Prevalence of the Poultry Red Mite, Dermanyssus gallinae, in Different Types of Production Systems for Egg Layers in Sweden

摘要: Abstract This study was undertaken between May and December 1994 to investigate the prevalence of hematophagous mites in Sweden. A particular aim establish relationship occurrence certain types production systems for egg layers. Initially a postal questionnaire performed. Some months later this followed up by inspections, sampling, interviews on farms. The only mite species found red poultry mite, Dermanyssus gallinae. Although be present cage batteries, deep-litter systems, backyard flocks, it less prevalent among birds housed cages. About 4% were affected both according results inquiry from field study. However, discrepancies when comparing obtained with these two investigations regarding alternative, flocks. According inquiry, 21% flocks afflicted whereas 33% investigation. Among 19% as many 67% upon inspection. These probably due fact that situation had actually changed some farms during period, but possibly also inherent methodological errors. Farmers interviewed focus methods husbandry control strategies. Most farmers answered they combatting cleaning empty houses using chemicals such organophosphorous compounds, carbamates, synthetic pyrethroids. In several instances problems still not solved despite curative or preventive measures. program D. gallinae is suggested regular screening certification ectoparasite status before their transfer sites.