Rhombognathine Mites (Acari : Halacaridae) from Hokkaido, Northern Japan

Abstract

A total of 16 species of mites in the subfamily Rhombognathinae (Acari : Halacaridae) are recorded from Hokkaido, northern Japan. Five Isobactrus and six Rhombognathus new species are described, viz. Isobactrus dentatus sp. nov., I. gryposetus sp. nov., I. hamatus sp. nov., I. latistriatus sp. nov., I. tuberculatus sp. nov., Rhombognathus compressus sp. nov., R. incertus sp. nov., R. medialis sp. nov., R. neotenus sp. nov., R. tenui/ormis sp. nov. and R. teurinus sp. nov. Two Rhombognathus species new to Japan, R. leurodactylus Krantz, 1976 and R. sinensis Bartsch, 1990, are described on the basis of Japanese specimens. Three known species, R. atuy Abe, 1990, R. dissociates Abe, 1990 and R. ezoensis Abe, 1990, are redescribed on the basis of the paratype specimens. Key to the species and notes of habitats and distributional range for each species are presented. Their occurrence on various substrates in Hokkaido is examined by a correspondence analysis. The analysis indicates no distinct association of rhombognathine species with substrates in Hokkaido.