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At least 559 records · Page 31Linked to original sources
PubMed2001

A method for both mass and individual rearing of fungivorous astigmatid mites (Acari).

Several species of common fungi were assessed as food for fungivorous astigmatid mites. Hypocrea nigricans, Botrytis cinerea and Flammulina velutipes were generally good food sources for most mites examined. Fungal mycelia growing on PDA (potato dextrose agar) medium were not only nutritionally adequate but the system also maintained high humidity through the water-based agar medium. Among acarid mites, most species of Rhizoglyphinae could be reared easily with the method. Although filter-feeding histiostomatid mites do not feed directly on hyphae, some species were successfully maintained with the same method through multiple generations. Presumably, these mites obtained sufficient nutrition from the agar medium and fungal metabolites leaching into it. Most species ultimately produced dispersing heteromorphic deutonymphs on these media. Individual mites were also maintained in isolation within glass rings on fungal colonies. Using this technique, we were able to compare developmental periods, fecundity and survival periods of mites reared under different conditions.

Animal Husbandry↗
PubMed2003

Effects of prey mite species on life history of the phytoseiid predators Typhlodromalus manihoti and Typhlodromalus aripo.

The effects of prey mite suitability on several demographic characteristics of phytoseiid predators and the relationship of these effects to the potential of phytoseiid predators to control herbivorous mite populations are well documented. Evidence has also accumulated in the last 20 years demonstrating that phytoseiid predators utilize herbivorous prey mite-induced plant volatiles as olfactory cues in locating their herbivorous mite prey. but less well established is the predictability of reproductive success from the ability of the predators to utilize olfactory cues to locate their prey, and how these processes are related to the success of the predators as biological control agents of the herbivorous mite. In this study, we determined in laboratory no choice experiments, the development, survivorship and fecundity of the two neotropical phytoseiid predators Typhlodromalus manihoti Moraes and T. aripo DeLeon when feeding on three herbivorous mites, including the key prey species Mononychellus tanajoa (Bondar), and the two alternative prey species Oligonychus gossypii (Zacher) and Tetranychus urticae (Koch). Intrinsic rate of increase (rm) of T. aripo was 2.1 fold higher on M. tanajoa as prey compared with T. urticae as prey, while it was almost nil on O. gossypii. For T. manihoti, rm was 2.3 fold higher on M. tanajoa as prey compared with O. gossypii as prey, while reproduction was nil on T. urticae. An independent experiment on odor-related prey preference of the two predator species (Gnanvossou et al. 2002) showed that T. manihoti and T. aripo preferred odors from M. tanajoa-infested leaves to odors from O. gossypii-infested leaves. Moreover, both predator species preferred odors from M. tanajoa-infested leaves over those from T. urticae-infested leaves. As reported here, life history of the two predatory mites matches odor-related prey preference if the key prey species is compared to the two inferior prey species. The implications of our findings for the persistence of T. manihoti and T. aripo and biological control of M. tanajoa in the cassava agroecosystem in Africa are discussed.

Analysis of Variance↗
PubMed2004

State-dependent and odour-mediated anemotactic responses of the predatory mite Phytoseiulus persimilis in a wind tunnel.

Anemotaxis in the predatory mite Phytoseiulus persimilis (both well-fed and starved), has previously been studied on a wire grid under slight turbulent airflow conditions yielding weak, yet distinct, gradients in wind speed and odour concentration (Sabelis and Van der Weel 1993). Such conditions might have critically influenced the outcome of the study. We repeated these experiments, under laminar airflow conditions on a flat surface in a wind tunnel, thereby avoiding variation in wind speed and odour concentration. Treatments for starved and well-fed mites were (1) still-air without herbivore-induced plant volatiles (HIPV) (well-fed mites only), (2) an HIPV-free air stream, and (3) an air stream with HIPV (originating from Lima bean plants infested by two-spotted spider mites, Tetranychus urticae). Well-fed mites oriented in random directions in still-air without HIPV. In an air stream, starved mites always oriented upwind, whether plant odours were present or not. Well-fed mites oriented downwind in an HIPV-free air stream, but in random directions in an air stream with HIPV. Only under the last treatment our results differed from those of Sabelis and Van der Weel (1993).

Animals↗
PubMed2004

Random amplified polymorphic DNA analysis of kinship within host-associated populations of the symbiotic water mite Unionicola foili (Acari: Unionicolidae).

Kinship relations within populations of unionicolid water mites are not well known, owing to their complex life cycles and the fact that interactions between active and resting stages for some species are transitory. A number of species of unionicolid water mites are, however, obligate symbionts of freshwater mussels and spend most of their life cycle in association with these hosts. Among these species of mites, parents and offspring are more likely to co-occur and thus provide opportunities to address questions related to the structure of the mating system. The present study employs random amplified polymorphic DNA (RAPD) analysis to address kinship within populations of Unionicola foili living in symbiotic association with the host mussel Utterbackia imbecillis. DNA was amplified from adult mites and a representative number of eggs or larvae (n = 20-30) that were removed from mussels collected on three separate occasions (July, November, and March) over a 12-month period. Parsimony analyses of the molecular data for adults and progeny collected from mussels during July, November, and March revealed distinct groupings, that for the most part, corresponded to mites collected from each of the sampling periods. Many of the genetic markers obtained for male and female U. foili were not evident among the larvae or eggs, suggesting that adults obtained from a host mussel at the time of collection were not the parents of a majority of the progeny. However, female mites and eggs collected from mussels during March and November shared more markers than did females and progeny examined during July. Furthermore, many offspring in the July sampling period were found to have one or more parents absent from the sampled population. Overall, RAPD profiling appears to have limited usage in determining kinship within populations of U. foili, due to its recruitment patterns, and the relatively large number of adults and progeny per mussel. It may, however, prove to be a useful method for assessing genetic relatedness among unionicolid mussel-mites that have substantially lower population densities.

Animals↗
PubMed2004

Of spates and species: responses by interstitial water mites to simulated spates in a subtropical Australian river.

The 'hyporheic refuge hypothesis' predicts that the hyporheic zone, the saturated sediments below and alongside rivers and streams, is a refuge from the scouring effects of spates for many aquatic invertebrates including water mites. We tested this hypothesis in two lateral gravel bars and two riffles in a subtropical Australian river by collecting water mites from the hyporheic zone at two depths (10 and 50 cm) at two 'pre-flood' sampling times before experimentally diverting water through the sites for 14 h to simulate a spate. Taxon richness of mites washigh (46 taxa) and dominated by the Prostigmata, with nearly half the species being new to science. Oribatids were also common at the four sites. Samples were collected twice during each 'spate', and again soon after flow was returned to normal. The experimental spate induced changes in the strength and even direction of subsurface-surface water exchange; however, these changes seldom persisted after the experiment, nor after a subsequent natural spate. The hyporheic refuge hypothesis was not supported by our water mite data. Neither during nor shortly after the experimental spates did we find more epigean (surface-dwelling) water mites in downwelling zones where surface streamwater enters the hyporheic zone, demonstrating that these mites were not using the hyporheic zone as a refuge at these locations. There was also no evidence for a 'wash out' effect, because hyporheic mitedensities did not significantly decline late in the spate. Our data indicate that floods of the low magnitude simulated in this study apparently do not pose a lasting disturbance for hypogean water mites. The fact that the same response was found at four sites indicates that the hyporheic refuge hypothesis may not always be an appropriate explanation for rapid post-flood recolonisation. Possibly, the use of the hyporheic zone as a refuge from floods may be dictated by the strength of the disturbance and substrate composition and stability.

Animals↗
PubMed2004

Combining plant- and soil-dwelling predatory mites to optimise biological control of thrips.

The efficiency of a natural enemy combination compared to a single species release for the control of western flower thrips (WFT) Frankliniella occidentalis (Pergande) on cucumber plants was investigated. Since a large part of F occidentalis seems to enter the soil passage, a joint release of the plant-inhabiting predatory mite Amblyseius cucumeris (Oudemans) that feeds on thrips first-instar larvae and the soil-dwelling predatory mite Hypoaspis aculeifer (Canestrini) that preys on thrips pupae in the ground might offer a promising approach for a holistic control strategy. Therefore, two sets of experiments were conducted in cooperation with a commercial vegetable grower where the plants in plots were infested with a defined number of larval and adult F occidentalis. Two species of natural enemies were released either synchronously or solely, and their efficacy was compared to control plots devoid of antagonists. In both experiments, the predatory mites were released twice with a density of 46 A. cucumeris/m2, and 207 H. aculeifer/m2 (low-density) in the first experiment and 528 H. aculeifer/m2 (high-density) in the second one. Population growth of all arthropod species on the plants and in the soil was quantified at regular intervals and included all soil-dwelling mites and alternative preys present in the substrate. The results showed that H. aculeifer alone had a significant impact on thrips population development only when released at high-densities, but competence was lower compared to the other antagonist treatments. The impact of A. cucumeris alone and A. cucumeris & H. aculeifer combined was similar. Thus, the pooled exploitation of natural enemies did not boost thrips control compared to the single species application of A. cucumeris (non-additive effect), which could be explained by resource competition between both predatory mite species. Species number and population size in the soil of the experimental plots both showed a high variability, a possible consequence of their interaction with released soil-dwelling predatory H. aculeifer mites. The impact of resource competition and presence of alternative preys on thrips biological control is exhaustively discussed. From our study, we can extract the subsequent conclusions: (1) the combined use of H. aculeifer and A. cucumeris cannot increase thrips control on cucumber compared to the release of A. cucumeris alone, but the overall reliability of thrips biological control might be enhanced, (2) the availability of alternative preys seemed to affect the thrips predation rate of H. aculeifer, and (3) the impact of naturally occurring soil predatory mites on the control of WFT seemed to be partial.

Animals↗
PubMed1998

Direct measurements of temperature and humidity in dust mite microhabitats.

BACKGROUND: Up to 70% of atopic asthmatics have a positive skin test to the dust mite allergen Der p 1. Reduction of dust mite numbers by lowering room humidity control is one suggested technique for reducing dust mite allergen levels to clinically acceptable levels. Trials of this technique in temperate climates have reported mixed results. It has been speculated that one reason for this is that humidity changes in room ambient air are not tightly linked to humidity changes in the dust mite microenvironment (in the base of carpets, bedding, furniture etc.). OBJECTIVE: To directly measure humidities and temperatures in dust mite microenvironments and compare these to ambient conditions, and so gather data on how the microclimates are influenced by room conditions and moisture and heat sources, such as an occupant in a bed. METHODS: A special small humidity device has been developed which can discriminate humidity changes over distances of millimetres. With these devices microclimates have been measured in the base of carpets, in layers through bedding, and in furniture. RESULTS: Measured base-of-carpet humidities were significantly higher than room humidities. Bedding relative humidities show complex behaviour according to the distance separation between the measuring point and the occupant. Immediately below the occupant, bed relative humidities fall when the person enters the bed. Similar behaviour is observed in a sofa. CONCLUSION: Some dust mite microclimates have been shown to be very different from room conditions. Consequently, reduction of dust mite numbers and allergen levels cannot be guaranteed by the controlling of room humidities.

Allergens↗
PubMed1999

Identification of cecidophyopsis mites (Acari: Eriophyidae) based on variable simple sequence repeats of ribosomal DNA internal transcribed spacer-1 sequences via multiplex PCR.

A PCR multiplex technique was developed for identifying Cecidophyopsis mites using species-specific differences in rDNA ITS-1 sequences. Four PCR primers derived from ITS-1 were used for the simultaneous amplification (multiplex PCR) of interspecifically variable simple sequence repeats (vSSRs). Mites were identified by electrophoresing PCR products alongside those obtained from plasmids containing ITS copies of known mite species. The multiplex PCR assay was rapid, reproducible and had a sensitivity comparable to sequencing. It was used to identify mite specimens on Ribes from around the world. It also identified a profile from mites on R. rubrum that had no equivalent amongst the known Cecidophyopsis species. Sequence and ecological analysis of this mite suggest that it is a new species of nongall-forming Cecidophyopsis mite.

Animals↗
PubMed2001

House dust mite and cockroach exposure are strong risk factors for positive allergy skin test responses in the Childhood Asthma Management Program.

BACKGROUND: Children with asthma have a high prevalence of environmental allergies, especially to indoor allergens. The relationships of exposure to indoor allergens (dust mites, cat, dog, cockroach, and molds) and other host factors to allergy sensitization have not been evaluated simultaneously in a large cohort. OBJECTIVES: We studied 1041 children aged 5 to 12 years with mild-to-moderate asthma to determine risk factors associated with having positive allergy skin test responses to indoor allergens. Also, we described, compared, and contrasted 6 allergens in the home environments of these children from 8 North American cities. METHODS: Data were used from baseline visits of the Childhood Asthma Management Program. Patients' sensitivities to house dust mites (Dermatophagoides farinae and Dermatophagoides pteronyssinus), cats, dogs, cockroaches, and molds were examined for relationships to demographic variables, home dust allergen exposures, number of other positive allergy skin test responses, total serum IgE levels, and smoking in the home. RESULTS: San Diego (78.5%) and Toronto (59.3%) had the topmost percentages of homes with moderate-to-high house dust mite levels. Boston (21.5%), St Louis (16.3%), and Baltimore (13.4%) had the highest percentages of homes with detectable levels of cockroach allergen. For house dust mites, the higher the level of allergen exposure, the more likely patients were to have positive allergy skin test responses, with relative odds of 9.0 (95% confidence interval, 5.4-15.1) for those exposed to high mite levels (>10.0 microg/g dust) relative to those unexposed. Even exposure to low levels of mite allergen (0.020-2.0 microg/g) was found to be a significant risk factor for sensitization. For cockroach allergen, those with detectable home exposure were more likely to have positive skin test responses (relative odds, 2.2; 95% confidence interval, 1.3-3.8) than those with undetectable exposure. In contrast, levels of exposure to cat, dog, and mold allergens were not related to sensitization rates. For cat allergen, this may reflect lower rates of cat ownership among highly sensitized subjects. Furthermore, the number of allergy skin test responses that were positive, excluding the test for the outcome of interest for each model, and total serum IgE levels were strong independent predictors of sensitization. CONCLUSIONS: Levels of exposure determined by house dust analysis are important determinants of sensitization for dust mite and cockroach allergen. This relationship was not demonstrable for cat, dog, or mold allergens, possibly because of confounding factors. For all allergens studied, the degree of atopy, determined by the total number of positive skin test responses or by total serum IgE levels, is an important contributing risk factor for sensitization.

Air Pollution, Indoor↗
PubMed2001

Reducing relative humidity is a practical way to control dust mites and their allergens in homes in temperate climates.

BACKGROUND: Maintaining a relative humidity (RH) of less than 50% is one recommendation for reducing numbers of house dust mites and their allergens in homes. OBJECTIVE: The purpose of this study was to determine whether, in a humid temperate climate, indoor RH could be sufficiently lowered to control dust mites and their allergens. METHODS: During a period spanning 2 humid summers (May 1998 to October 1999), dust mite and allergen densities were determined in 3 groups of homes. One group (low RH group, n = 23) maintained an RH of less than 51%. Most of these homes used a high-efficiency dehumidifier and air conditioning. A second group of homes (group A) used air conditioning only (n = 19) or air conditioning and dehumidification (n = 5) but did not maintain an RH of less than 51%. A third group of homes (group C, n = 24) controlled climate by opening windows and had an RH of greater than 51%. Normal housecleaning was maintained in all homes during the study. RESULTS: The low RH group homes started in June with a mean +/- SE of 401 +/- 124 live mites and 17 +/- 3 microg of total Der 1 allergen per gram of dust. After 17 months of maintaining an RH of less than 51%, these declined significantly to 8 +/- 3 live mites per gram (P =. 004) and 4 +/- 1 microg of Der 1 per gram of dust (P <.001). In contrast, group A and C homes exhibited seasonal peaks of 500 to 1000 mites and 40 to 70 microg of Der 1 per gram of dust. At all time points after the baseline sample, the low RH group homes had significantly less (P <.001) allergen than the group A and C homes. After 17 months, allergen levels were more than 10 times lower in low RH homes compared with humid homes. CONCLUSION: This study showed that it is practical to maintain an indoor RH of less than 51% during the humid summer season in a temperate climate, and this resulted in significant reductions in mite and allergen levels.

Air Pollution, Indoor↗
PubMed2003

Assessment of Aegilops tauschii for resistance to biotypes of wheat curl mite (Acari: Eriophyidae).

Aegilops tauschii, the wild diploid D-genome progenitor of wheat, Triticum aestivum L., is an important source of resistance to several arthropod pests and pathogens. A total of 108 Ae. tauschii accessions from different geographic regions were evaluated for resistance to biotypes of the wheat curl mite, Aceria tosichella Keifer, from Kansas, Nebraska, and Montana. The wheat curl mite is the only vector known to transmit wheat streak mosaic virus. Wheat curl mite resistance was detected in germplasm from all the geographic locations represented. The highest percentage of resistant accessions originated from Turkey, followed by Afghanistan and the Caspian Sea region of Iran. Sixty-seven percent of the accessions exhibited resistance to at least one wheat curl mite biotype and 19% were resistant to all the three biotyopes. Resistance to the accessions tested occurred more frequently in the Nebraska and Kansas biotypes (69% and 64%, respectively) than did resistance to the Montana biotype (42%), although the frequency of resistance was not significant. The differential reactions of accessions to the different wheat curl mite biotypes suggests that Ae. tauschii has at least five different genes for resistance to mite colonization. Ae. tauschii continues to be a very useful source for wheat curl mite resistance genes for bread wheat improvement.

Afghanistan↗
PubMed2004

Effects of fungicide residues on the survival, fecundity, and predation of the mites Tetranychus urticae (Acari: Tetranychidae) and Galendromus occidentalis (Acari: Phytoseiidae).

Representative fungicides from three or four families used for management of powdery mildew and other diseases in tree fruits were evaluated for their effects on a common spider mite and predator mite species, respectively. A modified Munger cell technique was effective in measuring the response of phytophagous and predaceous mites to fungicide residues on detached leaves in the laboratory. Demethylation-inhibiting (DMI) (imidazole [triflumazole] and triazole [myclobutanil]) and strobilurin (trifloxystrobin) fungicides were not toxic to female Tetranychus urticae Koch and Galendromus occidentalis (Nesbitt), and no sublethal effects were found on fecundity and predation rate after 3-5-d exposure to residues. Benomyl, a benzimidazole fungicide, increased adult mortality and reduced fecundity for both mite species; however, it did not alter the predation rate of G. occidentalis females on T. urticae eggs and larvae. Female G. occidentalis that survived the lethal effects of benomyl and the comparison acaricide pyridaben were unimpaired in predation. Our results for benomyl substantiate those of earlier studies and provide evidence for nontoxic effects of DMI and strobilurin fungicides on mites. We propose that DMI and strobilurin fungicides are a good fit for integrated mite management programs due to conservation of phytoseiid predatory mites.

Animals↗
PubMed1990

Localization of antigens and allergens in thin sections of the house dust mite, Dermatophagoides pteronyssinus (Acari: Pyroglyphidae).

Cryostat sections of the house dust mite, Dermatophagoides pteronyssinus, were probed in fluorescent microscopy studies with rabbit polyclonal and mouse monoclonal antibodies specific for mite allergens including the major allergen, Der p I. Sections also were probed for allergens with sera from human mite-allergic subjects containing IgE antibodies to mite allergens and with lectins. Antibody binding was mainly to the gut lining and gut contents of the mite, although some specific labeling also was associated with the head region and cuticle. This is the first detailed localization of mite allergens in situ. The morphology of the mite was investigated using plastic embedded thin sections and was found to be similar to that previously described for D. farinae.

Allergens↗
PubMed1996

Fixation affects morphometric characters of Psoroptes cuniculi mites (Acari:Psoroptidae).

Thirteen morphologic characters were evaluated on Psoroptes cuniculi (Delafond) mites to determine if measurements for these variables were influenced by the use of different fixatives and varying periods of fixation. Morphologic structures composed primarily of chitin (outer opisthosomal setal lengths and right 3rd tarsal pedicle length) were not affected by either fixative type or duration of fixation. In contrast, alcohol and formalin fixation both resulted in significant reductions (P < 0.05) in mean body size measurements when compared with mites mounted in Hoyer's medium without prior fixation. The largest reduction in size was seen in mites fixed for the longest period, but there was no apparent association between size reduction and increasing concentration of alcohol or formalin. Surprisingly, when mites were remeasured 4 yr later, Hoyer's mounting medium was found to have had the opposite effect of fixation and caused an increase in body size. Mites mounted in Hoyer's medium without prior fixation had significantly increased body lengths, whereas mites mounted in Hoyer's following fixation in alcohol and formalin had significant increases in both body length and posterior body width. Our results indicate that fixation and mounting can significantly influence the morphometric analysis of mites and other arthropods. We recommend that morphometric studies be conducted using consistent methodology to reduce experimental bias, and these methodologies be reported in publications dealing with morphometric analyses.

Animals↗
PubMed1995

Damp housing and childhood respiratory symptoms: the role of sensitization to dust mites and molds.

In 1990, a case-control study was conducted in the Netherlands into the association between damp housing, childhood respiratory symptoms, and sensitization to house dust mites and mold allergens. In this study, 259 children with chronic respiratory symptoms and 257 control children were involved. Total serum immunoglobulin E (IgE) and specific IgE against house dust mites and a mixture of molds were determined. A visual inspection for signs of home dampness was performed in all homes. A questionnaire was given to the parents of the children to elicit information about the presence of signs of dampness in the previous 2 years and about risk factors for childhood respiratory disease. In the case group, 94 children had elevated serum IgE levels to house dust mites and 24 children to the mixture of molds. In the control group, house dust mite allergy was found in 31 children and mold allergy in two children. In a crude analysis, cases were slightly more likely to have been living in homes where damp or mold was reported or observed than were the controls. In cases as well as controls, home dampness was associated with increased sensitization to dust mites and molds. There was no relation between home dampness and case-control status after stratification for sensitization, however. Restriction of the analysis to cases with elevated serum IgE levels against dust mites and/or molds, and to controls without elevated serum IgE, increased the odds ratios, and several became significant at p < 0.05. This supports a connection between damp housing and sensitization to dust mites and/or molds and childhood respiratory symptoms.(ABSTRACT TRUNCATED AT 250 WORDS)

Allergens↗
PubMedDate not supplied

Kawasaki syndrome and house dust mite exposure.

We investigated exposure to house dust mites and freshly cleaned carpets in patients with Kawasaki syndrome (KS) who resided in Denver, CO. House dust samples were analyzed for mites (Dermatophagoides pteronyssinus and Dermatophagoides farinae) and convalescent sera were assayed for immunoglobulin G antibody to mite antigen. House dust samples from case and neighborhood control homes showed no difference in the prevalence of mites. Fewer than 10% of dust samples from either group revealed evidence of live or dead mites. Nine of 18 (50%) children with KS had a prior history of exposure to freshly cleaned rugs within the 45 days of the onset of KS compared with 3 of 11 (27%) neighborhood controls. There was no difference in mean anti-mite antibody concentrations between convalescent sera from KS cases and sera from pediatric hospitalized controls. We conclude that in Denver KS can occur in the absence of significant mite exposure as defined by environmental studies or serologic means.

Antibodies↗
PubMed1975

A comparison of mite populations in mattress dust from hospital and from private houses in Cardiff, Wales.

Fifty mattress dust samples from private houses were examined--all were mite infested. Dermatophagoides pteronyssinus occurred in all samples and accounted for 81% of all mites. In thirty-two paired samples the total mite population of bedroom floor dust was only 10% of that found in the corresponding mattress dust. D. pteronyssinus was the dominant species in both and the population of this mite amounted to 7-5% of that found in the mattress dust. An analysis of mattress dust from 100 hospital beds showed that ninety-four mattresses were mite free; the other six contained only seven mites, all D. pteronyssinus. It is suggested that frequent changing and washing of bed linen and brushing and cleaning of mattresses were the main factors in preventing mite infestation in the Cardiff hospitals.

Bedding and Linens↗
PubMed1985

Storage mite allergy is common in a farming population.

The prevalence of storage mite allergy was investigated in an epidemiological study of respiratory symptoms in farmers on Gotland, an island in the Baltic Sea. A questionnaire concerning work-related and chronic symptoms from the airways and eyes was completed by 2578 farmers. A sample of 440 farmers subsequently underwent examination comprising skin-prick tests (animal danders, pollens, moulds and house dust mite), blood sampling for RAST against four storage mites (Acarus siro, Lepidoglyphus destructor, Tyrophagus putrescentiae and Glycyphagus domesticus) and total IgE analyses. Immediate onset hypersensitivity reactions in the airways and eyes were very common among active farmers on Gotland, the prevalence being as high as 40.0%. The prevalence of atopic allergy was 15.6%. Allergy to storage mites was diagnosed, from the case history and a positive RAST to at least one of the four storage mites, in fifty-two of 440 studied farmers (12%), corresponding to a calculated prevalence of storage mite allergy in the whole farming population of Gotland of 6.2%. The corresponding prevalence among farmers with hypersensitivity symptoms was 15.4% and among those with possibly IgE-mediated symptoms it was as high as 37.8%. The present study clearly demonstrates a high prevalence of allergy to storage mites among farmers with respiratory symptoms.

Adolescent↗