Prevalence Of Mites Research Articles

The presence of parasitic mites on small mammals in Algonquin Provincial Park, Ontario, Canada

Here we identify, for the first time, a generalist orange parasitic mite found on multiple small-mammal species in Algonquin Provincial Park, Ontario, Canada. Results from 18S rRNA sequencing suggest that these mites may belong to the family Trombiculidae (Acari: Trombidiformes), although morphological and additional genetic analyses are needed to confirm this identification. The presence of these mites was associated with lower body condition in North American red squirrels (Tamiasciurus hudsonicus (Erxleben, 1777)), suggesting that these mites may be a detriment to fitness in small mammals or are more successful when targeting individuals in poorer condition. A lack of sex-biased host infection, emergence dates outside of the host reproductive season, and stability of mite prevalence across study years indicate mite population dynamics may be driven predominantly by factors external from host status, such as climatic conditions or habitat preference. Future research should focus on providing additional reliable identification of these mites, as well as broadening our knowledge on their range, pathogenicity, and impact on small-mammal community dynamics.

Detection, Prevalence and Phylogenetic Relationships of Demodex spp and further Skin Prostigmata Mites (Acari, Arachnida) in Wild and Domestic Mammals.

This study was conceived to detect skin mites in social mammals through real-time qPCR, and to estimate taxonomic Demodex and further Prostigmata mite relationships in different host species by comparing sequences from two genes: mitochondrial 16S rRNA and nuclear 18S rRNA. We determined the mite prevalence in the hair follicles of marmots (13%) and bats (17%). The high prevalence found in marmots and bats by sampling only one site on the body may indicate that mites are common inhabitants of their skin. Since we found three different mites (Neuchelacheles sp, Myobia sp and Penthaleus sp) in three bat species (Miotis yumanensis, Miotis californicus and Corynorhinus townsendii) and two different mites (both inferred to be members of the Prostigmata order) in one marmot species (Marmota flaviventris), we tentatively concluded that these skin mites 1) cannot be assigned to the same genus based only on a common host, and 2) seem to evolve according to the specific habitat and/or specific hair and sebaceous gland of the mammalian host. Moreover, two M. yumanensis bats harbored identical Neuchelacheles mites, indicating the possibility of interspecific cross-infection within a colony. However, some skin mites species are less restricted by host species than previously thought. Specifically, Demodex canis seems to be more transmissible across species than other skin mites. D. canis have been found mostly in dogs but also in cats and captive bats. In addition, we report the first case of D. canis infestation in a domestic ferret (Mustela putorius). All these mammalian hosts are related to human activities, and D. canis evolution may be a consequence of this relationship. The monophyletic Demodex clade showing closely related dog and human Demodex sequences also supports this likely hypothesis.

Phylogeny affects host's weight, immune response and parasitism in damselflies and dragonflies.

Host–parasite interactions are an intriguing part of ecology, and understanding how hosts are able to withstand parasitic attacks, e.g. by allocating resources to immune defence, is important. Damselflies and dragonflies show a variety of parasitism patterns, but large-scale comparative immune defence studies are rare, and it is difficult to say what the interplay is between their immune defence and parasitism. The aim of this study was to find whether there are differences in immune response between different damselfly and dragonfly species and whether these could explain their levels of gregarine and water mite parasitism. Using an artificial pathogen, a piece of nylon filament, we measured the encapsulation response of 22 different damselfly and dragonfly species and found that (i) there are significant encapsulation differences between species, (ii) body mass has a strong association with encapsulation and parasite prevalences, (iii) body mass shows a strong phylogenetic signal, whereas encapsulation response and gregarine and water mite prevalences show weak signals, and (iv) associations between the traits are affected by phylogeny. We do not know what the relationship is between these four traits, but it seems clear that phylogeny plays a role in determining parasitism levels of damselflies and dragonflies.

Der f 34, a Novel Major House Dust Mite Allergen Belonging to a Highly Conserved Rid/YjgF/YER057c/UK114 Family of Imine Deaminases

The high prevalence of house dust mite (HDM) allergy is a growing health problem worldwide, and the characterization of clinically important HDM allergens is a prerequisite for the development of diagnostic and therapeutic strategies. Here, we report a novel HDM allergen that belongs structurally to the highly conserved Rid/YjgF/YER057c/UK114 family (Rid family) with imine deaminase activity. Isolated HDM cDNA, named der f 34, encodes 128 amino acids homologous to Rid-like proteins. This new protein belongs to the Rid family and has seven conserved residues involved in enamine/imine deaminase activity. Indeed, we demonstrated that purified Der f 34 had imine deaminase activity that preferentially acted on leucine and methionine. Native Der f 34 showed a high IgE binding frequency as revealed by two-dimensional immunoblotting (62.5%) or ELISA (68%), which was comparable with those of a major HDM allergen Der f 2 (77.5 and 79%, respectively). We also found that Der f 34 showed cross-reactivity with another prominent indoor allergen source, Aspergillus fumigatus This is the first report showing that the Rid family imine deaminase represents an additional important pan-allergen that is conserved across organisms.

Mite infection of Carabus violaceus in rural forest patches and urban parks

Background and purpose We investigated phoretic mite (Acari: Mesostigmata) infection of Carabus violaceus (Coleoptera: Carabidae ) in rural forest patches and urban forested parks in and around Debrecen city, Hungary. We hypothesized that the prevalence of mite infection, mean abundance, mean and median intensity of mites is higher in rural forest patches than in urban parks. Materials and methods We collected C. violaceus individuals using live-capture pitfall traps and preserved them frozen. We identified and counted each mite of the host beetle individuals. Chi 2 , Bootstrap t-test, Mood’s median test were used. Results We trapped altogether 199 C. violaceus individuals (101 in the rural forest patches and 98 in the urban parks). There were 250 phoretic mite individuals on the C. violaceus representing two species ( Poecilochirus carabi , Macrocheles glaber ). We found 224 mite individuals in the rural forest patches, and 26 in the urban parks. We found that the prevalence, mean abundance, mean and median intensity of phoretic mites were significantly higher in the rural forest patches, than in the urban parks. Discussion The studied phoretic mite species use beetles only for transfer and not harming them. Thus, the prevalence and mean intensity of these species depend primarily on the number of available prey density. The cause of decreased number of these phoretic mite species in the urban forest patches should be investigated in more details analysing the effect of disturbance due to urbanisation on a mite fauna and evaluating mite infection on carabids as potential bioindication of habitat disturbances or degradation. Keywords: urbanization, prevalence, Mesostigmata, live-capture traps

Seasonal and environmental variations in community structure of house dust mites (Acari) in subtropical southern Brazil

ABSTRACTHouse dust mites (HDM) are globally distributed in human habitats. The most favourable locations for their development are carpets, curtains, couches, mattresses and pillows. This association with indoor environments makes HDM one of the most important sources of indoor allergens. Distribution and concentration may be influenced by food availability, temperature and, mostly, humidity. This study investigated seasonal and environmental patterns in HDM communities in order to understand the influence of housing type and climate conditions on their richness, abundance and concentration. We sampled four different types of housing (brick houses, wooden houses, carpeted apartments and tiled-floor apartments) and four habitats (double mattress, couch, curtain and carpet). We carried out four samplings in 2010, each one in a season of the year, and collected a total of 128 samples. We analysed richness, abundance and concentration of all sample units. We found a total of 1653 mites. Blomia tropicalis (van Bronswijk, Cock & Oshima, 1973), Dermatophagoides farinae Hughes, 1961 and Tarsonemus fusarii Cooreman, 1941 were the most abundant species. All variables tended to decrease from winter to summer. Wooden and carpeted houses had higher richness and abundance than brick houses and tiled-floor apartments. Curtain had the highest concentration, followed by double mattress, couch and carpet. We found seasonal and environmental variations in the community structure of HDM. Concluding, we demonstrated the prevalence of allergenic indoor mites in the coldest months, in more favourable conditions of wooden and carpeted houses. This study indicates that through careful regulation of climatic conditions, housekeeping policies and laundering procedures, dust mite and allergen levels can be controlled even in a climate suitable for the development of breeding mite populations.

Field application of menthol for Japanese honey bees, Apis cerana japonica (Hymenoptera: Apidae), to control tracheal mites, Acarapis woodi (Acari: Tarsonemidae)

The first record of tracheal mites, Acarapis woodi, in Japan was made in 2010. These mites have since caused serious damage to the colonies of Japanese honey bees, Apis cerana japonica. In the present study, to control the mites on Japanese honey bees with l-menthol, an agent used for European honey bees, Apis mellifera, we investigated (1) the seasonality of menthol efficacy, (2) the overwintering mortality of menthol-treated colonies, and (3) the menthol residue in honey under field conditions in cooperation with private beekeepers of Japanese honey bees. Seasonal menthol efficacy was tested by applying 30g of l-menthol for 1month in different seasons. Mite prevalence was measured by dissecting the honey bee thorax. Overwintering mortality was monitored during winter after checking the mite prevalence in autumn, and was compared with that of untreated colonies reported in our previous study. The residual level of menthol in honey was measured by GC-MS. The results showed that the menthol-treated colonies had a smaller rate of increase in mite prevalence than the untreated colonies. The effects of menthol were highest in March and April. The winter mortality was depressed by menthol treatment. Honey samples extracted from the menthol-treated colonies included 0.4ppm of menthol residue on average. Our findings suggest that menthol treatment is effective for controlling the tracheal mites on Japanese honey bees.

Large males have fewer water mites (Arrenurussp.) on the variable bluet (Coenagrionpulchellum) damselfly

Ectoparasitic water mites of the genus Arrenurus Dugès, 1834 may affect damselflies in different ways, resulting in lower longevity and reproduction success. We studied the variation of water mite occurrence on the variable bluet (Coenagrion pulchellum (Vander Linden, 1823)) damselfly in relation to the host’s sex, location, and wing length, as well as the amount of black pigment on the abdomens of males. In our study, we found that water mite prevalence and abundance were higher on females. Location of the populations did not affect the prevalence of water mites, nor did the colouring of males. The prevalence and abundance of water mites was lower on larger males than on smaller ones. Our results suggest that females are likely to have more water mites due to different behaviour and life-history strategies. According to our results, male body size is a sign of good condition and, thus, of sufficient resources available to be directed to strengthening their immune systems.

Tracheal mites, Acarapis woodi, greatly increase overwinter mortality in colonies of the Japanese honeybee, Apis cerana japonica

AbstractThis study evaluated the damage caused by the tracheal mite Acarapis woodi to colonies of the Japanese honeybee Apis cerana japonica, by investigating mite prevalence and colony death of the honeybees during winter. Honeybees of 114 colonies were sampled from October to December to detect mite prevalence. The colony death was monitored up to the end of April. The observed mortality due to mite infestation was compared with data from two previous studies about European honeybees. Under normal conditions in the absence of mites, 21 % of intact colonies died during the winter season. However, once the honeybee colonies were infested with A. woodi, the overwinter mortality was drastically increased. The mortality of Japanese honeybee colonies infested with the tracheal mites was higher than that reported historically in European honeybee colonies infested with the mites. Investigation of colony mortality at the apiary level showed that mortality was significantly higher in mite-infested than non-infested apiaries, but there were no significant differences related to the estimated winter air temperature. These results suggest that tracheal mite infestation seriously increases the overwinter mortality of Japanese honeybees.

Factors influencing the prevalence and infestation levels of Varroa destructor in honeybee colonies in two highland agro-ecological zones of Uganda.

Varroa mites are ecto-parasites of honeybees and are a threat to the beekeeping industry. We identified the haplotype of Varroa mites and evaluated potential factors that influence their prevalence and infestation levels in the eastern and western highland agro-ecological zones of Uganda. This was done by collecting samples of adult worker bees between December 2014 and September 2015 in two sampling moments. Samples of bees were screened for Varroa using the ethanol wash method and the mites were identified by molecular techniques. All DNA sequences obtained from sampled mite populations in the two zones were 100 % identical to the Korean Haplotype (AF106899). Mean mite prevalence in the apiaries was 40 and 53 % for the western and eastern zones, respectively, during the first sampling. Over the second sampling, mean mite prevalence increased considerably in the western (59 %) but not in the eastern (51 %) zone. Factors that were associated with Varroa mite infestation levels include altitude, nature of apiary slope and apiary management practices during the first sampling. Our results further showed that Varroa mites were spreading from lower to higher elevations. Feral colonies were also infested with Varroa mites at infestation levels not significantly different from those in managed colonies. Colony productivity and strength were not correlated to mite infestation levels. We recommend a long-term Varroa mite monitoring strategy in areas of varying landscape and land use factors for a clear understanding of possible changes in mite infestation levels among African honeybees for informed decision making.

Ectoparasites in Stray Cats in Alexandria Province, Egypt: A Survey Study

This study was designed to investigate the prevalence of external parasites that infect stray cats at Alexandria Province, Egypt. Between May 2013 and April 2015 a total of 70 cats were captured and examined thoroughly for the presence of external parasites. Results showed that 60 cats (85.71%) were found to be infected with at least one ectoparasite species. Fleas were the most frequently recovered ectoparasites, with an overall prevalence (78.57%); the flea species were identified as Ctenocephalides felis (57.14%) and C. canis (18.57%); Nosopsyllus fasciates was also recorded in 2 cats (2.58%). In comparison, the prevalence of mites was much lower (7.41%). Mites recorded were identified as Otodectus cyanotis (5.71%) and, on a single cat, Sarcoptes scabie (1.42%). Neither ticks nor lice were found. Infection with a single species of ectoparasites was most prevalent (80%); the prevalence of infection with two species was 5.7%; infection with 3 or more species of ectoparasites was not found. Female cats were slightly less infected (84.37%) than males (86.84%). Ectoparasites were found somewhat less prevalent on smaller cats, with body weight ≤ 1.4kg (75%) than on cats that were bigger, with body weight> 1.5kg (90%). Younger cats of ≤ 1 year old were less infected (81.3%) than adult cats of > 1 year old (87%).There was a marked seasonal prevalence detected, with the infection most prevalent in summer (100%), followed by autumn (95%), spring (80%), and significantly less in winter (50%). The current study shows that ectoparasites are highly prevalent on stray cats at Alexandria Province, Egypt. It reports new and updated results that may be of help in controlling these parasites. Further investigations into external parasites on cats in Egypt are strongly recommended.

Sheep Mange Mites and Lice: Prevalence and Risk Factors in Asella and its Surroundings, South Eastern Ethiopia

A cross-sectional study was conducted to determine the prevalence and risk factors for sheep mange mites and lice infestation in Asella and its surroundings of south eastern Ethiopia, from November, 2009 to April, 2010. The study revealed that 212 (55.21%) of the 384 sheep examined were infested with mange mites or lice in the study area. A higher prevalence of pediculosis (49.5%) was observed compared to mange mite infestation which was rarely observed with prevalence rate of 5.72%. Mange mites genera identified in the present study were Sarcoptes (2.6%), Psoroptes (2.3%), Chorioptes (0.8%) while no Demodex was identified in the study settings of sheep. Pertaining to lice infestation, Bovicola ovis (36.7%) and Linognathus ovillus (16.9%) were the only identified species of lice. A negative association (p>0.05) of mange mites and lice infestation was observed among the sex groups while only lice infestation was positively associated (p 0.05) with different body condition scores as the statistical analysis revealed. The result of this study revealed that as an ever increasing threat of mange mite and lice infestation on overall sheep productivity and tanning industry in Ethiopia warrants urgent control intervention. Hence, to reduce mange mite and lice infestation prevalence and impact on the productivity and health status, planning of integrated control measures with sustainable veterinary services aiming at creating awareness about the importance and control of the ectoparasites for small ruminant’s owners is recommended.

Ear Mite Removal in the Santa Catalina Island Fox (Urocyon littoralis catalinae): Controlling Risk Factors for Cancer Development.

Ear mites (Otodectes cynotis) and ear canal tumors are highly prevalent among federally endangered Island foxes (Urocyon littoralis catalinae) living on Santa Catalina Island off the coast of Southern California. Since studies began in the 1990s, nearly all foxes examined were found to be infected with ear mites, and ceruminous gland tumors (carcinomas and adenomas) were detected in approximately half of all foxes ≥ 4 years of age. We hypothesized that reduction of ear mite infection would reduce otitis externa and ceruminous gland hyperplasia, a risk factor for tumor development. In this study, we conducted a randomized field trial to assess the impact of acaricide treatment on ear mite prevalence and intensity of infection, otitis externa, ceruminous gland hyperplasia, and mite-specific IgG and IgE antibody levels. Treatment was highly effective at eliminating mites and reducing otitis externa and ceruminous gland hyperplasia, and mite-specific IgG antibody levels were significantly lower among uninfected foxes. Ceruminous gland hyperplasia increased in the chronically infected, untreated foxes during the six month study. Our results provide compelling evidence that acaricide treatment is an effective means of reducing ear mites, and that mite removal in turn reduces ear lesions and mite-specific IgG antibody levels in Santa Catalina Island foxes. This study has advanced our understanding of the underlying pathogenesis which results in ceruminous gland tumors, and has helped inform management decisions that impact species conservation.

Feather mites (Acari, Astigmata) associated with birds in an Atlantic Forest fragment in Northeastern Brazil

The present study reports associations between feather mites (Astigmata) and birds in an Atlantic Forest fragment in Rio Grande do Norte state, in Brazil. In the laboratory, mites were collected through visual examination of freshly killed birds. Overall, 172 individuals from 38 bird species were examined, between October 2011 and July 2012. The prevalence of feather mites was 80.8%, corresponding to 139 infested individuals distributed into 30 species and 15 families of hosts. Fifteen feather mite taxa could be identified to the species level, sixteen to the genus level and three to the subfamily level, distributed into the families Analgidae, Proctophyllodidae, Psoroptoididae, Pteronyssidae, Xolalgidae, Trouessartiidae, Falculiferidae and Gabuciniidae. Hitherto unknown associations between feather mites and birds were recorded for eleven taxa identified to the species level, and nine taxa were recorded for the first time in Brazil. The number of new geographic records, as well as the hitherto unknown mite-host associations, supports the high estimates of diversity for feather mites of Brazil and show the need for research to increase knowledge of plumicole mites in the Neotropical region.

Are sexes equally parasitized in damselflies and dragonflies?

Parasitism plays an essential part in ecology and evolution of host species and understanding the reasons for differential parasitism within and among hosts species is therefore important. Among the very important factors potentially affecting parasitism is the gender of the host. Here, we studied whether either females or males are more likely to harbour parasites among Odonatan insects, by relying on an extensive literature review and new field data. We collected data on numerous dragonfly and damselfly species and their ectoparasites (water mites) and endoparasites (gregarines) to examine the generality of similarities and differences in prevalence, intensity and maximum number of parasites of male and female hosts. We found three main results. Firstly, most of the odonate host species showed no differences between sexes in either gregarine or water mite prevalence and intensity. The only exception was female damselflies’ higher gregarine prevalence and intensity compared to conspecific males. These inequalities in gregarine parasitism may be due to behavioral and physiological differences between conspecific males and females. In comparison, there were no differences in dragonflies between sexes in water mite or gregarine prevalence and intensity. Secondly, damselflies had higher prevalence and intensity levels of both gregarine and water mite parasites compared to dragonflies. Finally, we found a strong species level pattern between female and male parasitism: a certain level of gregarine or water mite parasitism in one sex was matched with a similar parasitism level for the other. This indicates similar exposure and susceptibility to parasites on both sexes. Even though significant differences of parasite levels between the sexes were observed within certain host species, our results strongly suggest that on a general level a more parasitized sex does not exist in the order, Odonata.

Mites of sheep and goats in Oromia Zone of Amhara Region, North Eastern Ethiopia: species, prevalence and farmers awareness.

BackgroundMites are one of the most common and widely distributed ectoparasites of small ruminants in Ethiopia, contributing to major hindrances in livestock productivity in the country. Despite of this fact, specific study was not conducted on mites of small ruminants in Ethiopia. Therefore, the present study was performed from October 2009 to May 2010 to determine the prevalence and species composition of mites in three agroecological zones in north eastern Ethiopia. In addition, a questionnaire survey on mites was conducted to assess the control practices and awareness of farmers in the study areas.ResultsOut of a total of 1280 sheep and 1264 goats examined, 97(7.6 %) of sheep and 174(13.8 %) goats were infested with one or more species of mites. In goats an overall prevalence of 10.3 % Sarcoptes, 2.8 % Demodex and 0.6 % Psoroptes were recorded whereas in sheep an overall prevalence of 3.5 % Sarcoptes, 2.1 % Demodex and 1.6 % Psoroptes were observed. Sarcoptes (P = 0.03; OR = 2.1) and Demodex (OR = 3.25; p = 0.004) were significantly more common in young than in adult sheep. Demodectic mange was significantly higher in young (4.1 %) compared to adult (2.3 %) goats (OR = 2.2; P = 0.02). Significantly higher (P < 0.01) overall prevalence of sarcoptic and demodectic mites in both sheep and goats with poor than with good body condition was recorded. Results of the questionnaire survey supported results of our cross-sectional study.ConclusionsThis study demonstrates high prevalence of mange mites in sheep and goats of the study area. The study revealed that Sarcoptes is the predominant mite in both sheep and goats. Animal owners and veterinarians should consider mite control in small ruminants as part of the routine ectoparasite control in Ethiopia.

Communities of gamasid mites on Eothenomys miletus in southwest China

AbstractThe Yunnan red-backed vole (Eothenomys miletus) is an endemic and specific wild rodent species in China. From 39 sites across southwest China, a total of 12,536 individuals of gamasid mites were collected from 2,463 voles between 2001 and 2013. The 12,536 mites were identified as comprising 106 species, 26 genera and 9 families. The overall mite prevalence and mean abundance from all the voles were 48.36% and 5.09 mites/per examined vole, respectively. Laelaps chini (C

Differential water mite parasitism, phenoloxidase activity, and resistance to mites are unrelated across pairs of related damselfly species.

Related host species often demonstrate differences in prevalence and/or intensity of infection by particular parasite species, as well as different levels of resistance to those parasites. The mechanisms underlying this interspecific variation in parasitism and resistance expression are not well understood. Surprisingly, few researchers have assessed relations between actual levels of parasitism and resistance to parasites seen in nature across multiple host species. The main goal of this study was to determine whether interspecific variation in resistance against ectoparasitic larval water mites either was predictive of interspecific variation in parasitism for ten closely related species of damselflies (grouped into five “species pairs”), or was predicted by interspecific variation in a commonly used measure of innate immunity (total Phenoloxidase or potential PO activity). Two of five species pairs had interspecific differences in proportions of individuals resisting larval Arrenurus water mites, only one of five species pairs had species differences in prevalence of larval Arrenurus water mites, and another two of five species pairs showed species differences in mean PO activity. Within the two species pairs where species differed in proportion of individuals resisting mites the species with the higher proportion did not have correspondingly higher PO activity levels. Furthermore, the proportion of individuals resisting mites mirrored prevalence of parasitism in only one species pair. There was no interspecific variation in median intensity of mite infestation within any species pair. We conclude that a species’ relative ability to resist particular parasites does not explain interspecific variation in parasitism within species pairs and that neither resistance nor parasitism is reflected by interspecific variation in total PO or potential PO activity.

Populations of the damselflyCoenagrion hastulatumat the edge of the species range have fewer gregarine and water mite parasites

SummaryThe metapopulation theory predicts that the more distant a host population is from other populations, the more challenged will be a parasite to colonise it. We studied parasite prevalence of two parasite taxa across the geographical range of their host in Finland, from more dense host population structure in the south of Finland, towards the northern edge of the host distribution characterised by more isolated populations.We found that prevalence of both water mites and gregarines decreased with increasing latitude towards the distribution edge with more isolated population structure of the host damselfly,Coenagrion hastulatum. Furthermore, the prevalences of the two parasite groups were positively correlated.The results are discussed in the context of three non‐mutually exclusive hypotheses, explaining why host species have fewer parasites at the edge of their geographic range: (i) unsuitable host hypothesis, (ii) physiological barrier hypothesis and (iii) metapopulation hypothesis.

Repeatability of feather mite prevalence and intensity in passerine birds.

Understanding why host species differ so much in symbiont loads and how this depends on ecological host and symbiont traits is a major issue in the ecology of symbiosis. A first step in this inquiry is to know whether observed differences among host species are species-specific traits or more related with host-symbiont environmental conditions. Here we analysed the repeatability (R) of the intensity and the prevalence of feather mites to partition within- and among-host species variance components. We compiled the largest dataset so far available: 119 Paleartic passerine bird species, 75,944 individual birds, ca. 1.8 million mites, seven countries, 23 study years. Several analyses and approaches were made to estimate R and adjusted repeatability (Radj) after controlling for potential confounding factors (breeding period, weather, habitat, spatial autocorrelation and researcher identity). The prevalence of feather mites was moderately repeatable (R = 0.26–0.53; Radj = 0.32–0.57); smaller values were found for intensity (R = 0.19–0.30; Radj = 0.18–0.30). These moderate repeatabilities show that prevalence and intensity of feather mites differ among species, but also that the high variation within species leads to considerable overlap among bird species. Differences in the prevalence and intensity of feather mites within bird species were small among habitats, suggesting that local factors are playing a secondary role. However, effects of local climatic conditions were partially observed for intensity.