Piophila atrifrons Melander & Spuler, 1917: 66 (type locality: United States of America. Idaho: Troy). Allopiophila calceata Duda, 1924: 174 (type locality: Sweden: Gällivare and Abisko), syn. n.
NBP/NIS material examined. 9 ♂, 9 ♀ from the following sites: Manitoba: Churchill; Northwest Territories: Norman Wells; Nunavut: Kugluktuk; Ontario: Moosonee; Quebec: Schefferville (vi.1952, 1962; vii. 2010, vi–vii. 2011; viii. 1952) (CNC, LEM).
Other material examined. Lectotype of P. atrifrons: 1 ♂ labelled Troy, Idaho, 14.vi.08, Paratype Piophila atrifrons M-S, Lectoholotype P. atrifrons, d. G Steyskal 1963, Lectotype Piophila atrifrons Melander, Spuler, 1917: 66, by Steyskal, 1964: 177, det. A Ozerov, 2002 (USNM). Paralectotypes: UNITED STATES OF AMERICA. Washington: Oroville, Paratype M.-S., Paralectotype, Melander et Spuler, 1917: 66, det. A.L. Ozerov 2003, USNM ENT 0 1071201, (1 ♀, USNM); Oroville, Type M.-S., Paralectotype, Melander et Spuler, 1917: 66, det. A.L. Ozerov 2003, USNM ENT 0 1071192, (1 ♀, USNM).
Comments. Parapiophila atrifrons is widespread in northern Canada and the northern United States (Washington, Idaho, Maine) (Melander & Spuler 1917; McAlpine 1977). It is also known from the Palaearctic region (McAlpine 1977; Ozerov 2004 b).
Steyskal (1964) suggested that Allopiophila calceata might be conspecific with Parapiophila atrifrons but that examination of more specimens would be required. We examined 185 specimens of both species from CNC and LEM. The only reliable difference between A. calceata and P. atrifrons is the shape of the tip of the pregonite: one round and one pointed tip in P. atrifrons; two pointed tips in A. calceata (McAlpine 1977). The male genitalia are otherwise identical, and the minor difference in the pregonite may not be enough to justify two species. Parapiophila nitidissima (Melander & Spuler) has variation in the shape of the pregonite tip (Steyskal 1975). There is variation in the colour of the fore tibia in some specimens, but such variation is seen in multiple species of Parapiophila (e.g., P. vulgaris (Fallén), P. fulviceps (Holmgren), P. kugluktuk).
In addition to morphological evidence, there was almost no divergence in DNA barcodes (658 bp of CO 1) between five specimens of P. atrifrons and A. calceata from Ontario, Quebec and the Northwest Territories in LEM (Barcode of Life Database numbers: BOLD LYMAA 315–14, 316 – 14, 319–14, 320 – 14, 321 – 14) identified by S. Rochefort based on morphological characters and compared with types of P. atrifrons and original descriptions of both species. Based on morphological and molecular evidence, we consider A. calceata a junior synonym of P. atrifrons.