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Poultry red mites (Dermanyssus gallinae, PRMs), tropical fowl mites (Ornithonyssus bursa, TFMs), and northern fowl mites (O. sylviarum, NFMs) are blood-feeding pests that debilitate poultry worldwide. Glutathione S-transferase (GST) plays an important role in the detoxification and drug metabolism of mites. However, research on avian mite GSTs as vaccine antigens is still lacking. Therefore, we aimed to evaluate the potential of avian mite GSTs for vaccine development. We identified GST genes from TFMs and NFMs. We prepared recombinant GST (rGST) from TFMs, NFMs, and PRMs, and assessed their protein functions. Moreover, we evaluated the cross-reactivity and acaricidal effect of immune plasma against each rGST on TFMs, NFMs, and PRMs. The deduced amino acid sequences of GSTs from TFMs and NFMs were 80% similar to those of the PRMs. The rGSTs exhibited catalytic activity in conjugating glutathione to the 1-chloro-2,4-dinitrobenzene substrate. Immune plasma against each rGST showed cross-reactivity with rGST from different mite species. Moreover, the survival rate of PRMs fed with immune plasma against the rGST of TFMs and NFMs was significantly lower than that of the control plasma. These results demonstrate the potential application of GST as an antigen for the development of a broad-spectrum vaccine against avian mites. [ABSTRACT FROM AUTHOR]

The two most economically important poultry ectoparasites are the northern fowl mite, Ornithonyssus sylviarum (Canestrini and Fanzago), and the poultry red mite, Dermanyssus gallinae (De Geer). Both mites are obligate blood feeders but differ in where they reside. Sampling methods thus focus on-host, especially the vent feathers, for northern fowl mite and off-host, especially cracks and crevices near the nighttime roosting areas, for poultry red mite. Much remains unknown, however, about the basic biology and ecology of both mites. Here we discuss mite detection, quantification, and decision making and provide thoughts on future directions for research.

Poultry red mites (Dermanyssus gallinae, PRMs), tropical fowl mites (Ornithonyssus bursa, TFMs), and northern fowl mites (O. sylviarum, NFMs) are blood-feeding pests that debilitate poultry worldwide. Glutathione S-transferase (GST) plays an important role in the detoxification and drug metabolism of mites. However, research on avian mite GSTs as vaccine antigens is still lacking. Therefore, we aimed to evaluate the potential of avian mite GSTs for vaccine development. We identified GST genes from TFMs and NFMs. We prepared recombinant GST (rGST) from TFMs, NFMs, and PRMs, and assessed their protein functions. Moreover, we evaluated the cross-reactivity and acaricidal effect of immune plasma against each rGST on TFMs, NFMs, and PRMs. The deduced amino acid sequences of GSTs from TFMs and NFMs were 80% similar to those of the PRMs. The rGSTs exhibited catalytic activity in conjugating glutathione to the 1-chloro-2,4-dinitrobenzene substrate. Immune plasma against each rGST showed cross-reactivity with rGST from different mite species. Moreover, the survival rate of PRMs fed with immune plasma against the rGST of TFMs and NFMs was significantly lower than that of the control plasma. These results demonstrate the potential application of GST as an antigen for the development of a broad-spectrum vaccine against avian mites.

IntroductionPoultry red mites (PRMs, Dermanyssus gallinae), blood-sucking ectoparasites, are a threat to the poultry industry because of reduced production caused by infestation. In addition, tropical fowl mites (TFMs, Ornithonyssus bursa) and northern fowl mites (NFMs, Ornithonyssus sylviarum) are hematophagous, distributed in various regions, genetically and morphologically close to PRMs, and cause similar problems to the poultry industry. Vaccine approaches have been studied for PRM control, and several molecules have been identified in PRMs as candidates for effective vaccine antigens. The development of an anti-PRM vaccine as a universal vaccine with broad efficacy against avian mites could improve the productivity of poultry farms worldwide. Molecules that are highly conserved among avian mites and have critical functions in the physiology and growth of mites could be ideal antigen candidates for the development of universal vaccines. Ferritin 2 (FER2), an iron-binding protein, is critical for the reproduction and survival of PRMs and has been reported as a useful vaccine antigen for the control of PRMs and a candidate for the universal vaccine antigen in some tick species.Method and resultsHerein, we identified and characterized FER2 in TFMs and NFM. Compared with the sequence of PRM, the ferroxidase centers of the heavy chain subunits were conserved in FER2 of TFMs and NFMs. Phylogenetic analysis revealed that FER2 belongs to clusters of secretory ferritins of mites and other arthropods. Recombinant FER2 (rFER2) proteins from PRMs, TFMs, and NFMs exhibited iron-binding abilities. Immunization with each rFER2 induced strong antibody responses in chickens, and each immune plasma cross-reacted with rFER2 from different mites. Moreover, mortality rates of PRMs fed with immune plasma against rFER2 from TFMs or NFMs, in addition to PRMs, were higher than those of control plasma.DiscussionrFER2 from each avian mite exhibited anti-PRM effects. This data suggests that it has the potential to be used as an antigen candidate for a universal vaccine against avian mites. Further studies are needed to access the usefulness of FER2 as a universal vaccine for the control of avian mites.

The northern fowl mite (NFM), Ornithonyssus sylviarum (Mesostigmata: Macronyssidae), is the primary blood-feeding ectoparasite found on poultry in the U.S.A. Three experiments were conducted in vitro to test the acaricidal properties of cade, garlic, lavender, lemongrass, pine and thyme essential oils against NFM, and to evaluate whether these effects are altered by adjusting oil application rates and application modality (direct vs. vapour contact). Applied at the rate of 0.21 mg/cm2 , the essential oils of cade, thyme, lemongrass and garlic resulted in higher NFM mortality at 24 h post-application than lavender and pine oils, and the untreated and ethanol-treated controls. Cade and thyme were the most consistent and fast-acting of the essential oils in terms of toxicity to NFM. Cade applied at 0.21 mg/cm2 and 0.11 mg/cm2 and thyme applied at 0.21 mg/cm2 were effective in eliminating NFM within 2 h through direct contact. The modality of application did not affect the efficacy of cade and thyme essential oils. The results suggest that essential oils may be utilized as alternatives to chemical pesticides and could be used as fumigants for the control of NFM.

Poultry red mites (PRMs, Dermanyssus gallinae), tropical fowl mites (TFMs, Ornithonyssus bursa), and northern fowl mites (NFMs, Ornithonyssus sylviarum) are hematophagous mites that are distributed worldwide which pose a serious challenge to the poultry industry and negatively impact poultry production and welfare. Vaccines represent a promising approach for controlling avian mites, and the identification of antigens with broad efficacy against multiple avian mite species is advantageous for vaccine control. This study aimed to identify histamine release factor (HRF), which was previously reported as a candidate vaccine antigen against PRMs, from TFMs and NFMs and to analyze its cross-reactivity and acaricidal effects on different avian mite species. The deduced amino acid sequences of the HRFs identified in the TFMs and NFMs were highly homologous to those of the PRMs. We generated recombinant HRF (rHRF) of TFMs, NFMs, and PRMs, and immune plasma against each rHRF was produced by immunization with each antigen. The immune plasma contained antibodies specific to each antigen and showed cross-reactivity with rHRFs from different avian mites. Moreover, PRM nymphs (protonymphs) artificially fed each immune plasma showed higher mortality rates than those fed the control plasma. These results suggest that HRFs can be used as candidate antigens for a universal vaccine with broad efficacy across avian mites.

Ornithonyssus sylviarum (Acari: Macronyssidae) is a common ectoparasite that feeds on the blood of poultry. Following infestation, this mite will cause symptoms such as weight loss, anemia, and decreased egg production. To explore green and safe drugs for the prevention and treatment of O. sylviarum, this study evaluated the effects of ethanol extracts of seven Chinese medicinal herbs—Leonurus artemisia (motherwort), Illicium verum (star anise), Cinnamomum cassia (cinnamon), Hibiscus syriacus, Artemisia argyi (Chinese mugwort), Taraxacum sp. (dandelion), and Syzygium aromaticum (clove)—on O. sylviarum at different life stages. The results showed that different methods of administration affected the acaricidal efficacy of these plant extracts on O. sylviarum. After 6 h of administration with the fumigation method, the acaricidal efficacy of S. aromaticum on adults, nymphs and larvae of O. sylviarum reached 100%. 30 min after administration with the infiltration method, S. aromaticum, H. syriacus and L. artemisia showed acaricidal effects on adults and nymphs of O. sylviarum reaching 100%. In another experiment evaluating the inhibition of egg hatching of O. sylviarum with alcohol extracts of these seven herbs, at 48 h after treatment, A. argyi and C. cassia showed inhibition rates of 19.4%. The results of this study indicate that S. aromaticum induced mortality at all stages of O. sylviarum, whereas A. argyi was found to be the most effective at inhibiting the mite's egg hatching among the seven herbs. These herbs can therefore be used as potential substitutes for chemical pesticides to prevent and control O. sylviarum. These results provide practical knowledge for the control of O. sylviarum. [ABSTRACT FROM AUTHOR]

Abstract Background Among Dermanyssoidea, the chicken red mite (Dermanyssus gallinae) and the northern fowl mite (Ornithonyssus sylviarum) are considered to be the cause of high economic losses endured by the poultry industry in the Holarctic region, with O. sylviarum predominating in North America and D. gallinae in Europe. Both species have a short life-cycle (thereby allowing a rapid build-up of massive infestations), a wide range of hosts, synanthropic presence and the ability to bite humans. The aim of this study was to analyze dermanyssoid mite specimens, collected in two human dwellings and two racing pigeon premises in different urban areas in Hungary, with molecular–phylogenetic methods. Methods Mite species were identified morphologically. This was followed by DNA extraction and molecular–phylogenetic analyses of selected mites, based on the cytochrome c oxidase subunit I (cox1) and 28S rRNA (28S) genes. Results Mites that had invaded a home from a pigeon nest and were linked to human dermatitis were morphologically and molecularly identified as D. gallinae special lineage L1. Specimens collected at all other sampling sites were identified as O. sylviarum, including mites that had invaded a home from a house martin (Delichon urbicum) nest, as well as those which were collected from racing pigeons. House martin- or pigeon-associated O. sylviarum specimens showed the highest sequence identity and closest phylogenetic relationship with conspecific mites reported in GenBank from Israel or Canada, respectively. Conclusions Detailed morphological and molecular–phylogenetic analyses of D. gallinae lineage L1 confirmed its status as a cryptic species within D. gallinae (s.l.). Taking into account the well-documented latitudinal migratory routes of house martins between Hungary and Africa, O. sylviarum associated with this bird species most likely arrived on its host from the eastern Mediterranean region. On the other hand, mites collected from pigeons in Hungary showed cox1 genetic homogeneity with North American O. sylviarum, which can only be explained by a long-distance (west-to-east intercontinental) connection of birds and their mites as part of human activity (e.g. transportation to exhibitions or trading). In summary, this is the first molecularly confirmed and phylogenetically analyzed case of O. sylviarum infestation of birds in Hungary, implicating urban environment and involving distant parts of the country. This is also the first report of D. gallinae lineage L1 in central Europe.

Background: Among Dermanyssoidea, the chicken red mite (Dermanyssus gallinae) and the northern fowl mite (Ornithonyssus sylviarum) are considered to be the cause of high economic losses endured by the poultry industry in the Holarctic region, with O. sylviarum predominating in North America and D. gallinae in Europe. Both species have a short life-cycle (thereby allowing a rapid build-up of massive infestations), a wide range of hosts, synanthropic presence and the ability to bite humans. The aim of this study was to analyze dermanyssoid mite specimens, collected in two human dwellings and two racing pigeon premises in different urban areas in Hungary, with molecular–phylogenetic methods. Methods: Mite species were identified morphologically. This was followed by DNA extraction and molecular–phylogenetic analyses of selected mites, based on the cytochrome c oxidase subunit I (cox1) and 28S rRNA (28S) genes. Results: Mites that had invaded a home from a pigeon nest and were linked to human dermatitis were morphologically and molecularly identified as D. gallinae special lineage L1. Specimens collected at all other sampling sites were identified as O. sylviarum, including mites that had invaded a home from a house martin (Delichon urbicum) nest, as well as those which were collected from racing pigeons. House martin- or pigeon-associated O. sylviarum specimens showed the highest sequence identity and closest phylogenetic relationship with conspecific mites reported in GenBank from Israel or Canada, respectively. Conclusions: Detailed morphological and molecular–phylogenetic analyses of D. gallinae lineage L1 confirmed its status as a cryptic species within D. gallinae (s.l.). Taking into account the well-documented latitudinal migratory routes of house martins between Hungary and Africa, O. sylviarum associated with this bird species most likely arrived on its host from the eastern Mediterranean region. On the other hand, mites collected from pigeons in Hungary showed cox1 genetic homogeneity with North American O. sylviarum, which can only be explained by a long-distance (west-to-east intercontinental) connection of birds and their mites as part of human activity (e.g. transportation to exhibitions or trading). In summary, this is the first molecularly confirmed and phylogenetically analyzed case of O. sylviarum infestation of birds in Hungary, implicating urban environment and involving distant parts of the country. This is also the first report of D. gallinae lineage L1 in central Europe. [ABSTRACT FROM AUTHOR]

Abstract Background Northern fowl mite, Ornithonyssus sylviarum (Canestrini & Fanzago, 1877), infestations can stress birds, impairing welfare and causing substantial economic losses. A study was undertaken to determine the efficacy of an ectoparasiticide solution (fluralaner) for oral administration in the treatment of mite-infested hens. Methods Clinically healthy, naturally mite-infested laying hens (n = 132), approximately 32 weeks of age, were ranked by Day -9 mite vent counts and randomized among 12 study pens, each to hold one of four treatment groups. Three groups received fluralaner-medicated water by oral gavage at dose rates of 0.25, 0.5 or 1.0 mg/kg on Days 0 and 7; one group was an untreated control (three pens for each group). Five naturally infested untreated birds were included in each pen to act as mite-infested source birds. Thus each pen, treated and control, had six non-source birds for assessment of efficacy, plus five source birds to provide ongoing challenge. Primary efficacy assessments were based on mean O. sylviarum vent counts from non-source birds in the control and treated group pens on Days 1, 2, 6, 8, 12, 15, 19, 22 and 26. Results Source-birds maintained infestations throughout the study, validating the challenge to study birds. On Days 1 through 22, mean control group mite counts were significantly greater than those of the treated groups (P ≤ 0.013). Relative to the control group, mean O. sylviarum counts were reduced by at least 90% from Day 6 through Days 19, 22 and 22 in the fluralaner 0.25, 0.5 and 1.0 mg/kg groups, respectively. On Day 19, mean mite counts were lower in the 0.5 and 1.0 mg/kg groups compared with the 0.25 mg/kg group (P ≤ 0.018), and in the 1.0 mg/kg compared with the 0.5 mg/kg group (P = 0.014). There were no adverse events in treated birds. Conclusions A fluralaner solution administered twice by gavage to laying hens with a one-week between-treatment interval was safe and effective in quickly controlling O. sylviarum infestations despite continuous challenge from infested birds. By eliminating mites, this fluralaner solution has the potential to improve bird health and productivity, and to eliminate the burden of topical pesticide application.

• Nocturnal laying hen behavior was affected by northern fowl mites. • Behaviors became more fragmented, being performed at higher frequencies. • Resting quantity & quality were reduced because hens woke up often and rested less. • This behavioral change was interpreted as restlessness due to irritation. The northern fowl mite (Ornithonyssus sylviarum) is a key pest for caged laying hens. High infestation levels can lead to anemia, reduced production, and mortality. Although the mites cause skin irritation and thus likely affect resting behavior, the nocturnal behavior of infested chickens has not yet been studied. We investigated the impact of mite infestation on nighttime behavior of 16 beak-trimmed White Leghorn hens. The hens were housed individually in wire cages. They were experimentally inoculated with approximately 35 mites at 25 weeks of age and observed for the behaviors dozing, sleeping, preening and being active. Continuous observations were made from video recordings taken from 22:00 h until 06:00 h for two consecutive nights at pre-infestation week 0 and post-infestation weeks 3, 5 and 7. Mite infestation levels were measured weekly on an 8-point scale (0 (no mites) to 7 (≥10,000 mites per hen)). For statistical analyses with linear mixed models, mite infestation levels were categorized as score 0 (no mites), 3–4 (51–500), 5 (501–1000) and 6–7 (>1000). Higher levels of mite infestation were associated with hens spending less time dozing (P < 0.001) and more time preening (P < 0.001) and being active (P = 0.012). Dozing decreased from 90% of the observed time for mite score 0 to 76% for score 6–7. Preening increased from 2% (score 0) to 9% (6–7) and time spent being active increased from 1% (0) to 7% (6–7). Mite infestation increased the number of uninterrupted bouts of all behaviors (P ≤ 0.020), especially dozing and preening (P < 0.001), suggesting restlessness in the mite-infested hens due to irritation and itching. The mite-infested hens' increased nocturnal activity, including preening, as well as the fragmentation of behavioral activities together with decreased dozing, indicate disturbed resting behavior and suggest a reduction in the welfare of mite-infested hens. [ABSTRACT FROM AUTHOR]

O presente trabalho teve por objetivo avaliar a eficácia de um produto à base de extrato de nim, no controle da infestação por O. sylviarum em poedeiras comerciais. O experimento foi realizado observando-se a eficácia do extrato de nim a 2% após duas, três e quatro aplicações com intervalo de sete dias. Os resultados obtidos permitem concluir que o extrato de nim a 2% é efetivo no controle da infestação por O. sylviarum, sendo necessárias pelo menos três pulverizações semanais do produto para que haja o controle efetivo do parasito.This study evaluated the effectiveness of a neem extract-based product to control O. sylviarum infestations in commercial laying hens. The birds were divided in 3 groups, which received 2, 3, or 4 applications of the product at 7 day intervals. The results obtained allow the conclusion that the neem extract at 2"% is effective to control infestations by O. sylviarum, and at least 3 sprays of the product are required weekly for an effective control of the parasite.

Northern fowl mite management on conventionally caged birds relies on synthetic pesticide sprays to wet the vent. Cage-free chickens cannot be effectively treated this way, and pesticide use is restricted in organic production. Dustbathing behavior is encouraged in newer production systems for increased hen welfare. Diatomaceous earth (DE) is an approved organic insecticide that can be mixed with sand in dustboxes, suppressing mites but not excluding them, and potentially allowing development of mite immunity. We tested two hypotheses: 1) that DE-filled dustboxes placed before northern fowl mite introduction (prophylactic use) prevents mite populations from reaching economically damaging thresholds, and 2) that bird exposure to low mite numbers allows for protective hen immunity to develop and suppressmites after dustboxes are removed. We also tested if different beak trimming techniques (a commercial practice) affect mite growth. Mites were introduced to birds after dustboxes were made available. Average mite densities in flocks remained below damaging levels while dustboxes were available. Average mite populations rebounded after dustbox removal (even though DE persisted in the environment) regardless of the timing of removal. Mite densities on birds where a traditional hot-blade beak trimming technique was used (trial 1) were high. Mite densities in trial 2, where a newer precision infra-red trimming was used, were lower. The newer infra-red trimming method resulted in nearly intact beaks, which were better for mite control by bird grooming behaviors. The combination of early dustbox use and infra-red beak trimming should allow producers to avoidmostmite damage in cage-free flocks. [ABSTRACT FROM AUTHOR]

The northern fowl mite, Ornithonyssus sylviarum, is the most damaging ectoparasite on egg-laying hens in the United States. One potential strategy for management is breeding for mite resistance. Genes of white leghorn chickens linked to the major histocompatibility complex (MHC) were previously identified as conferring more (B21 haplotype) or less (B15 haplotype) mite resistance. However, immune responses can be energetically costly to the host and affect the economic damage incurred from mite infestations. We tested energy costs (resting metabolic rate) of mite infestations on egg-laying birds of both MHC B-haplotypes. Resting metabolic rates were documented before (pre-) mite infestation, during (mid-) infestation, and after peak (late) mite infestation. Mite scores, economic parameters (egg production, feed consumption), and physiological aspects such as skin inflammation and skin temperature were recorded weekly. Across experiments and different infestation time points, resting metabolic rates generally were not affected by mite infestation or haplotype, although there were instances of lower metabolic rates in infested versus control hens. Skin temperatures were recorded both at the site of mite feeding damage (vent) and under the wing (no mites), which possibly would reflect a systemic fever response. Ambient temperatures modified skin surface temperature, which generally was not affected by mites or haplotype. Feed conversion efficiency was significantly worse (4.9 to 17.0% depending on trial) in birds infested with mites. Overall egg production and average egg weight were not affected significantly, although there was a trend toward reduced egg production (2 to 8%) by infested hens. The MHC haplotype significantly affected vent skin inflammation. Birds with the mite-resistant B21 haplotype showed earlier onset of inflammation, but a reduced overall area of inflammation compared to mite-susceptible B15 birds. No significant differences in resting energy expenditure related to mite infestation or immune responses were detected. Potential breeding for resistance to mite infestation using these two haplotypes appears to be neutral in terms of impact on hen energy costs or production efficiency, and may be an attractive option for future mite control. [ABSTRACT FROM AUTHOR]

Animal welfare-driven legislation and consumer demand are changing how laying chickens are housed, thus creating challenges for ectoparasite control. Hens housed in suspended wire cages (battery cages) are usually treated with high-pressure pesticides. This application type is difficult in enriched-cage or cage-free production. Alternatives to pesticide sprays are needed in enriched-cage or cage-free systems. In this study, we tested the efficacy of sulfur dust deployed in "dust bags" for control against the northern fowl mite (Ornithonyssus sylviarum), which causes host stress, decreased egg production, and reduced feed conversion efficiency. Dust bags were hung from the tops of cages or were clipped to the inside front of cages. We also tested permethrinimpregnated plastic strips, marketed for ectoparasite control in caged or cage-free commercial and backyard flocks. Previous work has shown sulfur to be very active against poultry ectoparasites; however, we found that the placement of bags was important for mite control. Sulfur in hanging bags reduced mites on treatment birds by 95 or 97% (depending on trial) within one week of being deployed, and mite counts on these birds were zero after 2 wk. Clipped sulfur bags acted more slowly and did not significantly reduce mites in one trial, but reduced mite counts to zero after 4 wk in trial 2. Permethrin strips had no effect on mite populations. This may have been due to mite resistance, even though this mite population had not been exposed to pyrethroids for several years. Sulfur bags should be effective in caged or cage-free systems. [ABSTRACT FROM AUTHOR]

The northern fowl mite (NFM), Ornithonyssus sylviarum, is the most common ectoparasite of laying hens in North America. Infestation can cause a reduction in egg production, egg weights, and feed conversion efficiency. However, there is a lack of information on the effects of NFM on hen physiology, physical condition, and egg quality. Singly caged beak-trimmed White Leghorn hens (N = 32) were infested with mites at 25 wk of age. The condition of each hen was assessed at wk 0 (infestation) and wk 5 and 7 post-infestation to determine comb temperatures and feather, skin, and comb condition. Heterophil-lymphocyte (H/L) ratios and body weight (BW) were evaluated at wk 0 and wk 1, 3, 5, and 7 post-infestation. Egg weight, egg specific gravity, yolk color, Haugh unit (HU), and eggshell thickness were determined prior to infestation (wk -1) and at 1, 3, 5, and 7 wk post-infestation. The H/L ratio (P < 0.0001), HU (P < 0.0001), and egg specific gravity (P = 0.001) were lowest, and the egg yolk color was lightest (P = 0.087) at wk 5, the peak of infestation. At wk 5 and 7, more than 65% of the hens had red skin and more than 75% had scabs on the vent; in addition more than 84% had grey-black vent feathers. There were no effects of infestation on comb color, comb temperature, feather cover, BW, or eggshell thickness. It was concluded that infestation with NFM has negative effects on interior egg quality and hen integument. A decrease in H/L ratio was also observed at the peak of infestation. However, the effects of NFM on the immune system are unclear, and H/L ratio might not be a good stress measure in hens highly infested with NFM. [ABSTRACT FROM AUTHOR]

Introduction: Poultry red mites (PRMs, Dermanyssus gallinae ), blood-sucking ectoparasites, are a threat to the poultry industry because of reduced production caused by infestation. In addition, tropical fowl mites (TFMs, Ornithonyssus bursa ) and northern fowl mites (NFMs, Ornithonyssus sylviarum ) are hematophagous, distributed in various regions, genetically and morphologically close to PRMs, and cause similar problems to the poultry industry. Vaccine approaches have been studied for PRM control, and several molecules have been identified in PRMs as candidates for effective vaccine antigens. The development of an anti-PRM vaccine as a universal vaccine with broad efficacy against avian mites could improve the productivity of poultry farms worldwide. Molecules that are highly conserved among avian mites and have critical functions in the physiology and growth of mites could be ideal antigen candidates for the development of universal vaccines. Ferritin 2 (FER2), an iron-binding protein, is critical for the reproduction and survival of PRMs and has been reported as a useful vaccine antigen for the control of PRMs and a candidate for the universal vaccine antigen in some tick species., Method and Results: Herein, we identified and characterized FER2 in TFMs and NFM. Compared with the sequence of PRM, the ferroxidase centers of the heavy chain subunits were conserved in FER2 of TFMs and NFMs. Phylogenetic analysis revealed that FER2 belongs to clusters of secretory ferritins of mites and other arthropods. Recombinant FER2 (rFER2) proteins from PRMs, TFMs, and NFMs exhibited iron-binding abilities. Immunization with each rFER2 induced strong antibody responses in chickens, and each immune plasma cross-reacted with rFER2 from different mites. Moreover, mortality rates of PRMs fed with immune plasma against rFER2 from TFMs or NFMs, in addition to PRMs, were higher than those of control plasma., Discussion: rFER2 from each avian mite exhibited anti-PRM effects. This data suggests that it has the potential to be used as an antigen candidate for a universal vaccine against avian mites. Further studies are needed to access the usefulness of FER2 as a universal vaccine for the control of avian mites., Competing Interests: TS, EO, and AT were employed by Vaxxinova Japan K.K, Tokyo, Japan. SM, SK, and KO are authors of the patent-covering materials and techniques described in this manuscript (EU patent, EP15800403.6; Japanese patent, 2016-523581). The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Win, Murata, Fujisawa, Seo, Sato, Motai, Sato, Oishi, Taneno, Htun, Bawm, Okagawa, Maekawa, Konnai and Ohashi.)

A presumed function of dustbathing behavior is to remove ectoparasites. Providing dustbathing substrates in furnished cages for laying hens might therefore offer an alternative to pesticide use to reduce ectoparasite populations. We investigated the effectiveness of dustbathing substrates for controlling northern fowl mites in individually caged beak-trimmed White Leghorn hens ( N = 32). Each cage contained a 32 cm × 32 cm plastic tray that was either: (1) filled with 1200 g of sand (SAND); (2) empty (CONTROL); (3) covered with Astroturf (AT); or (4) covered with AT on to which 150 g of feed was delivered daily (ATF). AT and ATF are used in the dustbathing/foraging area of many newer commercial furnished cages. Hens were infested with approximately 35 mites at 25 weeks of age. Mite numbers were estimated weekly. Time spent dustbathing and dustbathing bout numbers and lengths in the tray and on the wire cage floor were determined from video recordings made for 2 consecutive days from 12:00 to 20:00 h immediately before and after infestation and at weeks 1, 3, 5, and 7 post-infestation. Data were analyzed using a repeated-measures ANOVA in SAS. Treatment did not influence the total time spent dustbathing (average across substrates: 11.3 min). However, there were treatment effects on the time spent dustbathing in the trays ( F 2,21 = 3.67, P = 0.043) and on wire ( F 2,21 = 7.68, P = 0.031). SAND and ATF hens spent more time dustbathing in the trays (11.4 and 9.1 min, respectively) than AT (2.3 min), and CONTROL and AT hens spent more time dustbathing on wire (11.6 and 4.7 min, respectively) than ATF (0.4 min). There was a treatment effect on infestation ( F 3,28 = 3.08, P = 0.04), with ATF having more mites (back-transformed mean = 1500) than AT (330), and with SAND (460) and CONTROL (447) intermediate. This study confirmed that the substrate type affected dustbathing behavior. SAND was a preferred dustbathing substrate but was not effective for controlling mite numbers, nor was the time spent dustbathing in any substrate or in total influenced by infestation levels. Our data also suggest that adding feed to the AT pad in furnished cages might lead to increased mite numbers in infested hens. The reason for this effect is unclear, but could be due to feed particles contributing to a change in feather structure that creates a more favorable mite habitat. [ABSTRACT FROM AUTHOR]

Haematophagous mites were collected from the vent region and plumage of chickens in six hobby flocks of ornamental breeds in Sweden, one of which included turkeys. Soiled vent skin and feathers, dermatitis, hyperkeratosis, skin necroses and ulcers were observed in 12 necropsied birds from two of the flocks. The mites were identified as the northern fowl mite Ornithonyssus sylviarum (Mesostigmata: Macronyssidae). This was supported by sequence analysis of a 642-bp region in the mitochondrial cytochrome oxidase subunit 1 ( COI) gene ( COI) in mites collected from five flocks, which showed 97-99% sequence similarity to O. sylviarum by blast analysis. Pairwise sequence comparisons revealed nucleotide variations in the range of 0-2.8%, whereas amino acid sequences were highly conserved. This paper represents one of very few records of O. sylviarum in European poultry, and is the first to report COI sequence data for O. sylviarum from poultry in Europe. [ABSTRACT FROM AUTHOR]

This study was carried out to identify mite species infesting passerine birds in eastern Iran. A total of 106 passerine birds from 37 species were captured and examined for mite infestation. Of the 106 birds examined, 35 birds (33.01%) were infested with mites. Fourteen mite species were removed from infested birds and identified as follows:Leptotrombidium (Ericotrombidium) limpidumKudryashova, 1976,Harpyrhynchoides rubeculinusCerny and Sixl, 1971,Neoschoengastia longitarsalisSchluger and Belskaj, 1966,Ptilonyssus pirangaeCerny, 1969,Ptilonyssus hirstiCastro and Pareira, 1947,Ptilonyssus icteridiusStrandtmann and Furman, 1956,Proctophyllodes styliferBuhholz, 1869,Proctophyllodes clavatusFritsch, 1961,Proctophyllodes truncatusRobin, 1877,Proctophyllodes orientalisGaud, 1953,Dolichodectes edwardsiTrouessart, 1885,Strelkoviacarus critesiSpory 1965,Dermanyssus brevisEwing, 1936 andOrnithonyssus sylviarumCanestrini and Fanzago, 1877. In this studyO. sylviarum,D. brevis, P. pirangae, P. hirsti, P. icteridius, H. rubeculinus, N. longitarsalis, D. edwardsi, P. stylifer, P. truncatesandP. clavatusare new records of these mites for Iran. Proctophyllodes clavatuson Common Chiffchaff,D. edwardsi onTree Sparrow and Olivaceous Warbler,S. critesion Common Chiffchaff, House sparrow and Corn Bunting,P. pirangaeon Common Greenfinch,H. rubeculinuson Common Nightingale andP. icteridiuson Red-headed Bunting were recorded for the first time in the world. [ABSTRACT FROM PUBLISHER]

The article discusses a study which determined whether the comparatist of nestlings may be a factor to the declining population of American Kestrel (Falco sparverius) in North America. Broods of kestrels in nest boxes in New Jersey were examined to identify and quantify the arthropod ectoparasites of nestlings. No significant differences in nestling wing length, tail length, body mass, or nesting survival were found. The study showed that comparatist removal would not be an effective strategy in increasing the nesting success of American Kestrels.

Adult White Leghorn hens (Hy-Line strain W-36) were inoculated with either northern fowl mites or chicken body lice, and the ectoparasite populations were monitored over periods of 9 to 16 wk. Two beak conditions (beak trimmed or beak intact) and 2 housing densities (1 or 2 hens per 25 × 31 cm suspended wire cage) were tested. Populations of both ectoparasites were at least 10 times lower on beak-intact hens compared with populations on beak-trimmed hens. Cage density did not influence mite numbers, but higher numbers of lice (2 to 3 times) developed on hens held at the higher cage density. Louse distribution on the body and louse population age structure were also influenced by host beak condition. Beak-intact hens had a higher proportion of lice under the wings, whereas beak-trimmed hens had the majority of lice on the lower abdomen. Louse populations on beak-trimmed hens also comprised relatively more immature stages than populations found on beak-intact hens. The effects are likely related to decreased grooming efficiency by beak-trimmed hens and, in the case of lice, the higher host density. The high mite and louse populations on most commercial caged laying hens are probably a direct result of beak trimming. However, selection of more docile breeds that can be held without trimming may allow the hens themselves to reduce ectoparasites below economically damaging levels. This could benefit producers, animal welfare advocates, and human health by reducing 1) costs of beak trimming, 2) pesticide treatment costs (including human and bird chemical exposure concerns), and 3) objections to beak trimming from the animal welfare community. [ABSTRACT FROM AUTHOR]

Research on immune function in evolutionary ecology has frequently focused on avian ectoparasites (e.g., mites and lice). However, host immunogenetics involved with bird resistance to ectoparasites has not been determined. The critical role of the major histocompatibility complex (MHC) in adaptive immunity and high genetic variation found within the MHC make this gene complex useful for exploring the immunogenetic basis for bird resistance to ectoparasites. The objective of this study was to determine if the avian MHC influenced resistance to a blood-feeding ectoparasite. Four congenic lines of chickens, differing only at the MHC, were comparatively infested with a cosmopolitan ectoparasite of birds—northern fowl mite (NFM)—which is also a serious pest species of poultry. Mite infestations were monitored over time and mite densities (weekly and maximum) were compared among lines. Chickens with the MHC haplotype B21 were relatively resistant to NFM, compared with birds in the B15 congenic line ( P < 0.02). To test for similar effects in an outbred genetic background, a separate experiment was performed with 107 commercial chickens ( white leghorn, W-36 strain) infested with NFM. Hens were genotyped using a MHC microsatellite marker (LEI0258) and associations between MHC haplotype and NFM density were tested. The highest peak NFM populations occurred more often on hens with the B15 haplotype versus the B21 haplotype ( P = 0.012), which supported the results of the congenic study. These data indicate the avian MHC influences ectoparasite resistance, which is relevant to disease ecology and avian–ectoparasite interaction. [ABSTRACT FROM AUTHOR]

Southern California caged layer operations were visited over 3 yr. Northern fowl mites from 26 field populations were tested for acaricide resistance using a capillary pipette and glass dish bioassay. One was a susceptible field population with no pesticide exposure for over 30 yr (reference site for resistance ratio calculation). Technical and commercial formulations of malathion, carbaryl (Sevin), permethrin, and a commercial formulation of tetrachlorvinphos/dichlorvos (Ravap) were tested. Malathion did not have high activity for mites relative to other materials, but resistance to both technical and commercial formulations was low (<5×). Resistance to other materials was moderate to extreme. Frequency of carbaryl resistance (>10×) was higher with the commercial (88%) than the technical material (41%); 19% of the populations had resistance >100× to commercial carbaryl. Fre- quency of Ravap resistance (>10×) was 68%; 8% of populations had resistance >100×. Frequency of permethrin resistance (>10×) was 72% for the technical material and 88% for the commercial formulation. Extreme permethrin resistance (>1,000×) was observed in 56 and 50% of mite populations assayed using the technical and commercial formulations, respectively. Among sites, resistance to permethrin was uncorrelated with resistance to other chemicals, suggesting a different resistance mechanism. Resistance to carbaryl and Ravap was highly correlated [r = 0.76 at the LC50 level (concentrations estimated to be lethal to 50% of the test population) and r = 0.99 at the LC95 level], suggesting a common resistance mechanism. Producers currently depend completely on pesticides to control mite infestations. Mite resistance to registered materials emphasizes the need for integrated control measures. [ABSTRACT FROM AUTHOR]

Abstract Background Dermanyssus gallinae (poultry red mite) is a major threat for the poultry industry and is of significant interest for public health. Identification of D. gallinae can be difficult for scientists not familiar with mite morphology and terminology especially when trying to use identification keys. Moreover, this species may easily be confused with another dermanyssoid mite, Ornithonyssus sylviarum (northern fowl mite), which often shares the same hosts and environment. Methods Specimens of D. gallinae were collected at poultry farms in the Puglia and performed for light and scanning electron microscopy observations, identification and micrographs. Moreover specimens of O. sylviarum were collected separately macerated and mounted on slides for light microscopy observations, identification and pictures. Results The micrographs used in this study, based on LM and SEM observations, highlight the following important identifying characters of D. gallinae: the prominent shoulders of the dorsal shield and the jagged edges of the shield reticulations, the position of setae j1, s1 and the epigynal pores, and the presence on tibia IV pl of one seta. Additional micrographs highlighting the shape of the dorsal (abruptly narrowed posteriorly) and epigynal (narrowly rounded posteriorly) shields and the chelicera (elongate, with distinct digits) of O. sylviarum enable its differentiation from D.gallinae. Conclusion The photographic support provided here (both LM and SEM pictures) can be considered a practical tool for scientists who are not well acquainted with the morphology of D.gallinae, and who are involved with classical and molecular systematics, veterinary and human health aspects of poultry red mites.

Background: Northern fowl mite, Ornithonyssus sylviarum (Canestrini & Fanzago, 1877), infestations can stress birds, impairing welfare and causing substantial economic losses. A study was undertaken to determine the efficacy of an ectoparasiticide solution (fluralaner) for oral administration in the treatment of mite-infested hens. Methods: Clinically healthy, naturally mite-infested laying hens (n = 132), approximately 32 weeks of age, were ranked by Day -9 mite vent counts and randomized among 12 study pens, each to hold one of four treatment groups. Three groups received fluralaner-medicated water by oral gavage at dose rates of 0.25, 0.5 or 1.0 mg/kg on Days 0 and 7; one group was an untreated control (three pens for each group). Five naturally infested untreated birds were included in each pen to act as mite-infested source birds. Thus each pen, treated and control, had six non-source birds for assessment of efficacy, plus five source birds to provide ongoing challenge. Primary efficacy assessments were based on mean O. sylviarum vent counts from non-source birds in the control and treated group pens on Days 1, 2, 6, 8, 12, 15, 19, 22 and 26. Results: Source-birds maintained infestations throughout the study, validating the challenge to study birds. On Days 1 through 22, mean control group mite counts were significantly greater than those of the treated groups (P ≤ 0.013). Relative to the control group, mean O. sylviarum counts were reduced by at least 90% from Day 6 through Days 19, 22 and 22 in the fluralaner 0.25, 0.5 and 1.0 mg/kg groups, respectively. On Day 19, mean mite counts were lower in the 0.5 and 1.0 mg/kg groups compared with the 0.25 mg/kg group (P ≤ 0.018), and in the 1.0 mg/kg compared with the 0.5 mg/kg group (P = 0.014). There were no adverse events in treated birds. Conclusions: A fluralaner solution administered twice by gavage to laying hens with a one-week between-treatment interval was safe and effective in quickly controlling O. sylviarum infestations despite continuous challenge from infested birds. By eliminating mites, this fluralaner solution has the potential to improve bird health and productivity, and to eliminate the burden of topical pesticide application. [ABSTRACT FROM AUTHOR]