Responses of soil-inhabiting mesostigmatid mites to deforestation and disturbance in oak (Quercus brontii) forests of southwestern Iran

The impacts of deforestation on edaphic mesostigmatid mites were investigated in oak forests of Lordegan, southwestern Iran, from April to October. A total of twenty-one species belonging to eighteen genera and ten families were collected and identified. The Shannon-Wiener, Simpson, Jaccard's and Margalef biodiversity indices were used for data analyses. Among the collected species, Antennoseius bacatus with 29% and Sessilunchus hungaricus with 16% relative abundance were the most abundant and dominant species in human-disturbed and natural forests, respectively. The estimated values were higher in natural oak forest than in disturbed and cultivated habitat. Significant differences were observed in soil nitrogen content and soil organic carbon between the two habitats, but not in pH values. Significant effects of sampling time and habitat were found on all four indices, but the effect of their interactions on these indices was not significant. It can be concluded that the changes in soil quality that resulted from deforestation may have a major role in reducing the soil mite density and related diversity indices in disturbed forests.

Damage and spatiotemporal dynamics of the Ngaio flat mite, Brevipalpus ferraguti (Trombidiformes: Tenuipalpidae), with observations on the development of the female insemination system

We studied the Ngaio flat mite, Brevipalpus ferraguti Ochoa & Beard, on Myoporum laetum (Scrophulariaceae), a common introduced plant used as hedgerows in gardens and green areas of the Mediterranean, where the mite causes considerable damage. We first describe the damage, and then the patterns of mite seasonal abundance and spatial distribution. Finally, we address the development of the female insemination system at the population level. Damage occurs on both sides of the leaves, starting with a uniform stippling and bronzing and ending in the leaves drying out and extensive defoliation that coincides with summer. Mite population peaked between June and August, maintained moderate levels in autumn and winter and reached its lowest density in early spring. Active motile immatures and eggs were present throughout the year. Females and motile immature forms were more abundant on the abaxial (lower) leaf surface, but eggs were deposited on both surfaces indistinctly, suggesting that females actively move to the adaxial (upper) surface in summer to oviposit. All the developmental stages were aggregated on the leaves throughout the year regardless of their population density. Our study suggests that a binomial or presence-absence sampling, examining only the number of females on the abaxial surface, can accurately estimate the total mite density levels. Only 23.5% of females possessed a fully developed spermatheca, whereas in 76.5% of the cases the seminal receptacle was not present or not developed. Females with a complete spermatheca were less abundant in summer. Average temperatures and host plant species affected the occurrence of this reproductive structure.

First record and verification of Tyrophagus putrescentiae (Acari: Acaridae) causing direct damage on anthurium plants cultivated in vitro

The population size at which Tyrophagus putrescentiae can produce damage on anthurium plants (Anthurium sp.), cultivated in vitro, was determined. Symptoms caused by these mites on the plants are described. Two anthurium varieties coded as ANMIRO and ANWHGE, were cultivated in a Murashige and Skoog medium for four weeks. The treatments for each variety were as follows: a) Absolute Control (AC), b) fungus inoculated in the cultured medium (CF), c) fungus on leaves + mites (FLM), d) fungus in medium + mites (FMM), and e) only mites (OM). Mite density within the vessels increased through time. Fifty-five days after the first evaluation, the highest amount of injury was observed in the treatments FLM, FMM, and OM. The observed symptoms were holes on the foliar lamina produced by the feeding of mites until complete plant deterioration. According to the prediction model, when there is an average population close to 62 mites per vessel, it would be expected to find 20% damaged. The probability of observing damage on the variety ANWHGE was 1.7 times higher than on the variety ANMIRO. Although T. putrescentiae is a known contaminant in tissue culture laboratories as it carries bacteria and fungi on its body, this is the first record of this species causing direct damage to plants cultivated in vitro.

Safety and Efficacy of Topical Lotilaner Ophthalmic Solution 0.25% for the Treatment of Demodex Blepharitis: A Pilot Study

Purpose. Evaluate safety and efficacy of topical lotilaner ophthalmic solution, 0.25% for the treatment of Demodex blepharitis. Patients and Methods. 15 patients with Demodex blepharitis, defined as >10 collarettes on the upper lid, lid margin erythema, and Demodex density of ≥1.5 mites/lash on microscopy, were treated bid for 28 days with lotilaner ophthalmic solution, 0.25%. Contact lens wear, artificial eyelashes, and lid structural abnormalities were among the exclusion criteria. No other antibacterial, antiparasitic, or anti-inflammatory treatment or lid hygiene products were permitted. Patients were assessed on Days 7, 14, 28, 60, and 90. Outcome measures were changes in collarette grade and mite density on Day 28. Adverse events and changes in intraocular pressure (IOP), corrected distance visual acuity (CDVA), and slit-lamp biomicroscopy were assessed. Results. Mean collarette grade (upper lids) improved from 3.07 ± 0.21 to 0.79 ± 0.19 on Day 28; the change was statistically significant for both upper and lower lids from Day 14 on. Mean mite density per lash decreased from 2.28 ± 0.16 at baseline to 0.14 ± 0.05 at Day 28 p < 0.0001 . Mite eradication (0 mites) was documented in 57.1% of eyes. The effects were durable through Day 90. There were no adverse events and little to no change in CDVA or IOP. The drop was well tolerated, with no discontinuations due to ocular irritation. Conclusion. Topical lotilaner ophthalmic solution, 0.25% for 4 weeks, showed promising efficacy for the treatment of Demodex blepharitis. This novel treatment appears to be safe and well tolerated. Randomized controlled studies are needed to confirm the results.

Abundance of domestic mites in dwellings of children and adolescents with asthma in relation to environmental factors and allergy symptoms

Exposure to house dust allergens, mainly from domestic mites, is an important cause of allergic reactions in sensitized asthmatic patients. A total of 63 dust samples were collected from 16 flats in Bytom (south Poland); in each flat a person (age 4–17 years) suffering from bronchial asthma lived with his/her family. Mite density was calculated as the number of specimens per g of dust. The results were compared with household features and the data were statistically analyzed. In total 566 mite specimens were isolated, including 526 members of the family Pyroglyphidae (93%). The dominant species were Dermatophagoides pteronyssinus (60% of the total count) and Dermatophagoides farinae (32%). Pyroglyphids were found in all mite positive samples (68%) of which 35% also contained non-pyroglyphids, including glycyphagids, cheyletids and gamasids. The results suggest associations between the density of some mite taxa (per g of dust) and the following indoor environmental factors: presence of pets, number of inhabitants, coal-stoves as a type of heating, cleaning frequency, higher relative humidity, presence of flowers and PVC windows. The severity of asthma seems to be associated with the numbers of D. farinae, total domestic mites and live mites per g of dust.

Immunological detection in indoor environments of house dust mite allergens using avian antibodies - IgY: An innovative tool

IgY technology has emerged as an alternative for antibody production with immunodiagnostic purposes. Recently, we produced avian antibodies (IgY) against group-1 dust mite allergens of Dermatophagoides sp (Dsp) and Blomia tropicalis (Bt). These allergens are important sensitizing agents that contribute to the pathophysiology of allergy rhinitis and asthma in patients living in tropical areas. The purpose was to explore the utility of IgY for detecting dust mite allergens in indoor environments. We collected 100 samples of dust from mattresses of asthmatic individuals living in two cities on the Colombian Caribbean coast. We used an in-home indirect enzyme-linked immunosorbent assay (ELISA) to detect the mite allergens using two IgYs (IgY-PO2 and IgY-PO4). We determined the IgY detection limit using whole body extracts of Dsp and Bt; likewise, IgY specificity was probed against one crude extract of cockroach, as well as the precision and accuracy of measurements. Both antibodies recognized allergens in the mite extracts, even at the lowest tested concentration (0.05 µg/mL); none reacted with the cockroach extract demonstrating their specificity for mite allergens. On the other hand, IgY-PO4 showed the best precision (intra-assay: CV < 6.99%; inter-assay: CV ≤ 8.71%) and an accuracy: 80.62 – 100.39%. Allergen levels detected were consistent with the mite density present in the dust samples. We confirmed the usefulness of IgY-PO2 and IgYPO4 for detecting dust mite pollution in indoor environments.

Biocontrol Potential of Neoseiulus californicus (Mesostigmata : Phytoseiidae) Against Oligonychus punicae (Acari: Tetranychidae) in Avocado

Oligonychus punicae (Hirst) (Trombidiformes: Tetranychidae) is a common pest in Mexican avocado orchards. Neoseiulus californicus (McGregor) (Mesostigmata: Phytoseiidae) is frequently found associated with avocado orchards in Mexico and may be an important aid for controlling O. punicae. Given the lack of information in the scientific literature, this study evaluated the predation and oviposition of N. californicus when fed O. punicae at different developmental stages in a no-choice experiment. We also assessed fluctuations in the population size of O. punicae and N. californicus in commercial avocado orchards; correlations among mite density and air temperature, humidity, and precipitation in commercial avocado orchards; and the correlations between prey and predator populations. The no-choice test revealed that N. californicus adult females fed on O. punicae of all developmental stages, with higher levels of predation being recorded for eggs, followed by larvae. The highest oviposition values of N. californicus females were observed when females were fed O. punicae eggs. In orchards, the populations of both mites increased between February and June. The populations peaked during the warmest months of the year, with O. punicae populations peaking between June and July and N. californicus peaking in August. In addition, the population size of N. californicus was significantly and positively correlated with rainfall, air temperature, and the population densities of O. punicae. Meanwhile, O. punicae population size was positively correlated with air temperature, and the population of its predator N. californicus.

Microbiome variation during culture growth of the European house dust mite, Dermatophagoides pteronyssinus

ABSTRACT In culture, the house dust mite, Dermatophagoides pteronyssinus, shows different growth patterns, but the composition and changes in the associated microbial community during mite culture growth are poorly known. In this study, we analyzed temporal changes in microbial communities including ‘internal’ communities (inside mites, ingested) and ‘environmental’ communities (from culture environment). Microbial community structure was correlated with guanine content (a nitrogenous waste product of mites) and mite population density. Both internal and environmental microbial communities were remarkably consistent between biological replicates from the same culture age group and were composed of relatively few dominant taxa–11 bacterial and 3 fungal operational taxonomic units (OTUs). Significant changes over time in microbial community structure in the bulk culture environment and in internal mite samples were observed. The yeast, Saccharomyces cerevisiae, a main component of the mite diet, gradually disappeared during mite culture growth and was replaced by fungi from the genera Aspergillus and Candida in both ‘internal’ and ‘environmental’ samples. In environmental samples, bacteria from the genus Lactobacillus and S. cerevisiae were negatively correlated, and Aspergillus and Candida positively correlated, with guanine content. The relative abundance of bacteria from the genus Kocuria increased with mite density but declined with increasing guanine content. The relative abundance of bacteria from the genus Virgibacillus was negatively correlated with mite density in ‘internal’ samples. Gram-positive bacteria dominated bacterial microbiomes at all time points in our experiments, indicating a more limited possibility for vaccine contamination by bacterial endotoxins (heat-stable lipopolysaccharides produced mostly by Gram-negative bacteria) in our experimental cultures.

Allium cepa L. responses when Gaeolaelaps aculeifer Canestrini and Parasitus bituberosus Karg are used to control Thrips tabaci Lindeman

Thrips tabaci Lindemann is the main insect pest of Allium cepa L., causing both direct and indirect damage to crops. T. tabaci is controlled by applying chemically synthesized products; however, this insect has already developed resistance to organophosphates, carbamates, and pyrethroids. This study evaluated the effect of soil predatory mites (Gaeolaelaps aculeifer Canestrini and Parasitus bituberosus Karg) on the population density of T. tabaci in potted bulb onion (Allium cepa L.) plants and on the response of physiological variables related to photosynthesis and plant development. Seven treatments were evaluated that released 50, 75 or 100 G. aculeifer or P. bituberosus adults, along with a control without predatory mites. Significant differences (P≤0.05) in the population density of T. tabaci were observed for 13 weeks, with a 78% reduction of individuals in the presence of G. aculeifer and a 72% reduction with P. bituberosus, regardless of mite density, as compared to the control. In addition, the relative chlorophyll index, foliar area, dry leaf weight and fresh bulb weight increased, as compared to the control. The application of 100 individuals of the two species recorded the highest values in the evaluated variables. These results indicate that G. aculeifer and P. bituberosus controls should be explored as an option for integrated T. tabaci management.