Since the rediscovery of the role of mites in provoking house-dust allergies (VOORHORST et al. 1964) more attention has been paid to the mite fauna of house dusts of different geographical areas. Blomia has been found in house dust in Taipei (Taiwan) and Paramaribo (Surinam), some times in large numbers (OSHIMA 1970, BRONSWIJK 1972). Allergological investigations (MIYAMOTO et al. r969) showed a cross antigenicity with Dermatophagoides farinae Hughes 1961 indicating that Blomia could be important in the house-dust allergy problem in Japan. Taxonomical investigations revealed that a not yet described species Blomia tropicalis sp. n. is involved