Canadian Journal of Arthropod Identification

Soldier flies of the subfamily Pachygastrinae of Canada (Diptera, Stratiomyidae)

CJAI 42 -- December 4, 2020

Linley M. Sherin

| Abstract | Introduction | Materials & Methods | Checklist | Species Key | Results | Acknowledgments | References | PDF | Cite | Appendix |

In total, 439 specimens were examined (52 DEBU, 20 BOLD, 262 CNC, 1 LEMQ, 101 QMOR, 2 UBCZ, 1 iNaturalist) that correspond to nine species and seven genera (Table 1). Within this material, three specimens were damaged and not identifiable to species. See Appendix 1 for a complete list of examined specimens. Notably, no pachygastrine species have been recorded from provinces east of Quebec. This is potentially due to sampling bias, as the most widespread species appear to exist wherever there are forested areas.

The genus Zabrachia needs revision, which is beyond the scope of this review. Therefore, the key identifies Zabrachia specimens only to generic level. Neopachygaster Austen is also in need of revision. All Neopachygaster species are included within the key although only a single character separates the three most widespread species (Neopachygaster reniformis Hull, N. vitrea Hull and N. maculicornis (Hine)). As Pachygastrinae are a predominantly tropical subfamily, it is recommended that revisions of any Canadian genera take place within larger revisions, ideally of the global fauna. It has been previously recommended that the entire subfamily is revised (Woodley 2001; Hauser, M., pers. comm) and the findings presented here support this recommendation for a global revision of the Pachygastrinae.

In total, I present 21 new provincial distribution records and four new national distribution records. This includes records from four provinces from which the subfamily had not previously been known. The following species are recorded from Canada for the first time; Cosmariomyia pallidipennis (Williston), Gowdeyana punctifera (Malloch), Neopachygaster vitrea Hull and Pachygaster pulchra Loew. This increases the known pachygastrine fauna in Canada from seven to 11 species, and the known stratiomyid fauna from 114 to 118 species (Savage et al. 2019).