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

Evaluation of in-house factors affecting the population distribution of Dermanyssus gallinae in cage and backyard rearing systems by using a modified monitoring method

Dermanyssus gallinae (poultry red mite, PRM) is a main ectoparasite of poultry that represents a serious economic threat to all farming systems, including cages and backyard flocks. In recent years, economic losses associated with this ectoparasite have progressively increased, mainly because of the lack of information regarding its population dynamics and appropriate control methods. In this study, we used a modified monitoring method to examine the in-house factors affecting the population density of D. gallinae. PRMs have been found in all poultry houses examined in Turkey. The largest population was detected in the front and back parts of the middle rows in cage systems as well as in perches in backyard systems. Relative humidity, light, and temperature might be the most affecting factors on the mite distribution inside the poultry houses. Besides, the mite populations are influenced mainly by the last (chemical) treatment date and the construction materials of the building. Dermanyssus gallinae were found to be the most dominant mite species (98.9%), followed by Cheyletus sp. (Cheyletidae); also some Acaridae (Tyrophagus spp.) and Oribatida were identified. Hence, further research on Cheyletus sp. is required to elucidate their predatory potential and develop future control strategies. This study contributes to understanding the PRM population behavior in poultry houses as well as their monitoring and control methods, which are key components in the appropriate application of integrated pest management programs.

Dermanyssus gallinae and chicken egg production: impact, management, and a predicted compatibility matrix for integrated approaches

The poultry red mite, Dermanyssus gallinae, is a worldwide threat to egg production and animal and human welfare. This mite is also a potential vector for several significant diseases. EU regulation that forbids the use of conventional cages for egg-laying hens may favour the growth of D. gallinae, a species known to thrive in more complex housing systems. Current control measures emphasize the use of chemical acaricides, which may have limited efficacy on D. gallinae considering its temporary blood-feeding behaviour. In integrated pest management (IPM), two or more compatible measures targeting physical, environmental, and/or biological aspects could be judiciously combined to enhance the effectiveness against D. gallinae infestation. To inform current and future IPM for D. gallinae, a compatibility matrix is proposed to guide the selection of control measures for field application.

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.