Dolichopus umbrosus Van Duzee, 1921: 100

Potential demasculinized species: unknown.

Dolichopus umbrosus was described from one male from Wisconsin, USA. Signs of nematode infection include the male having a wide face and a very small hypopygium with dark yellow cerci. Illustration of the genitalia (Van Duzee et al. 1921, fig. 57a) suggests they are not fully rotated and not centered beneath the abdomen. This species is also reported from Ontario, Canada (Pollet et al. 2004). Dissection of material from Ontario could determine if this species is demasculinized and might identify the host species, if collected with the unparasitized counterpart.