Identification Of Mite Species Research Articles

Species identification of spider mites (Tetranychidae: Tetranychinae): a review of methods.

Spider mites (Acari: Tetranychidae) are dangerous pests of agricultural and ornamental crops, the most economically significant of them belonging to the genera Tetranychus, Eutetranychus, Oligonychus and Panonychus. The expansion of the distribution areas, the increased harmfulness and dangerous status of certain species in the family Tetranychidae and their invasion of new regions pose a serious threat to the phytosanitary status of agro- and biocenoses. Various approaches to acarofauna species diagnosis determine a rather diverse range of currently existing methods generally described in this review. Identification of spider mites by morphological traits, which is currently considered the main method, is complicated due to the complexity of preparing biomaterials for diagnosis and a limited number of diagnostic signs. In this regard, biochemical and molecular genetic methods such as allozyme analysis, DNA barcoding, restriction fragment length polymorphism (PCR-RFLP), selection of species-specific primers and real-time PCR are becoming important. In the review, close attention is paid to the successful use of these methods for species discrimination in the mites of the subfamily Tetranychinae. For some species, e. g., the two-spotted spider mite (Tetranychus urticae), a range of identification methods has been developed - from allozyme analysis to loop isothermal amplification (LAMP), while for many other species a much smaller variety of approaches is available. The greatest accuracy in the identification of spider mites can be achieved using a combination of several methods, e. g., examination of morphological features and one of the molecular approaches (DNA barcoding, PCR-RFLP, etc.). This review may be useful to specialists who are in search of an effective system for spider mite species identification as well as when developing new test systems relevant to specific plant crops or a specific region.

A Case Report of a 12-Year Old Boy Infested with Poultry Red Mites, Dermanyssus gallinae (Acari: Mesostigmata), Acquired from his Syrian Hamster

The poultry red mite Dermanyssus gallinae, known as the primarily ectoparasite of laying hens and synanthropic birds (e.g. pigeons), can also bite humans, causing Red-Mite Dermatitis (RMD) with untypical symptoms of erythematous maculo-papular rash and urticaria-like lesions. In this study, we present the first case of RMD diagnosed in a 12 year old boy, resulting from bites of poultry mites derived from his pet hamster. The results show that the potential risk of human exposure to D. gallinae mites in the urban environment, is associated not only with the nesting and roosting feral pigeons in direct vicinity of human apartments, but may also result from the holding of hamsters. Since this hamster had no contact with other animals, we assume that its bedding was contaminated with D. gallinae, and played a role of the major source of these mites for the host and then the child. In conclusion, even if pet animals are rather accidental hosts for D. gallinae, effective measures to monitor and avoid cases of mite-dermatitis in urban dwellers require: (i) correct morphological identification of mite species, (ii) finding the sources of mite infestations, (iii) the removal of abandoned nests of their hosts, (iv) thorough disinfestation. Further eco-epidemiological research is urgently needed to identify non-avian host species including pet animals and mechanisms facilitating spreading of D. gallinae in urban environments.

Survey on Mite Infestations in Small Ruminants in Kindo Didaye District, Wolaita zone, Southern Ethiopia.

Background:Mange is a parasitic skin disease caused by microscopic mites that feed on the skin of small ruminants and affect animal productivity.Methods:A study was carried out to determine the prevalence and possible risk factors for mite infestation in small ruminants in Kindo Didaye district, Wolaita zone, southern Ethiopia. Skin scraping samples were collected from 384 small ruminants (196 goats and 188 sheep) for the identification of mite species following the standard parasitological protocol.Results:Of the 384 examined animals, 6.25% of sheep and goats were infested with different mite species, namely, Sarcoptes (3.67%), Demodex (1.54%), and mixed infestation of Sarcoptes and Demodex (1.04%). A relatively higher prevalence of mite infestation occurred in goats (7.14%) than in sheep (5.3%), and the highest prevalence of lesions of mange mites was recorded in the neck region (3.13%). The multivariate analysis of factors revealed that only BCS and herd size have a significant role in mite infestation of small ruminants. In addition, the correlation analysis of mite infestation with factors revealed that herd size (r = .106), sex (.0434), and body condition score (r = .104) had a positive correlation with mite infestation.Conclusion:Mites are among the most important health constraints of sheep and goats in the study area, requiring immediate attention and control interventions. Moreover, further epidemiological investigations that consider agroecology and other nonhost-related risk factors should be carried out for the appropriate control of mange mites.

Rapid Identification of Tropilaelaps Mite (Mesostigmata: Laelapidae) Species Using a COI Barcode-HRM.

Tropilaelaps mite (Mesostigmata: Laelapidae) is an ectoparasite of bees present, to date, only on the Asian continent. In the context of the threat of Tropilaelaps's introduction into new regions, accurate, rapid, and sensitive detection of the Tropilaelaps spp. is essential. In the present study, we developed a novel molecular method for bee mite's identification, which consists of a new real-time PCR method. A high-resolution melting analysis (HRM) was then performed on the amplified products to differentiate the species. PCR amplification was applied on the cytochrome c oxidase subunit I gene (580 bp). Short fragments from the most variable regions of this gene were identified in silico to amplify and discriminate among the four Tropilaelaps species. Four reference plasmids were synthesized to characterize species by well-distinguished melting curves. The method was then validated in terms of its specificity and sensitivity using a panel of 12 specimens. The results showed that an HRM method can be applied for the intended objective: for rapid and simultaneous identification of Tropilaelaps species. To our knowledge, this study reports the first direct HRM assay developed for the genome of a bee mite, specific for Tropilaelaps species. This COI barcode-HRM technique could be a promising tool for mite species identification.

A standardized method for rearing Rhizoglyphus robini (Astigmata: Acaridae)

Rhizoglyphus robini Claparede (Acari: Astigmata: Acaridae) is a mite infesting crop such as saffron corms, onions, garlic, leeks and lilies. Bulb mites were observed associated with diseased saffron corms in Vermont research sites, confirming their pest status in New England. To assess the efficacy of different IPM and biological controls a standard method to rear bulb mites in the laboratory was essential. This study focused on developing an efficient laboratory medium to rear R. robini. Bulb mites were extracted from infected saffron corms in Vermont (USDA plant-hardiness zone 5a [− 20° to − 15 °F]). A bulb mite culture was first established on potato dextrose agar (PDA) medium with an average moisture content of 67% at the Entomology Research Laboratory, University of Vermont. Bulb mite species identification and R. robini separation were done, and bulb mites were incubated in a dark chamber at 25 °C. While establishing the R. robini laboratory culture, contamination of microbial disease restricted populations. Experiments were conducted to determine the most suitable growth medium that supported bulb mite population and minimized microbial disease. Three treatments were tested: 1. antibiotics (chloramphenicol) + fungicide (dodine) + PDA, 2. antibiotics + PDA and 3. PDA only. The results showed significantly (P ≤ 0.05) larger populations of R. robini in Petri dishes containing PDA with antibiotics compared to other treatments. The greatest number of bulb mites was observed 14 to 20 days after introduction on the growth media.

Phylogenetic Analysis of Astigmatid Mites Sarcoptes scabiei and Dermatophagoides farinae using ITS-2 as a Genetic Marker


 
 
 Objective: The coding of astigmatid mites based on their morphological and developmental characteristics often leads to uncertainty in the results. The ribosomal internal transcribed spacer (ITS-2) region, being highly conserved in eukaryotes is commonly employed as a barcode for identification of mite species. The present study was an attempt to characterize the gene sequences of astigmatid mites i.e. Sarcoptes scabiei (S. scabiei), Dermatophagoides farinae (D. farinae) using ITS-2 as a genetic marker. Place and Duration of Study: The study was conducted at Department of Dermatology, Military Hospital (MH), Rawalpindi from September 2012 to October 2013. Materials and Methods: In order to characterize relationship of astigmatid mites, the ITS-2 marker was successfully amplified and sequenced. The resulting ITS-2 gene sequences were aligned using Clustal W. MEGA 7 was used to construct phylogenetic tree of the aligned sequence. Results: The phylogenetic tree showed an overall genetic distance of 0.53 indicating close genetic relationship among astigmatid mite species. Pairwise distance was calculated for the ITS-2 gene and low genetic diversity values were observed within S. scabiei and D. farinae that range from 0.003-0.008 and 0.006-0.038 respectively. Conclusion: The study supports the view that the ITS-2 region can be used to identify morphologically difficult astigmatid mites but is not useful in characterization of different species based on the geographical distribution. This study has important implication in our understanding of the epidemiology of S. scabiei and D. farinae and development of control strategies in human transmission.
 
 

Development and use of a single real‐time PCR assay to identify the three spider mite species Tetranychus urticae, Tetranychus lambi and Tetranychus ludeni (Acari: Tetranychidae)

AbstractTetranychid spider mites are a significant worldwide pest of agriculture with Tetranychus urticae being the most important. In Australian cotton, T. urticae is the most damaging, but Tetranychus ludeni and Tetranychus lambi are also present and can be difficult to distinguish morphologically. For this reason, a fast‐diagnostic assay was developed to identify T. urticae, T. lambi and T. ludeni in a single real‐time PCR reaction. The assay design was based on a universal primer pair to amplify the internal transcribed spacer of nuclear ribosomal DNA (ITS1) with three species‐specific TaqMan probes. The assay was validated by sequencing three known reference strains for T. urticae, T. lambi and T. ludeni and a blind test on 14 DNA samples that included species other than the three target species. The method correctly identified the target species and produced a negative result against other non‐target species. Furthermore, we examined 22 field‐collected spider mite populations from Australian cotton that had been laboratory maintained. Here, we found that 50% of the populations labelled as T. urticae were mixed with T. lambi and quarter of the populations labelled with T. lambi contained T. urticae. It demonstrates just how difficult it is to maintain strain integrity with multiple species in proximity. Finally, the assay was used by Biosecurity Australia to test 2125 mite quarantine intercept specimens. They found 1949 T. urticae, 1 T. lambi, 13 T. ludeni and 162 unknown specimens confirming assay accuracy and robustness. The diagnostic assay developed can provide quick spider mite species identification and can support multiple uses including species identification to support spray decisions or the precise identification of border quarantine intercepts where accuracy and turnaround time is critical.

Mites associated with blackberry (Rubus sp. cv. Tupy) in two areas of Michoacan, México

Damage caused by phytophagous mites is one of the main phytosanitary problems on blackberry crop. The mite species identification is a very significant activity to implement a program of integrated pest management. The aim of this study was to identify the species of phytophagous mites, predators, and other mites associated with blackberry crop in two locations of Michoacan, Mexico. The research was performed in two blackberry orchards located at Ziracuaretiro and Tacambaro municipalities, which had different type of management: conventional and non-conventional, respectively. In each orchard, 18 samples were collected at 15 d-intervals during an annual cycle, from June 2015 to May 2016. The collected mites were mounted in permanent slide for their taxonomic determination with specific keys with specific keys. Seventeen mite species belonging to ten families were identified, which six were phytophagous species, six were predatory, and five had varied habits. Six of the 17 taxa identified are new records of mites associated with blackberry crop. Most of the mites were collected in the conventional crop (65.4 %), while the abundance of predator mites was highest in the no-conventional crop.

DNA barcoding and minibarcoding as a powerful tool for feather mite studies.

Feather mites (Astigmata: Analgoidea and Pterolichoidea) are among the most abundant and commonly occurring bird ectosymbionts. Basic questions on the ecology and evolution of feather mites remain unanswered because feather mite species identification is often only possible for adult males, and it is laborious even for specialized taxonomists, thus precluding large-scale identifications. Here, we tested DNA barcoding as a useful molecular tool to identify feather mites from passerine birds. Three hundred and sixty-one specimens of 72 species of feather mites from 68 species of European passerine birds from Russia and Spain were barcoded. The accuracy of barcoding and minibarcoding was tested. Moreover, threshold choice (a controversial issue in barcoding studies) was also explored in a new way, by calculating through simulations the effect of sampling effort (in species number and species composition) on threshold calculations. We found one 200-bp minibarcode region that showed the same accuracy as the full-length barcode (602bp) and was surrounded by conserved regions potentially useful for group-specific degenerate primers. Species identification accuracy was perfect (100%) but decreased when singletons or species of the Proctophyllodes pinnatus group were included. In fact, barcoding confirmed previous taxonomic issues within the P.pinnatus group. Following an integrative taxonomy approach, we compared our barcode study with previous taxonomic knowledge on feather mites, discovering three new putative cryptic species and validating three previous morphologically different (but still undescribed) new species.

Mite species identification in the production of allergenic extracts for clinical use and in environmental samples by ribosomal DNA amplification

The identification of allergy-causing mites is conventionally based on morphological characters. However, molecular taxonomy using ribosomal DNA (rDNA) may be particularly useful in the analysis of mite cultures and purified mite fractions in the production of allergenic extracts. Full-length internal transcribed spacers (ITS1 and ITS2) were obtained from Dermatophagoides farinae, Dermatophagoides pteronyssinus, Dermatophagoides microceras and Euroglyphus maynei (Astigmata: Pyroglyphidae), Glycyphagus domesticus and Lepidoglyphus destructor (Astigmata: Glycyphagidae), Tyrophagus fanetzhangorum, Tyrophagus putrescentiae, Tyrophagus longior, Tyrophagus neiswanderi, Acarus farris and Acarus siro (Astigmata: Acaridae), and Blomia tropicalis (Astigmata: Echymopodidae), using mite-specific primers. Polymerase chain reaction (PCR) products were digested with HpaII and RsaI restriction enzymes in order to produce species-specific PCR restricted fragment length polymorphism (RFLP) profiles. A semi-nested re-amplification step was introduced before the RFLP in order to apply the method to environmental samples. Results demonstrate that rDNA sequences can be used for the unambiguous identification of mite species. The PCR-RFLP system allows the identification of species in purified mite fractions when the availability of intact adult mite bodies for morphological identification is limited. This reliable and straightforward PCR-RFLP system and the rDNA sequences obtained can be of use in the identification of allergy-causing mite species.

COI barcoding as a molecular assay for the identification of phytoseiid mites

Abstract Phytoseiid mites are the most studied family within the order Mesostigmata, especially because of their major interest for biological control programs. Phytoseiid mite species identification is essentially based on morphological characters. However, the development of faster and more accurate methods is under way. Molecular identification techniques, such as barcoding, are also used to improve mite diagnosis. The number of phytoseiid mite sequences used for diagnostic purpose has increased recently, but not all of them are reliable in the absence of voucher specimens or inaccurate taxonomy identification. In this study, we considered 14 common phytoseiid species collected from agricultural, urban, and wild ecosystems in different parts of China. We extracted genomic DNA from the mites and retained the mite specimens as vouchers to ensure the credibility of molecular data. Commonly used COI sequences were used as the most used barcoding marker. The results show that COI sequences are effective and...

ITS2 sequences as barcodes for identifying and analyzing spider mites (Acari: Tetranychidae)

The use of DNA barcodes, short DNA sequences from a standardized region of the genome, has recently been proposed as a tool to facilitate species identification and discovery. Here we show that second internal transcribed spacer of nuclear ribosomal DNA (rDNA-ITS2) barcodes effectively discriminate among 16 species of spider mites (Acari: Tetranychidae) from Israel. The barcode sequences of each species were unambiguously distinguishable from all other species and formed distinct, nonoverlapping monophyletic groups in the maximum-parsimony tree. Sequence divergences were generally much greater between species than within them. Using a 0.02 (2%) threshold for species diagnosis in our data set, 14 out of 16 species recognized by morphological criteria would be accurately identified. The only exceptions involved the low divergence, 0.011-0.015 (1.1-1.5%), between Tetranychus urticae and Tetranychus turkestani, where speciation may have occurred only recently. Still, these species had fixed alternative rDNA-ITS2 variants, with five diagnostic nucleotide substitutions. As a result, we tentatively conclude that rDNA-ITS2 sequence barcodes may serve as an effective tool for the identification of spider mite species and can be applicable as a diagnostic tool for quarantine and other pest management activities and decision-making. We predict that our work, together with similar efforts, will provide in the future the platform for a uniform, accurate, practical and easy-to-use method of spider mite species identification.

Dust Mite Species and Allergen Concentrations in Beds of Individuals Belonging to Different Urban Socioeconomic Groups in Brazil

Background. Dermatophagoides pteronyssinus, Dermatophagoides farinae and Blomia tropicalis dust mites are among the most important agents of hypersensitivity reactions in human beings. However, a role of other mites in the etiology of these reactions has not yet been excluded.Objectives. To investigate the nature of the dust mite fauna and the presence of Der p 1 (allergen 1 of Dermatophagoides pteronyssinus) and Blo t 5 (allergen 5 of Blomia tropicalis) on beds used by individuals with different socioeconomic backgrounds in Salvador, a major Brazilian city and to investigate possible associations of mite frequencies and allergen levels with (a) season of the year, (b) housing characteristics, (c) bed cleaning behaviors that could affect mite densities, and (d) allergy history.Methods. Dust samples were collected from 459 beds of 101 residences from two groups with different socioeconomic levels (hereafter called wealthy and poor groups) in the city of Salvador, Brazil, for the identification of mite species and determination of Der p 1 and Blo t 5 levels. History of allergy was collected using the ISAAC phase I questionnaire.Results. Eighty nine percent of the beds analyzed harbored at least one mite species. B. tropicalis was found in 71.8%, D. pteronyssinus in 39.9%, Cheyletus sp. in 33.9%, and Gohieria fusca in 21.1% of the beds. B. tropicalis was found with a similar frequency in beds of the two socioeconomic groups; D. pteronyssinus was found more frequently in the beds of the wealthy than of the poor group, whereas the reverse was observed with G. fusca. The concentrations of Der p 1 and Blo t 5 allergens exceeded the cut-off for sensitization of 2 μg/g of dust in 94.0% and 69.3% of the wealthy and poor group beds, respectively. No associations were found between history of allergy and mite species or between history of allergy and the concentrations of mite allergens.Conclusions. The observation of B. tropicalis and D. pteronyssinus as the most frequently found mites is consistent with previous reports from tropical regions. The higher frequency of G. fusca in beds of individuals from the poor group than those from the wealthy group could be a consequence of different bed cleaning behaviors between the two groups.

Association between Mite Allergen (Der p 1, Der f 1, Blo t 5) Levels and Microscopic Identification of Mites or Skin Prick Test Results in Asthmatic Subjects

Background: Mite allergens have been involved in airway sensitization and allergic diseases. Immunoassays for the identification and quantifiction of house dust mite (HDM) allergens are useful to improve the knowledge of regional mite fauna and the remediation of mite allergens in allergic diseases. The present study analyzed the association between levels of HDM allergen and results of mite identification or skin prick test (SPT) in two different areas of Bahia, Brazil. Methods: Forty-two asthmatic subjects from a rural area (group I; n = 21) and a slum (group II; n = 21) were evaluated through SPT with HDM allergens and had dust samples collected at their homes for mite identification and allergen measurements. Results: Positive SPT to Dermatophagoides pteronyssinus, Dermatophagoides farinae and Blomia tropicalis allergens were observed in 42.9, 38.0 and 42.9% subjects from group I and in 47.6, 19.0 and 33.3% subjects from group II, respectively. D. pteronyssinus and B. tropicalis were identified in approximately 76 and 50% of samples from both groups, respectively. D. farinae was identified in 38.0 and 9.5% of samples from groups I and II, respectively (p < 0.005). Der p 1, Der f 1 and Blo t 5 detection were associated with mite identification (p < 0.05). Association between HDM allergen levels over 2 µg/g of dust and positive SPT occurred only with D. pteronyssinus (p < 0.0001). Conclusions:D. pteronyssinus was the most prevalent mite species in this study followed by B. tropicalis and D. farinae. Immunoassays done to measure mite allergens were associated with mite-species identification. We conclude that these three mite species must be included on panels for the diagnosis of allergic airway diseases in subjects living in such regions.