Poultry Red Mite Research Articles

Impact of Dermanyssus gallinae infestation on persistent outbreaks of fowl typhoid in commercial layer chicken farms

Although it has rapidly decreased since the early 2000s, fowl typhoid still occurs in commercial layer chickens, causing a significant economic loss in Korea. There is growing concern about the emergence of new pathogenic strains of the causative agent, Salmonella Gallinarum, which is able to overcome vaccine immunity. It has also been suspected that the poultry red mite, Dermanyssus gallinae, which is commonly found in layer chicken farms, may be an important cause of the recurrence of fowl typhoid in the farms. This study was conducted to examine changes in the virulence of recent isolates of S. Gallinarum obtained from layer farms and estimate the potential of the disease transmission of D. gallinae in the farms. Clinical and environmental samples and mites collected from layer farms affected by fowl typhoid between 2013 and 2018 were tested for S. Gallinarum. The isolates were characterized by genotypic analyses and in vitro virulence assays with chicken-derived cell lines. Vaccine protection against recent isolates was examined in the chickens. A total of 45 isolates of S. Gallinarum were collected and there was no evidence of changes in their virulence. It has also been demonstrated that the S. Gallinarum 9R vaccine strain widely used in Korea is still effective in controlling fowl typhoid if the susceptibility of birds to the disease is not increased by stress. Salmonella Gallinarum isolated from the outer and inner parts of D. gallinae, environmental dust, and dead birds of the same farm showed the same or closely related genotypes. Consequently, the present study indicated that the horizontal transmission and environmental persistence of S. Gallinarum and the increased disease susceptibility of chickens in layer farms could be mediated by D. gallinae, causing persistent outbreaks of fowl typhoid.

Management of the poultry red mite, Dermanyssus gallinae, using silica-based acaricides

Four silica-based acaricides were examined in laboratory tests for their effectiveness against poultry red mite, Dermanyssus gallinae. All acaricides resulted in 100% mite mortality. Two groups of active ingredients could be differentiated. The products Silicosec® and Ewazid®, based on naturally occurring diatomaceous earth (DE), killed 100% of adult D. gallinae within 48 h exposure time. The time to kill 50% of the mites (LT50) was calculated to be 31.7 and 34.9 h, respectively. The other two products, containing aggregates and agglomerates of pyrogenic synthetic amorphous silicon dioxide as active ingredients, killed the mites in a significantly shorter time: LT50 was 6.3 h for the liquid product Fossil Shield® Instant White and 11.8 h for the powdery product Fossil Shield 90.0 White. This is more remarkable as the quantities of active ingredients used for the DE treatments were several folds higher. The effectiveness of all tested products was also shown in practical tests. A professional company treated five chicken houses on one farm in the Berlin–Brandenburg region with the test products, three houses with Fossil Shield Instant White and one each with Ewazid and Silicosec. Over a period of 46 weeks after stocking, the mite development in the houses was assessed. Only in one of the houses, treated with Fossil Shield Instant White, the mite population remained permanently low. In two houses treated with Fossil Shield Instant White, small mite colonies appeared in week 36, which were controlled by a follow-up spot treatment in week 41. In the houses treated with DE, the first mite colonies appeared 12 weeks after stocking. The number increased continuously over the experimental period and in week 31 after stocking there were clearly visible colonies (2–3 cm diameter) and the first mites could also be detected on the chicken eggs. At this time both houses were treated again with a follow-up spot-treatment, which only led to a slight improvement in one house and to a stabilization of the infestation in the other house. In week 41, large mite colonies were detected in both houses. A spot treatment at this point was ineffective in reducing the infestation. The tests showed faster acaricidal action of the products with the synthetic active ingredients compared to the natural DE-based products. This matches the shorter killing times under laboratory conditions. The experiments in a commercial chicken farm showed that it is possible to control the mite population for a period of 46 weeks by using physically effective SiO2-based products. These products are therefore an effective alternative to the use of chemical acaricides.

Phylogenetic Inference Using Cytochrome C Oxidase Subunit I (COI) in the Poultry Red Mite, Dermanyssus gallinae in the United Kingdom Relative to a European Framework.

The poultry red mite (Dermanyssus gallinae), an obligatory blood feeding ectoparasite, is primarily associated with laying hens where it is estimated to cause losses of ~€231 million per annum to European farmers. Moderate to high infestation levels result in negative impacts on hen welfare, including increased cannibalism, irritation, feather pecking, restlessness, anemia, and mortality. Acaricides are currently the prevailing method of population control for D. gallinae, although resistance against some classes of acaricide has been widely reported. The development of resistance highlights a growing need for research into alternative control methods, including the development of a suitable and effective vaccine. Understanding the genetic structure of D. gallinae populations can support improved management of acaricide resistance and sustainability of future vaccines, but limited data are currently available. The aim of this study was to characterize D. gallinae isolates from Europe, targeting the cytochrome c oxidase subunit 1 (COI) gene to gain an insight into population structure and genetic diversity of currently circulating mites. Dermanyssus gallinae isolates were collected from Albania, Belgium, Croatia, Czech Republic, Denmark, France, Greece, Italy, the Netherlands, Portugal, Romania, Slovenia, Turkey and the United Kingdom. Genomic DNA was extracted from individual adult D. gallinae mites and a 681bp fragment of the COI gene was amplified and sequenced. Phylogenetic analyses of 195 COI sequences confirmed the presence of multiple lineages across Europe with 76 distinct haplotypes split across three main haplogroups and six sub-haplogroups. Importantly there is considerable inter- and intra-country variation across Europe, which could result from the movement of poultry or transfer of contaminated equipment and/or materials and husbandry practices.

A nonexhaustive overview on potential impacts of the poultry red mite (Dermanyssus gallinae) on poultry production systems.

The poultry red mite (PRM) (Dermanyssus gallinae) is a worldwide problem for the poultry production industry. Prevalence rates of more than 80% are common in many countries (Sparagano et al., 2009; Tomley and Sparagano, 2018). Complete development of D. gallinae, from egg to adult through one larval stage and two nymphal stages, typically occurs over 2 weeks. They usually feed for short periods and retrieve in cracks and crevices to digest blood contrary to other poultry mites. Economic costs associated with both control and production losses due to D. gallinae have been estimated at €130 million per year for the European Union egg industry. There is a relationship between D. gallinae infestation and hen mortality; some reports record a 10-fold increase in death rates following severe infestation in Romania (Cosoroaba, 2001). Although causal factors may vary, in extreme cases D. gallinae numbers may be so high that hens become severely anemic, with mortality resulting from exsanguination. At a sublethal level, mite feeding may result in significant stress to hens, causing an increase in circulating corticosterone and adrenaline and a decrease in β- and γ-globulins. Bird sleep patterns can be disrupted by the need for increased preening, and changes in head-scratching and feather-pecking behavior could also be seen. Increases in aggressive feather-pecking and cannibalistic behaviors have been reported. These mites can survive for weeks if not months without a blood meal and can therefore reappear between flocks. As blood feeders, PRMs could induce anemia with economic losses related to smaller egg size, less eggs per hen per year, and higher mortality. A recent report in Belgium followed various production parameters for fluralaner-treated bird groups compared to control groups, highlighting the positive impact of such treatment (Sleeckx et al., 2019). These mites can harbor key symbionts needed for their survival (de Luna et al., 2009) and can be responsible for the transmission of bacterial and viral diseases such as Salmonella (Valiente Moro et al., 2007; Hamidi et al., 2011; Sylejmani et al., 2016), Avian Influenza (Sommer et al., 2016), Coxiella burnetii, and Borrelia burgdorferi (Raele et al., 2018) which can also decimate flocks in their own rights (Sparagano et al., 2014).

Association between the poultry red mite Dermanyssus gallinae and potential avian pathogenic Escherichia coli (APEC)

Avian pathogenic Escherichia coli (APEC) is a group of strains responsible for avian colibacillosis, an impactful disease for poultry farming. The spread of APEC is mainly horizontal, and insects may play a role in their dissemination. However, no data are available about the interaction of APEC with Dermanyssus gallinae, a major arthropodal parasite of poultry. Escherichia coli was detected in the microbiome of the mite, but no specific data have been published till now. Therefore, the presence of the most diffused APEC-associated serogroups has been assessed by PCR in mites collected from 30 flocks of 21 Italian commercial laying hens farms. Escherichia coli was found in 53.3% of the tested groups, corresponding to 66.7% of farms. The most frequent serogroup was O2, but O8, O78, and O109 were also detected. More detailed investigations were carried out in a laying hen farm that was experiencing colibacillosis by APEC O2. The same serogroup was found in both hens and mites, and the maximum likelihood estimation (MLE) of the infection rate (IR) resulted in 24.39 infected mites per thousand, with a pathogen load of 171.47 E. coli O2 cells per mite. The results strongly support the hypothesis of an association between PRM and APEC, confirmed by the contemporary circulation of the same serogroup in both hens and mites, suggesting the potential of D. gallinae as a reservoir or APEC.

Predation interactions among henhouse-dwelling arthropods, with a focus on the poultry red mite Dermanyssus gallinae.

Analysis of the poorly explored food webs of henhouse-dwelling arthropods would improve biological control against the poultry red mite (PRM) Dermanyssus gallinae (De Geer). This study aimed to identify trophic links among native predatory arthropods, PRM, and alternative preys. In vitro predation tests were carried out to assess (i) the ability of native predators to feed on PRM juvenile and adult stages in two physiological statuses (unfed and freshly blood-fed) in the absence of any physical barrier, (ii) predator preferences between PRM and astigmatic mites, and (iii) predation interactions between PRM predators. Ten arthropod taxa fed on PRM with predation rates ranging from 4% to 95% in our experimental conditions. They belonged to (i) Acari: Androlaelaps casalis (Berlese), Cheyletus spp., Macrocheles muscaedomesticae (Scopoli), M. penicilliger (Berlese), Parasitus fimetorum (Berlese), Dendrolaelaps spp. and Uroobovella fimicola (Berlese); (ii) other Arachnida: Lamprochernes nodosus (Schrank) (Pseudoscorpionida) and a linyphiid spider; and (iii) Insecta: Lyctocoris campestris (Fabricius). These predators varied in their preference for PRM stages and physiological statuses (unfed or freshly blood-fed). When given a choice, most predators preferred to feed on PRM than astigmatic mites. Bidirectional predation occurred within two pairs of PRM predators (M. penicilliger-Lamprochernes nodosus and A. casalis-Cheyletus spp.), and M. penicilliger had a 100% predation rate on A. casalis. Our study highlights the potential of various arthropod predators occurring naturally in poultry houses for conservation and augmentative biological control of PRM. Predation interactions between these predators should be accounted for before developing biocontrol agents against PRM. © 2020 Society of Chemical Industry.

Transcription profiling and characterization of Dermanyssus gallinae cytochrome P450 genes involved in beta-cypermethrin resistance

The poultry red mite, Dermanyssus gallinae, poses a significant threat to hen health and poultry husbandry. D. gallinae has typically been controlled using synthetic acaricides, like pyrethroids, but increased resistance to pyrethroids has been found in poultry red mite populations worldwide. Pyrethroids resistance in arthropods has been associated to cytochrome P450 monooxygenases (P450s), a main member of a group of detoxification enzymes. To explore the potential contribution of P450s to the resistance to pyrethroids in D. gallinae, we first identified and then characterized four P450s genes. Phylogenetic analysis revealed that the four P450s genes in D. gallinae belong to three different clades, with two in the CYP-6, one in the CYP-4 and one in the CYP-2. All four P450s genes were expressed in a similar pattern in D. gallinae at different stages of development, and showed high expression in the adult stage, indicating that they played a role in mite development. Simultaneously, constitutive over-expression of Deg-CYP-3, a clade associated with pesticide metabolism, was detected in a resistant strain (RS) compared with a susceptible strain (SS). When exposed to beta-cypermethrin, the four P450s gene transcripts in the RS strain increased in a time-dependent manner. In particular, Deg-CYP-3 expression increased 5-fold compared to gene expression in control group at 12 h, although the four P450s genes were not induced in the SS strain. Our results show the first insights into the molecular characteristics of P450s genes in D. gallinae. The elevated presence of P450s genes in the RS strain, indicated by their constitutive over-expression and their inducible expression, suggests that they confer resistance to beta-cypermethrin, and are involved in its detoxification.

<p class="Body"><strong>Efficacy of <em>Beauveria bassiana</em> against the poultry red mite, <em>Dermanyssus gallinae</em> (De Geer, 1778) (Mesostigmata: Dermanyssidae), under laboratory and hen house conditions</strong></p>

Dermanyssus gallinae (De Geer) (Mesostigmata: Dermanyssidae) is one of the most important hematophagous ectoparasites of laying hens. Chemical acaricides are the basis of a control program of this mite. In addition to their relative efficiency, there are many side effects associated with these chemical products. In an effort to generate more options for the mite control, entomopathogenic fungi were evaluated for use in the control of D. gallinae in laboratory and field conditions. Conidia suspensions of Beauveria bassiana strains were applied to mites (1×108 viable conidia/ml). Out of 39 strains, four isolates were selected according to their acaricidal activity (confirmed mortality ≥70%). Growth and reproduction parameters on culture media and fungal development at different temperatures were also evaluated. Finally, the efficacy of the selected strain was determined in a commercial laying hen house. A suspension of conidia (1 × 109 viable conidia/ml) was sprayed around the cages. Seven days later, another suspension was applied. A control group was sprayed with water. Paper towel traps were used to estimate the mite population before and after treatments. Mite traps were placed one week before the first fungal application and changed weekly for up to three weeks after application (-7; 0; 7; 14 and 21 days). In lab studies, B. bassiana strain Unioeste 88 was the most effective, causing 73.8% mortality and showing high conidia production (7.1 × 108 conidia/colony and 7.7 × 108 conidia/g, respectively, on PDA and rice). There was no fungal development at temperatures ranging from 35 to 45 °C. In the field test, the fungus reduced the mite population efficiently (64.8%), while the mite population increased by 281% in untreated plots. B. bassiana strain Unioeste 88 has the potential to be commercially used to control the poultry red mite.

Prevalence of poultry red mite (Dermanyssus gallinae) in Korean layer farms and the presence of avian pathogens in the mite.

The poultry red mite, Dermanyssus gallinae, is a blood-feeding parasite of layer hens and a potential vector of several avian infectious agents. High infestation with D. gallinae in layer farm buildings could result in economic losses, and the mites may act as a reservoir of avian pathogens within farms. This study aimed to assess the prevalence of D. gallinae in layer farm buildings in Korea and to investigate avian pathogens in the collected mites. The mite samples were collected from 36 Korean layer farm buildings on 21 farms nationwide. Information obtained from each farm building included the flock size, flock age, methods for controlling D. gallinae, and cleaning status. Association between these variables and the population density of D. gallinae was analyzed. Additionally, the presence of 10 avian pathogens was assessed using DNA samples from mites collected in 16 farm buildings. The prevalence of D. gallinae was 75% at the farm building level (90.5% at the farm level). Repetitive cleaning procedures for each building were significantly related with the mite infestation level, and the most influential factor for determining the mite population in the layer farm buildings. In the 16 DNA samples, we detected avian pathogenic Escherichia coli (n = 6), wild-type fowlpox virus (n = 3), wild-type Marek's disease virus (n = 2), chicken anemia virus (n = 1), and fowl adenovirus (n = 1). These findings suggest that repetitive cleaning procedures for the layer farm buildings could decrease the numbers of D. gallinae which may transmit avian pathogens within the farm.

Association of mechanical cleaning and a liquid preparation of diatomaceous earth in the management of poultry red mite, Dermanyssus gallinae (Mesostigmata: Dermanyssidae).

The poultry red mite (PRM), Dermanyssus gallinae, is an ectoparasite of great importance related to poultry farms worldwide. Problems associated with its control have led to the search for alternative treatments, especially using inert dust, which has recently been introduced into liquid formulations. Therefore, the objective of this work was to evaluate the acaricidal activity of a liquid diatomaceous earth (DE) preparation in the laboratory and its association with mechanical cleaning (brushing) in the field. In the laboratory it was first determined that a concentration of 10% DE would be necessary for field applications. The field experiment was conducted in a commercial poultry house. The 10% DE liquid preparation was administered in three applications and associated to mechanical cleaning. Then, 42 days after the first DE application, a population reduction of 94.7% was observed in relation to the initial population of mites. These results confirm the efficiency of DE applications in association with mechanical cleaning already adopted in poultry houses as an alternative for the control of D. gallinae, which can also contribute to avoiding mite resistance to chemical acaricides.

Molecular characterization of poultry red mite, Dermanyssus gallinae lineages in Turkey and first report of Plasmodium species in the mite populations

ABSTRACT Dermanyssus gallinae , the poultry red mite is an obligatory blood-sucking ectoparasite and has been involved in the transmission of several pathogens between both animals and humans. In order to develop effective control strategies against D. gallinae, it is essential to determine their genetic compositions and investigate the potential vector roles of these mites. Therefore, we aimed to analyse the mt-COI gene regions of D. gallinae populations and investigate avian haemosporidian parasites in order to point out their risk potentials for the presence of possible transmission by these mites. In total, 1985 mites were collected from five laying hen breeding facilities in Central Anatolia Region in Turkey. The mt-COI sequence analyses of 100 individual mites identified 6 haplotypes (TD1 to TD6) in three haplogroups. Although the local lineages are common in the region, our findings also support the possibility of international transmission of D. gallinae. A total of 126 pools of D. gallinae were screened for investigation of three genera of avian haemosporidians. In total, five pools from three facilities were identified as positive for species of Plasmodium. These findings provide novel molecular data on the possible vector role of D. gallinae in the transmission of avian haemosporidians and draw attention to the risk potentials in poultry farms.

Growth, behavioural and haematological responses to poultry red mite infestation in Japanese quail

Abstract The aim of the study was to investigate the effects of poultry red mite (PRM) infestation on Japanese quail. Two trials were carried out under same conditions, each using 80 one-week-old quail chicks. Half of the chicks were experimentally infested with PRM and the other half functioned as control group. The conditions of the two trial rooms were the same. Low infestation was observed in Trial I, while high infestation was seen in Trial II. Live weight (LW) and daily feed intake (DFI) were not significantly affected in Trial I (PÂ =Â 0.2190). However, infested birds scratched themselves 2.46 times more than the control birds (PÂ =Â 0.0002). Haemoglobin (Hg) of control and infested birds were 9.58 g∙dl –1 and 7.72 g∙dl –1 (PÂ =Â 0.0017), and eosinophil proportions 5.79% and 18.58% (PÂ =Â 0.0004), respectively. In Trial II differences of LW between control and infested birds reached a significant level at the 5th week (PÂ =Â 0.0038). DFI of control birds was higher than in infested birds (PÂ <Â 0.0001). Infested birds showed 4.22 times more scratching behaviour than the control (PÂ =Â 0.0003). Hg, erythrocyte and haematocrit were 5.52 g∙dl –1, 1.79∙10 6∙μl –1 and 29.36% in infested birds, respectively; 11.28 g∙dl –1, 3.78∙10 6∙μl –1 and 43.47% in the control (PÂ =Â 0.0001). Ratio of the spleen to carcass weight was 0.08% in control and 0.10% in infested birds (PÂ =Â 0.0595). The ratio of gizzard to carcass weight was higher in infested birds (PÂ =Â 0.0008). A higher mortality in infested birds was observed in Trial II compared to Trial I (PÂ <Â 0.0001). The carcasses of infested birds showed lower dry matter content than carcasses of control birds (PÂ =Â 0.0006). In conclusion, a low level of infestation did not lead to major negative effects, but decreased haemoglobin levels and increased scratching behaviour of the infested birds, indicating a negative impact on welfare. However, high infestations of PRM had severe effects on the quail.

Control of Dermanyssus gallinae (De Geer 1778) and other mites with volatile organic compounds, a review.

Dermanyssus gallinae (De Geer 1778), commonly named the poultry red mite (PRM), is considered to be the most harmful ectoparasite in poultry farms in Europe. This species feeds on the blood of laying hens, but spends most of its time hidden in cracks and crevices around hen nests. To control PRM populations in poultry houses, chemical pesticides are currently used; however, concern is growing regarding the harmful residues found in eggs and hens, along with the increased resistance of mites against several compounds. Alternatives to synthetic compounds are now being explored, including vaccines, biological control, physical control and semiochemical control based on the chemical ecology of PRM. This review focused on the different volatile organic compounds (VOCs) identified from D. gallinae and other mite species that have been discovered to control them. Pheromones (aggregation pheromone, sex pheromone and alarm pheromone) and kairomones promoting attraction behaviour in D. gallinae and other mite species are presented, while VOCs from essential oils and plant extracts with repellent properties are also explored. Finally, devices using VOCs on PRM in the field are described, with devices that have been tested on other Acari species being mentioned as potential directions for the future control of PRM.

Low-temperature storage of the poultry red mite, Dermanyssus gallinae, facilitates laboratory colony maintenance and population growth.

The poultry red mite, Dermanyssus gallinae, is currently the most common ectoparasite affecting egg-laying hens. Since continuous culture of D. gallinae on birds is a biologically and economically costly endeavour, storage techniques for mites are urgently needed. Effects of temperature on adult and nymph survival were first studied to optimize storage conditions. Then, fecundity of D. gallinae was studied after mites were stored at optimal storage conditions. Results showed the survival rates of protonymphs (42.11%), deutonymphs (8.19%) and females (19.78%) at 5°C after 84 days were higher than those at 0, 25 and 30°C. Thereafter the fecundity and the capability of re-establishing colonies of D. gallinae were evaluated after they were stored for 40 and 80 days at 5°C. After storage, the mean number of eggs showed no statistical difference between treated (5°C for 40 or 80 days) and control groups (25°C for 7 days), while the hatching rates of eggs were in all cases above 97%. The dynamic changes of mite populations and egg numbers showed similar trends to the control group after the stored adult or nymph mites were fed on chicks. Dermanyssus gallinae can be successfully stored at 5°C for 80 days with no interference with the fecundity of mites, and the stored mites could re-establish colonies successfully. Adults and nymphs were two main stages with capability for low temperature storage. These results suggest that low temperature storage is a viable option for colony maintenance of D. gallinae under laboratory conditions.

Sustainability challenges and innovations in the Dutch egg sector

While global demand for eggs is increasing, concerns are being raised about the environmental, economic and social impact of egg production. Efforts to address these sustainability concerns can, however, result in trade-offs. To enhance a transparent debate about future options and limitations in the egg sector, insight is needed in environmental, economic and social sustainability challenges as well as in potential trade-offs involved in addressing these challenges. Based on interviews with 24 stakeholders and supported by scientific literature, this paper presents an overview of current sustainability challenges and trade-offs in the Dutch egg sector. Moreover, the paper provides an overview of innovations suggested by stakeholders that can help to address the identified sustainability challenges, and describes current limitations for the implementation of these innovations. Innovations identified were related to animal health and welfare (n = 13), housing systems (n = 7), economy (n = 8), environment (n = 9), and organisation (n = 6). Stakeholders considered innovations to reduce particulate matter emissions as one with priority. In addition, controlling poultry red mite, approaches to translate costs for environmental investments to consumers, closing manure-feed cycles and improved collaboration in the chain were considered as important steps to address current sustainability challenges. Our results reveal the complex interactions between sustainability challenges in the egg sector and give insight in the different perspectives and considerations stakeholders have. Steps towards sustainable egg production therefore require multi-stakeholder dialogue to find consensus and jointly identify so-called small wins, i.e. meaningful and feasible steps that can contribute to a more sustainable food system.

Acaricidal activity, mode of action, and persistent efficacy of selected essential oils on the poultry red mite (Dermanyssus gallinae)

In this work, the essential oils (EOs) from Litchi chinensis, Clausena anisata, Heracleum sphondylium, Pimpinella anisum, Lippia alba, Crithmum maritimum and Syzygium aromaticum were tested for their contact toxicity against the poultry red mite, Dermanyssus gallinae, a deleterious ectoparasite of aviary systems. In addition, in order to give insights on their mode of action and effectiveness, the vapor phase and residual toxicity tests were also performed. Results showed that amongst all the tested EOs, that of S. aromaticum demonstrated the highest contact toxicity, with a LC50 value of 8.9 μg/mL, followed by C. maritimum and L. chinensis EOs, with LC50 values of 23.7 and 24.7 μg/mL, respectively. L. chinensis and C. anisata EOs showed higher vapor toxicity than the other EOs. L. chinensis and S. aromaticum EOs showed promising toxic effects up to 4 days post-application. Taken together, these results highlighted L. chinensis and S. aromaticum as two promising sources of biopesticides, able to cause severe contact, vapor and residual toxicity in the poultry red mites. Given the wide plant cultivation and uses in foodstuffs, cosmetics, flavour and fragrances, these EOs may be considered cheap and ready-to-use products as valid, eco-friendly alternatives to pesticides currently used in the aviary systems.

Laboratory and field evaluation of an autoinoculation device as a tool to manage poultry red mite, Dermanyssus gallinae, infestations with Beauveria bassiana

The poultry red mite, Dermanyssus gallinae, is a cosmopolitan ectoparasite in hens and has been considered an important threat to the egg production industry. This study evaluated an alternative to manage poultry red mite populations as a complement to conventional chemical treatments and other control strategies in poultry houses. A simple autoinoculation device prepared with corrugated cardboard (CB) or loofah sponge (LS) as inert supports to anchor Beauveria bassiana conidia was used to aggregate and infect mites from infested poultry houses. In the laboratory, mites gathered inside the traps and the average mortalities by the fungus were higher than 70% in CB and LS traps after 5 and 4days of exposure, respectively. Conidial viability was around 80% in CB and LS traps after 14 and 60days under unrefrigerated conditions (26°C), respectively. Both trap types tied to hen cages efficiently captured fed mites after blood meal, and fungal infection was observed in 65-90% of the mites in field tests. Between 5 and 25% of the mites recaptured in monitoring cardboard traps installed immediately after CB and LS removal were infected by B. bassiana. According to our results, the use of B. bassiana in an autoinoculation strategy is a potential alternative method for D. gallinae control.

Active components of essential oils as acaricides against Dermanyssus gallinae

ABSTRACT1. The aim was to evaluate the acaricidal effects of pure active components of essential oils against poultry red mite (Dermanyssus gallinae) as an alternative to chemical acaricides (organophosphates and pyrethroids).2. The toxicities of five pure active components of essential oils (eugenol from clove bud, eucalyptol from rosemary, limonene from citrus fruits, linalool from lavender and cinnamaldehyde from cinnamon) were tested on D. gallinae females in an impregnated paper assay.3. The active substances were dissolved in water and Tween 20 and applied at concentrations ranging from 0.002 to 0.06 µl/cm2. Toxicity was expressed as a lethal dose (LD50 or LD90).4. The highest mortality was observed with eugenol. The LD90 was estimated to be 5.1 µg/cm2 for this substance, followed by cinnamaldehyde, the LD90 of which was estimated to be 11.0 µg/cm2. Limonene and eucalyptol were generally less effective in controlling D. gallinae.

Application of carbon dioxide as a novel approach to eradicate poultry red mites.

Poultry red mites (PRMs), Dermanyssus gallinae, are one of the most harmful ectoparasites of laying hens. Because of their public health impact, safe, effective methods to eradicate PRMs are greatly needed. Carbon dioxide (CO2) was shown to eradicate phytophagous mites; however, there is no evidence that PRMs can be eradicated by CO2. Thus, the efficacy of CO2, applied by direct-spraying and dry ice-generated exposure, for eradicating PRMs was investigated. Both treatments eradicated > 85% of PRMs within 24 h and 100% of PRMs by 120 h of post-treatment. Therefore, these novel approaches may be useful for eradicating PRMs in clinical settings.

A sampling and estimation method for monitoring poultry red mite (Dermanyssus gallinae) infestation on caged-layer poultry farms.

BackgroundThe poultry red mite, Dermanyssus gallinae, is a serious problem in the laying hen industry worldwide. Currently, the foremost control method for D. gallinae is the implementation of integrated pest management, the effective application of which necessitates a precise monitoring method.ObjectivesThe aim of the study was to propose an accurate monitoring method with a reliable protocol for caged-layer poultry farms, and to suggest an objective classification for assessing D. gallinae infestation on caged-layer poultry farms according to the number of mites collected using the developed monitoring method.MethodsWe compared the numbers of mites collected from corrugated cardboard traps, regarding with length of sampling periods, sampling sites on cage, and sampling positions in farm buildings. The study also compared the mean numbers of mites collected by the developed method with the infestation levels using by the conventional monitoring methods in 37 caged-layer farm buildings.ResultsThe statistical validation provided the suitable monitoring method that the traps were installed for 2 days on feed boxes at 27 sampling points which included three vertical levels across nine equally divided zones of farms. Using this monitoring method, the D. gallinae infestation level can be assessed objectively on caged-layer poultry farms. Moreover, the method is more sensitive than the conventional method in detecting very small populations of mites.ConclusionsThis method can be used to identify the initial stages of D. gallinae infestation in the caged-layer poultry farms, and therefore, will contribute to establishment of effective control strategies for this mite.