The albinism of the feral Asinara white donkeys (Equus asinus) is determined by a missense mutation in a highly conserved position of the tyrosinase (TYR) gene deduced protein

A feral donkey population (Equus asinus), living in the Asinara National Park (an island north‐west of Sardinia, Italy), includes a unique white albino donkey subpopulation or colour morph that is a major attraction of this park. Disrupting mutations in the tyrosinase (TYR) gene are known to cause recessive albinisms in humans (oculocutaneous albinism Type 1; OCA1) and other species. In this study, we analysed the donkey TYR gene as a strong candidate to identify the causative mutation of the albinism of these donkeys. The TYR gene was sequenced from 13 donkeys (seven Asinara white albino and six coloured animals). Seven single nucleotide polymorphisms were identified. A missense mutation (c.604C>G; p.His202Asp) in a highly conserved amino acid position (even across kingdoms), which disrupts the first copper‐binding site (CuA) of functional protein, was identified in the homozygous condition (G/G or D/D) in all Asinara white albino donkeys and in the albino son of a trio (the grey parents had genotype C/G or H/D), supporting the recessive mode of inheritance of this mutation. Genotyping 82 donkeys confirmed that Asinara albino donkeys had genotype G/G whereas all other coloured donkeys had genotype C/C or C/G. Across‐population association between the c.604C>G genotypes and the albino coat colour was highly significant (P = 6.17E?18). The identification of the causative mutation of the albinism in the Asinara white donkeys might open new perspectives to study the dynamics of this putative deleterious allele in a feral population and to manage this interesting animal genetic resource.     

Blood serum retinol levels in Asinara white donkeys reflect albinism‐induced metabolic adaptation to photoperiod at Mediterranean latitudes

Previous works on albinism form of Asinara white donkeys (Equus asinus) identified the mutation leading to the peculiar phenotype spread to all specimens of the breed. Inbreeding naturally occurred under geographic isolation, on Asinara Island, in the Mediterranean Sea. Albino individuals can be more susceptible to develop health problems when exposed to natural sun radiation. Alternative metabolic pathways involved in photoprotection were explored in this trial. Nutrition‐related metabolites are believed to contribute to the conservation of Asinara donkeys, in which melanin, guaranteeing photoprotection, is lacking. Biochemical profiles with particular focus on blood serum β‐carotene and retinol levels were monitored. Identical natural grazing conditions for both Asinara (albino) and Sardo (pigmented) donkey breeds were assured on same natural pastures throughout the experimental period. A comparative metabolic screening, with emphasis on circulating retinol and nutrient‐related metabolites between the two breeds, was carried out over one year. Potential intra‐ and interspecimen fluctuations of metabolites involved in photoprotection were monitored, both during negative and positive photoperiods. Differences (p = .064) between blood serum concentrations of retinol from Asinara versus Sardo breed donkeys (0.630 vs. 0.490 μg/ml, respectively) were found. Retinol levels of blood serum turned out to be similar in the two groups (0.523 vs. 0.493 μg/ml, respectively, p = .051) during the negative photoperiod, but markedly differed during the positive one (0.738 vs. 0.486, respectively, p = .016). Blood serum β‐carotene levels displayed to be constantly around the limit of sensitivity in all animals of both breeds. Variations in blood serum concentrations of retinol in Asinara white donkeys can reflect the need to cope with seasonal exposure to daylight at Mediterranean latitudes, as an alternative to the lack of melanin. These results may suggest that a pulsed mobilization of retinol from body stores occurs to increase circulating levels during positive photoperiod.     

Morphological identification of ticks (Acari: Ixodidae) infesting donkeys (Equus asinus) in Maputo Province,Mozambique

Donkeys (Equus asinus) are rustic animals, but in Africa’s poorest regions, they can present multiple health problems, including tick infestation. The study’s objective was to determine the species composition of ticks that infest donkeys in Maputo Province (Mozambique). Ticks were collected in five conveniently selected southern districts of Maputo Province (Moamba, Matutuíne, Marracuene, Boane, and Matola) and were identified to species level using a stereoscopic microscope with the aid of dichotomous identification keys. In total, 500 ticks were collected from all 88 selected donkeys. Three genera of ticks were identified, namely Rhipicephalus (97.2%; 486/500), Amblyomma (2.2%; 11/500), and Hyalomma (0.6%; 3/500). Seven species were identified, of which Rhipicephalus evertsi evertsi with 50.4% (252/500) was the most prevalent, followed by Rhipicephalus appendiculatus (27.4%; 137/500), Rhipicephalus turanicus (11.6; 10/500), Rhipicephalus (boophilus) microplus (6.8; 20/500), Amblyomma hebraeum (2.2%; 11/500), Rhipicephalus sanguineus (1%; 5/500) and Hyalomma truncatum (0.6%; 3/500). Rhipicephalus evertsi evertsi occurred in all locations, whereas Hyalomma truncatum occurred only in the Boane district. Males were the most prevalent (67.2%; 336/500). The study revealed that donkeys in Maputo Province were infested with seven tick species of which R. evertsi evertsi was the main species.

     

Ticks (Acari: Ixodidae) infesting the Arabian Camel (Camelus dromedarius) in the Sinai,Egypt with a note on the acaricidal efficacy of Ivermectin

In this study, tick burdens on camels (Camelus dromedarius) were determined in the vicinity of the St. Catherine monastery, Sinai, Egypt. In total 2,545 ticks (1,491 adults and 1,054 nymphs) were collected and identified. Mean tick burdens were relatively heavy and the range in number of ticks per camel was very broad (6–173). Hyalomma dromedarii was the predominant tick species and accounted for 95.6% of the adult ticks. Other ticks found were H. marginatum subspp. and H. anatolicum excavatum. All nymphs collected were Hyalomma spp.In addition, the effect of ivermectin (Ivomec MSD AGVET) on tick burdens, when given subcutaneously at 0.2 mg/kg¹, was evaluated in nine camels in the date-palm plantation of Kibbutz Yahel in the Arava valley, Israel. Initial tick burdens on these camels (half-body tick counts) ranged from 20–105 ticks per camel. Seven camels from the same herd with half-body tick counts ranging from 40–107 ticks per camel were not treated and served as a control group. Ivermectin was not effective against Hyalomma tick infestation in camels under these conditions.     

Competition,facilitation or mediation via host? Patterns of infestation of small European mammals by two taxa of haematophagous arthropods

1. We studied the effect of flea infestation on the pattern of tick (Ixodes ricinus and Ixodes trianguliceps) infestation on small mammals. 2. We asked (1) whether the probability of an individual host being infested by ticks was affected by its infestation of fleas (number of individuals and species) and (2) whether the abundance and prevalence of ticks in a host population was affected by the abundance, prevalence, level of aggregation, and species richness of fleas. 3. The probability of a host individual being infested by ticks was affected negatively by flea infestation. At the level of host populations, flea abundance and prevalence had a predominantly positive effect on tick infestation, whereas flea species richness had a negative effect on tick infestation. 4. The effect of flea infestation on tick infestation was generally greater in I. ricinus than in I. trianguliceps, but varied among host species. 5. It can be concluded that the effect of fleas on tick infestation of small mammals may be either negative or positive depending on the level of consideration and parameters involved. The results did not provide support for direct interactions between the two ectoparasite taxa, but suggested population and community dynamics and the defence system of the hosts as possible factors.     

Prevalence of hard tick infestations in cattle of Mizoram,India

The present study was conducted to determine the prevalence of hard tick infestations in cattle of Mizoram from April 2017 to March 2018. The prevalence of hard tick infestations was studied in relation to sex and age of animals and seasonal changes in a year. Cattle of selected places were examined carefully for the presence of ticks and in positive cases ticks were collected manually and identified on the basis of morphological characters. A total of 713 cattle were examined and out of which 452 (63.39%) cattle were found to be infested with hard ticks and the prevalent tick species was Rhipicephalus (Boophilus) microplus. A significantly (p < 0.01) higher infestation was observed in female cattle (66.43%) than males (48.83%). Age-wise highest prevalence of tick infestations was found in 1–5 years (73.41%) age group followed by >5 years age group (61.92%) and < 1 year (42.65%) age group, respectively. Seasonally, the prevalence of hard tick infestation was found highest (p < 0.01) in monsoon (77.91%) and lowest in winter (43.16%). The present study provides data on tick infestation in cattle of Mizoram, India.     

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

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

Hard tick species (Acari: Ixodidae) and infestation in two livestock agroecosystems from Antioquia,Colombia

Tick infestation affects about 80% of livestock globally while transmitting various pathogens causing high economic losses. This study aimed to determine the degree of tick infestation in two regions, North and Middle Magdalena in Antioquia, Colombia, to identify the ixodid tick species found and the associated risk factors. A cross-sectional study was carried out in 48 farms distributed in six municipalities of Antioquia. Two paddocks and eight bovines per farm were evaluated to estimate tick infestation (adults, nymphs, and larvae). Tick species were identified through a morphological and molecular analysis based on partial sequences of data obtained from DNA molecular markers, two mitochondrial (16S rRNA and COI), and one genomic DNA gene (18S rRNA). A multivariate Poisson regression model was applied to estimate the associated risk factors with ticks in cattle. Rhipicephalus microplus, Amblyomma patinoi and Dermacentor nitens were present in the livestock agroecosystems in the Middle Magdalena region; the highest incidence of tick infestation in cows and paddocks was reported in the municipality of Puerto Triunfo. The livestock agroecosystems in Middle Magdalena were characterized by a higher presence of adult R. microplus in cattle. Larval infestation of R. microplus, followed by D. nitens, was also found in paddocks. The multivariate analysis showed that the origin of cattle was the main risk factor associated with the presence of ticks (i.e., when cattle came from outside the farm). Cattle movement between farms in Middle Magdalena can contribute to the spread of ticks in this region.

     

Tick prevalence and species diversity on Aldabran giant tortoises (Dipsochelys dussumieri) in relation to host range and host size in a restored ecosystem, Kenya

Tick species density and diversity on Aldabran tortoises was investigated in relation to the habitat range and size of each tortoise. Identification of tick infestation patterns forms an important aspect of effective tick control. Ten Aldabran tortoises were de‐ticked and monitored over the course of 2 months. Tick species found were Amblyomma sparsum, Amblyomma nuttalli, Amblyomma hebraeum and Boophilus decoloratus, with the most prevalent species found being A. sparsum. Tick loads varied considerably from 20 to 214 ticks per tortoise, with most ticks collected from the head/neck region. Tortoises ranging outside Haller Park had higher tick loads (70–214) compared with tortoises ranging within Haller Park (20–99). Tick load was not correlated with tortoise size. Results indicate that tick loads are related to the habitat range of the tortoises and may indirectly also be related to food preference and host food availability. Implications of the findings and appropriate tick control measures are discussed.     

Preference and performance of the two-spotted spider mite <Emphasis Type="Italic">Tetranychus urticae</Emphasis> (Acari: Tetranychidae) on strawberry cultivars

The first record of human infestation and feeding by the native tick species Ixodes australiensis is reported in Australia based on a specimen collected from an adult male. Human infestation by ticks in Australia is reviewed and a concise list of anthropophagic ticks occurring in Australia is presented.     

Detecting population structure and recent demographic history in endangered livestock breeds: the case of the Italian autochthonous donkeys

Since its domestication, about 5000 years ago, the donkey (Equus asinus) has been extensively used as a work or draft animal in agricultural activities and for the transportation of people and goods. In the last century, technology improvement and growing mechanization strongly affected agriculture and the management and use of this livestock species in the industrialized countries. Nowadays, the use of donkeys for work or transport has almost disappeared, together with the need for mules or hinny breeding. During the last five decades, Italian autochthonous donkey populations suffered from a severe reduction in population size, which led to the extinction of several breeds. At present, eight breeds remain, all classified by FAO as critically endangered or endangered: Asinara, Pantesco, Grigio Siciliano, Romagnolo, Amiatino, Sardo Grigio, Martina Franca, and Ragusano. To evaluate the extant genetic variability of Italian donkeys, we typed 16 microsatellite loci in 258 individuals from these breeds. The results highlighted moderate levels of inbreeding ( F _IS = 0.127) and a significant partition of genetic variation into breeds, as suggested by fixation index ( F _ST = 0.109) and analysis of molecular variance (10.86% of total variation assigned to the between‐breeds level) analyses. This was confirmed by a Bayesian clustering procedure that also highlighted a further partitioning at lower hierarchical levels corresponding to the farms of origin. This evidence suggests that an effective management strategy for Italian donkey populations should focus on breeds as conservation units. However, this requires a synergic management strategy at the farm level to maintain diversity and avoid inbreeding.     

Tick infestation on birds in an urban Atlantic Forest fragment in north-eastern Brazil

Birds are important hosts for various tick species, playing a significant role in their biological life cycle and dispersion. In this study, we investigated tick infestations on birds trapped in an urban remnant of Atlantic Forest in Pernambuco state, Brazil. From February 2015 to March 2017, 541 birds belonging to 52 species were trapped with mist nets and examined for ectoparasites. Birds trapped in the late successional forest were significantly more infested than birds trapped in the early successional forest. In the same way, ectoparasite infestation varied significantly according to bird weight and collection plot. Overall, 198 birds (36.6%) belonging to 27 species were parasitized by ectoparasites (i.e., ticks, lice and/or mites). Ectoparasites were effectively collected from 111 birds, of which 99 belonging to 20 species were infested by ticks (n?=?261), namely, Amblyomma longirostre (13 nymphs), Amblyomma nodosum (21 nymphs), Amblyomma varium (one nymph), and Amblyomma spp. (five nymphs and 221 larvae). Most of the ticks (>?90%) were collected from Passeriformes. This study provides the second record of A. varium in Pernambuco state and confirms that birds, especially Passeriformes, are important hosts for larvae and nymphs of Amblyomma spp. in the Atlantic Forest biome of Pernambuco.

     

Acquired resistance in dogs to repeated infestation with Ixodes scapularis (Acari: Ixodidae) reduces tick viability and reproductive success

The purpose of this study was to determine whether dogs develop acquired resistance to adult Ixodes scapularis infestation in an experimental model. Five dogs were each infested with ten mating pairs of ticks every week for 7 consecutive weeks, another five dogs were each infested with ten mating pairs once every 2 weeks for 10 weeks and four dogs served as controls not exposed to ticks. All ticks were allowed to feed to repletion and were collected only after dropping from the host. Several variables were measured to determine the extent of blood feeding success. Regression analysis indicated that the engorgement success, survival and mean tick engorgement weight declined with repeated infestation in both groups of dogs (p<0.05). Tick oviposition as well as the F1 viability declined with each successive infestation in both groups. These results suggest that repeated infestation with I. scapularis elicits a protective immune response against tick feeding and could serve as a limiting factor in the spread and transmission of Borrelia burgdorferi.     

Tick burden on European roe deer (<Emphasis Type="Italic">Capreolus capreolus</Emphasis>)

In our study we assessed the tick burden on roe deer (Capreolus capreolus L.) in relation to age, physical condition, sex, deer density and season. The main objective was to find predictive parameters for tick burden. In September 2007, May, July, and September 2008, and in May and July 2009 we collected ticks on 142 culled roe deer from nine forest departments in Southern Hesse, Germany. To correlate tick burden and deer density we estimated deer density using line transect sampling that accounts for different detectability in March 2008 and 2009, respectively. We collected more than 8,600 ticks from roe deer heads and necks, 92.6% of which were Ixodes spp., 7.4% Dermacentor spp. Among Ixodes, 3.3% were larvae, 50.5% nymphs, 34.8% females and 11.4% males, with significant seasonal deviation. Total tick infestation was high, with considerable individual variation (from 0 to 270 ticks/deer). Adult tick burden was positively correlated with roe deer body indices (body mass, age, hind foot length). Significantly more nymphs were found on deer from forest departments with high roe deer density indices, indicating a positive correlation with deer abundance. Overall, tick burden was highly variable. Seasonality and large scale spatial characteristics appeared to be the most important factors affecting tick burden on roe deer.     

Diversity,ecology, and seasonality of hard ticks (Acari: Ixodidae) in eastern Croatia

The diversity of hard tick fauna was studied in different forest communities in 48 localities of eastern Croatia using the dragging‐flagging method and by hand from ten different vertebrate hosts. A total of 2,225 specimens comprising seven species in three genera were identified. Ixodes ricinus, the most abundant species (72.8% of all collected specimens) was recorded in 44 localities, followed by Dermacentor reticulatus in 19 localities, while the other five species (D. marginatus, H. concinna, H. inermis, I. canisuga, and I. hexagonus) were recorded in fewer localities. The highest ratio (67% of collected ticks) was in the adult stage with the predominance of females. The numbers of collected females, males, and nymphs of I. ricinus and H. concinna differed significantly. Ten new tick‐host associations in Croatia were recorded. Fifty‐three animals were infested with one tick species. Single species infestation with I. ricinus was found in 45.8% of animals, followed by D. reticulatus with 25.4%, D. marginatus with 10.2%, H. inermis and I. hexagonus with 3.4%, and I. canisuga with 1.7%. Coinfestation with two species of ticks were recorded in six animals. Ixodes ricinus, H. inermis, and D. reticulatus showed bimodal seasonal activity; for other species unimodal activity patterns were recorded.     

Prevalence of Theileria in the tick Hyalomma detritum detritum in the Doukkala region,Morocco

Abstract. The overall prevalence of Theileria species, mainly, if not exclusively, T.annulata, in 901 Hyalomma detritum detritum collected from cattle in the Doukkala region of Morocco over a period of 2 years was 21.5%. The quantity of infection (number of sporoblasts per infected tick) followed the negative binomial distribution with between one and 250 sporoblasts per infected tick. Infected ticks were found in eight of fourteen areas examined whilst T.annulata was present in all fourteen. There were significant differences in both the prevalence and the quantity of infection between ticks collected from different farms, and between nymphs collected in the autumn from these farms, and moulted in the laboratory, and adults collected in the following summer. The prevalence, but not the quantity, of infection was higher in female than in male ticks. No correlations were established between infection of engorged nymphs and the breed, sex and Theileria piroplasm parasitaemia of the host animal. However, calves infected a greater proportion of nymphs than adult cattle and the heavier the infestation of nymphs on an animal, up to a plateau, the higher the prevalence of infection in those nymphs. There were no differences in infection between ticks moulted at 24^oC and 37^oC, after the engorged nymphs had been stored at 18^oC to simulate over-wintering.     

Tick infestation of small mammals in an English woodland

Tick infestations on small mammals were studied from April to November, 2010, in deciduous woodland in southern England in order to determine whether co‐infestations with tick stages occurred on small mammals, a key requirement for endemic transmission of tick‐borne encephalitis virus (TBEV). A total of 217 small mammals was trapped over 1,760 trap nights. Yellow‐necked mice (Apodemus flavicollis) made up the majority (52.5%) of animals, followed by wood mice (A. sylvaticus) 35.5% and bank voles (Myodes glareolus) 12%. A total of 970 ticks was collected from 169 infested animals; 96% of ticks were Ixodes ricinus and 3% I. trianguliceps. Over 98% of ticks were larval stages. Mean infestation intensities of I. ricinus were significantly higher on A. flavicollis (6.53 ± 0.67) than on A. sylvaticus (4.96 ± 0.92) and M. glareolus (3.25 ± 0.53). Infestations with I. ricinus were significantly higher in August than in any other month. Co‐infestations with I. ricinus nymphs and larvae were observed on six (3.6%) infested individuals, and fifteen small mammals (8.9%) supported I. ricinus – I. trianguliceps co‐infestations. This work contributes further to our understanding of European small mammal hosts that maintain tick populations and their associated pathogens, and indicates that co‐infestation of larvae and nymph ticks does occur in lowland UK. The possible implications for transmission of tick‐borne encephalitis virus between UK ticks and small mammals are discussed.     

Infestation of urban populations of the Northern white‐breasted hedgehog,Erinaceus roumanicus,by Ixodes spp. ticks in Poland

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.     

Feeding preferences of the red‐billed oxpecker,Buphagus erythrorhynchus: a parasitic mutualist?

The oxpecker–ungulate association of sub‐Saharan Africa is an example of a complicated interspecific association subject to variation in outcome. Oxpeckers (Buphagus spp.) are unusual birds because they not only glean ticks from an array of African ungulates, but they are one of the few avian species known to wound‐feed from their living hosts. The conditions under which oxpeckers wound‐feed and the mechanisms generating variation in this association are unclear. We took a unique approach to studying the relationship by conducting a series of feeding preference experiments on twelve captive red‐billed oxpeckers (B. erythrorhynchus). We assessed how oxpecker feeding behaviour is influenced by changes in tick abundance and tick type. In cafeteria‐style experiments, oxpeckers fed equally on ticks and liquid bovine blood. In experiments using donkeys as the host animal, oxpeckers spent more time wound‐feeding when a less‐preferred tick type was available and when tick abundance was low compared to when a preferred tick type was available and when tick abundance was high. However, oxpeckers still wound‐fed even when offered a large number of the ticks they prefer. Additional experiments incorporating tick species of different stages and multiple ungulate species are necessary to fully reveal the dynamics of this association.     

Staphylococcus saprophyticus is a pathogen of the cattle tick Rhipicephalus (Boophilus) microplus

During experimental Rhipicephalus (Boophilus) microplus (Acari: Ixodidae) infestation on cattle, approximately 5% of engorged female ticks showed symptoms of bacterial infection. The affected ticks were unable to oviposit, secreted a distinctive yellow exudate through the genital orifice and eventually died. Microscopic analysis of tick exudate showed abundant clusters of Gram-positive cocci bacteria that were isolated and cultured on bacteriological medium. Biochemical phenotyping and 16S rRNA ribotyping analysis on cultured bacteria identified it as Staphylococcus saprophyticus. This species was also isolated from healthy tick larvae, indicating that S. saprophyticus is commonly found in ticks during different developmental stages. However, conspicuous symptoms are only found on fully engorged females. Cultured S. saprophyticus induced identical pathological symptoms when the bacteria were experimentally inoculated into healthy ticks, demonstrating it to be the causative agent of the R. microplus infectious lethal disease described in this work.