EN
The studies were carried out on a poultry farm with about 85 thousands birds. The aim of the study was to estimate the intensity of a Dermanyssus galinae invasion in a complete productive cycle of laying hens. To collect the mites, their eggs, larvae and nymphs, on the front wall of the cages of the central part of corridor 20 paper tubes were hung at the levels of 0.5, 1.0 and 1.5 m from the floor, between the 16th and 73rd weeks of breeding. After 2-3 weeks, the tubes were removed, placed in jars and closed. In the laboratory the sediment was weighed and the number of parasites was counted. The most of D. gallinae females and developmental forms were found between 26 and 36 weeks of breeding in the tubes placed at the level of 0.5 m, followed by a significant decrease of their number. In the tubes placed at the level of 1.0 m, the number of mites and their forms increased until the 29th week and then slowly decreased until the 59th week. The number of D. gallinae from the tubes at the level of 1.5 m increased irregularly until the 38th week. From the 44th week the number of parasites significantly decreased and kept at the same level until the end of hens’ breeding. On the basis of the results obtained it was ascertained that the smallest number of mites occurred in the cages at the level of 1.0 m from the floor (average 49.6 individuals in 100 g of sediment), and the greatest in cages placed at the level of 0.5 m as well as 1.5 m (57.6 and 55.1 individuals in 100 g of sediment, respectively). Knowledge of the collection of the large number of mites at definite heights in a poultry-house can be used for the control of these parasites.