Family Pyroglyphidae belonging to the subclass Acari(mites). The subfamilies Dermatophagoidinae (D. pteronyssinus, D. farinae) and Pteroglyphidae (Euroglyphus maynei) belong to this family. Size: 170-500 μm, grey-white in colour; almost transparent; chitinous carapace with fine striated pattern; little hair. House dust mites have cutting and chewing mouth parts and live as commensals in the house dust of human dwellings. D. pteronyssinus (skin-eating feather mite) is the main source of the house dust allergen. E. maynei has a lesser significance. In the USA the Dermatophagoides farinae mite is more common. Main allergens are: Dermatophagoides pteronyssinus I and II (The p I and II). S.a.u. mites.
Both house dust mites and storage mites communicate through pheromones. They transmit 3 basic messages: alarm, aggregation, sexual behaviour. Neral (see Citral below) plays an important role as a volatile pheromone.
The Dermatophagoidines species feed on human skin scales as well as on microorganisms and certain moulds which are responsible for the breakdown of the lipid-containing components of the scales. Other organic material such as food supplies or pollen is also consumed.
The natural biotope of house dust mites is primarily the bed (mattress, duvet and pillow). Here sufficient materials are found as a source of food. Humans lose about 1 g of dandruff per day; this amount is sufficient as a food source for 1 million mites.
The microclimate is important. Optimal temperatures for mites are < 30 °C with a humidity of 70-80%. The minimum humidity must be at least 55%. Reproduction only at humidity > 60%. In heated dwellings there is relatively low air humidity, unfavourable living conditions for mites. Regular ventilation of the rooms also lowers the humidity! Local climatic factors such as the location of a house (e.g. southern slope, southern latitude and high mountain climate with relatively low humidity values prevent mite growth.
The mite population in carpets and rugs fluctuates with the seasons, increasingly in the summer months, when the room humidity is at its highest when central heating is switched off (Klimek L 2018). At the beginning of the summer, following the heating period, the mite population is small, and reaches a maximum in late summer. In late autumn and winter the mite population drops to a minimum again.