Acrosathe vialis (Osten Sacken)

Gibson, Joel F. & Cannings, Robert A., 2025, The Stiletto Flies (Diptera: Therevidae) of British Columbia, Yukon, and Alaska, Zootaxa 5618 (4), pp. 481-508 : 487

Acrosathe vialis (Osten Sacken)

( Fig. 6 )

Specimens examined (18). BC: Bowser, D’Arcy, Denman Island, Goldpan Provincial Park, Oliver, Langford, Nicola, Parksville, Saanich, Victoria. DEBU, PFC, RBCM, SEM.

Database and literature records (0).

iNaturalist records (1). BC: Central Saanich (iNat 84506944, Fig. 6 ).

Conservation status. BC: SNR.

Distributional notes. Newly reported for BC and Canada; Seattle, Washington, is the former northernmost locality ( Webb 2009). Collected in southern British Columbia from coastal southeastern Vancouver Island (Bowser, Victoria) east to the Thompson (Goldpan Provincial Park), Nicola, and Okanagan valleys (Oliver). Based on its United States range, it likely occurs in the Columbia-Kootenay region.

Ecoprovinces and other designations. BC: Georgia Depression, Southern Interior.

Range. Cordilleran. British Columbia south through Idaho and Washington to Wyoming,Arizona, and California ( Webb et al. 2013).

Biological notes. Flight period: 10 May–4 August. Specimens have been captured on sea beaches and dunes, on river shoreline rocks, in a small peaty fen, and on Garry Oak ( Quercus garryana ) and Douglas-fir ( Pseudotsuga menziesii ) trees.

Figures

FIGURES 6–13. Selected species documented in this paper. Fig. 6. Acrosathe vialis male, Central Saanich, British Columbia, 21 June 2021 (iNaturalist 84506944). Photo by Thomas Barbin. Fig. 7. Pallicephala pachyceras male, Lake Cowichan, British Columbia, 24 June 2020 (iNaturalist 51032384). Photo by Brian Starzomski. Fig. 8. Psilocephala vicina female, Nahatlatch Provincial Park, British Columbia, 25 June 2021 (iNaturalist 97392001). Photo by Lena Chiasson. Fig. 9. Spiriverpa albiceps female, Cape Scott, Vancouver Island, British Columbia, 28 June 2020 (iNaturalist 57752358). Photo by Thomas Barbin. Fig. 10. Spiriverpa albiceps male, Teslin, Yukon, 31 July 2020 (iNaturalist 55078839). Photo by Jukka Jantunen. Fig. 11. Tabuda planiceps female, Kilpoola Lake area, Osoyoos, British Columbia, 23 May 2022 (iNaturalist 122086201). Photo by Brian Starzomski. Fig. 12. Thereva brunnea female, Tipella, Harrison Lake, British Columbia, 6 July 2020 (iNaturalist 53228675). Photo by Blair Dudeck. Fig. 13. Thereva webbi female laying eggs in the soil. Whitehorse, Yukon, 12 July 2020 (iNaturalist 52909455). Photo by Jukka Jantunen.