Callomyia velutina Johnson

Cumming, Heather J. & Wheeler, Terry A., 2016, Revision of the Nearctic species of Callomyia Meigen (Diptera: Platypezidae) and phylogeny of the genus, Zootaxa 4111 (5), pp. 501-554 : 538-542

Callomyia velutina Johnson

( Figs 13 , 23 , 31 , 39 , 45 , 50, 52 , 63, 68 , 76 )

Callomyia velutina Johnson, 1916: 32 . Type locality: Mt. Washington, New Hampshire, USA.

Diagnosis. This apparently disjunct eastern and western Nearctic species is characterized by its abdominal colour patterns and male terminalia with a molar-like surstylus, apically rounded postgonite, and trifid hypandrial process. The female of C. velutina is very similar to the widespread Nearctic species C. venusta because of its similar thoracic and abdominal colour patterns, but differs by an extra presutural intra-alar seta on the scutum and a silverblue marking on tergite 5 that is interrupted by a median dorsal dark band (versus tergite 5 entirely silver-blue). The male of this species is similar to C. proxima from eastern and western North America, but differs by its lateral silver-grey dusting on abdominal tergites 1 and 2 (versus more distinct posterolateral to posteroventral silver-grey markings only on tergites 3 and 4) and terminalia with a molar-like surstylus and trifid hypandrial process (versus bifid surstylus and bifid hypandrial process). Callomyia velutina has male terminalia that are most similar to the Nearctic species C. argentea and C. venusta , but its terminalia differ primarily from these species by an apically rounded (versus apically truncate) postgonite.

Description. Male ( Figs 13 , 23 ). Body length 3.6–4.5 mm; wing length 3.65–4.0 mm. Head silver-grey with coppery reflections on gena and postgena; mouthparts brownish-yellow to light brown with palpus brown; antenna with scape, pedicel, first flagellomere and arista brown. Antenna with first flagellomere short-oval (as in Fig. 41 ).

Thorax mainly dark brown to black with indistinct silver-grey dusting on notopleuron, supra-alar area of scutum, posterior portion of postsutural scutum and postalar callus; propleuron, mesopleuron, metapleuron, mediotergite and laterotergite silver-grey; postpronotal lobe yellowish-brown posteroventrally. Scutum with 6 notopleural setae.

Legs brown, hind leg darker with tibia and tarsomeres dark brown; apex of femur and base of tibiae brownishyellow; coxae silver-grey dusted in most specimens. Mid tibia with median anterodorsal seta absent, median dorsal seta present ( Fig. 50 ); base of hind femur with long thin posteroventral seta (as in Fig. 54 ). Hind tarsomere 1 slightly expanded, subequal to apical width of hind tibia, length approximately 2.5X width.

Wing hyaline with cell sc faintly yellow. Halter with stem brown; knob orange, yellow in some specimens.

Abdomen mainly dark brown to black with lateral silver-grey dusting on tergites 1 and 2; ventrolateral silvergrey dusting on tergites 3 and 4 in some specimens; tergite 7 entirely silver-grey dusted; sternites light brown, sternite 8 brown to grey.

Terminalia ( Figs 63, 68 ) brown to grey, surstylus darker; hypandrial process and cercus brownish-yellow. Epandrium with short tooth-like ventral lobe, pointed at apex, slightly anteriorly directed; apical process short to moderately long, pointed at apex. Surstylus molar-like, with 2 large cusps moderately excavated in between; dorsal outer cusp broadly rounded in lateral view; ventral inner cusp slightly pointed in lateral view, narrowly truncate and minutely serrate medially in posterior view ( Fig. 68 ). Hypandrium with moderately long apical process; process trifid, with 2 short apical projections and short stout rounded basoventral lobe. Postgonite long and moderately wide, rounded at apex. Phallus with sharp extended hook at apex. Cercus short.

Female ( Figs 31 , 39 ). Body length 3.3–4.25 mm; wing length 2.95–4.2 mm. Head silver-blue with occiput silver-grey to silver-brown; mouthparts including palpus pale yellow to brownish-yellow; antenna with scape and pedicel brown, pale yellow apically, first flagellomere and arista entirely brown. Antenna with first flagellomere short-oval (as in Fig. 43 ).

Thorax mainly black to velvety black with silver-blue markings on postpronotal lobe, entire lateral portion of presutural scutum, notopleuron, most of postsutural scutum and postalar callus; propleuron, mesopleuron, metapleuron, mediotergite and laterotergite silver-blue dusted; postpronotal lobe posteroventrally, supra-alar area of scutum, postalar callus anteriorly and anepimeron pale yellow to yellowish-brown. Scutum with 2–3 presutural intra-alar setae, usually 3 at least on one side ( Fig. 45 ).

Fore leg and mid leg pale yellow to yellowish brown with tarsomeres 3–5 brown; hind leg darker with apex of femur, tibia and tarsomeres dark brown; coxae silver-blue dusted in most specimens. Mid tibia with short median dorsal seta present in most specimens ( Fig. 52 ).

Wing hyaline with cell sc bluish-white in some specimens. Halter yellow.

Abdomen dark brown to black with tergites 1–3 yellow; lateral silver-white markings or dusting on tergites 1 and 2; tergite 4 dark brown to black, brownish-yellow in a few specimens; tergite 5 silver-blue, interrupted by median dorsal dark band (partially interrupted in some specimens); sternites white to light brown.

Terminalia with segment 8 and epiproct yellowish-brown to brown, silver-grey dusted; hypoproct and cercus yellow to brownish-yellow.

Type material. HOLOTYPE, ♂ labelled: “Mt Washington/ Betw. 1 & 2 m [hand written] N H [New Hampshire]/ VII.24.1915 [hand written]; “ HOLOTYPE / No. [red label]; “C.W. Johnson/ Collector; “MCZ-ENT/ 0 0 304204 ( MCZ). PARATYPES: USA: MASSACHUSETTS: Chester, 5.viii.1914, C.W. Johnson (1 ♂, MCZ) (paratype of C. velutina , but conspecific with C. proxima —see “Remarks); NEW HAMPSHIRE: Bretton Woods, 28.vi.1913, C.W. Johnson (1 ♂, MCZ); Mount Washington, 6.vii.1914, C.W. Johnson (1 ♂, MCZ), same except betw. 1 & 2 mile, 24.vii.1915 (1 ♂, MCZ) (both paratypes of C. velutina , but conspecific with C. proxima —see “Remarks); Mount Washington, Raymond Path, 8.vii.1914, C.W. Johnson (1 ♂, MCZ); Mount Washington, Raymond Path, 28.vii.1915, C.W. Johnson (1 ♂, MCZ) (paratype of C. velutina , but conspecific with C. proxima — see Remarks).

Additional material examined. CANADA: ALBERTA: Bilby, 1.vii.1924, O. Bryant (1 ♂, USNM); Fort Vermilion, 23.viii.1961, E.L. Kessel (1 ♀, CAS); Little Smokey River and Highway 43, 11.vi.1962, E.L. Kessel (1 ♂, CAS); BRITISH COLUMBIA: Cultus Lake Provincial Park, 6.ix.1960, E.L. Kessel (1 ♂, CNC); Kleanza Creek Province Camp Ground, Highway 16, 31.vii.1962, E.L. Kessel (1 ♂, CAS); Kleanza Creek, 12 mi. E. of Terrace, 14.viii.1965, E.L. Kessel (2 ♀, 3 ♂, CAS); Liard Hot Springs, 14.vii.1962, E.L. Kessel (1 ♀, CAS), same except 26.vii.1962 (1 ♀, CAS); Liard Hot Springs, Mile Post 496 Alaska Highway, 1500’, 9-10.vii.1959, R.E. Leech (1 ♂, CNC), same except 2.ix.1957, E.L. Kessel (1 ♀, 1 ♂, CAS); Liard River, 8.viii.1959, E.L. Kessel (1 ♀, CAS); Mile Post 104, Alaska Highway, 5.viii.1957, E.L. Kessel (3 ♀, 5 ♂, CAS), same except 5.viii.1959 (2 ♂, CAS); Mile Post 236, Alaska Highway, 13.vi.1962, E.L. Kessel (1 ♂, CAS); Mile Post 305, Alaska Highway, 6.viii.1957, E.L. Kessel (2 ♀, CAS), same except 6.viii.1959 (3 ♀, CAS); Mount Thornhill near Terrace, 29.vii.1960, W.R. Richards (1 ♀, CNC); Prince Rupert, 1.viii.1962, E.L. Kessel (1 ♂, CAS); Smithers, Highway 16, 30.vii.1962, E.L. Kessel (1 ♂, CAS); Vancouver, 13.ix.1932, H.B. Leech (1 ♀, CNC); NOVA SCOTIA: CBHNt. Pk. North Mt. PG765864, 1.vii.1984, dry spruce birch forest, H.J. Teskey, CNC DIPTERA 192200 (1 ♀, CNC); ONTARIO: Algonquin Provincial Park, Swan Lake Research Stn., Scott Lake, south end wet Hemlock Zone, 15.vi.1995, S.A. Marshall, JSS19226 (1 ♂, DEBU); Thunder Bay Distr., Pukaskwa N.P., Coastal Trail Playter Harbour, White River, sweep, 21.vii.2001, M. Buck, JSS25814 (1 ♀, DEBU); YUKON TERRITORY: Dawson City, 18.vi.1962, E.L. Kessel (3 ♀, 4 ♂, CAS; 1 ♂, CNC); Mile Post 102, Klondike Highway, 18.vi.1962, E.L. Kessel (4 ♀, 5 ♂, CAS; 1 ♂, CNC); USA: ALASKA: Anchorage, 19.vii.1921, J.M. Aldrich (2 ♂, USNM), same except 20.vii.1921 (1 ♂, USNM), same except 21.vii.1921 (2 ♀, 1 ♂, USNM); Chatanika River Camp Ground, 21.vi.1962, E.L. Kessel (2 ♂, CAS); Chickaloon River and Glenn Highway, 30.vi.1962, E.L. Kessel (1 ♀, 8 ♂, CAS), same except 1.vii.1962 (4 ♂, CAS); 20 mi. W. of Circle City, 23.vi.1962, E.L. Kessel (1 ♂, CAS); Clearwater, Alcan Camp Ground, 19.vi.1962, E.L. Kessel (1 ♀, CAS); Haines, 11.viii.1959, E.L. Kessel (1 ♀, CAS); Johnson Lake, 16 mi. S. of Soldatna, 5.vii.1962, E.L. Kessel (1 ♀, CAS); King Salmon, viii.1960, M.R. Wheeler & L. Throckmorton (1 ♀, CAS); 4 mi. S. of Livengood, 26.vi.1962, E.L. Kessel (1 ♂, CAS), same except 27.vi.1962 (1 ♀, 4 ♂, CAS); Matanuska River Camp Ground, 1.vii.1962, E.L. Kessel (2 ♂, CAS), same except 10.vii.1962 (2 ♂, CAS); Mile Post 90, 5 mi. E. of Soldatna, 5.vii.1962, E.L. Kessel (1 ♂, CAS); Mile Post 44 on Sterling Highway, 2.vii.1962, E.L. Kessel (2 ♀, 2 ♂, CAS); Mile Post 1231, E. Tetlin Junction, Alaska Highway, 14.vii.1962, E.L. Kessel (3 ♀, CAS); Moon Lake, Alaska Hwy. DC-1331, 8.vii.1978, P.H. Arnaud Jr. (1 ♀, CAS); Moose Creek Camp Ground, 1.vii.1962, E.L. Kessel (1 ♂, CAS); Peters Creek Camp Ground, 1.vii.1962, E.L. Kessel (1 ♀, CAS); Richardson Highway, 21 mi. N. of Delta Junction, 29.vi.1962, E.L. Kessel (11 ♂, CAS); same except 27 miles N. of Delta Junction (9 ♀, CAS); Salcha River Camp Ground, 20.vi.1962, E.L. Kessel (5 ♂, CAS), same except 29.vi.1962 (1 ♀, 10 ♂, CAS); Shaw Creek, 289 mi. Rich Highway, 11.vii.1951, Mason and McGillis (1 ♀, 1 ♂, CNC); Soldatna, 5.vii.1962, E.L. Kessel (1 ♂, CAS); 16 mi. S. of Soldatna, 3.vii.1962, E.L. Kessel (1 ♀, 5 ♂, CAS); Spenard, 25.viii.1957, E.L. Kessel (1 ♂, CAS), same except 16.viii.1959 (1 ♂, CAS), same except 17.viii.1959 (3 ♀, CAS), same except 7.vii.1962 (1 ♂, CAS); 9 mi. E. Valdez, 11.vii.1962, E.L. Kessel (1 ♀, 1 ♂, CAS); same except 12.vii.1962 (2 ♀, 5 ♂, CAS); CALIFORNIA: Eldorado County, Fallen Leaf, 13.vii.1961, J.G. Chillcott (1 ♀, CNC); Placer County, Sagehen, 22-24.vi.1985, Malaise trap, ROM 859999, CNC Diptera 96410 (1 ♀, CNC); NEVADA: Ormsby County, 1 mi. E. Lake Tahoe, 20.vii.1950, C.P. Alexander (1 ♀, CAS); NEW HAMPSHIRE: Franconia, collection of Mrs. A.T. Slosson (1 ♀, AMNH; 1 ♀, USNM); NEW YORK: Adirondacks, Avalanche Trail, 30.vii.1929, A.L. Melander (1 ♀, USNM).

Geographical distribution and seasonal occurrence ( Fig. 76 ). Callomyia velutina is currently distributed in both western North America (Alaska, Yukon Territory, British Columbia, Alberta, California and Nevada) and eastern North America (Ontario, Nova Scotia, New York and New Hampshire). Adults have been collected from early June to early September.

Remarks. The female of C. velutina is very similar to that of the widespread Palaearctic species C. amoena , particularly in thoracic and abdominal colour patterns. However, the males of these two species differ in features of the terminalia, as well as in abdominal colour pattern.

One male specimen of this species yielded a barcode (JSS19226) as did two female specimens, initially identified as C. venusta (CNC DIPTERA 192200 and JSS25814) ( Table 1 ). Until now, the female of C. velutina was unknown and was hidden within females of C. venusta . Barcode data initially revealed these cryptic females of C. velutina because they clustered with the C. velutina male (<2% genetic divergence) in the Neighbour-joining tree ( Fig. 78 ). Upon further inspection, subtle morphological differences were found that distinguish females of C. velutina from those of C. venusta , which are indicated in the “Diagnosis of C. velutina above.

Kessel & Buegler (1972) considered four of the seven paratypes of C. velutina to be conspecific with their new species C. liardia (= C. proxima ). An additional paratype of C. velutina was also discovered to be conspecific with C. proxima (see Remarks under C. proxima ). These records have been added to the “Additional material examined of C. proxima .

Figures

FIGURE 76. Known distribution of C. velutina.

FIGURE 78. Neighbour-joining tree of 17 Callomyia specimens and two outgroup specimens. Nearctic species names as used by Kessel & Buegler (1972). Current species concepts shown by different colours (red = C. proxima, blue = C. venusta, pink = C. amoena, orange = C. velutina, aqua blue = C. dives, purple = C. speciosa) with outgroup specimens shown in black.

FIGURES 9 − 14. Callomyia males, lateral view. 9. C. calla. 10. C. corvina. 11. C. gilloglyorum. 12. C. proxima. 13. C. velutina. 14. C. venusta.

FIGURES 19 − 24. Callomyia males, dorsal view. 19. C. calla. 20. C. corvina. 21. C. gilloglyorum. 22. C. proxima. 23. C. velutina. 24. C. venusta.

FIGURES 29 − 32. Callomyia females, lateral view. 29. C. gilloglyorum. 30. C. proxima. 31. C. velutina. 32. C. venusta.

FIGURES 37 − 40. Callomyia females, dorsal view. 37. C. gilloglyorum. 38. C. proxima. 39. C. velutina. 40. C. venusta.

FIGURES 45 − 48. Callomyia thoracic bristles and wings. 45. C. velutina, female (scutum with 3 presutural intra-alar setae). 46. C. venusta, female (scutum with 2 presutural intra-alar setae). 47. C. argentea, male wing. 48. C. corvina, male wing.

FIGURES 49 − 54. Callomyia legs. 49. C. proxima, male mid leg (with tibial setae). 50. C. velutina, male mid leg (with tibial seta). 51. C. proxima, female mid leg (with tibial seta). 52. C. velutina, female mid leg (with tibial seta). 53. C. argentea, male hind leg (with femoral seta). 54. C. corvina, male hind leg (with femoral seta). Abbreviations: ad s—anterodorsal seta; d sdorsal seta; pv s—posteroventral seta.

FIGURES 63 − 69. Callomyia male terminalia, lateral view (63 − 64); surstyli, posterior view (65 − 69). 63. C. velutina. 64. C. venusta. 65. C. argentea. 66. C. browni. 67. C. calla. 68. C. velutina. 69. C. venusta. Abbreviations: d o csp—dorsal outer cusp; v i csp—ventral inner cusp. Scale bar: Figs 63 − 64 = 0.1 mm; Figs 65 − 69 = 0.05 mm.

FIGURES 41 − 44. Callomyia antennae. 41. C. calla, male antenna (first flagellomere short-oval). 42. C. gilloglyorum, male antenna (first flagellomere elongate-conical). 43. C. venusta, female antenna (first flagellomere short-oval). 44. C. gilloglyorum, female antenna (first flagellomere subtriangular).