The critical character which both author focused on was the narrow elongate abdomen. Later Hull (1949: 312) noted the unusually well-developed basal patches of short thick setae on pro- and mesofemora and placed his genus as a junior synonym of Parocyptamus. In overall habitus, these species are similar to the Neotropical bidens species group, which lacks the distinctive basal femoral setal patches (from Cheng and Thompson 2008).
Hull (1949) said that Parocyptamus has scape and pedicel moderately elongate; first segment of the abdomen flattened, its lateral margins are not convex; in both males and females there is a very pronounced anterior plate at the base of the pro- and mesofemora, covered with very stiff, dense, long setiferous, reddish bristles, much more pronounced than the stiff patches of pile seen on some other microdons; the abdomen (female) is strongly pinched in between the second and third segments, and less so between the third and fourth.
See attached document for original description (in German).
Microdon (Parocyptamus) sonamii (Shiraki, 1930).
Shiraki, T. (1930) Die Syrphiden des japanischen Kaiserreichs, mit Berucksichtigung benachbarter Gebiete. Memoirs of the Faculty of Science and Agriculture, Taihoku Imperial Univeristy 1, xx + 446 pp. [1930.01.30]
Shiraki described Parocyptamus as belonging to the subfamily Microdontinae but related his genus to Ocyptamus Macquart, a member of the subfamily Syrphinae. Later Hull (1937a: 26) named this group Stenomicrodon. Hull (1949) considered Parocyptamus as a subgenus of Paramixogasteroides Shiraki, and synonymized Stenomicrodon with it.
Species described from Taiwan.
unless otherwise stated