Prochyliza brevicornis

Prochyliza brevicornis Melander

NBP/NIS material examined. 13 ♂, 7 ♀ from Manitoba: Churchill (vi–vii.1962; vii–viii.1961; vi.1967; vii.1969) (CNC).

Comments. Prochyliza brevicornis is a widespread Nearctic species (Melander 1924; Steyskal 1965; McAlpine 1977). The NIS specimens extend the known range of P. brevicornis northeast.

A total of 960 specimens was collected by the NBP and NIS at the 12 sites in the boreal, subarctic and high arctic ecozones. There were distinct latitudinal patterns in diversity across the three ecozones (Fig. 12).

Abundance and species richness of Piophilidae were lowest in the boreal sites. Only 13 specimens representing five species were collected (Liopiophila varipes, Parapiophila atrifrons, P. dudai, P. penicillata, P. xanthopoda). All species collected in the boreal were also collected in the subarctic (Fig. 12).

In contrast, species richness of Piophilidae was highest at the subarctic sites. All but one species (Arctopiophila nigerrima) were collected in the subarctic ecozone. Some species collected in multiple ecozones were much more abundant in the subarctic sites (e.g., Liopiophila varipes, Neopiophila setaluna, Parapiophila penicillata) (Fig. 12). Although Actenoptera hilarella was collected only in subarctic sites in this study, published records (McAlpine 1977) show that it is more widespread in the Nearctic, although rarely collected.

Piophilidae were most abundant at the high arctic sites (701 specimens), but species richness was low. Five species were collected: Arctopiophila arctica, Arctopiophila nigerrima, Lasiopiophila pilosa, Neopiophila setaluna and Parapiophila fulviceps. Arctopiophila nigerrima was collected only at high arctic sites and A. arctica, L. pilosa and P. fulviceps were much more abundant at high arctic than subarctic sites (Fig. 12). The dominance of these species in the high arctic suggests that they may be particularly well-adapted to the harsh conditions on the arctic islands (Downes 1962; McAlpine 1965), although a better understanding of their ecology would be required to identify those adaptations.

Half of the recorded Nearctic species of Piophilidae were identified in the 12 sites sampled in this study, including a new, widespread Holarctic species, and two new North American records. We are aware of additional, undescribed species from other northern sites. A taxonomic revision of Nearctic Piophilidae is ongoing, which will allow for a more comprehensive analysis of geographic patterns of diversity.