Callomyia bertae Kessel

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 : 515-516

Callomyia bertae Kessel

( Figs 8 , 17 , 26 , 34 , 57 , 71 )

Callomyia bertae Kessel, 1961a: 193 . Type locality: Pinos Altos Mountains, New Mexico, USA.

Diagnosis. This southwestern Nearctic species is characterized by its silver-blue thoracic and abdominal markings and male terminalia with a bifid surstylus. Callomyia bertae is most similar in colour to the southwestern Nearctic species C. arnaudi , but can be distinguished from this species by a different pattern of silver-blue markings on the abdomen, paler legs and a paler halter colour, and differences in the male terminalia that are indicated in the key to species. The male terminalia of C. bertae are similar to those of C. proxima from eastern and western North America, but are yellow with a dark brown surstylus (versus brown to grey with a dark brown to black surstylus) and have a longer dorsal projection on the hypandrial process.

Description. Male ( Figs 8 , 17 ). Body length 3.5 mm; wing length 3.55 mm. Head dark silver-grey; mouthparts including palpus brownish-yellow; antenna with scape, pedicel, first flagellomere and arista dark brown. Antenna with first flagellomere short-oval (as in Fig. 41 ).

Thorax dark brown to black with silver-blue markings on lateral portion of presutural scutum, notopleuron, most of postsutural scutum, and postalar callus; propleuron, mesopleuron, metapleuron, mediotergite and laterotergite silver-grey dusted. Scutum with 5 notopleural setae.

Legs pale yellow with fore and mid tarsomeres 4 and 5 dark brown, hind leg darker with tibia and tarsomeres dark brown. Mid tibia with median anterodorsal seta absent, median dorsal seta present (as in Fig. 50 ); base of hind femur with long thin posteroventral seta (as in Fig. 54 ). Hind tarsomere 1 long, slightly narrower than apical width of hind tibia, length approximately 3X width.

Wing hyaline. Halter yellowish-orange.

Abdomen black with dorsolateral silver-blue markings on tergites 1 and 2; posterolateral silver-blue markings on tergites 3 and 4; tergite 7 entirely light brown; sternites pale yellowish-brown, sternite 8 light brown.

Terminalia ( Fig. 57 ) yellow, except surstylus dark brown. Epandrium with minute ventral lobe, barely apparent; apical process short, broad at apex. Surstylus bifid with long outer and inner process, both rounded at apex; outer process broader and longer; inner process narrower and shorter. Hypandrium with moderately long apical process; process bifid, with 2 apical projections; dorsal projection narrow and long, ventral projection broad and short. Postgonite long and moderately wide, somewhat truncated and slightly pointed at apex. Phallus sharply hooked at apex. Cercus short.

Female. Unknown.

Type material. HOLOTYPE, ♂ labelled: “Pinos Altos/ Mts.,Grant/ Co.,N.M./ 8-28-51; “E.L.Kessel/ Collector; HOLOTYPE / Callomyia / bertae / Kessel [red label]; “California Academy/ of Sciences/ Type No. 6452 [dissected, first flagellomere and arista missing from antenna] ( CAS).

Geographical distribution and seasonal occurrence ( Fig. 71 ). Callomyia bertae is only known from the holotype collected from the Pinos Altos Mountains in Grant County, New Mexico, in late August.

Remarks. Callomyia bertae is closely related to the Nearctic species C. proxima and the Palaearctic species C. dorsimaculata Shatalkin , C. elegans , and C. sonora , as shown in the strict consensus tree ( Fig. 79 ).

A series of seven female specimens from Durango, Mexico ( Fig. 71 ) may be conspecific with the male of C. bertae , based on similarities in colour. Five specimens are from 10 miles west of El Salto, collected on 14- 21.vi.1964 at 9000 feet and two specimens are from 14 miles southwest of El Salto, collected on 26.vi.1964 at 8000 feet (all collected by J.F. McAlpine, deposited in CNC). These females ( Figs 26 , 34 ) have similar metallic bluishwhite thoracic and abdominal colour patterns to the females of C. arnaudi (which is similar to C. bertae —see “Diagnosis above), but abdominal tergite 4 is entirely metallic bluish-white and is not interrupted by a median dorsal dark band. In addition, these females are larger in size than those of C. arnaudi . They are also similar in appearance to the females of C. gilloglyorum because of similar thoracic and abdominal colour patterns. However, the colour of the potential C. bertae females is more metallic bluish-white than silver-grey and abdominal tergites 2, 4 and 6 are complete and not interrupted by a median dorsal dark band.

Figures

FIGURE 71. Known distribution of C. arnaudi, C. bertae, and C. browni.

FIGURE 79. Strict consensus tree of the 136 most parsimonious cladograms of the world species of Callomyia and outgroups, produced by the analysis of the data matrix in Table 2. Bremer support values are listed above each internode. The Oriental species, Callomyia coei Kessel and C. triangulata Tkoč, were excluded from the analysis because they are only known from females.

FIGURES 4 − 8. Callomyia males, lateral view. 4. C. argentea. 5. C. arnaudi (abdomen removed). 6. C. arnaudi abdomen in glycerin (coloured markings more metallic bluish-white than depicted). 7. C. browni. 8. C. bertae.

FIGURES 15 − 18. Callomyia males, dorsal view. 15. C. argentea. 16. C. arnaudi (abdomen removed). 17. C. bertae. 18. C. browni.

FIGURES 25 − 28. Callomyia females, lateral view. 25. C. arnaudi (pale orange on tergites 1 – 2 mostly obscured in photograph by silver-white dusting). 26. Possible C. bertae female. 27. C. calla. 28. C. corvina.

FIGURES 33 − 36. Callomyia females, dorsal view. 33. C. arnaudi (pale orange on tergites 1 – 2 mostly obscured in photograph by silver-white dusting). 34. Possible C. bertae female. 35. C. calla. 36. C. corvina.

FIGURES 55 − 58. Callomyia male terminalia, lateral view. 55. C. argentea. 56. C. arnaudi. 57. C. bertae. 58. C. browni. Abbreviations: ap prj—apical projection; bv lb—basoventral lobe; cerc—cercus; d lb—dorsal lobe; d o csp—dorsal outer cusp; d prj—dorsal projection; epand—epandrium; epand ap proc—epandrial apical process; epand v lb—epandrial ventral lobe; hypd—hypandrium; hypd proc—hypandrial process; i proc—inner process; o proc—outer process; pgt—postgonite; phphallus; sur—surstylus; v i csp—ventral inner cusp; v prj—ventral projection; v proc—ventral process. Scale bar = 0.1 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).

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.