Seasonal dynamics and distribution of house dust mites in China.

House dust mites are widely distributed in the human habitat and work environment and produce very powerful allergens. The most important allergy-causing mites found in homes worldwide are the house dust mites Dermatophagoides farinae and D. pteronyssinus and the storage mite Blomia tropicalis. It is important to know which mite species are present in a geographical area when performing diagnostic testing and prescribing immunotherapy. We classified the breeding situations of house dust mites in dwellings in northern China. Mites are detectable in March and their number increases from April or May, reaching a peak from July to September. The seasonal distribution of different acaroid mite species may differ: temperature, humidity, and eating habits were the major limiting factors determining species composition and diversity of acaroid mite communities in house ecosystems; comparing to the field and the forest, in human living area including house and working place, acaroid mites showed less bio-diversity.