×10-3 Pa vacuum pressure and electron beam irradiation with accelerated voltages (2-5 kV), many ticks remained alive and moved their legs. After 30-min observation, we removed the ticks from the SEM stage; they could walk actively under atmospheric pressure. When we tested 20 ticks (8 female adults and 12 nymphs), they survived for two days after SEM observation. These results indicate the resistance of ticks against SEM observation. Our second survival test showed that the electron beam, not vacuum conditions, results in tick death. Moreover, we describe the reaction of their legs to electron beam exposure. These findings open the new possibility of SEM observation of living organisms and showed the resistance of living ticks to vacuum condition in SEM. These data also indicate, for the first time, the usefulness of tick as a model system for biology under extreme condition. [ABSTRACT FROM AUTHOR]

Background: Ticks are among the most important vectors of zoonotic diseases in temperate regions of Europe, with widespread distribution and high densities, posing an important medical risk. Most ticks feed on a variety of progressively larger hosts, with a large number of small mammal species typically harbouring primarily the immature stages. However, there are certain Ixodidae that characteristically attack micromammals also during their adult stage. Rodents are widespread hosts of ticks, important vectors and competent reservoirs of tick-borne pathogens. Micromammal-tick associations have been poorly studied in Romania, and our manuscript shows the results of a large scale study on tick infestation epidemiology in rodents from Romania. Methods: Rodents were caught using snap-traps in a variety of habitats in Romania, between May 2010 and November 2011. Ticks were individually collected from these rodents and identified to species and development stage. Frequency, mean intensity, prevalence and its 95% confidence intervals were calculated using the EpiInfo 2000 software. A p value of <0.05 was considered statistically significant. Results: We examined 423 rodents (12 species) collected from six counties in Romania for the presence of ticks. Each collected tick was identified to species level and the following epidemiological parameters were calculated: prevalence, mean intensity and mean abundance. The total number of ticks collected from rodents was 483, with eight species identified: Ixodes ricinus, I. redikorzevi, I. apronophorus, I. trianguliceps, I. laguri, Dermacentor marginatus, Rhipicephalus sanguineus and Haemaphysalis sulcata. The overall prevalence of tick infestation was 29.55%, with a mean intensity of 3.86 and a mean abundance of 1.14. Only two polyspecific infestations were found: I. ricinus + I. redikorzevi and I. ricinus + D. marginatus.Conclusions: Our study showed a relatively high diversity of ticks parasitizing rodents in Romania. The most common tick in rodents was I. ricinus, followed by I. redikorzevi. Certain rodents seem to host a significantly higher number of tick species than others, the most important within this view being Apodemus flavicollis and Microtus arvalis. The same applies for the overall prevalence of tick parasitism, with some species more commonly infected (M. arvalis, A. uralensis, A. flavicollis and M. glareolus) than others. Two rodent species (Mus musculus, Rattus norvegicus) did not harbour ticks at all. Based on our results we may assert that rodents generally can act as good indicators for assessing the distribution of certain tick species. [ABSTRACT FROM AUTHOR]

Two new species of oribatid mite subgenus Phyllolohmannia of Mixacarus (Acari: Oribatida: Lohmanniidae), Mixacarus (Phyllolohmannia) tenasserimensis n. sp. and Mixacarus (P.) variata n. sp., are described and illustrated from Thailand based on adult and immature instars collected from the leaf-litter of dry evergreen forests. An identification key to six recognized species of the subgenus Phyllolohmannia is also presented. [ABSTRACT FROM PUBLISHER]

This study assesses the weight gain of partially engorged Rhipicephalus sanguineus females that were artificially fed via capillary tubes and the influence of capillary tube feeding on the biological parameters of the non-parasitic stage of the species. The ticks were sorted into four groups, each containing ten females of a homogeneous weight. The groups were each treated for different feeding times, 2, 6, 12 and 24 hours. The weight gain of the artificially fed females was measured, and the biological parameters of the non-parasitic stage of the tick were observed for each treatment group. The statistical non-parametrical Dunn and Kruskal-Wallis tests were used to compare the results. The mean weights (mg) were 0.2±2.4; 4.3±5.8; 7.4±5.8 and 12.0±11.2 for the 2, 6, 12 and 24 hours feeding groups, respectively. The weight of the fed groups increased as the capillary feeding time increased, and this relationship was highly significant (P<0.05) between the groups fed for 2 and 24 hours. No statistically significant differences (P>0.05) were observed in the parameters of the non-parasitic stage for the artificially fed groups. It can be concluded that artificial feeding via capillary tubes provides an efficient and easy method for the artificial intake of blood by R. sanguineus. Furthermore, it was noted that the ticks fed in vitro were able to establish a new generation. The experimental method shows great promise in studies that aim to investigate biological disease agents. [ABSTRACT FROM AUTHOR]

Studies have shown that ticks are susceptible to infection by entomopathogenic nematodes. These studies indicate different susceptibilities of ticks to infection by these fungi, depending on the tick species, development phase, entomopathogenic nematodes species and Strains and the time the ticks are exposed to them. Usually this period ranges from 24 to 72 hours. The aim of this study was to evaluate the infection times in vitro of engorged Rhipicephalus (Boophilus) microplus females by the entomopathogenic nematodes Steinernema glaseri CCA strain, by analysis of the ticks' biological parameters. The results show that a 2-hour exposure time was sufficient for the engorged R. microplus females to be infected by S. glaseri CCA, but that a minimum exposure time of 24 hours was necessary to generate treatment efficacy above 90%. [ABSTRACT FROM AUTHOR]

The article describes the study which aims to identify the structural features of longicin, a defensin-like peptide found in the hard tick Haemaphysalis longicornis. The authors reveal that based on the chemicophysical characteristics, the antimicrobial motif (P4) is claimed to be a cationic peptide with hydrophobic and amphipathic character. They mention that the secondary structure depicted the existence of a β-sheet. They also emphasize that the peptide P4 can be suggested as an antimicrobial domain which indicates future therapeutic agent against bacteria.

Infestations of larval and nymphal Ixodes spp. were identified in 16 dogs and 16 cats from several small animal clinics in Sydney. Cases occurred in late summer or autumn, peaking in February, and were seasonally recurrent in some individuals. Clinical signs of infestation included a papular dermatitis and irritation or pruritus that ranged from severe to mild or absent. The distribution of tick attachment tended to be cranial and ventral, with the face, legs, axillae and ventrum the most commonly affected sites. The estimated number of ticks in each infestation varied from less than 10 to more than 100. Basic morphological examination of ticks collected from affected animals was performed by attending veterinarians using light microscopy, and larvae and nymphs belonging to the Ixodes genus were identified. Ticks collected from 17 animals and submitted to the Department of Medical Entomology, Westmead Hospital were putatively identified as I. trichosuri (57%) and I. holocyclus (25%) larvae. Histopathological samples of attachment sites collected from three dogs and one cat were characterised by ticks attached in well-demarcated invaginations of the skin (‘tick craters’) associated with variable epidermal and/or dermal necrosis, focal eosinophilic intraspinous pustules, mild to marked eosinophilic and neutrophilic, superficial to deep, dermal perivascular to interstitial inflammation, and moderate to marked superficial dermal oedema and red cell extravasation. A range of topical acaricidal preparations, including fipronil and synthetic pyrethroids, were used for treatment. [ABSTRACT FROM AUTHOR]

The repellent efficacies of the U.S. military repellent 33% N,N-diethyl-3-methylbenzamide (deet), 10% and 20% (1S, 2′S) 2-methylpiperidinyl-3-cyclohexene-1-carboxamide (SS220) and 10% and 20% 1-methyl-propyl-2-(hydroxyethyl)-1-piperidinecarboxylate (Bayrepel) cream formulations on human volunteers against the lone star tick Amblyomma americanum (L.) were evaluated in a simulated forest floor environment over a 12-h testing period. At 2-h intervals, volunteers, with repellent applied in a 5-cm-wide band around each ankle, stood for 5 min in plastic tubs containing leaf litter and 100 host-seeking A. americanum nymphs. Ticks were allowed to remain on a volunteer’s feet and ankles for an additional 5 min after the volunteer exited the tub. All repellent formulations provided high levels of protection for the entire 12 h. No ticks crossed 5-cm-wide bands of 20% SS220 and Bayrepel during any challenge, and thus 100% protection was afforded throughout the test. These formulations showed a long-lasting efficacy hitherto unknown in tick repellents intended for use on human skin. [ABSTRACT FROM AUTHOR]

An investigation of the risk of human tick infestation, together with the prevalence of Borrelia burgdorferi s.l. infection, was conducted in a sylvatic habitat in western Germany to provide data needed for future risk-benefit evaluations of acaricides used for clothing impregnation. Additionally, data were collected on behavioural changes in Borrelia burgdorferi s.l.-infected adult female I. ricinus ticks and the possible impact of such changes on host-finding efficacy. The risk of I. ricinus-infestation was determined by collecting from the protective clothing of volunteers and by dragging in known tickinfested sites in the Kühkopf Mountain area, Koblenz, Germany, from June through October 2006. The overall tick infestation rate per person per hour was 7.4 ± 5.5, with the following sex- and stage-specific differences: males 0.32 ± 0.37, females 1.1 ± 1.2, nymphs 3.6 ± 4.4, larvae 2.4 ± 3.5. Concurrent dragging revealed an average 19.4 ± 16.2 times higher infestation rate as well as a markedly lower infection rate with borreliae in adult I. ricinus ticks when compared to ticks collected from exposed human volunteers. Although the difference in infection rates was statistically significant (P < 0.023) only in adult female ticks, our data indicate that B. burgdorferi s.l. infection may increase host-finding efficacy in adult I. ricinus. The overall exposure risk was 1.0 B. burgdorferi s.l.-infected ticks per person per hour of exposure, or 0.25 ticks per 100 m walking distance in the study area. [ABSTRACT FROM AUTHOR]

Abstract: The central issue dealt with here is the role of copulation in the control of feeding behaviour in ticks and some haematophagous insects. Female ticks of the family Ixodidae normally engorge to ∼100× their unfed body weight, and then drop from the host, produce and lay eggs, and die. Virgins, on the other hand, normally do not exceed 5–40% (depending on species) of the normal engorged body weight. But instead of detaching voluntarily at that point most virgins remain fixed to the host for extended periods, waiting for males to find them so they can complete engorgement. Virgin haematophagous insects, and virgin ticks of the family Argasidae display little, if any, reduction in blood meal size compared to mated females, at least not during the first ovarian cycle. During subsequent ovarian cycles, meal size in some virgin insects may be somewhat reduced depending on how many eggs are retained in the reproductive tract, but the reduction is not nearly to the same extent as that observed for virgin ixodid females. The stimulatory effect of copulation on engorgement in the latter is caused by a pair of proteins (voraxin α and β) produced in the testis and transferred to the female with the spermatophore. Here, I propose why it might be adaptive for an ixodid female to remain small until mated. The hypothesis is suggested from the facts that ixodid ticks remain attached to the host for days (rather than minutes), and that virgin ticks, above a certain critical weight, lose all opportunity for producing viable offspring should they be groomed off the host prematurely, or should the host die while ticks are still attached. [Copyright &y& Elsevier]

Studies in the biology, ecology and behaviour of R. appendiculatus in Zambia have shown considerable variation within and between populations often associated with their geographical origin. We studied variation in the mitochondrial COI (mtCOI) gene of adult R. appendiculatus ticks originating from the Eastern and Southern provinces of Zambia. Rhipicephalus appendiculatus ticks from the two provinces were placed into two groups on the mtCOI sequence data tree. One group comprised all haplotypes of specimens from the Eastern province plateau districts of Chipata and Petauke. The second group consisted of a single haplotype of specimens from the Southern province districts and Nyimba, an Eastern province district on the fringes of the valley. This variation provides additional evidence to the earlier observations in the 12S rDNA and ITS2 data for the geographic subdivision of R. appendiculatus from Southern province and Eastern province plateau. The geographic subdivision further corresponds with differences in body size and diapause between R. appendiculatus from these geographic areas. The possible implications of these findings on the epidemiology of East Coast fever (ECF) the disease for which R. appendiculatus is one of the vectors are discussed. [ABSTRACT FROM AUTHOR]

Questing Ixodes ricinus L. (Acari: Ixodidae) ticks were collected on a forest trail that had been completely cleared of shrubs and ground vegetation in winter 2002 and on a nearby control uncleared forest transect in South Moravia (Czech Republic). Samples were collected each May in 2003, 2004 and 2005. Nymphal ticks were 3.4 times, 1.9 times and 1.2 times less frequent on cleared forest than on uncleared forest trails in the three respective years, whereas adult tick abundance was 27.2 times, 4.0 times and 2.2 times lower, respectively. The ticks were examined for borreliae by dark-field microscopy: prevalence of nymphal ticks infected with Borrelia burgdorferi sensu lato (12.6% to 20.0%) did not differ significantly between the cleared and uncleared trail during the 3 years. In conclusion, the habitat modification appeared to result in a decreased abundance of I. ricinus as well as a reduced frequency of infected ticks (and thus indirectly a lower potential risk of Lyme borreliosis), which lasted, however, for only 2 years. Eight cultures of borreliae isolated from the ticks were all identified as the ‘ornithophilic’ genomic species Borrelia garinii, possibly indicating a greater role of forest birds than that of forest rodents as the hosts of immature I. ricinus in the tick (and borrelial) colonization of the cleared part of the forest. [ABSTRACT FROM AUTHOR]