Epidemiology of Dermanyssus gallinae and Acaricidal Efficacy of Phoxim 50% in Alternative Housing Systems during the Laying Period of Hens

Abstract

The objective was to evaluate the epidemiology and population dynamics of a Dermanyssus gallinae infestation during a one-year period, in both amultilevel aviary system and a one-floor plastic slat system. The used layer houses had a history of a D. gallinae problem and were treated during the service period when the chicken houses were empty. In the present study, mites were detected in the monitoring traps for the first time in both sheds 26 and 39 days after restocking. The number of mites steadily increased from the first detection of mites until a first phoxim treatment. The highest numbers of mites were trapped in the supply and resting areas in both housing systems. A 2,000 ppm phoxim spray solution against the D. gallinae infestation was administered twice with a seven-day interval in the two systems on days 227/234 and 278/285. The reduction in the number ofmites after treatment was 99.3% to 90.0% in the aviary system, whereas it was 97% to 94.5% in the plastic slat system. There was no evidence that the growing mite population had any effect on the average daily egg-laying rate or the number of dead hens.