 While most likely not a parasite of snow flies, a species of nematode, similar to "Rhabditis", can sometimes be found in a ringed capsule, which is called a (dauer), around the neck of adult snow flies.Immature nematodes develop inside the dauer before ultimately dispersing from it.It has been speculated that the female nematode lays this ring around the fly's neck when it emerges from the pupa and cannot yet move properly.