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.

Participatory epidemiology on major camel calf health and management problems in pastoral and semi-pastoral zones of Somali region, Ethiopia.

A cross-sectional study was conducted from May 2017 to March 2019. A participatory epidemiological appraisal was used to gain a rapid overview of the range of camel calf health problems and traditional management, a measure of the importance that people place on each of them, and to identify and prioritize economically important diseases in target zones. The most important constraints to camel production were identified to be the widespread prevalence of diseases such as camelpox, contagious ecthyma, calf scour, ticks, and nonspecific pneumonia; poor management and husbandry practices such as restrictive colostrum feeding, lack of concentrate and salt supplementation and inappropriate housing; shortage of feed; and scarce seasonal variation in water. Additionally, the livestock herders not only showed their knowledge of common camel calf diseases for affected organs and symptoms but also indicated the seasonality of disease occurrences with strong agreement (W = 0.899, P< 0.003) among the informants of all focus group discussions. The overall prevalence of mange, tick infestation, and bacteria-induced diarrhea in the study area was found to be 36.3%, 36%, and 74%, respectively. Sarcoptes scabie var. cameli was the only identified mite species from mange-infested calves, while Hyalomma, Rhipicephalus, and Amblyoma were the most commonly identified tick species. Similarly, the overall prevalence of diarrhea was 74% among this about 34.6% was caused by E. coli while 38.9% was affected by Salmonella and E. coli. Therefore, based on these findings, five diseases have been prioritized as the most significant calf diseases in the area (Camelpox, contagious ecthyma, and causes of pneumonia among camel calves). Improving veterinary health infrastructure and capacity, and increasing community awareness on camel health constraints are also recommended to enhance optimal camel calf rearing.

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.

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.

Traitement réussi de 3 cas de cheylétiellose canine acquis naturellement avec du fluralaner. Trois chiens ont été diagnostiqués avec une cheylétiellose acquise naturellement sur la base des signes cliniques et la visualisation des parasites et des œufs. Un traitement avec du fluralaner (oralement) a résulté en une résolution rapide des signes cliniques sans aucune évidence de mites ou d'œufs à 1 ou 2-mois post-traitement. Ceci semble être le premier rapport publié d'un isoxazoline utilisé pour traiter avec succès la cheylétiellose en médecine vétérinaire. Ainsi, le fluralaner serait une option efficace pour le traitement ou la prévention de la cheylétiellose canine, bien que de la recherche soit nécessaire pour confirmer son efficacité pour le traitement de la cheylétiellose chez les chiens et les autres espèces.Message clinique clé :Ceci semble être le premier rapport publié de l'utilisation d'un isoxazoline pour traiter avec succès la cheylétiellose en pratique des animaux de compagnie. Ces parasites sont contagieux et zoonotiques et il n'y a à l'heure actuelle aucun produit approuvé pour le traitement ou la prévention de la cheylétiellose.(Traduit par Dr Serge Messier).

Treat Yourself: Pilot Testing a New Method to Treat Mange in Wild Carnivores.

Mange is a skin disease caused by mites that parasitize an animal's skin, often yielding inflamed immune responses and hair loss. At a population level, mange may reduce survival and cause population declines. Many forms of mange can be treated quite effectively when an animal is in hand; however, this is not often feasible for many free-ranging wildlife populations. Some animals, particularly territorial carnivores, will rub or roll to scent mark and transmit information about their presence to other individuals. We posited that rub stations comprised, in part, of anthelmintic medication and foreign scents that induce rubbing could be used to remotely treat mange in the wild. We deployed 39 rub stations containing lure and dye in Santa Monica Mountains National Recreation Area, Southern California, USA, October-November 2022. Carnivores rubbed or rolled at >97% of rub stations, with coyotes (Canis latrans), gray foxes (Urocyon cinereoargenteus), and bobcats (Lynx rufus) being the most abundant species. Time to first rub or roll was generally <1 wk. Several sympatric species (e.g., mule deer, Odocoileus hemionus) were detected at rub stations but did not rub. Our pilot test provides strong evidence that treating mange in wild carnivores may be possible using the remote medicinal rub stations we describe. Future efforts to add medicine to rub stations and monitor for a change in mange prevalence are a logical next step.

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.

Assessing the efficacy and zootechnical performance in laying hens after administration of a 1% aqueous solution of fluralaner (Exzolt) for treating natural infestation by Menacanthus cornutus.

A brood of laying hens infested with the lice Menacanthus cornutus (Phthiraptera: Menoponidae) evidenced itching, irritation, and damage to their zootechnical performance. A study was conducted to evaluate the zootechnical performance and infestation control using a 1% solution of fluralaner in a brood of white laying hens infested naturally with lice. The experiment was carried out using 10,560 naturally infested chickens divided into 2 groups: a treatment group of animals that received a 1% solution of fluralaner in drinking water, at a dose of 0.05 mL/kg of body weight, in 2 administrations, 7 d apart; and a control group of infested and untreated chickens. The groups of chickens were followed for 120 d to evaluate the score of infestation and zootechnical performance. It was observed that birds in the treatment group became free of lice infestation 7 d after the administration of the first dose of a 1% solution of fluralaner. For up to 120 d after the experiment was initiated, there was no evidence of subsequent lice infestation, while continued infestation with all life stages of lice (adults, young, or eggs) was evident in the untreated control group, remaining stable during all evaluations performed. The birds in the treatment group showed improved zootechnical performance when compared to a 9.94% egg production decrease in the control group. The feed conversion and egg mass data showed statistically significant differences between the 2 groups. This study allows us to conclude that treatment with a 1% solution of fluralaner effectively controlled Menacanthus cornutus lice infestation and promoted recovery of egg production in a brood of laying hens treated with the test formulation.

Host space, not energy or symbiont size, constrains feather mite abundance across passerine bird species.

Comprehending symbiont abundance among host species is a major ecological endeavour, and the metabolic theory of ecology has been proposed to understand what constrains symbiont populations. We parameterized metabolic theory equations to investigate how bird species' body size and the body size of their feather mites relate to mite abundance according to four potential energy (uropygial gland size) and space constraints (wing area, total length of barbs and number of feather barbs). Predictions were compared with the empirical scaling of feather mite abundance across 106 passerine bird species (26,604 individual birds sampled), using phylogenetic modelling and quantile regression. Feather mite abundance was strongly constrained by host space (number of feather barbs) but not by energy. Moreover, feather mite species' body size was unrelated to the body size of their host species. We discuss the implications of our results for our understanding of the bird-feather mite system and for symbiont abundance in general.

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.

Alleviating lesions of chronic progressive lymphedema in Belgian draft horses by successfully treating Chorioptes bovis infestation with moxidectin 0.5% pour-on.

The aim of this prospective, randomized, single-blinded, and placebo-controlled clinical trial was to investigate the efficacy of a moxidectin pour-on solution for the treatment of Chorioptes bovis infestation in Belgian draft horses, and in addition, to evaluate the effect of this treatment on the clinical signs and lesions associated with chronic progressive lymphedema (CPL). Nineteen privately owned Belgian draft horses were randomly assigned to either a treatment group (moxidectin pour-on formulation, n = 10) or a placebo group (phosphate-buffered saline (PBS), n = 9). On Day 0, all 19 horses tested positive for the presence of C. bovis in superficial skin scrapings. Prior to treatment, all feathering on the distal limbs of the horses was clipped. Treatment was applied twice (Day 0 and 7). Pour-on moxidectin (Cydectin 0.5% Pour-On; Zoetis) was evenly distributed over the distal legs of the horses at a dose of 1.5 mg moxidectin/kg body weight. Animals in the placebo group were treated with PBS. Pretreatment and follow-up examinations consisted of counting living mites in superficial skin scrapings, scoring pruritus, and scoring mange-associated and CPL-associated lesions (skinfold score and skin lesion score). Horses in the placebo group and moxidectin group were followed up to 8 weeks and 24 weeks after the first treatment, respectively. On Day 14, no living mites were found in any of the horses in the moxidectin group (p = 0.013). These horses continued to remain free of mites, until the final sampling conducted at 24 weeks following the initial application of moxidectin, when three horses again showed living mites in skin scrapings. Treatment with moxidectin resulted in a significant reduction of both CPL-associated skin lesion scores (p = 0.003) and pruritus scores (p = 0.001) after only seven days. By Day 56, still no signs of pruritus (p < 0.0001) were detected, with significant improvement of mange-associated lesions (p < 0.0001). Although the skinfold score did not show a significant reduction by Day 56, the score for skin lesions associated with CPL had significantly improved (p < 0.0001). In conclusion, the results of this study demonstrate that pour-on moxidectin, at a high dose and applied directly to the mite predilection site, was an effective treatment for C. bovis infestation in feathered draft horses, providing positive effects on CPL lesions, pruritus and mange-associated lesions. Furthermore, these findings emphasize the therapeutic significance of addressing mange in the management of CPL-affected draft horses.

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.

Treatment of sheep prior to movement: its contribution to an effective scab (psoroptic mange) management strategy.

BACKGROUND: Ovine psoroptic mange (sheep scab) is an important disease of sheep worldwide caused by the parasitic mite, Psoroptes ovis. It has a negative impact on animal welfare and leads to significant economic losses for the sheep industry. Effective and targeted management is required to limit its transmission. METHODS: A stochastic metapopulation model of sheep scab transmission is used to investigate the contribution of the treatment of sheep prior to movements to sales, gatherings (predominantly markets) and away grazing to the reduction of prevalence of farms with scab in Great Britain. RESULTS: Treatment prior to movement to gatherings resulted in an 86% reduction in the overall prevalence of farms with scab and was more effective at reducing the overall prevalence of farms with scab than treatment before other categories of movements. The relative risk of farms having scab infection was inversely related to the percentage of farms which treated, but this relationship was not linear, with the biggest declines in the prevalence of farms with scab being achieved by small percentages of farms treating; a 50% relative reduction in the farm prevalence was achieved with only 15% of farms treating prior to gathering movements. CONCLUSIONS: The results suggest that pre-movement treatment of sheep could make an important contribution to national scab control and, in practice, the approach could be more highly targeted if used in conjunction with known geographic and management risk factors for scab.

Methods to develop and evaluate attitudinal scales to measure farmer perceptions: Using sheep scab as an example.

There is limited information on the attitudes and opinions of British sheep farmers when preventing and managing sheep scab in their flocks. Attitudes are examples of latent traits, which are not directly observable. They must be measured indirectly which can be achieved using measurement scales. Attitudinal measurement scales are used frequently in research, but are seldom evaluated prior to use, particularly in veterinary research. Therefore, the aim of this study was to identify and assess latent traits which influence the control of sheep scab with the use of exploratory factor analysis, and then further evaluate these factors with the use of item response theory to determine how they perform as scales. An online survey was completed by 726 British sheep farmers during October 2021 (725 useable responses), which included a section with 37 belief statements related to the opinions and attitudes of sheep farmers around the management of sheep scab. These belief statements were developed and adapted from previous research. During the analysis, they were subjected to exploratory factor analysis, which suggested that the scales performed reasonably well. The scales were then evaluated further by item response theory. The graded response models for each attitudinal scale were assessed by graphical evaluation. They demonstrated that the scales were able to distinguish those respondents with low perceptions of control, responsibility, and trust, and those who had high perceptions of luck. This study provides insights into some of the factors influencing the management of sheep scab, and how well these scales perform. Additionally, it further highlights the importance of evaluating attitudinal scales for use in research, and that exploratory factor analysis alone does not provide enough information on how well they perform.

Natural Products as Mite Control Agents in Animals: A Review.

Mites have been a persistent infectious disease affecting both humans and animals since ancient times. In veterinary clinics, the primary approach for treating and managing mite infestations has long been the use of chemical acaricides. However, the widespread use of these chemicals has resulted in significant problems, including drug resistance, drug residues, and environmental pollution, limiting their effectiveness. To address these challenges, researchers have shifted their focus towards natural products that have shown promise both in the laboratory and real-world settings against mite infestations. Natural products have a wide variety of chemical structures and biological activities, including acaricidal properties. This article offers a comprehensive review of the acaricidal capabilities and mechanisms of action of natural products like plant extracts, natural compounds, algae, and microbial metabolites against common animal mites.

Successful long-term control of poultry red mite (Dermanyssus gallinae) infestations in floor-kept laying hens via integrated pest management-a case report.

This case report describes the successful control of poultry red mite [PRM] (Dermanyssus gallinae) infestations in an experimental laying hen house via a combined use of cleaning and disinfection measure, the preventive application of a synthetic silica-based acaricide and frequent mite monitoring. The high number of PRM in the laying hen house was reduced by 99.8% by treatment with fluralaner (Exzolt®, MSD Animal Health Unterschleißheim, Germany; 0.5 mg/kg body weight via drinking water twice, 7 days apart). After the laying hens were removed, the hen house was dry-cleaned, wet-cleaned and disinfected. After drying, synthetic amorphous silica (Fossil Shield® instant white, Bein GmbH, Eiterfeld, Germany) was applied as a preventive measure before the hen house was restocked with pullets for two housing periods of 58 and 52 weeks. Over these periods (i.e. more than 2 years), no PRM was detected during mite monitoring at two-week intervals via tube traps and visual monitoring. This result therefore suggests that the combined use of appropriate chemical and physical prevention measures within an integrated pest management regime can be successfully used for the long-term control of PRM. This could reduce the use of acaricidal drugs, thereby helping maintain their efficacy.

Development of the first PCR for detection of Psoroptes ovis var. cuniculi infection and its comparison to microscopic examination and serological assay in rabbits.

Psoroptes mites are the common ecto-parasites of wild and domestic animals worldwide, which causes considerable economic losses in livestock industry. Microscopy is deemed to be the 'gold standard' for the diagnosis of Psoroptes mite infection but it has poor sensitivity for low mite infections and/or sub-clinical infections. To overcome these shortcomings, we screened four genes to develop a sensitive and specific PCR for the detection of Psoroptes mite infection in rabbits, and confirmed its practicability in detecting early infection and monitoring treatment outcome with traditional microscopy and serological tests. Results showed that PCR assay targeting ITS2 (ITS2-PCR) had a high specificity and sensitivity (detection limit: 40.3 pg/µL DNA) for detecting P. ovis DNA. In rabbits artificially infected with P. ovis, all three diagnostic tests showed the same detection rate from 14 days post infection (dpi) to 42 days dpi. However, these diagnostic tests behave differently at 7 dpi and after treatment: at 7 dpi, the detection rate of ITS2-PCR was higher than rPsoSP3-based iELISA and traditional microscopy (ITS2-PCR: 88.9%, rPsoSP3-iELISA: 77.7%, microscopy: 33.3%); at 7 days post treatment (dpt), positivity rates of ITS2-PCR and microscopy rapidly decreased to 0.00% and 11.1%, whereas rPsoSP3-iELISA remained 100% positive rate. Furthermore, the comprehensive comparisons of diagnostic performance and features of three diagnostic tests at 7 dpi were performed. Compared to ITS2-PCR or rPsoSP3-iELISA, microscopy had the lowest sensitivity, and the agreement between these assays was low (κ < 0.3). Field study showed that ITS2-PCR showed a higher detection rate than microscopy (19.4% and 11.1%, respectively). Our results suggested that the ITS2-PCR developed in this study provided a new laboratory tool for diagnosis of P. ovis var. cuniculi infection, and it had advantages over microscopic examination in detection low-level mite infections and serological assay in monitoring treatment outcome.

Characterization of cysteine proteases from poultry red mite, tropical fowl mite, and northern fowl mite to assess the feasibility of developing a broadly efficacious vaccine against multiple mite species.

Infestation with poultry red mites (PRM, Dermanyssus gallinae) causes anemia, reduced egg production, and death in serious cases, resulting in significant economic losses to the poultry industry. As a novel strategy for controlling PRMs, vaccine approaches have been focused upon and several candidate vaccine antigens against PRMs have been reported. Tropical (TFM, Ornithonyssus bursa) and northern (NFM, Ornithonyssus sylviarum) fowl mites are also hematophagous and cause poultry industry problems similar to those caused by PRM. Therefore, ideal antigens for anti-PRM vaccines are molecules that cross-react with TFMs and NFMs, producing pesticidal effects similar to those against PRMs. In this study, to investigate the potential feasibility of developing vaccines with broad efficacy across mite species, we identified and characterized cysteine proteases (CPs) of TFMs and NFMs, which were previously reported to be effective vaccine antigens of PRMs. The open reading frames of CPs from TFMs and NFMs had the same sequences, which was 73.0% similar to that of PRMs. Phylogenetic analysis revealed that the CPs of TFMs and NFMs clustered in the same clade as CPs of PRMs. To assess protein functionality, we generated recombinant peptidase domains of CPs (rCP-PDs), revealing all rCP-PDs showed CP-like activities. Importantly, the plasma obtained from chickens immunized with each rCP-PD cross-reacted with rCP-PDs of different mites. Finally, all immune plasma of rCP-PDs reduced the survival rate of PRMs, even when the plasma was collected from chickens immunized with rCP-PDs derived from TFM and NFM. Therefore, CP antigen is a promising, broadly efficacious vaccine candidate against different avian mites.

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.

Acarofauna associated with organic matter in laying aviaries of different rearing systems in Brazil.

Due to the high density of chickens housed within the same space in aviaries, a large volume of organic matter accumulates on the floor. This large supply of available resources allows the development of arthropods, including organisms that affect poultry productivity and health. This study aimed to evaluate the composition of the mite community associated with organic matter in poultry houses with different rearing systems and the verification of potential predators to be evaluated in clean management techniques, such as biological control. The study was carried out in the state of Rio Grande do Sul (Brazil) in a total of six poultry houses, two of the 'Californian' system (SIG) and four of the 'cage free' system (SIF). In total, 839,459 specimens were collected, of which 358,044 were collected from SIF and 481,415 specimens from SIG. Fifty-two species/morphospecies were found and we observed a grouping of aviaries from the same rearing model. Species of medical veterinary importance were found, such as Dermanyssus gallinae, Megninia ginglymura, Ornithonyssus sylviarum and Tyrophagus putrescentiae. The results demonstrate that the organic matter present in the aviaries harbors a high diversity of mites of medical-veterinary importance and predators, which are influenced by the rearing system.

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.