Acaricidal and repellent effects of Cnidium officinale-derived material against Dermanyssus gallinae (Acari: Dermanyssidae)

Efficacy of Liquid Smoke to Mitigate Infestations of the Storage Mite, Tyrophagus putrescentiae, in a Model Semi-Moist Pet Food

The storage mite Tyrophagus putrescentiae infests a wide range of food products including pet food. Control of this mite depends on chemical methods such as fumigation and spraying with insecticides. Methyl bromide was used as a fumigant for high-value stored products, especially to control mite infestation in dry-cured hams and cheeses, but it is now banned for most uses in many countries because of its atmospheric ozone-depleting effects. Effective alternatives to methyl bromide are needed to develop integrated pest management programs for this pest. Liquid smoke is a naturally derived flavoring and preservative with known antimicrobial properties. The objective of this study was to investigate the efficacy of liquid smoke preparations, with varying phenol and carbonyl concentrations and pH, on the survivability and orientation behavior of T. putrescentiae in a model semi-moist pet food. The mite survivability assays using liquid smoke-treated and untreated semi-moist pet food samples indicated that there was no difference among treatments (p > 0.05) for mite infestation and survival. Two-choice behavioral assays using semi-moist pet food cubes dipped in varying concentrations (0%, 0.3%, 1%, 5%, 10%, 25%, 50%, or 100% v/v) of liquid smoke preparations found that some of the liquid smoke preparations containing medium to high carbonyl content repelled the mites. In conclusion, liquid smoke did not kill or inhibit the mite population growth in semi-moist pet food. However, some liquid smoke fractions containing medium to high carbonyl content were repellent to mites and may retard mite infestation in stored semi-moist foods.

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.

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

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

In Vitro Acaricidal Activity of Silver Nanoparticles (AgNPs) against the Poultry Red Mite (Dermanyssus gallinae)

Dermanyssus gallinae (PRM) is the most common blood-sucking ectoparasite in laying hens and is resistant against numerous acaricides. Silver nanoparticles (AgNPs) represent an innovative solution against PRM. The current study aimed to assess the in vitro acaricidal activity of AgNPs against PRM and describe their potential mechanism of action. Nanoparticles were produced using a wet chemistry approach. Mites were collected using AviVet traps from 18 poultry farms in Greece. Contact toxicity bioassays were carried out for 24 h with negative controls, 20, 40, 60, or 80 ppm AgNPs. Analysis of variance was used to compare the mortality rates of PRM between the control and treatment groups, while LC₅₀, LC₉₀, and LC₉₉ values were estimated using probit regression analysis for the total farms jointly and separately. Nanoparticles displayed strong acaricidal activity, and mortality rates were significantly different between groups and increased by AgNPs concentration. Overall mean LC₅₀, LC₉₀, and LC₉₉ values were 26.5, 58.8, and 112.3 ppm, respectively. Scanning electron microscopy on mites treated with 80 ppm AgNPs revealed cracks in their exoskeleton and limb detachments, presumably resulting from the interaction between AgNPs and the mites' chitin. Future studies should focus on assessing AgNPs residues in chicken tissues before moving into field trials.

Evaluation of the Acaricidal Effectiveness of Fipronil and Phoxim in Field Populations of Dermanyssus gallinae (De Geer, 1778) from Ornamental Poultry Farms in Italy

The poultry red mite Dermanyssus gallinae is the most important blood-sucking ectoparasite in egg-laying hen facilities. The aim of this study was to evaluate the in vitro acaricidal activity of different concentration of authorized (phoxim, ByeMite®, 500 mg/mL) and unauthorized (fipronil, Frontline® 250 mg/100 mL spray) molecules on 14 field isolates of D. gallinae collected from different ornamental poultry farms from different Italian regions. The sensitivity test was performed by contact exposure to four concentrations of each insecticide diluted at 1:5 (10,000-2000-400-80 ppm for phoxim, 500-100-20-4 ppm for fipronil) on a filter paper. The effectiveness of the treatment was significantly (p < 0.0001) associated with the dose of the pesticide used. Considering the mean lethality, phoxim has greater efficacy compared to fipronil (p < 0.001). A great variability of lethality rate was observed with the increase in fipronil dilution; conversely, for phoxim, some outliers were observed, particularly in one farm, suggesting the hypothesis that a certain degree of resistance in the mite population could occur possibly as a consequence of the continual contact with the molecule. This underlines the importance of the use of licensed products administered at correct dosages and the need for alternative molecules to avoid the onset of drug resistance phenomena.

Acaricidal Activity of Annonaceae Plants for Dermanyssus gallinae (Acari: Dermanyssidae) and Metabolomic Profile by HPLC-MS/MS

The poultry red mite Dermanyssus gallinae (De Geer) is the most important haematophagous ectoparasite in the poultry industry. The use of synthetic acaricides for this control is presenting risks related to human food. In this sense, plant secondary metabolites are promising for controlling this pest. Thus, this study aimed to evaluate the acaricidal activity of Duguetia lanceolata A.St.-Hil. (stem bark), Xylopia emarginata Mart. (stem bark), and Xylopia sericea A.St.-Hil. (stem bark and fruits) against D. gallinae. Additionally, the secondary metabolite profile of the X. emarginata was analysed by UFLC-DAD-ESI(+)-MS/MS (micrOTOF-QII) and data analysis was performed using the Molecular Networking. In a topical application test, all plant species tested showed bioactivity, in that order of toxicity with the respective probability survival: X. emarginata (stem bark) (0.28) > X. sericea (stem barks) (0.35) > X. sericea (fruits) and D. lanceolata (stem bark) (0.47). The most promising results were found for X. emarginata (LC₅₀ = 331.769 μg/cm²). It is noteworthy that the LC₅₀ of the insecticide cypermethrin was 1234.4 μg/cm², which was 73% higher than that of X. emarginata. The metabolomic profile of X. emarginata revealed the presence of alkaloids, amides, terpenoids, and phenolic compounds. This is the first report of X. emarginata acaricidal activity against D. gallinae and exploratory chemical analysis by untargeted metabolomics and the molecular network of this plant.

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.

In vitro acaricidal activity of essential oil and alcoholic extract of Trachyspermum ammi against Dermanyssus gallinae

This study aimed to assess in vitro acaricidal activity of essential oil (EO) and alcoholic extracts (AE) of Ajowan against D. gallinae. Using contact and spraying bioassays, different doses of EO and AE were tested. Cypermethrin and thymol (positive controls), and ethanol and distilled water (negative controls) were also tested. The results indicated that effects were method and dose dependent. Statistical analysis showed a highly significant difference for contact and spraying bioassays and various doses of EO and AE (p < 0.0001) as, the spraying method was more effective than the contact method for acaricidal activity at 24 h post treatment (PT). In this method, Cypermethrin, EO and thymol caused over 90 % mite mortality at 50 μgcm^-2, while AE caused this rate at 150 μgcm^-2. In the contact bioassay, all tests produced low mortality rates except for Cypermethrin. Thymol was the main constituent of EO (Area = 42.26 %) and AE (Area = 45.8 %). Results of the present study indicated that Ajowan had a satisfactory acaricidal effect against D. gallinae in vitro. It was also found that the spraying method could be used to control the D. gallinae as the most appropriate method.

Toxicity and effects of essential oils and their components on Dermanyssus gallinae (Acari: Dermanyssidae)

The acaricidal activity of 30 essential oils against the poultry red mite, Dermanyssus gallinae, female adults and behavioral responses of the mites to these essential oils were investigated. Cinnamon bark oil and clove bud oil showed 100% acaricidal activity after 24 h in the 1.3 μg/m² treatment. In addition, four components in cinnamon bark oil and three components in clove bud oil were identified using gas chromatography-mass spectrometry. Cinnamon bark oil showed the highest LD₅₀ value among all of the components, and eugenol showed 0.97-fold higher relative toxicity (RT) than the other components of clove bud oil. The fumigant effects of both essential oils and their seven components were observed using a vapor phase toxicity bioassay. All the substances showed repellent activity except for cinnamyl acetate, which did not show any repellent response even in the > 10 μg treatment. In the experiment using the T-tube olfactometer with the 10 μg treatment of each substance, D. gallinae female adults responded to all the substances except cinnamyl acetate. However, eugenol and eugenol acetate showed an attractant effect after 240 and 120 min of treatment, respectively. These results suggest that the two studied essential oils and their components may be used as control agents against D. gallinae.