Sisyromyia thomsoni Evenhuis & Greathead, 1999

Li, Xuankun & Yeates, David K., 2019, Revision of the Australian bee fly genus Sisyromyia White, 1916 (Bombyliidae, Bombyliinae, Acrophthalmydini), Zootaxa 4711 (2), pp. 201-244 : 229-232

9. Sisyromyia thomsoni Evenhuis & Greathead, 1999

( Figs 20 , 21 , 29a )

Bombylius scutellaris Thomson, 1869: 488 . Type-locality: Australia (NSW); holotype, NHRS. [Preoccupied by Wiedemann, 1828.]

Sisyromyia thomsoni Evenhuis & Greathead, 1999: 170 (new replacement name for Bombylius scutellaris Thomson, 1869 ).

Other specimen examined. Australia, ACT, ♀ Gibraltar Creek , 18 Oct 1967, Z Liepa. NSW, ♂ Killara, 6 Aug 1934, D Waterhouse. ♂ Narrabeen, 10 Aug 1935, MF Day. ♂ Mungo, Myall Lakes, 23 Aug 1934, D Waterhouse. ♀ (2) Medlow, 4 Oct 1926. ♂ Sydney, Feb 1952. Qld., ♀ -28.828 151.978, North slopes, Girraween NP, 14 Aug 2009, MG Jefferies ( QM) .

Diagnosis. Medium-sized fly, body with mostly brownish hairs. Wing membrane dark brown on anterior half and clear on posterior half. Male eyes holoptic. Gap between inner apices of gonocoxites narrow. Inner apex of gonocoxite short.

Redescription. Male. Body length 10.3–11.5 mm, wing length 9.9–10.4 mm.

Head. Head about 2.2 x wider than long, mostly blackish with thick pale pruinescence and covered in admixed white to black hairs and scales. Eyes holoptic. Frons short, 1.8 x length of ocellar tubercle, upper narrow and black; lower half triangular, 0.8 x length of upper half, with thick pale pruinescence and pale yellow to brown scales admixed with few brown hairs. Ocellar tubercle slightly raised, blackish brown to black with thick grey pruinescence, with long black hairs. Face with thick pale pruinescence and golden scales admixed with some long black hairs; parafacial area with long white scales admixed with long yellow hairs. Gena with thick pale pruinescence and long white to yellow hairs. Clypeus with thick pale pruinescence and otherwise bare. Occiput with thick pale pruinescence and white to brown scales. Posterior eye margin slightly convex. Antennal scape and pedicel brown with thick pale pruinescence, scape with long black hairs admixed with few golden hairs laterally, pedicel with short black hairs; flagellum black without pruinescence, subapex with 3–5 long hairs. Scape 2.9 x as long as wide, and 2.5 x as long as pedicel, uniform from base to apex. Pedicel 1.3 x as long as wide. Flagellum 8.0 x as long as wide, 1.6 x as long as scape + pedicel, 2.4 x as long as scape, conical and slightly laterally compressed, one-segmented with apical stylus ( Fig. 20c ). Palpus long, just extending beyond oral cavity, dark yellow with pale yellow hairs, except apex with black hairs, one-segmented, without palpal pit. Mouthparts slender, 3.1 x as long as eye length, 2.1 x as long as head length, labellum thin and filiform ( Fig. 20h ).

Thorax. Integumental colour of scutum mostly black with thick brown pruinescence except two median wide white pruinescent stripes, postalar callus brown with sparse pale pruinescence. Scutum covered with short pale yellow to brown hairs, admixed with few short black hairs, lateral stripe consisting of short white to pale yellow scales, and posteriorly with few short white scales. Six brownish yellow notopleural setae present. Scutellum black with sparse pale pruinescence, anterior margin with an indistinct band consisting of short white scales, posterior margin with long brown hairs admixed with some long black hairs. Pleura black with thick pale pruinescence, mostly covered in long pale yellow hairs, except dorsal half of anepisternum with brown hairs, anepimeron, meron, laterotergite and mediotergite bare.

Legs. Legs mostly brown, except tibiae yellow. Femora with long brown hairs. Mid femur with one anterior bristle on apical half; hind femur with one row of anteroventral bristles and one row of posteroventral bristles, more separate bristles on apical half. Bristles and other hairs on legs brown. Fore tibia 2.0 x longer than fore basitarsus, mid tibia 2.3 x longer than mid basitarsus, hind tibia 2.2 x longer than hind basitarsus.

Wings. Wing membrane dark brown on anterior half and clear on posterior half, darker towards wing base. Cell r 5 open, M 1 close to R 5; cell br nearly as long as cell bm, crossvein r-m arising from base of cell dm; crossvein m-m nearly as long as crossvein r-m; cell cup open ( Fig. 20d ). Haltere stem brown, and knob yellow.

Abdomen. Integumental colour of tergites black mostly with sparse pale pruinescence. Tergite 1 with thick pale pruinescence and dense brown hairs; tergites 2–7 with yellow to brown hairs, more pale hairs on anterior half, posterior half admixed with some black hairs, hairs darker and denser laterally, and with median stripe consisting of dense, decumbent short white scales; tergites 3–7 with pale yellow to white scales on lateral side, best viewed from posterodorsal side. Sternites black except posterior margin yellow, with thick pale pruinescence, covered with pale yellow to brown hairs, hairs darker laterally. Genitalia. Epandrium anterior margin slightly concave, posterior margin slightly convex ( Fig. 21d ). Lateral margin of gonocoxite nearly straight ( Figs 21 ab); lateral ejaculatory process wide; inner apex of gonocoxite short and acute, outer apex of gonocoxite long and sharp; gap between inner apices of gonocoxites narrow; phallus shorter than gonocoxite ( Fig. 21c ).

Female. Body length 7.4–11.1 mm, wing length 9.1–12.2 mm. Very similar to male, except frons black with thick pale pruinescence, 3.4 x as wide as ocellar tubercle, frons with short golden scales admixed with long black hairs ( Fig. 20l ). Body hairs paler than male. Around 30 acanthophorite spines present on each side of tergite 9+10 ( Fig. 21g ).

Remarks. Bombylius scutellaris was first considered a synonym of Sisyromyia decorata by Roberts (1928: 429). However, this synonymy was not followed by Evenhuis & Greathead (1999). We compared the specimens from NSW and WA, and agree with Evenhuis & Greathead’s decision (also see ‘4. Sisyromyia decorata ( Walker, 1849) ’ earlier). Therefore, Sisyromyia thomsoni is recognised as a valid species in the present revision.

Sisyromyia thomsoni is similar to Sisyromyia decorata , but differs as follows: male eyes holoptic; gap between inner apices of gonocoxites narrow; inner apex of gonocoxite short.

Distribution. Australia (ACT, NSW, Qld.).

Figures

FIGURE 20. Sisyromyia thomsoni Evenhuis & Greathead, 1999. External (a–i (♂); j–o (♀)): (a, j) dorsal; (b, k) lateral; (c) antenna, lateral; (d) wing; (e, l) head, dorsal; (f, m) head, frontal; (g, n) head, profile; (h, o) head, lateral; (i) abdomen, dorsal. Scale bars = 1 mm (a, b, d–o); = 0.1 mm (c).

FIGURE 21. Sisyromyia thomsoni Evenhuis & Greathead, 1999. Genitalia (a–e (♂); f, g (♀)): (a) genitalic capsule, dorsal; (b) genitalic capsule, ventral; (c) genitalic capsule, lateral; (d) epandrium, dorsal; (e) epandrium, lateral; (f) sternite 8, ventral; (g) genitalia and spermathecae. Scale bars = 0.1 mm.

FIGURE 29. Sisyromyia females visiting Leucopogon sp. flowers from WA. (a) Sisyromyia thomsoni Evenhuis & Greathead; (b) Sisyromyia vittata sp. nov. Photograph by Jean and Fred Hort.