Family Sericostomatidae Stephens
Author: Naoki KAWASE*and Takao NOZAKI
E-mail: kawasen[AT]nifty.com
Last updated: 9 February 2026
Only the genus Gumaga is known from Japan. Tsuda (1938) recorded two unnamed sericostomatin species from Okinawa-jima, and provided figures of a pupal case and a larva with it's case.
Genus Gumaga Tsuda
Tsuda (1938) described this genus based on a single species, G. okinawaensis, from Okinawa-jima, and G. okinawaensis has been widely recorded from Honshu and Kyushu. However, Kumanski (1991) synonymized N. cahoi with G. okinawaensis, and Malicky (1995) did it with G. orientalis. Malicky (2013, 2014) also proposed the synonymy of G. okinawaensis with G. orientalis. On th other hand, Tanida (1997) suggested that materials from Honshu and other major islands belong to a distinct species or a subspecies of G. okinawaensis. Nozaki and Tanida (2007) recognized that records of G. okinawaensis from Honshu were misidentifications of G. orientalis, but suspended the decision of the specific status of G. okinawaensis. Kuhara and Ito (2017) reported that a genitalic character of males collected from Yaku-shima is intermediate between that of males collected from Honshu and Okinawa-jima. Tanida (2018) recognized again two species, G. okinawaensis and G. orientalis, for the Japanese fauna.
In this list, records of this genus from Japanese major islands or Okinawa islands are tentatively listed under the names of G. orientalis or G. okinawaensis, respectively. It is necessary to clarify the specific status of G. okinawaensis.
Gumaga okinawaensis Tsuda 1938
Distribution. Okinawa.
Gumaga orientalis (Martynov 1935)
Oecismus (?) orientalis Martynov 1935
Gumaga okinawaensis: Tsuda 1942a
Notidobia chaoi Hwang, 1957
Oecismus orientalis: Fischer 1970
Gumaga orientalis: Levanidova 1982
Gumaga amudita Schmid 1990
Distribution. Japan (Honshu, Shikoku, Kyushu, Yaku-shima), Russia (Far East), China, Korea, Taiwan, India.