XdemvyTM (Lotilaner Ophthalmic Solution) 0.25% Topical Solution for the Treatment of Demodex Blepharitis.

XdemvyTM (lotilaner ophthalmic solution) 0.25% topical solution was recently approved for the treatment of Demodex blepharitis in adults aged ≥18 years. As an antiparasitic agent, lotilaner selectively inhibits gamma-aminobutyric acid chloride channels specific to the parasite and induces spastic paralysis, leading to death of Demodex blepharitis mites. In two randomized, double-masked, vehicle-controlled, multi-center, phase-3 clinical trials (Saturn-1 and Satuirn-2), lotilaner 0.25% topical solution was investigated for the treatment of Demodex blepharitis. Patients were assigned to receive either lotilaner 0.25% topical solution or vehicle (solution that did not contain lotilaner as an active ingredient) twice daily for 6 weeks. On day 43, lotilaner group demonstrated primary efficacy in achieving collarette cure ([collarette grade 0], Saturn-1: study group 44% [92/209], vehicle 7.4% [15/204]; Saturn-2: study group 56% [108/193], vehicle 12.5% [25/200]). Secondary efficacy was achieved by eradication of mite ([0 mite/lash], Saturn-1: study group 67.9% [142/209], vehicle 17.6% [36/304]; Saturn-2: study group 51.8% [99/193], vehicle 14.6% [29/200]), composite cure ([grade 0 collarette as well as grade 0 erythema], Saturn-1: study group 13.9% [29/209], vehicle 1.0% [2/204]; Saturn-2: study group 19.2% [37/193], vehicle 4% [8/200]), and erythema cure ([grade 0 erythema], study group 19.1% [40/209], vehicle 6.9% [14/204]; Saturn-2: study group 31.1% [60/193], vehicle 9.0% [18/199]). The adverse events were mild, with the most common being pain at instillation site. The recommended regimen for lotilaner 0.25% solution is one drop in each eye twice daily for 6 weeks.

The Poultry Red Mite, Dermanyssus gallinae, travels far but not frequently, and takes up permanent residence on farms.

Management of Dermanyssus gallinae, a cosmopolitan hematophagous mite responsible for damage in layer poultry farming, is hampered by a lack of knowledge of its spatio-temporal population dynamics. Previous studies have shown that the circulation of this pest between farms is of strictly anthropogenic origin, that a mitochondrial haplogroup has been expanding on European farms since the beginning of the 21st century and that its local population growth may be particularly rapid. To refine our understanding of how D. gallinae spreads within and among farms, we characterized the genetic structure of mite populations at different spatial scales and sought to identify the main factors interrupting gene flow between poultry houses and between mitochondrial haplogroups. To this end, we selected and validated the first set of nuclear microsatellite markers for D. gallinae and sequenced a region of the CO1-encoding mitochondrial gene in a subsample of microsatellite-genotyped mites. We also tested certain conditions required for effective contamination of a poultry house through field experimentation, and conducted a survey of practices during poultry transfers. Our results confirm the role of poultry transport in the dissemination of mite populations, but the frequency of effective contamination after the introduction of contaminated material into poultry houses seems lower than expected. The high persistence of mites on farms, even during periods when poultry houses are empty and cleaned, and the very large number of nodes in the logistic network (large number of companies supplying pullets or transporting animals) undoubtedly explain the very high prevalence on farms. Substantial genetic diversity was measured in farm populations, probably as a result of the mite's known haplodiploid mode of sexual reproduction, coupled with the dense logistic network. The possibility of the occasional occurrence of asexual reproduction in this sexually reproducing mite was also revealed in our analyses, which could explain the extreme aggressiveness of its demographic dynamics under certain conditions.

Africanized honey bee colonies in Costa Rica: first evidence of its management, brood nest structure and factors associated with varroa mite infestation.

Management, brood nest structure and factors associated with varroa mite infestation were studied in 60 apiaries of Africanized honey bees in the northwest region of the Central Valley of Costa Rica. Apiaries were monitored two times. The first monitoring was taken forward during the rainy season between May and November 2019. The second monitoring during the dry season between February and March 2020. Information about the beekeepers, apiaries and management was collected through a survey. Amount of open and capped brood, honey and pollen were measured in the field. The infestation rate of varroa (IRV) was quantified using standard laboratory methods. A determination of multi-residue pesticides in bee bread was made through GC-MS/MS and LC-MS/MS techniques. According to the results, most of the beekeepers produce honey (96.7%), participate in training activities (82.2%), and change the bee queens annually (70%). The first monitoring was characterized by a lower amount of capped brood and honey reserves compared to the second one. IRV was significantly higher in the first monitoring (6.0 ± 0.4) in comparison with the second one (3.0 ± 0.3) (U Mann-Whitney p < 0.001). The maximum value for the first monitoring exceeds 40%, while this value was close to 25% in the second monitoring. Mite infestation exposed significant differences in relation to the variables associated to the beekeeper's management, i.e., change of bee queen (p = 0.002) or when beekeepers monitor varroa mites (p = 0.004). Additionally, the IRV had inverse correlations (p < 0.01) with the number of comb sides with capped brood (Spearman's rho coefficient = - 0.190), and honey reserves (Spearman's rho coefficient = - 0.168). Furthermore, 23 of 60 bee bread samples presented one to five pesticide residues, being the most frequent antifungal agrochemicals.

Feline straelensiosis: Clinical and histopathological description of a case and first genetic characterisation of Straelensia cynotis.

Straelensia cynotis is a trombidioid mite that causes painful, usually nonpruritic nodular dermatitis mainly in the dorsal region of dogs. This case report describes the first observation of feline straelensiosis in Europe with clinicopathological findings. Molecular characterisation of the parasite was performed and compared with mites collected from dogs.

Straelensia cynotis est un acarien trombidioïde qui provoque une dermatite nodulaire douloureuse, généralement non prurigineuse, principalement dans la région dorsale des chiens. Ce cas constitue la première observation de straelensiose féline en Europe avec des données clinicopathologiques. L'identification moléculaire du parasite a été réalisée et comparée à celle d'acariens prélevés sur des chiens.

Straelensia cynotis es un ácaro trombidioide que causa dermatitis nodular dolorosa, generalmente no pruriginosa, principalmente en la región dorsal de los perros. Este informe de caso describe la primera observación de estraelensiosis felina en Europa con hallazgos clínico-patológicos. Se realizó la caracterización molecular del parásito y se comparó con ácaros recolectados de perros.

Straelensia cynotis é um ácaro trombiculídeo que causa dermatite nodular dolorosa e geralmente não pruriginosa principalmente na região dorsal de cães. Este relato de caso descreve a primeira observação de stralensiose felina na Europa com achados clinicopatológicos. A caracterização molecular do parasita foi realizada e comparada com ácaros coletados de cães.

Efficacy of afoxolaner or the combination of afoxolaner with milbemycin oxime against Otodectes cynotis in naturally infested dogs.

Otodectes cynotis, commonly known as "the ear mite," is a highly contagious ectoparasite and a significant cause of otitis externa in canines. The objective of the current study was to determine the efficacy of the isoxazoline afoxolaner (Nexgard®), and the combination of afoxolaner with milbemycin oxime (Nexgard Spectra®), in dogs naturally infested with O. cynotis. In total, 32 infested client-owned dogs from two different sites in Greece were included. The animals were randomly divided into four equal groups based on their infestation score. Group 1 served as the negative control, group 2 received one oral administration of Nexgard (Day 0), group 3 received two monthly oral administrations of Nexgard (Days 0, 30), and group 4 received two monthly oral administrations of Nexgard Spectra (Days 0, 30), according to label instructions. Otoscopic examinations for mites and observations on debris/cerumen in the ears were carried out on Days 0, 15, 30, and 45. A quantitative assessment of ear mites by ear duct flushing and live mite counts was performed on Day 45. The results demonstrated that a single oral dose of afoxolaner and two monthly doses of afoxolaner or afoxolaner with milbemycin oxime resulted in a 99.9% reduction in live mite counts compared to the untreated control group by Day 45. Additionally, treated dogs showed improved clinical symptoms, such as ear cerumen/debris decrease, while untreated dogs experienced worsening symptoms over the study duration. No adverse events were reported. Overall, these results support the use of afoxolaner-based products to treat O. cynotis infestation in dogs.

Effectiveness of transdermal fluralaner in the treatment of Lynxacarus radovskyi (Acari: Listrophoridae) in naturally infested domestic cats.

Mites of the species Lynxacarus radovskyi, which are commonly found on domestic cats in Brazil, can cause discomfort, itching, and alopecia. The development of new, safer and more effective treatments with a broad spectrum of activity, including the use of isoxazolines, is needed. The purpose of this study was to assess the efficacy of transdermal fluralaner in domestic cats naturally infested with L. radovskyi. Twenty cats were evaluated by trichograms and divided into two groups of 10 animals. The control group was not treated, while the treated group was given a single topical dose of fluralaner, as per the manufacturer's instructions. The cats were reassessed for the presence of L. radovskyi eggs and mites on days D+7, D+14, D+28, D+42, D+56, D+70, D+84, and D+98. As of D+42, all the animals (100%) tested negative for mites, and remained parasite-free until the end of the study, while the control group tested positive throughout the experiment. It can be concluded that a single dose of fluralaner applied topically was effective in treating cats naturally infested with L. radovskyi.

Species diversity and related ecology of chiggers on small mammals in a unique geographical area of Yunnan Province, southwest China.

Chiggers are common ectoparasites and the exclusive vector of scrub typhus. Based on previous investigations from a unique geographical area in Yunnan Province of southwest China, the Three Parallel Rivers Area, we retrospectively studied the species diversity and related ecology of chiggers on rodents and other small mammals. A very high species diversity of 120 chigger species was identified. Five dominant chigger species accounted for 59.4% (5238/8965) of total chiggers, and among them Leptotrombidium scutellare is the second major vector of scrub typhus in China. Species diversity of the chigger community fluctuates greatly in different altitudinal and latitudinal gradients. There are significant differences in species composition, species diversity and dominant species of chiggers among hosts with apparent community heterogeneity. Based on the species abundance distribution, the expected total number of chigger species was estimated to be 170, 50 more than the number of actually collected species; this further indicates a very high chigger species diversity in this area. The bipartite ecological network analysis revealed the intricate relationships between chigger and host species-positive and negative correlations existed among some species of dominant and vector chiggers.

Acaricidal activity of bioactive compounds isolated from Aspergillus oryzae against poultry red mites, Dermanyssus gallinae (Acari: Dermanyssidae).

Dermanyssus gallinae, the poultry red mite (PRM), is an obligate ectoparasite feeding on poultry blood, seriously affecting the health of layers and egg production. The control of PRMs mainly relies on chemical drugs, which is facing several challenges such as the environment pollution and drug resistance. Using fungal metabolites is an environmentally friendly alternative for the control of pests. However, few studies have been conducted on the efficacy of fungal metabolites against D. gallinae. In this study, five strains of fungi were isolated from D. gallinae under laboratory conditions, and their extracts with ethyl acetate were tested for acaricidal activity on D. gallinae. The crude extract of Aspergillus oryzae caused 75.55 ± 6.94% mortality of mites at a concentration of 12.5 mg/mL, showing the highest acaricidal effect in all extracts. Subsequently, the extract of A. oryzae was isolated by bio-guided fractionation, and ten major compounds were identified by LC-MS/MS analysis. The results of bioassays indicated that five compounds exhibited acaricidal activity against D. gallinae. N, N-dimethyldecylamine N-oxide was the optimal acaricidal compound with LC50 of 0.568 mg/mL. Additionally, palmitic acid, triethanolamine, cuminaldehyde, and 2,4-dimethylbenzaldehyde also showed acaricidal activity. These compounds have great application potential in the mite control, and the analysis of these fungal acaricidal substances provides a new idea and basis for the subsequent development of PRM control technology.

Mite non-reproduction, recapping behavior, and hygienic behavior (freeze-kill method) linked to Varroa destructor infestation levels in selected Apis mellifera colonies.

The genetic selection of honey bees (Apis mellifera) possessing specific social hygienic behaviors offers the beekeeping industry the possibility of controlling the Varroa destructor parasite and thus reducing its dependence on acaricides. However, the links between these behavioral traits are not yet well defined, which limits genetic progress in breeding programs. We measured the following behavioral varroa resistance traits: freeze-kill brood (FKB) and pin-kill brood (PKB) assays, varroa-sensitive hygiene (VSH), pupae removal, mite non-reproduction (MNR), and recapping activity. We found 2 negative and significant relationships: 1) between the recapping of cells infested with varroa and the total number of recapped cells, and 2) between the recapping of cells infested with varroa and VSH. We also selected the best predictive model of varroa infestation levels using the "step-wise" approach based on the Akaike information criterion. Our model revealed that MNR and FKB were significantly related to the varroa population levels, with a negative relationship; recapping was significantly related to mite infestation levels, with a positive relationship. Thus, a higher MNR or FKB score was linked to lower levels of mite infestation in colonies on August 14 (prior to fall infestation treatments); a higher recapping activity was linked to a higher level of mite infestation. Recapping behavior could be a useful trait to aid the selection of varroa-resistant bee lineages.

A rapid diagnosis and treatment of Ornithonyssus bacoti infection.

Mites serve as pathogens, allergens, or microbial containers, which can seriously damage the health of humans and animals. The substantial amount of mite species and their similar morphology make it complicated to identify and classify. Our mouse breeder incidentally noticed papular-type erythema with itching and peeling of the skin in several places, and an investigation revealed that this symptom was caused by an uncommon parasite that appeared on the skin and around the nest of the mice. By morphological observation, DNA extraction, PCR amplification, and DNA sequencing, we roughly identified the category of the parasite as a mite. Then, we designed a specific primer cox1, amplified and sequenced the mitochondrial cox1 gene fragment of the mite, calculated the intraspecific and interspecific differences, and reconstructed the phylogenetic tree for sequence alignment. Finally, this species was identified and named this Ornithonyssus bacoti-KF. According to the ivermectin gradient test, we found that 0.1 mg/mL concentration of ivermectin solution was the most effective for mite removal in the bath, with no recurrence after 6 months of treatment. Ornithonyssus bacoti, diagnosed by microscopic exam and confirmed by PCR amplification sequencing, was treated with ivermectin to control the rodent-borne parasite effectively.

Blood-feeding adaptations and virome assessment of the poultry red mite Dermanyssus gallinae guided by RNA-seq.

Dermanyssus gallinae is a blood-feeding mite that parasitises wild birds and farmed poultry. Its remarkably swift processing of blood, together with the capacity to blood-feed during most developmental stages, makes this mite a highly debilitating pest. To identify specific adaptations to digestion of a haemoglobin-rich diet, we constructed and compared transcriptomes from starved and blood-fed stages of the parasite and identified midgut-enriched transcripts. We noted that midgut transcripts encoding cysteine proteases were upregulated with a blood meal. Mapping the full proteolytic apparatus, we noted a reduction in the suite of cysteine proteases, missing homologues for Cathepsin B and C. We have further identified and phylogenetically analysed three distinct transcripts encoding vitellogenins that facilitate the reproductive capacity of the mites. We also fully mapped transcripts for haem biosynthesis and the ferritin-based system of iron storage and inter-tissue trafficking. Additionally, we identified transcripts encoding proteins implicated in immune signalling (Toll and IMD pathways) and activity (defensins and thioester-containing proteins), RNAi, and ion channelling (with targets for commercial acaricides such as Fluralaner, Fipronil, and Ivermectin). Viral sequences were filtered from the Illumina reads and we described, in part, the RNA-virome of D. gallinae with identification of a novel virus, Red mite quaranjavirus 1.

Variation of bacterial community assembly over developmental stages and midgut of Dermanyssus gallinae.

Bacterial microbiota play an important role in the fitness of arthropods, but the bacterial microflora in the parasitic mite Dermanyssus gallinae is only partially explored; there are gaps in our understanding of the microbiota localization and in our knowledge of microbial community assembly. In this work, we have visualized, quantified the abundance, and determined the diversity of bacterial occupancy, not only across developmental stages of D. gallinae, but also in the midgut of micro-dissected female D. gallinae mites. We explored community assembly and the presence of keystone taxa, as well as predicted metabolic functions in the microbiome of the mite. The diversity of the microbiota and the complexity of co-occurrence networks decreased with the progression of the life cycle. However, several bacterial taxa were present in all samples examined, indicating a core symbiotic consortium of bacteria. The relatively higher bacterial abundance in adult females, specifically in their midguts, implicates a function linked to the biology of D. gallinae mites. If such an association proves to be important, the bacterial microflora qualifies itself as an acaricidal or vaccine target against this troublesome pest.

Management of the poultry red mite Dermanyssus gallinae with physical control methods by inorganic material and future perspectives.

Poultry red mite (PRM), the ectoparasitic mite Dermanyssus gallinae found in laying hen farms, is a significant threat to poultry production and human health worldwide. It is a suspected disease vector and attacks hosts' other than chickens, including humans, and its economic importance has increased greatly. Different strategies to control PRM have been widely tested and investigated. In principle, several synthetic pesticides have been applied to control PRM. However, recent alternative control methods to avoid the side effects of pesticides have been introduced, although many remain in the early stage of commercialization. In particular, advances in material science have made various materials more affordable as alternatives for controlling PRM through physical interactions between PRM. This review provides a summary of PRM infestation, and then includes a discussion and comparison of different conventional approaches: 1) organic substances, 2) biological approaches, and 3) physical inorganic material treatment. The advantages of inorganic materials are discussed in detail, including the classification of materials, as well as the physical mechanism-induced effect on PRM. In this review, we also consider the perspective of using several synthetic inorganic materials to suggest novel strategies for improved monitoring and better information regarding treatment interventions.

Poultry red mite eradication potential of ivermectin and allicin combination treatment.

BACKGROUND: Existing treatments against poultry red mite (PRM; Dermanyssus gallinae) infestation have reduced efficacy or exhibit hazardous effects on chickens. Considering the economic importance of chickens, development of a safe and effective method for exterminating PRMs is necessary. Ivermectin and allicin are effective against some ectoparasites; however, their acaricidal efficacies against PRMs remain unknown. OBJECTIVE: To evaluate individual and combined efficacies of ivermectin and allicin in exterminating PRMs. METHODS: Different concentrations (0.10-1.0 mg/mL) of ivermectin (1 mL) were applied via dropping method in different insect culture dishes (ICDs), prior to transferring PRMs. For the spraying method, PRMs were transferred to ICDs, before spraying ivermectin (1 mg/mL) solution (1 mL). Further, the acaricidal effect of allicin on PRMs was evaluated by applying different concentrations (0.25-1.0 mg/mL) of allicin (1 mL). The combined acaricidal effects of ivermectin and allicin were analysed using four concentration combinations. PRM death rates were determined after 2 h, 24 h, 2 days, 5 days and 7 days of drug application. RESULTS: Ivermectin application (1 mg/mL) exterminated 64% and 100% of PRMs on 1 and 5 days, respectively, and prevented their revival. Further, 0.5 mg/mL ivermectin and 1 mg/mL allicin individually exterminated 98% and 44% of PRMs, respectively, within 7 days of treatment. In combination, 0.5 mg/mL ivermectin and 0.5 mg/mL allicin exterminated 100% of PRMs within 5 d of treatment. The most effective combination was 0.25 mg/mL ivermectin + 1.00 mg/mL allicin. CONCLUSIONS: The efficacy of ivermectin-allicin combination in exterminating PRMs was demonstrated. This novel approach could be optimised for industrial applications.

Investigation of peripheral blood responses in chickens infested with Dermanyssus gallinae.

Among haematophagous ectoparasites that infest chickens, poultry red mite (Dermanyssus gallinae, PRM) is one of the most serious threats to poultry farms. Mass PRM infestation causes various health problems in chickens, resulting in significant productivity reduction in the poultry industry. Despite the efficiency of acaricides for controlling PRMs, the emergence of acaricide-resistant PRMs represents a challenging setback. Infestation with haematophagous ectoparasites, such as PRMs, induces inflammatory and haemostatic reactions in the host. Therefore, we aimed to explore the gene expression in chicken peripheral blood cells to elucidate host responses against PRM infestation in detail. RNA sequencing of blood-fed PRMs was performed, and the levels of the chicken-derived transcripts obtained from the ingested blood cells were analysed. Genes encoding haemoglobin subunits were found to be significantly more expressed, suggesting that PRM infestation causes anaemia in chickens. Additionally, the mRNA and plasma concentrations of CC chemokine ligand 4 and ß2 microglobulin among the immune-related molecules were found to be significantly higher in PRM-infested chickens compared with non-infested animals. These results suggest that PRM infestation induce inflammation in chicken. Further studies are warranted to better understand the influence of PRM infestation on the host physiological states, including immunity.

Macrophage Migration Inhibitory Factor in Psoroptes ovis: Molecular Characterization and Potential Role in Eosinophil Accumulation of Skin in Rabbit and Its Implication in the Host-Parasite Interaction.

Psoroptes ovis, a common surface-living mite of domestic and wild animals worldwide, results in huge economic losses and serious welfare issues in the animal industry. P. ovis infestation rapidly causes massive eosinophil infiltration in skin lesions, and increasing research revealed that eosinophils might play an important role in the pathogenesis of P. ovis infestation. Intradermal injection of P. ovis antigen invoked massive eosinophil infiltration, suggesting that this mite should contain some relative molecules involved in eosinophil accumulation in the skin. However, these active molecules have not yet been identified. Herein, we identified macrophage migration inhibitor factor (MIF) in P. ovis (PsoMIF) using bioinformatics and molecular biology methods. Sequence analyses revealed that PsoMIF appeared with high similarity to the topology of monomer and trimer formation with host MIF (RMSD = 0.28 angstroms and 2.826 angstroms, respectively) but with differences in tautomerase and thiol-protein oxidoreductase active sites. Reverse transcription PCR analysis (qRT-PCR) results showed that PsoMIF was expressed throughout all the developmental stages of P. ovis, particularly with the highest expression in female mites. Immunolocalization revealed that MIF protein located in the ovary and oviduct of female mites and also localized throughout the stratum spinosum, stratum granulosum, and even basal layers of the epidermis in skin lesions caused by P. ovis. rPsoMIF significantly upregulated eosinophil-related gene expression both in vitro (PBMC: CCL5, CCL11; HaCaT: IL-3, IL-4, IL-5, CCL5, CCL11) and in vivo (rabbit: IL-5, CCL5, CCL11, P-selectin, ICAM-1). Moreover, rPsoMIF could induce cutaneous eosinophil accumulation in a rabbit model and increased the vascular permeability in a mouse model. Our findings indicated that PsoMIF served as one of the key molecules contributing to skin eosinophil accumulation in P. ovis infection of rabbits.

Pigeon mite: An underdiagnosed cause of papular urticaria.

BACKGROUND: Dermanyssus gallinae, known as bird mite, generally lives on nestlings' featherless skin. Humans are accidentally infected, and itchy dermatitis is induced when the mites are unable to use birds' blood. The diagnosis is difficult due to the very small size and rapid movement of the mites, which make them hard to spot. CASE PRESENTATION: A 14-year-old male and his mother were referred to the allergy clinic complaining of a 2-week generalized itchy cutaneous papular lesion, unresponsive to antihista-mines, with the feeling of an insect moving on the surface of the skin. Due to the history of recently hatched pigeons nesting on their balcony and finding very small bugs, diagnosed as D. gallinae, they were instructed to clean the pigeon's nest as the source of these parasites, which successfully solved the problem. CONCLUSION: Bird mite infestation should be considered in the differential diagnosis of recurrent pruritus and urticaria, refractory to conventional treatments. Physicians should be aware of this mite infestation in approach to any patient with papular urticaria.

Suppressive modulation of host immune responses by Dermanyssus gallinae infestation.

The poultry red mite (Dermanyssus gallinae, PRM) is a blood-sucking ectoparasite in chickens and is one of the most serious threats to poultry farms. Mass infestation with PRMs causes various health problems in chickens, resulting in significant productivity reduction in the poultry industry. Infestation with hematophagous ectoparasites, such as ticks, induces host inflammatory and hemostatic reactions. On the other hand, several studies have reported that hematophagous ectoparasites secrete various immunosuppressants from their saliva to suppress host immune responses to maintain blood sucking. Here, we examined the expression of cytokines in peripheral blood cells to investigate whether PRM infestation affects immunological states in chickens. In PRM-infested chickens, anti-inflammatory cytokines, IL-10 and TGF-ß1, and immune checkpoint molecules, CTLA-4 and PD-1, were highly expressed compared to noninfested chickens. PRM-derived soluble mite extracts (SME) upregulated the gene expression of IL-10 in peripheral blood cells and HD-11 chicken macrophages. In addition, SME suppressed the expression of interferons and inflammatory cytokines in HD-11 chicken macrophages. Moreover, SME induces the polarization of macrophages into anti-inflammatory phenotypes. Collectively, PRM infestation could affect host immune responses, especially suppress the inflammatory responses. Further studies are warranted to fully understand the influence of PRM infestation on host immunity.

Mites associated with budgerigars Melopsittacus undulatus (Psittaciformes: Psittacidae) and the first report of Ornithonyssus bursa (Mesostigmata: Macronyssidae) in Mexico.

Background: Hematophagous mites affect numerous bird species, causing severe injuries to the budgerigars. Some species can cause dermatitis in humans. Aims: The purpose was to morphologically identify the mites related to budgerigars (Melopsittacus undulatus) and their nests in Yucatan, Mexico. Methods: In May 2022, a private budgerigar hatchery was visited and mites were collected from the bodies of the birds and their nests. The morphological traits of the mites were confirmed by scanning electron microscopy. Results: Four of 30 birds showed severe clinical signs of mite infestation. The Budgerigars revealed lesions in the cere, nostrils, eyelids, beak, and paws. The bird's skin showed signs of dryness and beige coloring. The birds with severe damage also presented anorexia and had deformed paws and beaks. The parasitosis was caused by the "burrowing mites," Knemidocoptes pilae. The burrowing mites and the Grallacheles bakeri were recovered and identified from paw scabs. To eliminate mites, a topical application of Ivermectin was administered to the necks of the birds. The dose was a single, which has a residuality of 21 days. Two drops (0.115 mg/ml) of ivermectin were applied to each bird. A gradual reduction in crusted lesions due to mite mortality was noted. The "tropical fowl mite" Ornithonyssus bursa was identified in the nests, which represents the first record in Mexico. Conclusions: Three species of mites were discovered in a single budgerigar hatchery. This emphasizes the importance of deworming birds and keeping a clean environment in their cages to reduce the potential for parasitic mite infestation.