Fauna and spatial distribution of house-dust mites in Japanese mattress

Abstract

Twenty Japanese mattresses with various periods of use were collected from 11 localities in Japan in 2014. Samples of the mattresses including the padding were removed at 5 collection points in each mattress. The samples were divided into 3 layers (upper, middle, and bottom layers), and the fauna and density of house-dust mites were examined. A total of 12,734 mites of 10 families were collected and 97.0% of them belonged to Pyroglyphidae. The total number of mites was estimated as 4,640 to 394,240 per mattress. A positive correlation was found between the number of dead and alive mites and the number of exuviae. The dominant species in Pyroglyphidae was Dermatophagoides pteronyssinus (Trouessart) and D. farinae Hughes, and the proportion of D. pteronyssinus ranged from 0 to 100% among the samples. Multiple samples collected within the same locality (Tokyo, Kanagawa) showed a wide variation in the proportion of D. pteronyssinus. The distribution of mites in the 3 layers differed among the 5 sampling points. More mites were distributed in the middle layers at sampling points located at the edge of the mattresses. The proportion of Pyroglyphid mites distributed in the upper and bottom layers ranged from 15.6 to 94.3%.