Mite Survival Research Articles

Typhlodromalus aripo De Leon (Acari: Phytoseiidae) development and reproduction on major cassava pests at different temperatures and humidities: an indication of enhanced mite resilience

Both prey type and abiotic conditions limit performance of phytoseiid predators. The exotic predatory mite, Typhlodromalus aripo developed and reproduced when maintained on eggs and active stages of the cassava green mite (CGM) Mononychellus progresivus at three different temperatures. At the highest temperature of 33 °C and the lowest at 12 °C, mite survival was less than 15 % over a period of ten days with low fecundity. At 12 °C, immatures took longer to reach maturity, while at 33 °C high mortality (>80 %) occurred. The best performance was recorded at 27 °C and 75 % relative humidity. Typhlodromalus aripo was also able to feed, develop and reproduce on the crawlers’ stage of the whitefly, Bemisia tabaci and the nymphal stage of the mealybug, Phenacoccus manihoti, though a low survival rate (<10 %) was observed for the stages of protonymph, deutonymph and adults. Normal life stage development and egg hatchability were recorded at 27 °C and 75 % RH. The egg stage exhibited high drought tolerance (70 % hatching at 40 % RH). Typhlodromalus aripo females consumed less than 3 crawlers and produced less than one egg/day when fed with B. tabaci and P. manihoti at 75 % RH. The study indicated that for successful utilization of T. aripo in the biological control of CGM, it would be important to introduce the predator at low prey density whether in absence or presence of alternative prey on cassava. In conclusion, results revealed T. aripo to have drought resilient survival attributes which enhances this phytoseiid as an effective biological control agent.

Apple pollen as a supplemental food source for the control of western flower thrips by two predatory mites, Amblyseius swirskii and Neoseiulus cucumeris (Acari: Phytoseiidae), on potted chrysanthemum.

It has been shown that pollen as a dietary supplement may increase the establishment (development and reproduction) and survival of phytoseiid predatory mites, and therefore the pest control these mites can provide. In this study, the role of apple pollen as a supplemental food source was assessed as a means to increase the efficiency of two predatory mite species, Neoseiulus cucumeris and Amblyseius swirskii, for control of western flower thrips, Frankliniella occidentalis, under greenhouse conditions. The impact of apple pollen on thrips populations and predator establishment on a greenhouse chrysanthemum crop was determined over a 4-week period. The two mite species were released separately and in combination with and without pollen with two control treatments (thrips only and thrips + pollen). The introduction of A. swirskii together with pollen application provided the best control of thrips (adults and immatures). The establishment of N. cucumeris was very low in the crop during the greenhouse trial. This could be attributable, in part, to their response to extreme temperature ranges that were encountered during the greenhouse cage trials. The use of A. swirskii alone and the mixed population of the two predatory mite species without pollen resulted in the lowest frequencies of plants with heavy damage, followed by the same treatments with the addition of apple pollen.

Does pollen availability mitigate the impact of pesticides on generalist predatory mites?

The effect of the provision of pollen on the impact of pesticides on the predatory mite Kampimodromus aberrans was assessed at individual and population levels. In the laboratory we evaluated the influence of pollen amount and pollen application frequency on lethal and sub-lethal effects of chlorpyrifos and spinosad. In a potted plant experiment, the effects of pesticides and pollen were assessed on predatory mite population abundance. In the laboratory, survival and fecundity of predatory mites were reduced by insecticides, and spinosad was more toxic than chlorpyrifos. In the same experiment, high pollen application frequency alleviated the sub-lethal effect induced by chlorpyrifos. On potted plants, pollen applications reduced the impact of chlorpyrifos on K. aberrans, whereas without pollen applications the impact of spinosad and chlorpyrifos on the predatory mite population was similar. Results obtained here highlight that the provision of fresh pollen is of particular importance for predatory mites when pesticides are applied.

Effect of Pollens of Various Ornamental Pepper Cultivars on the Development and Reproduction ofAmblyseius swirskii(Acari: Phytoseiidae)

The rationale behind the current study was to assess if the commercially available generalist phytoseiid mite, Amblyseius swirskii Athias-Henriot (Acari: Phytoseiidae), can survive and reproduce when fed on pollen from ornamental pepper (Capiscum annum L.; Solanales: Solanaceae). Results from this study will help in the selection of ornamental pepper cultivars as candidate banker plants for establishment of A. swirskii in ornamental nurseries. To determine the effect of different types of pepper pollen on survival and multiplication ability of mites; their longevity, daily rate of oviposition and total egg deposition was assessed. Amblyseius swirskii was reared on pollen collected from 4 ornamental pepper cultivars namely ‘Red Missile’, ‘Masquerade’, ‘Black Pearl’ and ‘Explosive Ember’. Amblyseius swirskii was able to survive, develop and oviposit when fed with pollens of all the 4 ornamental pepper cultivars and the 2 standard controls i.e., commercially available olive pollen Olea europaea L. (Lamiales: Oleaceae) and Scirtothrips dorsalis Hood (Thysanoptera: Thripidae). No significant differences were observed among the various diet treatments for the following biological parameters: mean duration from larvae to adult death (22.8–23.7 days), duration from larvae to eggs (11.8–12.5 days) and adult longevity (12.4–13.1 days). However, for mites fed on pollen the highest daily rate of oviposition (∼1.07 eggs/female/day) and total oviposition (∼10.23 eggs/female) was recorded on the ‘Red Missile’. Outcome of this study can boost the management strategies being used against S. dorsalis and other pest species affecting ornamental plants in Florida.

Differential Transmission of Triticum mosaic virus by Wheat Curl Mite Populations Collected in the Great Plains.

Wheat is an important food grain worldwide and the primary dryland crop in the western Great Plains. A complex of three wheat curl mite (WCM)-transmitted viruses (Wheat streak mosaic virus, High plains virus, and Triticum mosaic virus [TriMV]) is a cause of serious loss in winter wheat production in the Great Plains. TriMV was first reported in Kansas in 2006 and later found in most other Great Plains states. Currently, three populations of WCM have been identified by genetic characterization and differential responses to mite resistance genes in wheat. In this study, we examined TriMV transmission by these three WCM populations: 'Nebraska' (NE), 'Montana' (MT), and 'South Dakota' (SD). Mite transmission using single-mite transfers revealed that the NE WCM population transmitted TriMV at 41%, while the MT and SD WCM populations failed to transmit TriMV. In multi-mite transfers, the NE WCM population transmitted TriMV at 100% level compared with 2.5% transmission by MT and SD WCM populations. Interestingly, NE mites transferred during the quiescent stages following the first and second instar transmitted TriMV at a 39 to 40% rate, suggesting that immature mites were able to acquire the virus and maintain it through molting. In addition, mite survival for single-mite transfers was significantly lower for NE mites when transferred from TriMV-inoculated source plants (60%) compared with mock-inoculated source plants (84%). This demonstrates potentially negative effects on WCM survival from TriMV. TriMV transmission differences demonstrated in this study underscore the importance of identification of mite genotypes for future studies with TriMV.

Effect of temperature and time exposure on the survival of scabies mites and its eggs

Effect of temperature and time exposure on the survival of scabies mites and its eggs

An Aspartic Protease of the Scabies Mite Sarcoptes scabiei Is Involved in the Digestion of Host Skin and Blood Macromolecules

BackgroundScabies is a disease of worldwide significance, causing considerable morbidity in both humans and other animals. The scabies mite Sarcoptes scabiei burrows into the skin of its host, obtaining nutrition from host skin and blood. Aspartic proteases mediate a range of diverse and essential physiological functions such as tissue invasion and migration, digestion, moulting and reproduction in a number of parasitic organisms. We investigated whether aspartic proteases may play role in scabies mite digestive processes.Methodology/Principle FindingsWe demonstrated the presence of aspartic protease activity in whole scabies mite extract. We then identified a scabies mite aspartic protease gene sequence and produced recombinant active enzyme. The recombinant scabies mite aspartic protease was capable of digesting human haemoglobin, serum albumin, fibrinogen and fibronectin, but not collagen III or laminin. This is consistent with the location of the scabies mites in the upper epidermis of human skin.Conclusions/SignificanceThe development of novel therapeutics for scabies is of increasing importance given the evidence of emerging resistance to current treatments. We have shown that a scabies mite aspartic protease plays a role in the digestion of host skin and serum molecules, raising the possibility that interference with the function of the enzyme may impact on mite survival.

Bayesian spatial modelling and the significance of agricultural land use to scrub typhus infection in Taiwan

Scrub typhus is transmitted by the larval stage of trombiculid mites. Environmental factors, including land cover and land use, are known to influence breeding and survival of trombiculid mites and, thus, also the spatial heterogeneity of scrub typhus risk. Here, a spatially autoregressive modelling framework was applied to scrub typhus incidence data from Taiwan, covering the period 2003 to 2011, to provide increased understanding of the spatial pattern of scrub typhus risk and the environmental and socioeconomic factors contributing to this pattern. A clear spatial pattern in scrub typhus incidence was observed within Taiwan, and incidence was found to be significantly correlated with several land cover classes, temperature, elevation, normalized difference vegetation index, rainfall, population density, average income and the proportion of the population that work in agriculture. The final multivariate regression model included statistically significant correlations between scrub typhus incidence and average income (negatively correlated), the proportion of land that contained mosaics of cropland and vegetation (positively correlated) and elevation (positively correlated). These results highlight the importance of land cover on scrub typhus incidence: mosaics of cropland and vegetation represent a transitional land cover type which can provide favourable habitats for rodents and, therefore, trombiculid mites. In Taiwan, these transitional land cover areas tend to occur in less populated and mountainous areas, following the frontier establishment and subsequent partial abandonment of agricultural cultivation, due to demographic and socioeconomic changes. Future land use policy decision-making should ensure that potential public health outcomes, such as modified risk of scrub typhus, are considered.

Development of a Methodology and Evaluation of Pesticides Against &lt;I&gt;Aceria litchii&lt;/I&gt; and Its Predator &lt;I&gt;Phytoseius intermedius&lt;/I&gt; (Acari: Eriophyidae, Phytoseiidae)

The litchi erineum mite, Aceria litchii (Keifer), is the major pest of litchi, Litchi chinensis Sonnerat (Sapindaceae). This study evaluated the effect of 11 pesticides on the survival of A. litchii as well as on the survival and reproduction of Phytoseius intermedius Evans & McFarlane, the predator most found in association with it in Brazil. The containment of A. litchii in small petri dishes whose bottoms were covered with a solidified paste made of a mixture of gypsum and activated charcoal (9:1 in volume), kept humid, was shown to be adequate for this type of study. For the evaluation of the effect of pesticides on A. litchii, mites leaving the erinia from the pieces of litchi leaves (removed from the plants approximately 24 h earlier) were sprayed under a Potter tower and immediately transferred to the 2.5-cm-diameter petri dishes. After 2, 12, 24, and 48 h of the application, the dishes were examined to evaluate the mite survival. The four pesticides causing the highest levels A. litchii mortality, as well as azadirachtin, were tested for the effect on P. intermedius. For this test, experimental units consisted of discs of uninfested litchi leaves also sprayed under a Potter tower before introducing the predators. Survival and oviposition of the predator were evaluated every 24 h for 5 consecutive days; viability of the eggs laid was also evaluated. Highest mortality of A. litchii occurred with the application of fenpyroximate, sulfur, abamectin, and hexythiazox. Azadirachtin was considered moderately harmful to the predator P. intermedius, whereas other pesticides were classified as harmful. Despite the low efficiency of azadirachtin in the control of the pest, its relative selectivity to P. intermedius would encourage the evaluation on field condition, especially for use in organic production systems.

Effects of Rosmarinus officinalis and Salvia officinalis essential oils on Tetranychus urticae Koch (Acari: Tetranychidae)

Laboratory trials were carried out to characterize Rosmarinus officinal and Salvia officinalis essential oils and to evaluate their pesticidal activities against Tetranychus urticae. Slide-dip and leaf-disk bioassays were employed to study the mortality caused by these plant oils on two-spotted spiders. Different dilutions of both essential oils (0.10–0.25%, v/v) caused acute contact toxicity, although the sage extract showed greater acaricidal activity than rosemary oil. Mortality rates of 95–100% were observed at all the sage oil dosages and when rosemary emulsions contained at least 0.20% of essential oil. In the residual contact experiments (leaf-disk assays), 0.15–0.25% of sage oil or 0.25% of rosemary extracts significantly reduced mite survival. Leaf-disk bioassays were also used to evaluate the effects of oils on T. urticae fecundity. The total number of eggs oviposited decreased as the oil dosage increased and rate reductions were significant when 0.15–0.25% of sage or 0.25% of rosemary extracts were sprayed onto leaf-disks. The effect of oil treatments on the number of emerged larvae was similar to that on egg oviposition. Mite eggs were more susceptible to sage residuals, and significant reductions in larva emergence rates were observed with both sage dosages after 8 days of treatment. Rosemary and sage extracts showed no insecticidal activity against Ceratitis capitata, although sage oil greatly attracted adult flies (see supplementary file).

The Bunsen–Roscoe reciprocity law in ultraviolet-B-induced mortality of the two-spotted spider mite Tetranychus urticae

To determine whether the Bunsen–Roscoe reciprocity law (i.e., the extent of photochemical effects is determined by cumulative irradiance) is applicable to ultraviolet-B (UVB) damage in the twospotted spider mite Tetranychus urticae, egg hatchability and survival of individuals were assessed after irradiation with a UVB lamp using various combinations of intensity and time length. A positive linear correlation between probit mortality and cumulative UVB irradiance was detected in eggs, larvae, teleiochrysalis females, and adult females, regardless of UVB intensity (0.19–0.58Wm−2). LD50 values were clearly higher in adult females, followed by teleiochrysalis females, larvae, and eggs. In eggs, reciprocity was obeyed not only at the UVB intensities listed above, but also at very low UVB intensity (0.014–0.023Wm−2). Such reciprocity in the negative effects of UVB radiation was also observed for the developmental rate of juveniles and egg production of adult females. However, the LD50 value of eggs obtained using the UVB lamp (0.58kJm−2) was lower than that elicited by solar UVB radiation in a previous outdoor experiment (about 50kJm−2). These results suggest that a photoreactivation mechanism plays an important role in the survival of this mite under solar radiation.

Effect of Activated Charcoal Fibers on the Survival of the House Dust Mite, Dermatophagoides pteronyssinus: A Pilot Study

House dust mites produce potent allergens that exacerbate asthma in sensitized patients, whom are recommended to practice allergen avoidance within their home environment. We tested the effect of activated charcoal impregnated fibers on house dust mite survival. One hundred live adult house dust mites (Dermatophagoides pteronyssinus) were added to eight culture dishes preequilibrated at room temperature (n = 4) and 70% humidity (n = 4) containing house dust mite food and active charcoal fibers. At 10 minute intervals, live and dead house dust mites were counted. All house dust mites instantly attached to the activated charcoal fibers and started to shrink almost immediately. There were no live house dust mites present as early as 40 minutes in some dishes while after 190 minutes all house dust mites were dead. In conclusion, activated charcoal fibers, if incorporated into bedding items, have the potential to control house dust mites in the indoor environment.

Accumulation and toxicity of metals (copper, zinc, cadmium, and lead) and organic compounds (geraniol and benzo[a]pyrene) in the oribatid miteOppia nitens

The oribatid mite Oppia nitens has been suggested as a test species for ecotoxicological assessment of contaminated boreal soils. Knowledge of the ecotoxicity of pollutants of different modes of action to this species is necessary to assess its relative sensitivity in comparison with other invertebrates. The toxicity of four metals and two organic chemicals to O. nitens was evaluated over a 28- or 35-d period. Mite survival, reproduction, and tissue accumulation were assessed at the end of the test. Reproduction was a more sensitive endpoint than survival for all of the compounds except geraniol. The reproduction median inhibitory concentration (IC50) values for Cu, Zn, Cd, and Pb were 2,896, 1,562, 137, and 1,678 mg/kg, respectively, whereas those for benzo[a]pyrene and geraniol were greater than 1,600 and 283 mg/kg. The median lethal concentration (LC50) values for Cu, Zn, Cd, and Pb were 3,311, 2,291, 603, and 6,761 mg/kg, respectively, whereas those for benzo[a]pyrene and geraniol were greater than 1,600 and 251 mg/kg. When effects on reproduction are compared with those of other soil invertebrates, O. nitens appears less sensitive to Cu and Zn but within the same order of magnitude of sensitivity as that for Cd and Pb. Despite its lower sensitivity to Cu and Zn, O. nitens is a member of a group underrepresented in ecotoxicological evaluations and should therefore be included in test battery for risk assessment of contaminated boreal and other northern soils.

Indoor Allergens in the Rocky Mountains: Dust Collection and Analysis in the Arid North

With asthma being prevalent in the northern Rocky Mountains, indoor dust and the allergens it contains can pose a problem. Little research in this geographical area has been conducted to determine what allergens are present and in what quantity they exist in indoor dust. It has been assumed as well for many years that Montana's elevation and climate are not conducive to dust mite survival and thus many allergists don't consider them as a potential problem for their patients. Using 40 homes located around rural western Montana and eastern Idaho, dust samples were collected using three methods along with collecting humidity data during winter months from 2008-2010. Dust samples were analyzed using new extraction techniques and a pre-mixed multiplex array for indoor allergens to determine presence and concentration of these five allergens: Canine, Feline, European dust mite, American dust mite, and a secondary mite group (Can f 1, Fel d 1, Der p 1, Der f 1, Der p 2/Der f 2, respectively). Skin prick tests were performed on subjects less than 18 years old in each home. Preliminary data shows evidence of canine and feline in the majority of house dust samples. Allergen sensitivity to these two allergens was also very prevalent. Two homes show presence of dust mite allergen, with two different subjects showing allergen sensitivity to dust mite. Additional analyses are being performed to verify positive allergen results in house dust, and to determine accurate concentrations of each allergen.

The association of Tarsonemus mites (Acari: Heterostigmata) with different apple developmental stages and apple core rot diseases

ABSTRACT Information on the role of mites in the genus Tarsonemus Canestrini and Fanzago, 1876 in the epidemiology of apple core rots (wet and dry) is limited. The aims of this study were to (1) assess the effect of different apple developmental stages (buds, blossoms, 4-cm diameter fruit, mature fruit and mummies) on the relative abundance of Tasonemus mites, (2) determine if there is a tendency of Tarsonemus mites to be associated with wet core rot (WCR) and dry core rot (DCR) apples, and (3) evaluate the suitability of three core-rot-associated fungal genera as food sources for the mites. Investigations into four orchards, two core-rot-susceptible (Red Delicious) and two-core-rot resistant (Granny Smith), revealed that Tarsonemus mites were the dominant mite genus in all the apple developmental stages in all orchards. The Tarsonemus mites had the highest incidence in mature fruits and mummies in all the orchards. In the cores of healthy and DCR Red Delicious fruits, Tarsonemus mites had a high occurrence of 56% and 84%, respectively. In these fruits, a significant association was found between DCR and the presence of mites in the core. In contrast, in Granny Smith fruits, mites were restricted to the calyx tubes, and only a calyx tube decay symptom was identified. The Tarsonemus mites were fungivorous and reproduced on cultures of a Cladosporium sp. Cultures of Alternaria sp. and Penicillium sp. were unsuitable for mite reproduction, even though the mites did ingest a red fluorescently labeled Alternaria sp. culture. The survival and reproduction of mites on fungal cultures were better at 30°C than at 25°C.

TABELA DE VIDA DE FERTILIDADE DE BREVIPALPUS PHOENICIS (GEIJSKES, 1939) (ACARI: TENUIPALPIDAE) EM DIFERENTES CULTIVARES DE CAFÉ (COFFEA SPP.)

RESUMO Este trabalho foi realizado visando elaborar a tabela de vida de fertilidade do ácaro da mancha-anular do cafeeiro, Brevipalpus phoenicis (Geijskes) (Acari: Tenuipalpidae), criado em folhas de quatro cultivares de café (‘Icatu Vermelho’, ‘Apoatã’, ‘Obatã’ e ‘Mundo Novo’), mantidas em câmara climatizada a 25º ± 1º C, UR 70 ± 10% e fotofase de 14 horas. Fêmeas de B. phoenicis foram colocadas sobre a superfície das folhas (arenas), por um período de 24 horas, para oviposição. Após este período, as fêmeas e os ovos excedentes foram retirados deixando-se apenas um ovo por arena. As arenas foram examinadas diariamente para se avaliar a sobrevivência e o número de ovos depositados. Preparou-se uma tabela de vida de fertilidade com os dados obtidos. Os ácaros B. phoenicis apresentaram diferenças de sobrevivência e taxas de crescimento populacional, quando criados nos diferentes cultivares de café. Os cultivares mais favoráveis para a multiplicação de B. phoenicis foram, nesta ordem: ‘Apoatã’, ‘Mundo Novo’ e ‘Obatã, baseando-se nas taxas finitas de incremento. ‘Icatu Vermelho’ mostrou-se o cultivar menos favorável à multiplicação de B. phoenicis.

Characterization of Aedes albopictus akirin for the control of mosquito and sand fly infestations

The control of arthropod vectors of pathogens that affect human and animal health is important for the eradication of vector-borne diseases. Recent evidences showed a reduction in the survival and/or fertility of mosquitoes, sand flies and poultry red mites fed in vitro with antibodies against the recombinant Aedes albopictus akirin. These experiments were the first step toward the development of a multi-target arthropod vaccine. In this study, we showed that the oviposition of A. albopictus and Phlebotomus perniciosus fed on mice vaccinated with recombinant A. albopictus akirin was reduced by 17% and 31%, respectively when compared to controls. However, Aedes aegypti mosquitoes were not affected after feeding on vaccinated mice. These results showed that recombinant A. albopictus akirin could be used to vaccinate hosts for the control of mosquito and sand fly infestations and suggested new experiments to develop improved vaccine formulations.

Effects of Pollen in Lobelia laxiflora (Lobeliaceae) Long-Lived Flowers on Fecundity of Tropicoseius chiriquensis (Acari: Mesostigmata: Ascidae)

Abstract Pollen and nectar are the most important floral rewards in plant—pollinator interactions. These rewards are voraciously consumed by hummingbird flower mites (Acari: Mesostigmata: Ascidae), and nectar and pollen feeding by mites have a strong impact on plant—hummingbird interactions. Tropicoseius chiriquensis (Acari: Mesostigmata: Ascidae) feed on nectar and pollen of Lobelia laxiflora H.B.K. (Lobeliaceae) flowers, and within the floral corolla they mate and lay eggs. Yet the benefits of nectar and pollen feeding in terms of survival and fecundity of flower mites are quite unexplored. Here, we evaluate the fecundity and numerical response of T. chiriquensis to the availability of pollen in long-lived protandrous flowers of L. laxiflora. Under field conditions, unmanipulated flowers with pollen had more mites (adults, nymphs, larvae, and eggs) than emasculated flowers without pollen, Numbers of mites fluctuated throughout the flower life span. More adult mites were found for the first 2 d of the flower (staminate phase) and decreased for the last three days of life of the flower (pistillate phase). In contrast, we found higher number of larvae in the pistillate phase. In a laboratory experiment, the fecundity of flower mites was 4 times as high when pollen was available as that when flower mites were not provided with pollen. They completed their life cycle in approximately a week, the life span of L. laxiflora flowers. Our results suggest that pollen availability in L. laxiflora long-lived flowers could influence the population dynamics of T. chiriquensis by having a positive impact on numbers and fecundity of the mites.

Vector and virus induce plant responses that benefit a non-vector herbivore

The negative cross-talk between induced plant defences against pathogens and arthropod herbivores is exploited by vectors of plant pathogens: a plant challenged by pathogens reduces investment in defences that would otherwise be elicited by herbivores. This negative cross-talk may also be exploited by non-vector herbivores which elicit similar anti-herbivore defences in the plant. We studied how damage by the thrips Frankliniella occidentalis and/or infection with Tomato spotted wilt virus (TSWV) affect the performance of a non-vector arthropod: the two-spotted spider mite Tetranychus urticae, a parenchym feeder just like F. occidentalis. Juvenile survival of spider mites on plants inoculated with TSWV by thrips was higher than on control and on thrips-damaged plants. However, thrips damage did not reduce spider-mite survival as compared to the control, suggesting that the positive effect of TSWV on spider-mite survival is independent of anti-thrips defence. Developmental and oviposition rates were enhanced on plants inoculated with TSWV by thrips and on plants with thrips damage. Therefore, spider mites benefit from TSWV-infection of pepper plants, but also from the response of plants to thrips damage. We suggest that the positive effects of TSWV on this non-vector species cannot be explained exclusively by cross-talk between anti-herbivore and anti-pathogen plant defences.

Infestation of sheep withPsoroptes ovis, the sheep scab mite, results in recruitment of Foxp3+T cells into the dermis

Regulatory T cells (Tregs) play a central role in maintenance of immune homeostasis by controlling harmful immune responses to inappropriate antigens and are thought to play a key role in modulating hypersensitivity reactions. Infestation of sheep with Psoroptes ovis results in a pronounced cutaneous hypersensitivity-type response, which appears to be crucial for mite survival. We hypothesize that (i) Tregs are involved in sheep scab lesions and (ii) Treg responses may crucially affect lesion development and subsequent mite survival. Foxp3 is a key transcription factor required for generation and maintenance of Tregs in rodents and humans, and is the most widely used marker for Tregs in these species. In this study, we sequence ovine foxp3 and show that it exhibits a high degree of homology with foxp3 from other species. Using a validated immunohistochemical staining technique, we demonstrate that infestation of sheep with P. ovis results in an influx of Foxp3(+) T cells into the skin. Future work will investigate the regulatory function of ovine Foxp3(+) T cells and determine whether the quality of the Treg response to P. ovis plays a role in individual susceptibility to the mite.