Sphecomyia vittata (Wiedemann, 1830)

M. Moran, Kevin & H. Skevington, Jeffrey, 2019, Revision of world Sphecomyia Latreille (Diptera, Syrphidae), ZooKeys 836, pp. 15-79 : 46-49

Sphecomyia vittata (Wiedemann, 1830) Figs 1, 2N, 5C, 6B, 16F, 17F, 18F, 19A, 21D, 23

Chrysotoxum vittatum Wiedemann 1830: 87. Type locality. Unknown. LT male designated in Thompson 1988: 222 [NMW]

Psarus ornatus Wiedemann 1830: 91 - Macquart 1835: 491. Type locality. U.S.A.: Georgia [ZMHU]

Sphecomyia vittata , Macquart 1842: 75 - Gorski 1852: 170; Zetterstedt 1855: 4646; Osten Sacken 1875: 62, 1877: 342; Roder 1879: 96; Williston 1886: 257; Portschinsky 1887: 8; Smith 1890: 388; Hunter 1896: 101; Johnson 1900: 664, 1910: 349, 1914: 125, 1925: 178, 1929: 374; Chagnon 1901: 71; Aldrich 1905: 405; Jones 1907: 99; Osburn 1908: 14; Kertész 1910: 349; Metcalf 1913: 98, 1916: 111; Winn and Beaulieu 1915: 138; Banks et al. 1916: 192; Cockerell 1917: 16; Britton 1920: 188; Wehr 1924: 42; Shannon 1925: 43; Leonard 1928: 802; Curran 1932: 8; Winn and Maltais 1932: 53; Brimley 1938: 355; Stone (et al.) 1965: 613; Weisman 1965: 268, 1966a: 50, 1966b: 191; Cole and Schlinger 1969: 331; Waldbauer 1970: 45, 1983: 81; Shorter and Drew 1976: 89; Finnamore and Neary 1978: 172; Maier and Waldbauer 1979: 60; Waldbauer and LaBerge 1985: 101; Thompson 1988: 222.

Sphecomyia boscii Desmarest 1848: 730 - Evenhuis and Thompson 1990: 254. Type locality. U.S.A.: Carolinas. [MNHN]. Syn. n.

Diagnosis.

It can be confused with S. vespiformis but can be distinguished by the following characters: anepimeron pruinose; anterior three-fourths of scutellum pruinose; sternite 2 with anterior corners and lateral margins pruinose.

Redescription.

Male. Body length: 10.9-17.1 mm. Wing length: 7.9-12.1 mm. Head. Face yellow pruinose with shiny, black, medial vitta extending from oral margin to base of antenna; frons not enlarged antero-dorsally, longer than broad and as broad at vertex as at antenna, bare, with yellow pruinosity along posterior fourth; vertex triangular, longer than broad, shiny, with ocullar triangle yellow, black or mixed black and yellow pilose; postocular border yellow pruinose; postocular and occipital pile yellow; male narrowly dichoptic; antenna black, black pilose, with length of segments roughly in a 4:4:1 ratio.

Thorax. Matte black; postpronotum, scutum completely yellow pilose, except sometimes with black pile posteromedially; scutellum yellow pilose, except sometimes with black pile on non-pruinose portion; postalar callus, proepimeron, posterior an episternum yellow pilose; posterior katepisternum yellow pilose with broadly separated patches; anterior anepimeron yellow pilose; metasternum yellow pilose; postpronotum, anterior three-fourths of scutellum, broad posterior margin of anepisternum, dorso-posterior corner of katepisternum and yellow pruinose; anepimeron pruinose anteriorly; scutum with two pairs of tear shaped pruinose vittae, anterior pair short stopping before transverse suture, posterior pair longer but terminating before posterior edge; ventral calypter with long yellow pile.

Legs. Legs yellow to reddish-yellow. Legs yellow pilose.

Wing. Hyaline; microtrichia absent from following areas: cell bc; basal third of cell sc; 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 posterior margins of about apical half; broad anterior margin of cell cua.

Abdomen. Tergites and sternites shiny to sub-shiny, black with yellow pruinose markings as follows: tergite 1 pruinose along posterior margin; tergite 2 with broad, interrupted, truncate medial band which meets a broad, uninterrupted, posterior band in the posterolateral corners of tergite; tergite 3 with similar band, but more narrowly interrupted; pattern on tergite 4 same as tergite 3 except medial band very narrowly or incompletely interrupted; sternite 1 shiny; sternite 2 with anterior corners and lateral margins pruinose; sternite 3 mostly pruinose with posteromedial region of non-pruinosity, sternite 4 pruinose on anterior third and lateral margins; sternites 6 to 8 pruinose; pile of abdomen yellow.

Male genitalia. Surstylus elongated, about 2½ times as long as broad, apex rounded, directed ventrally; pile on dorsal surface of surstylus, increasing in length posteriorly; minute spines on ventral surface and apical three-fourth of lateral inner and outer 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 invagination on posterior border; aedeagus as in Fig. 2N.

Female.

Similar to male except normal sexual dimorphism.

Distribution.

Manitoba east to New Brunswick south to Florida west to New Mexico and Utah. Widespread east of the Great Plains (Fig. 23).

Biology.

Collected on flowers of Acer spicatum Lam., Alliaria petiolata (M. Beib.) Cavara and Grande, Corema (D. Don) sp., Cornus florida L., Crataegus marshallii Eggl., Sassafras albidum (Nutt.) Nees, Prunus gracilis Engelm. and A. Gray, Prunus serotina Ehrh., Prunus virginiana L., Aronia melanocarpa (Michx.) Elliott, Physocarpus opulifolius (L.) Maxim., Symplocos Jacq. sp., Corus sp., Viburnum cassinoides L., Viburnum lentago L., Viburnum prunifolium L., and Viburnum rafinesquianum Schult. Also collected at Acer L. sap runs. Usually collected in deciduous woods, often near a stream or river, but has also been taken in sphagnum bog. One female has been collected in leaves at base of a hardwood tree.

Known hilltopper. Authors have personally observed specimens flying in a lazy-S-type pattern similar to that of wasps. Recorded flying early March through late July.

Remarks.

Desmarest (1848) assigned the name Sphecomyia boscii to the specimens Latreille used to establish Sphecomyia . The name was forgotten until its rediscovery in Evenhuis and Thompson (1990). We do not assign a neotype as it is uncertain if the series is lost. It is not listed among the MNHN types, nor did the primary author encounter it during a visit to the collection.

COI barcoding recovered two clusters of S. vittata with a maximum barcode divergence barcode of 2.41%. Specimens of both clusters were compared, and no morphological differences were found.