Polypedilum (Cerobregma) yamasinense (Tokunaga) Niitsuma, 2017

Niitsuma, Hiromi, 2017, Review of the Japanese Microtendipes tera: Chironomidae: Chironominae), with description of a new species, Zootaxa 4320 (3), pp. 535-553 : 550

Polypedilum (Cerobregma) yamasinense (Tokunaga) comb. nov.

Chironomus (Microtendipes) yamasinensis Tokunaga, 1940: 295 .

Microtendipes yamasinensis: Sasa & Kikuchi 1995: 34 .

Polypedilum kamotertium Sasa, 1989b: 64 ; Sasa & Kikuchi 1995: 37 (as Polypedilum s. str.). Syn. nov.

Remarks. In the original description of Chironomus (Microtendipes) yamasinensis Tokunaga, 1940 , the author (p. 296) wrote, “R2+3 extending closely along R1”, and “ventral appendages compressed, with three long setae on apical end”. The combination of these features occurs in Polypedilum , rather than Microtendipes ( Edwards 1929, Freeman 1955, Cranston et al. 1989). He continued, “styles swollen basally, narrowed on apical half, with long bristles on apical part”. It shows that the species belongs to the subgenus Cerobregma Saether & Sundal, 1999 of the genus Polypedilum . The type of Polypedilum (Cerobregma) yamasinense may be still extant in the Kyushu University Museum as an alcoholic specimen, but even so, its condition may be too poor to make necessary observations. Therefore, no type material was examined.

Saether & Sundal (1999: 345) transferred P. (P.) kamotertium Sasa to the subgenus Cerobregma . Kobayashi et al. (2003) redescribed P. (C.) kamotertium based on the males, females, pupae and larvae collected from Aomori, Kyoto and Nagasaki in Japan, including the types, and noted that the male is characterized by an AR of 1.1–1.3; the inferior volsella bilobed apically, bearing many setae on the dorsal lobe and a few setae on the ventral lobe; the superior volsella arcuated, bearing 1–4 lateral and 2–13 basal setae; and the gonostylus apically with a row of 4–7 long setae. Further, according to Sasa (1989b: 64), the holotype male has a long setal beard (BR 3.8–4.4) on the foretarsi. These features are consistent with the description by Tokunaga (1940), especially in the inferior and superior volsellae (plate 3, figs 69 and 72). Polypedilum (C.) kamotertium is a junior synonym of P. (C.) yamasinense .