6. Chasmacryptum Becker, 1907

(Figs. 15, 29, 41–42, 65)

Chasmacryptum Becker, 1907: 261 . Type species: Chasmacryptum seriatimpunctatum Becker, 1907 (monotypy). Pseudopherbina Elberg, 1965: 192 . Type species: Pseudopherbina loewi Elberg, 1965 (monotypy).

Diagnosis. Relatively small species, about 5 mm. Body mainly yellow. Body color and external characters similar to most species of genus Tetanocera, but wing with black spots and male sternites 4 and 5 densely covered with short setae. Frontal vitta reaching foremargin of frons. One pair of ocellar setae and 2 pairs of scutellar setae present. Prosternum setulose.

Remarks. As one of 21 monotypic genera in the family Sciomyzidae, Chasmacryptum comprises only 1 described species, Chasmacryptum seriatimpunctatum Becker, 1907; he described both sexes from Bomyn (Bomi County), Tibet, China. The species is restricted to the Palearctic Region.

During our study we found 6 specimens of C. seriatimpunctatum: 1 male from Heilongjiang, 3 males and 1 female from Qinghai, and 1 female from Inner Mongolia, all collection sites being in the Palearctic Region of China, which is consistent with the known distribution of the genus in the Eastern Hemisphere.