Studies on the mite fauna of house dust in Scotland with special reference to that of bedding.

A survey was made of the mite fauna of house dust collected from private houses in Scotland, mainly from the Glasgow area. Sampling was carried out largely with the aid of a suction device developed to enable discrete samples of dust to be taken from specific substrates. The Pyroglyphid Dermatophagoides pteronyssinus (Trt.) was the most abundant and widespread species encountered, its relative Euroglyphus maynei (Cooreman) being second in abundance. Other mites found were species of Gohieria, Glycyphagus, Acarus, Tyrophagus, Cheyletus, Tarsonemus and undetermined Labidophorids. Beds showed much higher infestations than did carpets or other sites [cf. RAE/B 58, 372] and their importance as centres of infestation is stressed. They were sampled layer by layer; the highest populations occurred in blankets but the number of layers present did not influence the level of infestation. Beds of bronchial asthmatics, of patients with papular urticaria and of healthy patients had similar infestations, but beds in ill-kept houses were more heavily infested than those in well-kept ones. New beds were free of mites, whereas hospital beds had low infestations and, possibly due to frequent disinfestation, so had beds in common lodging houses. Differing distributions of the sexes and immature stages of D. pteronyssinus and of E. maynei in beds suggested that these species and their development forms may have differing ecological requirements. A more thorough knowledge of the physiology of these mites and of bed microclimates seems a necessary prelude to ecological control.