A Delphi approach to establishing consensus on best practice for the diagnosis and treatment of Demodex blepharitis

Demodex blepharitis does not have agreed standardized guidelines. The aim of this study was to classify signs and symptoms and to develop appropriate management strategies for Demodex blepharitis from a consensus of expert advice.

METHODS

A total of 11 anterior segment experts (ophthalmologists, optometrists and a contact lens optician) working in the United Kingdom participated in a modified 2-round Delphi panel. A mixed-methods approach was adopted and a survey questionnaire for round 1 was formulated, constructed from information in the available literature. Based on panel responses from round 1, feedback was provided and a round 2 questionnaire was formulated. More than two-thirds majority (72%) was used for consensus building.

RESULTS

Based on the clinical presentation of signs and symptoms along with associated conditions and risk factors, a diagnostic algorithm was proposed for the clinical investigation of Demodex blepharitis. A treatment algorithm was also proposed with first-line and second-line treatment recommendations for Demodex blepharitis.

CONCLUSION

The recommendation from this study provides the first effort in formulating clinical diagnostic algorithm and management guidelines for Demodex blepharitis. The guidelines include appropriate magnification on the slit lamp, associated signs, symptoms, risk factors and suggested management options. These guidelines can be used in a routine eyecare setting to encourage eyecare practitioners in tailoring the investigation and management of Demodex blepharitis.

Automated precision beekeeping for accessing bee brood development and behaviour using deep CNN

Bees play a significant role in the health of terrestrial ecosystems. The decline of bee populations due to colony collapse disorder around the world constitutes a severe ecological danger. Maintaining high yield of honey and understanding of bee behaviour necessitate constant attention to the hives. Research initiatives have been taken to establish monitoring programs to study the behaviour of bees in accessing their habitat. Monitoring the sanitation and development of bee brood allows for preventative measures to be taken against mite infections and an overall improvement in the brood's health. This study proposed a precision beekeeping method that aims to reduce bee colony mortality and improve conventional apiculture through the use of technological tools to gather, analyse, and understand bee colony characteristics. This research presents the application of advanced digital image processing with computer vision techniques for the visual identification and analysis of bee brood at various developing stages. The beehive images are first preprocessed to enhance the important features of object. Further, object is segmented and classified using computer vision techniques. The research is carried out with the images containing variety of immature brood stages. The suggested method and existing methods are tested and compared to evaluate efficiency of proposed methodology.

Correlation between Demodex species in primary and recurrent chalazia

OBJECTIVE

To determine the correlation between the infestation by species of Demodex spp. and the occurrence of primary and recurrent chalazia.

METHODS

Prospective and observational study. Patients with primary or recurrent chalazia were included. Eyelash samples were taken to determine the microscopic presence of Demodex spp. The correlation between the recurrence of the chalazia and the infestation by Demodex spp. mites was determined using Spearman's rank correlation coefficient test.

RESULTS

Sixty-eight adult patients diagnosed with chalazia were included. In 63.2% of the total cases, the presence of one or more parasites of the genus Demodex spp. was documented. In the quantitative parasitological study, it was found that 25% of all cases presented infestation by Demodex spp. defined by an index greater than or equal to 0.5 parasites per eyelash. The most frequently found species was Demodex folliculorum. Of the 14 patients with recurrent chalazia, 50% presented infestation by Demodex spp. and in 91.7% of the cases the infestation was by D. folliculorum. There is a positive, directly proportional correlation between these factors (rθ=+0.665, P<.05). In the group of patients with primary chalazion, only 18.5% presented infestation by Demodex spp., and in 81.6% of these cases it was caused by D. folliculorum. There is a non-statistically significant correlation between these two factors.

CONCLUSION

There is a direct, high and statistically significant correlation between the recurrence of the chalazion and the infestation by Demodex spp., there is no statistically significant correlation between the primary chalazia and the presence of Demodex spp.

Resistance of dwarf Cocos nucifera L. (Arecaceae) cultivars to Raoiella indica Hirst (Acari: Tenuipalpidae)

The red palm mite Raoiella indica Hirst, 1924 (Acari: Tenuipalpidae) is an important pest of the coconut palm Cocos nucifera L. (Arecaceae) and has caused problems in coconut production worldwide. Research has been carried out aiming at controlling the mite through chemical, biological, alternative, and host plant resistance methods. Identifying coconut palm cultivars resistant to R. indica is important to reduce the problems caused to plantations. Therefore, the objective of this work was to evaluate the performance of R. indica in six dwarf coconut palm cultivars, to identify sources of resistance. The cultivars of the sub-varieties green, red, and yellow evaluated were Brazilian Green Dwarf-Jiqui (BGDJ), Brazilian Red Dwarf-Gramame (BRDG), Cameroon Red Dwarf (CRD), Malayan Red Dwarf (MRD), Brazilian Yellow Dwarf-Gramame (BYDG), and Malayan Yellow Dwarf (MYD). Confinement and free choice tests of R. indica on the cultivars were performed, in which biological parameters and preference were evaluated. Mite performance was different in the cultivars evaluated. In the confinement bioassay, R. indica had the worst performance in the cultivar BGDJ, the best performance in CRD, MRD, and BRDG, and intermediate performance in BYDG and MYD. In the free choice test, the cultivars MRD and MYD were preferred in relation to BGDJ, and CRD was less preferred in relation to BGDJ. Therefore, we considered that the cultivar BGDJ is the most resistant to R. indica, by antibiosis and antixenosis; CRD has resistance by antixenosis; and MRD, BRDG, BYDG, and MYD are susceptible.

Successful treatment of 3 naturally acquired cases of canine cheyletiellosis with fluralaner

Three dogs were diagnosed with naturally occurring cheyletiellosis based on clinical signs and visualization of parasites and ova. Treatment with fluralaner (orally) resulted in a rapid resolution of clinical signs with no evidence of mites or ova at 1 or 2 mo post-treatment. This is apparently the first published report of an isoxazoline being used to successfully treat cheyletiellosis in veterinary medicine. Therefore, fluralaner may be an effective option for treatment or prevention of canine cheyletiellosis, although research is needed to confirm its effectiveness for treatment of cheyletiellosis in dogs and other species. Key clinical message: This is apparently the first published report of an isoxazoline being used to successfully treat cheyletiellosis in companion animal practice. These parasites are both contagious and zoonotic and there are currently no approved products for treatment or prevention of cheyletiellosis.

Mixta mediterraneensis as a novel and abundant gut symbiont of the allergen-producing domestic mite Blomia tropicalis

Blomia tropicalis is an allergen-producing mite in the human environment in tropical regions. The microbiome of B. tropicalis was described using the barcode sequencing region of V4 16S rDNA and genome assemblage. Mixta mediterraneensis, previously isolated from human skin swabs, was identified as a B. tropicalis gut symbiont based on genome assembly. The microbiome contains two bacteria, Staphylococcus and M. mediterraneensis. The number of M. mediterraneensis 16S DNA copies was 106 per mite and 109 per feces in the rearing chamber based on qPCR quantification. The profile of this bacterium reached 50% of reads in the mite gut and feces. Genomic analyses revealed that the bacterium has several metabolic pathways that suggest metabolic cooperation with the mite host in vitamin and amino acid synthesis, nitrogen recycling, and antimicrobial defense. Lysozyme is present in the symbiotic bacterium but absent in the mite. The B. tropicalis microbiome contained Staphylococcus, which accelerates mite population growth. Mites can digest Staphylococcus by using specific enzymes with hydrolytic functions against bacterial cell walls (chitinases and cathepsin D), leading to endocytosis of bacteria and their degradation in lysosomes and phagosomes. Gene expression analysis of B. tropicalis indicated that phagocytosis was mediated by the PI3-kinase/Akt pathway interacting with the invasins produced by M. mediterraneensis. Moreover, the symbiont had metabolic pathways that allowed it to recycle the mite metabolic waste product guanine, known as a mite attractant. The mite host symbiont enhances mite aggregation in the feces, and the fecal-oral transmission route is excepted.

Life-history stage determines the diet of ectoparasitic mites on their honey bee hosts

Ectoparasitic mites of the genera Varroa and Tropilaelaps have evolved to exclusively exploit honey bees as food sources during alternating dispersal and reproductive life history stages. Here we show that the primary food source utilized by Varroa destructor depends on the host life history stage. While feeding on adult bees, dispersing V. destructor feed on the abdominal membranes to access to the fat body as reported previously. However, when V. destructor feed on honey bee pupae during their reproductive stage, they primarily consume hemolymph, indicated by wound analysis, preferential transfer of biostains, and a proteomic comparison between parasite and host tissues. Biostaining and proteomic results were paralleled by corresponding findings in Tropilaelaps mercedesae, a mite that only feeds on brood and has a strongly reduced dispersal stage. Metabolomic profiling of V. destructor corroborates differences between the diet of the dispersing adults and reproductive foundresses. The proteome and metabolome differences between reproductive and dispersing V. destructor suggest that the hemolymph diet coincides with amino acid metabolism and protein synthesis in the foundresses while the metabolism of non-reproductive adults is tuned to lipid metabolism. Thus, we demonstrate within-host dietary specialization of ectoparasitic mites that coincides with life history of hosts and parasites.

Water mites of the genus Lebertia Neuman (Acari: Hydrachnidia: Lebertiidae) from China, with description of three new species

Three new water mite species of the genus Lebertia Neuman, 1880Lebertia (Lebertia) gimina sp. nov., Lebertia (Mixolebertia) dinghuensis sp. nov. and Lebertia (Mixolebertia) wuyiensis sp. nov.are described from China, along with one new Chinese recordLebertia (Lebertia) ignatowi Sokolow, 1930. The key characteristics for the subgenera of Lebertia are given.

Disentangling detrimental sand fly-mite interactions in a closed laboratory sand fly colony: implications for vector-borne disease studies and guidelines for overcoming severe mite infestations

BACKGROUND

Vector sand fly colonies are a critical component of studies aimed at improving the understanding of the neglected tropical disease leishmaniasis and alleviating its global impact. However, among laboratory-colonized arthropod vectors of infectious diseases, the labor-intensive nature of sand fly rearing coupled with the low number of colonies worldwide has generally discouraged the widespread use of sand flies in laboratory settings. Among the different factors associated with the low productivity of sand fly colonies, mite infestations are a significant factor. Sand fly colonies are prone to infestation by mites, and the physical interactions between sand flies and mites and metabolites have a negative impact on sand fly larval development.

METHODS

Mites were collected from sand fly larval rearing pots and morphologically identified using taxonomic keys. Upon identification, they were photographed with a scanning electron microscope. Several mite control measures were adopted in two different laboratories, one at the Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases-National Institutes of Health (Rockville, MD, USA), and the other at the University of Calgary (Calgary, AB, Canada).

RESULTS

The mite species associated with sand fly colonies in the two laboratories were morphologically identified as Tyrophagus sp. and Stratiolaelaps scimitus. While complete eradication of mites in sand fly colonies is considered unrealistic, drastically reducing their population has been associated with higher sand fly productivity.

CONCLUSIONS

We report a case of detrimental interaction between sand flies and Tyrophagus sp. and S. scimitus in a closed laboratory sand fly colony, discuss their impact on sand fly production and provide guidelines for limiting the mite population size in a closed laboratory colony leading to improved sand fly yields.

Description of the second species of Cingulacarus Elsen (Acari, Mesostigmata, Diplogyniidae), and notes on the genus

Cingulacarus Elsen is a monotypic genus of Trigynaspida based on C. gangeticus Elsen, collected from the scarabaeid beetle Scarabaeus gangeticus (Castelnau) (Col., Scarabaeidae) in the Democratic Republic of the Congo. Herein, a second species of the genus, C. kermanensis sp. nov. is described based on female and male specimens collected in southeastern Iran, in association with Oryctes elegans L. (Col., Scarabaeidae). The diagnosis of the genus Cingulacarus is revised, with a discussion of the impact on current generic keys for the family Diplogyniidae, and a proposal to eliminate the current subfamilial classification within that family.

Ectoparasites of European hedgehogs (Erinaceus europaeus) in Germany and their health impact

BACKGROUND

The European hedgehog (Erinaceus europaeus) is known for high levels of ectoparasitism that not only represents a health risk for the animals themselves, but also for pet animals and humans as hedgehogs are frequently taken into human care. In the present study, patterns of ectoparasite infestation were assessed in hedgehogs taken into care at northern German animal rehabilitation centres.

METHODS

Ectoparasites (ticks, fleas and mites) of 498 hedgehogs were collected over a period of 3 years from July 2018 to May 2021. Species were identified based on morphological characteristics and also via amplification and sequencing of the partial cytochrome c oxidase subunit 2 (COX-2) gene for fleas of the family Ceratophyllidae. Seasonal changes in infestation patterns as well as correlations with animal age, body weight and health status were assessed using generalised linear models.

RESULTS

Infestation with ticks, fleas and mites occurred throughout the year. Overall, 86.5% (431/498) of the examined hedgehogs were infested with ticks, 91.4% (455/498) with fleas and 17.7% (88/498) with mites. Ixodes ricinus and Ixodes hexagonus/Ixodes canisuga were the most common tick species detected, with the additional occurrence of one Ixodes frontalis. Significant seasonal changes were observed for I. ricinus, but not for I. hexagonus/I. canisuga. Additionally, I. ricinus nymph prevalence declined significantly as of 2020, probably as a consequence of the climate change-related drought as of 2018. In hedgehogs with flea infestations, Archaeopsylla erinacei, Ceratophyllus sciurorum, Nosopsyllus fasciatus and Ctenocephalides felis were identified. In all cases of mite infestation, Caparinia tripilis was detected, in addition to specimens of the family Macronyssidae and free-living mites of the family Acaridae. Statistical analyses showed correlations regarding the factors month, year, body weight and age, but no correlation was evident regarding the health status of the animals.

CONCLUSIONS

With a detected infestation rate of 98.6%, almost all of the examined hedgehogs were infested with at least one ectoparasite species. The seasonal activity patterns of the different ectoparasite species together with the complex annual cycle of hedgehogs lead to different seasonal patterns in ectoparasite prevalence and infestation intensities. Due to the risk of transmission of zoonotic pathogens as well as the possible negative impact on the host itself, hedgehogs should be treated against ectoparasites when taken into care facilities.

Impact of the mites Dermanyssus gallinae and Tyrophagus putrescentiae on production and health of laying hens

Mites are considered a threat to the commercial poultry industry due to their direct and indirect pathogenic effects. Dermanyssus gallinae is among the mite species that endanger production, as it is hematophagous and poses a serious sanitary risk. Recently, Tyrophagus putrescentiae has also drawn attention as a potential pest in the poultry industry, and its attacks have been related to clinical symptoms such as cutaneous eruptions and bird restlessness. Considering the potential economic, sanitary, and productive losses both species represent to the laying-hen industry, the aim of the present study was to evaluate the influence of D. gallinae and T. putrescentiae on the health and productivity of commercial laying hens by carrying out infestation experiments and by monitoring laying hens for a period of 60 days. Tyrophagus putrescentiae and D. gallinae affected egg quality and zootechnical parameters in laying hens. Hens infested by T. putrescentiae had behavioral changes, weight loss, stress symptoms, and decreased egg laying and quality, as well as diarrhea, gradual feather loss, and itching. Hens infested by D. gallinae also had weight loss, behavioral changes, and stress symptoms, leading to decreased laying and egg quality. The present study proposes an experimental model to understand the impacts caused by T. putrescentiae and D. gallinae on commercial laying production and egg quality parameters.

Distribution of phoretic mites and lice in Pseudolynchia canariensis living on pigeons and the relationship with seasonality, carrier sex, plumage coloration and age of definitive hosts

Among the parasites, some groups that have a limited capacity for locomotion, such as mites and lice, the transmission is challenging to win. These ectoparasites disperse through direct contact between hosts or, in some cases, through phoresy. However, these processes are not well-documented in detail because they are difficult to observe and quantify. In the present study, the patterns of distribution of skin mites and phoretic lice on hippoboscid louse fly Pseudolynchia canariensis sampled from Columba livia were evaluated. The analyzed pigeons were juveniles and adults, with three distinct plumage colors: blue checker, spread, or wild type, and were caught over 24 months. A total of 1,381 hippoboscid flies were collected on 377 hosts. The plumage color did not influence the infestation patterns of louse flies on juvenile and adult pigeons, nor did it influence the infestation patterns of skin mites and phoretic lice on the hippoboscid flies. However, the environmental temperature was directly related to higher prevalence, mean infestation intensity, and phoretic species richness on P. canariensis during the hottest seasons. Furthermore, a higher abundance of phoretic mite eggs, including embryonated eggs, was observed in females of P. canariensis in all seasons.

Immunobiological properties and structure analysis of group 13 allergen from Blomia tropicalis and its IgE-mediated cross-reactivity

Blomia tropicalis is an important species of allergenic mite. Structurally related cross-reactive allergens are involved in pathogenesis of clinical symptoms. The present study focused on recombinant allergen rBlo t 13 from B. tropicalis, including investigation of its structure, immunological properties, IgE-mediated cross-reactivity. In this work, the prokaryotic expression plasmids pET-28(a)-Blo t 13, pET-28(a)-Der f 13, and pET-28(a)-Tyr p 13 were constructed, transformed into E. coli Rosetta (DE3) pLysS, and purified by nickel affinity chromatography, respectively. By using ELISA, the IgE-binding rates were detected for rBlo t 13 and its epitope peptides, as well as the cross-reactivity among rBlo t 13, rDer f 13, and rTyr p 13. The tertiary structure of rBlo t 13 was resolved using X-ray diffraction at 2.0 Å resolution. Using IgE-ELISA, the IgE binding rate of rBlo t 13 was 60 % with Blomia tropicalis-positive sera. In the experiments of ELISA for cross-reactivity with rBlo t 13 on solid phase, the inhibition rates were 65 %, 57 % and 63 % for rBlo t 13, rDer f 13, and rTyr p 13, respectively. The structure of Blo t 13 protein contains a β-barrel structure which is composed of 10 β strands and has 2 α helices at the end of the barrel. Comparison of the tertiary structures of rBlo t 13, rDer f 13, and rTyr p 13 revealed that the β-barrel structure is highly conserved, consistent with the alignment of amino acid sequences. We obtained the recombinant protein rBlo t 13, demonstrated its cross-reactivity with Der f 13 and Tyr p 13 due to their structural similarity.

Comorbidity of Ocular and Facial Demodicosis

PURPOSE

To determine the association between ocular and facial demodicosis, and the effect of facial treatment on ocular demodicosis.

DESIGN

Prospective clinical cohort study.

METHODS

Ocular demodicosis outpatients from a tertiary medical center were enrolled from April to December 2020. The diagnosis was based on epilation of 4 eyelashes from each upper eyelid. High ocular Demodex load (ODL) was defined as ≥8 mites per eye. Facial infestation was assessed by direct microscopic examination, with facial Demodex overgrowth (FDO) defined as a density >5 mites/cm2. All patients were prescribed 3 months of ocular treatment, and FDO patients received dermatologic treatment.

RESULTS

Eighty-nine patients were enrolled. Among those that completed the treatment course, 39 presented high ODL. Lower cylindrical sleeve counts were found in low ODL patients (low ODL vs high ODL: 8 vs 14, P = .009). FDO was less prevalent in this group (49% vs 77%, P = .012). The Ocular Surface Disease Index score decreased in patients without FDO (20.0 ± 17.1 to 14.0 ± 16.6, P = .027) after 3 months of topical tea tree oil treatment. Topical ivermectin treatment on the facial skin provided a higher ocular Demodex eradication rate in FDO patients (76% vs 16%, P < .001).

CONCLUSION

Concurrence of ocular and facial demodicosis is common, especially in cases of severe ocular demodicosis. Although ocular treatment alone is effective for patients with ocular demodicosis only, cotreatment with topical ivermectin on the facial skin enhances ocular Demodex eradication in patients with comorbid facial Demodex overgrowth.

Phyllocoptes parviflori is a distinct species and a vector of the pervasive blackberry leaf mottle associated virus

Several viruses are transmitted by eriophyid mites (Acariformes: Eriophyoidea) including blackberry leaf mottle-associated emaravirus (BLMaV) (Emaravirus rubi). BLMaV is transmitted by an unidentified eriophyid species and is involved in blackberry yellow vein, a devastating disease in the southeastern United States. In this study, we assessed the eriophyid mite Phylocoptes parviflori as a vector of BLMaV and clarified its taxonomic status as it was previously synonymized with Phyllocoptes gracilis. P. parviflori can efficiently transmit BLMaV. The virus was found to cause yellow vein disease symptoms on 'Ouachita' blackberry marking a paradigm shift as disease symptoms have always been associated with multiple virus infections. Therefore, we propose renaming the virus to blackberry leaf mottle virus. The occurrence of P. parviflori on wild and cultivated blackberries, as well as its ability to colonize other Rubus species, enhances its importance as a major contributor to the spread of yellow vein disease.

Compatibility of pesticides with the predatory mite Neoseiulus barkeri

Multiple arthropod pests can affect the same crop in agricultural systems, requiring the integration of control methods. In the present study, the effects of residual exposure to four broad-spectrum insecticides/acaricides (azadiractin, abamectin, chlorfenapyr, and fenpyroximate) on immature (development and survival time) and adult females (longevity, fecundity, and fertility life table parameters) of the predatory mite Neoseiulus barkeri were evaluated. Additionally, the insecticides/acaricides were categorized according to their selectivity based on the classification proposed by the International Organization for Biological Control (IOBC) for assessing the susceptibility of arthropods in laboratory experiments. Method 004, proposed by the Insecticide Resistance Action Committee (IRAC), was adopted for the bioassays with predators exposed to insecticide-acaricide residues. Among the insecticides/acaricides studied, azadirachtin had minimal effects on immature and adult N. barkeri (all non-significant) and was considered harmless based on the classification of toxicity according to the standards/categories proposed by the IOBC. All other insecticides/acaricides affected immature and adult N. barkeri and were considered slightly harmful in terms of toxicity, according to the IOBC.

Impacts of cultivar and management practices on the diversity and population dynamics of mites in soybean crops

The objective of this study was to evaluate the diversity and population dynamics of mites in soybean crops with different cultivars and management practices. The study was conducted in two soybean production fields in the municipalities of Mato Queimado (L1) and Três de Maio (L2), Rio Grande do Sul state, Brazil. Two transgenic cultivars were used, and insecticide applications varied among treatments. Sampling began at the V2 stage, with 60 leaves/area/collection that were sorted, mites were collected and identified using dichotomous keys. A total of 18,100 mites belonging to 12 species were found. Among the species, Tetranychus urticae Koch, Mononychellus planki (McGregor), and Tetranychus ludeni Zacher (Tetranychidae) were the most abundant, whereas the most abundant predatory mites were the phytoseiids Neoseiulus californicus McGregor and Neoseiulus idaeus Denmark and Muma, with N. idaeus being more abundant and present in all areas. The acarofauna was influenced by environmental conditions and management practices. Neoseiulus idaeus was commonly associated with populations of M. planki, T. ludeni, and T. urticae. Neoseiulus californicus tolerated pesticide use but was affected by severe water stress, whereas N. idaeus tolerated periods of low relative humidity and high temperatures.

Sublethal and transgenerational effects of lufenuron on the biological traits of Panonychus citri (McGregor) (Acari: Tetranychidae)

The citrus red mite, Panonychus citri (McGregor), is a globally important pest that has developed severe resistance to various pesticides. Lufenuron has been widely used in the control of the related pests in citrus orchard ecosystem. In this study, the susceptibilities of egg, larva, deutonymph and female adult of P. citri to lufenuron was determined, and the LC50 values were 161.354 mg/L, 49.595 mg/L, 81.580 mg/L, and 147.006 mg/L, respectively. Life-table analysis indicated that the fecundities were significantly increased by 11.86% and 26.84% after the mites were treated with LC20 concentrations of lufenuron at the egg or deutonymph stages, respectively. After eggs were treated with lufenuron, the immature stage and longevity were also affected, and resulted in a significant increase in r, R0 and λ. After exposure of female adults to LC20 of lufenuron, the fecundity and longevity of F0 generation significantly decreased by 31.99% and 10.94%, respectively. Furthermore, the expression level of EcR and Vg was significantly inhibited upon mites was treated with lufenuron. However, lufenuron exposure has a positive effect on fecundity and R0 in F1 generation, the expression of all reproduction-related genes was significantly up-regulated. In conclusion, there was a stimulating effect on the offspring population. Our results will contribute to the assessment of the resurgence of P. citri in the field after the application of lufenuron and the development of integrated pest control strategies in citrus orchards.

Prevalence of Demodex spp. in patients with chronic blepharitis

Blepharitis is a very common disease in ophthalmology, dermatology and allergy practice. It generally follows a chronic course and is frequently associated with objective and/or subjective symptoms such as epiphora, red eye, dandruff, gritty sensation, itching, burning, photophobia, and blurred vision. The purpose of this study is to analyze the prevalence of Demodex spp. in patients with symptoms of chronic blepharitis. An analytical cross-sectional study was conducted in the period between 2016 and 2020. All patients with symptoms of chronic blepharitis who underwent a parasitological test of eyelashes (Rapitest) in the Dermatology Department of the Hospital Italiano de Buenos Aires were included. Those with previously established blepharitis due to another infectious cause were excluded. We analyzed 972 patients. Sixty percent (n=585) underwent a positive Rapitest for the presence of Demodex spp. Seventy five percent (n=728) were women. There were no significant differences in the prevalence associated with sex (p=0.38). Among the patients positive for Demodex spp., 65% (n=628) were older than 60 years old. The most frequently associated symptom was itching, present in 35% (n=342). A statistically significant decrease in the number of consultations was observed during the cold months of the year (May-June-July-August). Our results show a high prevalence of Demodex spp. in patients with chronic blepharitis. As its presence reveals a direct association with age, we recommend looking for this parasite in this age group.

Influence of temperature on the population size of Aceria litchii (Acari: Eriophyidae) and the development of its galls

The lychee erinose mite, Aceria litchii (Keifer), is a tiny eriophyid mite known to induce the formation of open galls (erinea) on lychee plants, Litchi chinensis Sonn. In lychee infested by A. litchii, four stages of erineum are observed, based on erineum color: hyaline, white, amber and dark brown. The cause of the color change in erinea is unknown, but it might be linked to the extent of A. litchii infestation. Artificially infested lychee seedlings were used to determine the developmental time, trichome density, and mite population size in each of the four erineum stages. The effect of temperature (15, 25, and 35 °C) on A. litchii population size and erineum developmental time was also investigated. Overall, each erineum stage lasted approximately 50 days and the population size of A. litchii increased gradually through the hyaline, white and amber stages, and a strong decline was observed in dark brown erinea. Visual comparisons of the low-temperature scanning electron microscope (LT-SEM) images revealed that the trichome density was lower in the hyaline stage than in the other stages. Temperature influenced mite population size and amber erinea developmental time. Mite population was lower at 35 °C than at 15 and 25 °C, suggesting that high temperatures promote detrimental effects on A. litchii. Amber erinea developed slower at 15 °C than at 25 and 35 °C. Possible effects of the temperature on A. litchii population in lychee plants are discussed.