A new species of black fungus gnat from Canada, Peyerimhoffiajaschhoforum sp. n., is presented with a description, illustrations, biotope information and a brief discussion of the placement and concept of the genus Peyerimhoffia. P.jaschhoforum is characterized by a unique gonostylar structure where the apex is hollowed but not enclosed and contains a mass of mega setae housed within. P.jaschhoforum was reared from decomposing jack pine (Pinusbanksiana Lamb.) deadwood using both in-situ and ex-situ photoeclectors. We documented three additional specimens originating from Fennoscandia that resemble P.jaschhoforum but differ based on a broader tegmen, placement of setigerous papillae behind the tegmen and the fused intercoxal area. Based on this, these specimens are assigned to a new subspecies, Peyerimhoffiajaschhoforumfennoscandica ssp. n.
Keywords: Black fungus gnats; Boreal zone; Pinusbanksiana; new taxa; photoeclector.