Sphecomyia columbiana Vockeroth, 1965

M. Moran, Kevin & H. Skevington, Jeffrey, 2019, Revision of world Sphecomyia Latreille (Diptera, Syrphidae), ZooKeys 836, pp. 15-79 : 26-28

Sphecomyia columbiana Vockeroth, 1965 Figs 2C, 10A, 11A, 12A, 14A, 22C, 26

Sphecomyia columbiana Vockeroth 1965: 86 - Weisman 1965: 268, 1966: 194; Telford 1975: 21. Type locality: 32 miles southwest Terrace, British Columbia, Canada. [CNC]

Diagnosis.

It can be confused with S. cryptica sp. n., S. dyari , S. hoguei sp. n., S. oraria sp. n., and S. pattonii but is distinguished by a tergite 1 densely pruinose only in the posterior corners.

Redescription.

Male. Body length: 13.2-14.3 mm. Wing length: 9.9-10.5 mm. Head. Face yellow pruinose with shiny, black, medial vitta extending from oral margin to base of antenna; frons broad, about as long as broad at antenna, two-thirds as broad at vertex as at antenna, bare, with silver pruinosity along posterior half; vertex triangular, longer than broad, shiny, with ocellar triangle black pilose; postocular border yellow pruinose; postocular pile black; occipital pile yellow; male narrowly dichoptic; antenna black, black pilose, with length of segments roughly in a 3:3:2 ratio.

Thorax. Shiny black; postpronotum yellow pilose with occasional black pile; scutum and scutellum mostly black pilose with occasional yellow pile; postalar callus mixed black and yellow pilose; proepimeron yellow pilose; anepisternum yellow pilose posteriorly; posterior katepisternum yellow pilose with broadly separated patches; anterior anepimeron yellow pilose; metasternum yellow pilose; postpronotum, anterior eighth of scutellum, broad posterior margin of anepisternum and dorso-posterior corner of katepisternum yellow pruinose; area between postpronota weakly silver pruinose, except shiny medially; anepimeron shiny; scutum without pruinose vittae; ventral calypter with long yellow pile.

Legs. Foreleg black, except extreme apex of femur and anterior fourth of tibia reddish-yellow; fore tarsi slightly broadened; midleg reddish-yellow, except basal four-fifths of femur and last two tarsomeres black; hind leg reddish-yellow, except basal four-fifths of femur and last two tarsomeres black; legs yellow pilose, except black pilose on fore tibia, fore tarsi, extreme apex of fore femur, and last two mid and hind tarsomeres; hind coxa silver pruinose.

Wing. Hyaline; microtrichia absent from following areas: cell bc; basal sixth of cell c; basal fourth of cell sc; cell r1 from base almost to crossvein r-m; broad basal portion of cell br (before origin of M) and about basal two-fifths of narrower portion of this cell (caudad of spurious vein only); cell bm, except apex and narrow anterior and posterior margins of about apical fourth; broad anterior margin of cell cua; narrow, elongate, oval area proximal to vein A1.

Abdomen. Tergites and sternites shiny to sub-shiny, black with yellow pruinose markings as follows: tergite 1 pruinose in posterolateral corners; tergite 2 with broad, interrupted, truncate medial band which meets a narrow, uninterrupted posterior band in the posterolateral corners of tergite; tergite 3 with similar medial band, but more narrowly interrupted; pattern on tergite 4 same as tergite 3, except medial band very narrowly or incompletely interrupted; sternite 1 shiny; sternites 2 to 4 mostly pruinose, except with narrow anterior border and transverse subapical band shiny to dull black; sternites 6 to 8 pruinose; pile of abdomen yellow, except with some black pile present on posterior halves of tergites 3 and 4 and on postabdomen.

Male genitalia. Surstylus not elongated, about as long as broad, curving downward ventrally; pile on anterolateral outer surface of surstylus; minute spines on ventral surface and apical half of interior lateral surface; basal fourth of the ventral surface of the surstylus produced into a lobe directed posteroventrally, with minute pubescence on ventral and lateral inner surface; cerci rounded, with no invagination on posterior border; aedeagus as in Fig. 2C.

Female.

Similar to male except normal sexual dimorphism.

Distribution.

Canada: British Columbia. U.S.A.: Washington (Fig. 26). Known from two close localities on the central coast of British Columbia and several clustered localities in southeastern Washington.

Biology.

Collected visiting flowers of Heracleum maximum W. Bartram. Recorded flying April through June.