Methods for monitoring the population of the red mite in chickens (ARG), Dermanyssus gallinae

Proper monitoring can detect ARG infestation

In a previous post we already explained the health, economic and well-being problems that an infestation with Dermanyssus gallinae brings. Now we propose different scenarios and they will depend on the type of answer to a very simple question: Do you have mites on your farm?

If the answer is yes, you find yourself in conditions shared by more than 90% of the egg producers in Spain. If the answer is no, there are two possibilities: you belong to the exclusive chicken-free red mite (ARG) “club”, or else you are infested and you are not aware.

Whatever your answer is, our recommendation is that periodic evaluations of the infestation level be carried out, since by means of adequate monitoring, infestations by ARG can be detected early or it facilitates decision-making to determine when to apply a treatment.

Image 1 corresponds to a real farm in which 3 treatments were made (red arrow). The treatments took effect and reduced the mite population. However, the first treatment was performed with high levels of infestation, which limited the effectiveness of the treatment.

There are several methods to track the mite population in a layer house. And most have in common that they are inexpensive and easy to apply techniques. For example:

• Mite Monitoring System (MMS) (Cox et al, 2009): developed by Cox, M. et al., 2009. It is based on a periodic visual review of different points of the farm. It is a cheap and fast method, but it is not very sensitive to low levels of infestation, it is subjective and qualitative (Imagen 2).

Imagen 2: Mite colony at cage system angles

• Cardboard trap (Nordenfors and Chirico, 2001): consists of placing 10 × 7 cm corrugated cardboard traps for 2 days. It is a quantitative technique. However, it requires time on the mite counting task. 

• Examination of feathers, dust and other remains (Pavličević et al., 2007): it is based on the determination of the presence of mites in the remains of the farm, placing them inside a jar covered with white paper to facilitate their detection. It is a semi-quantitative and useful method for early detection.

• Dry stool examination (Zenner et al., 2009): consists of the examination of the underside of 5 cm dry stool. It is a semi-quantitative and economical method but it requires time.

• Automatic mite counter (Mul et al., 2015): a quantitative method in which an automatic device counts when a mite enters it. It is a saving in counting time, but does not identify mite species or stages of development.

• Tube trap (Van Emous et al., 2005): qualitative method in which the level of infestation is evaluated by means of a wooden cylinder inserted in a PVC tube and placed under the perches of the chickens. The devices are reviewed weekly and are given a score based on the level of infestation (Imagen 3).

Imagen 3: Tube traps with different levels of infestation

• AVIVET traps (Lmmers et al., 2016):  quantitative method in which the amount of mites is estimated based on the weight of the mites extracted from the trap. It requires an initial count, but it is a quick and convenient method

Imagen 4: Inside of an AVIVET trap after 48 hour.

Existe, por tanto, una amplia oferta de métodos de monitorización, cada uno con ventajas e inconvenientes. Sin embargo, sin importar el método empleado, la monitorización es una herramienta de gran utilidad para mejorar la eficacia de los tratamientos, ya que la detección temprana y el seguimiento de la evolución de la población de ácaros, facilita la toma de decisiones a la hora de implementar un tratamiento.

There is, therefore, a wide range of monitoring methods, each with advantages and disadvantages. However, regardless of the method used, monitoring is a very useful tool to improve the effectiveness of treatments, since early detection and monitoring of the evolution of the mite population facilitates decision-making at the time to implement a treatment.

Author: Jose Francisco Lima
 
References:

Cox, M., K. De Baere, E. Vervaet, J. Zoons, and T. Fiks-Van Niekerk. 2009. Red mites: monitoring method and treatment.Pages 18–22 in Book of Abstracts 8th European symposium on poultry welfare. Cervia, Italy.

van Emous, R. A. 2005. Wage war against the red mite! Poult. Int. 44:26.

Lammers, G. A., R. G. G. Bronneberg, J. C. M. Vernooij, and J. A. Stegeman. 2016. Experimental validation of the AVIVET trap, a tool to quantitatively monitor the dynamics of Dermanyssus gallinae populations in laying hens. Poult. Sci.

Mul, M. F., J. W. van Riel, B. G. Meerburg, M. Dicke, D. R. George, and P. W. G. Groot Koerkamp. 2015. Validation of an automated mite counter for Dermanyssus gallinae in experimental laying hen cages. Exp. Appl. Acarol. 66:589–603.

Nordenfors, H., and J. Chirico. 2001. Evaluation of a Sampling Trap for Dermanyssus gallinae (Acari: Dermanyssidae). J. Econ. Entomol. 94:1617–1621.

Pavličević, A., I. Pavlović, and N. Stajković. 2007. Method for early detection of poultry red mite Dermanyssus gallinae (De Geer, 1778). Biotechnol. Anim. Husb. 23:119–127.

Zenner, L., G. Bon, C. Chauve, C. Nemoz, and S. Lubac. 2009. Monitoring of Dermanyssus gallinae in free-range poultry farms. Exp. Appl. Acarol. 48:157–166.