Ole Kilpinen

Prevalence and key figures for the poultry red mite Dermanyssus gallinae infections in poultry farm systems

Recent surveys and sample collection have confirmed the endemicity of Dermanyssus gallinae in poultry farming worldwide. The reduction in number and efficacy of many acaricide products has accentuated the prevalence rates of this poultry ectoparasite observed more often in non intensive systems such as free-range, barns or backyards and more often in laying hens than in broiler birds. The lack of knowledge from producers and the utilisation of inadequate, ineffective or illegal chemicals in many countries have been responsible for the increase in infestation rates due to the spread of acaricide resistance. The costs for control methods and treatment are showing the tremendous economic impact of this ectoparasite on poultry meat and egg industries. This paper reviews the prevalence rates of this poultry pest in different countries and for different farming systems and the production parameters which could be linked to this pest proliferation.

Control methods for Dermanyssus gallinae in systems for laying hens: results of an international seminar

This paper reports the results of a seminar on poultry red mite (PRM), Dermanyssus gallinae. Eighteen researchers from eight European countries discussed life cycle issues of the mite, effects of mites on hens and egg production, and monitoring and control methods for PRM in poultry facilities. It was determined that PRM probably causes more damage than envisaged, with the cost in The Netherlands alone reaching 11 million euro per annum. However a great deal is still unknown about PRM (e.g. reproduction, survival methods, etc.) and that PRM monitoring is an important instrument in recognising and admitting the problem and in taking timely measures. Currently, the most promising control method combines heating the hen house in combination with chemical treatments. Future areas of development which show promise include the use of entomopathogenic fungi, vaccination and predatory mites. The final aim is to solve the problem of D. gallinae in housing systems for laying hens.

Activation of the poultry red mite, Dermanyssus gallinae (Acari: Dermanyssidae), by increasing temperatures

The poultry red mite, Dermanyssus gallinae, is a parasite of layers in Europe. In order to improve our understanding of the host-searching behaviour of these mites their sensitivity to slowly increasing temperatures was studied under laboratory conditions. Temperatures increasing as slowly as 0.005 °C/s (over a one min period) were effective in activating the mites. The speed of the temperature change is more important than the temperature change itself for this activation process. This knowledge of the host-searching process could facilitate the development of new control strategies.

Real-Time Measurement of Volatile Chemicals Released by Bed Bugs during Mating Activities

In recent years, bed bug (Hemiptera: Cimicidae) problems have increased dramatically in many parts of the world, leading to a renewed interest in their chemical ecology. Most studies of bed bug semiochemicals have been based on the collection of volatiles over a period of time followed by chemical analysis. Here we present for the first time, a combination of proton transfer reaction mass spectrometry and video analysis for real-time measurement of semiochemicals emitted by isolated groups of bed bugs during specific behavioural activities. The most distinct peaks in the proton transfer reaction mass spectrometry recordings were always observed close to the termination of mating attempts, corresponding to the defensive emissions that bed bugs have been suspected to exploit for prevention of unwanted copulations. The main components of these emissions were (E)-2-hexenal and (E)-2-octenal recorded in ratios between 1∶3 and 3∶1. In the current study, the quantity varied over 1000 fold for both of the compounds with up to 40 µg total release in a single emission. Males also emit defensive compounds due to homosexual copulation attempts by other males, and no significant differences were observed in the ratio or the amount of the two components released from males or females. In summary, this study has demonstrated that combining proton-transfer-reaction mass spectrometry with video analysis can provide detailed information about semiochemicals emitted during specific behavioural activities.