Megalothoraca undulosa ( Enderlein, 1912 )

Wendt, Lisiane Dilli & Marinoni, Luciane, 2019, Taxonomic revision of Megalothoraca (Diptera: Richardiidae) with description of a new species, synonyms and new combination, Zoologia (e 31456) 36, pp. 1-15 : 11-13

Megalothoraca undulosa ( Enderlein, 1912)

Figs 54–60

Phlebacrocyma undulosa Enderlein, 1912: 105 (fig. 6: wing). Type locality: Ecuador, Santa Inéz. Hennig 1938a: 121 (citation); Aczél

1950: 44 (catalogue).

Megalothoraca undulosa Steyskal, 1968: 5 (catalogue, new combination).

Diagnosis and comments. Megalothoraca undulosa , known from a female specimen, can be distinguished from all other species within the genus by having all tarsi yellowish white, sharply contrasted with the rest of leg, dark brown ( Figs 55, 56). The other species have the legs unicolor. The female sternite 6 and oviscape are yellow, highlighted from remainder of abdomen dark brown, almost black ( Figs 56, 60).

Redescription. Holotype female, MZPW: Measurements (in mm). Body length 10.0; abdomen length 4.6; wing length 9.5 (9.0 according to Enderlein 1912: 106). Head ( Figs 54–56, 58). Head width-to-height ratio 1.34. Frons-to-head ratio 0.35. Frons width-to-height ratio 0.95. Ocelli-distance ratio not measured; anterior ocellus inserted at dorsal third of frons ( Fig. 58). Entirely dark brown, with ocellar triangle and vertex darker. Vertex, in frontal view, straight ( Fig. 58). Frons and face sparsely whitish pollinose. Gena and ventral two-thirds of postcranium, at contour eye and extended to occipital foramen, densely greyish pollinose. Vertex and dorsal third of postcranium with polished appearance. Postcranium sparsely black setulose. Antenna brown. Clypeus, prementum, and palpus dark brown. Orbital and outer vertical area, extended to vertex, slightly tumescent and bright. Ocellar and orbital similar in length and thickness, inserted at same level. Thorax ( Figs 54, 55). Entirely reddish dark brown, with anatergite, mediotergite, and postmetacoxal bridge densely whitish pollinose. Scutum 1.33 times longer than wide. Postpronotal seta absent. Legs ( Figs 55, 56). Reddish dark brown, with tarsomeres yellowish white, sharply contrasting with the rest of leg ( Fig. 56). Fore and mid coxae without anterior spine. Fore femur slightly thicker than mid and hind femora. Left fore femur with two antero- and posteroventral spine-like setae, and right fore femur with two anteroventral and three posteroventral spine-like setae; different in size; occupying apical half of femur. Mid and hind femora with one preapical anteroventral spine like seta; stouter than those on fore femur. Hind coxa bare on posterior surface. Wing ( Fig. 57). Generally hyaline except for the following marks: cell bc yellow, and cell c slightly yellowish; faint and diffuse brownish basal band from vein R 1 at level of costal break, from base of bifurcation between R 2+3 and R 4+5 to vein bm-cu; oblique brownish yellow area in cell r 1 from costal break to medial band; incomplete and very narrow brown medial band, from costal margin to vein CuA 1, passing on spurious vein and vein r-m, with irregular margins; and wider and conspicuous apical brown spot, faint in cell m, with proximal margin irregular. Vein R 2+3 from apical third equally twice conspicuous and shortly sinuous. Spurious vein conspicuous, at same level of vein r-m. Vein M, distally to vein r-m, curved or inclined towards R 4+5. Vein r-m at distal third of cell dm. Halter brown. Abdomen ( Figs 54–56). Entirely reddish dark brown, almost black, except contrasting tergite 6 yellow orange. Tergites brownish setulose, not pollinose. Syntergite 1+2 with two pairs of preapical laterodorsal setae. Sternites 1–4 black, sternite 6 yellow orange. Female terminalia ( Fig. 60). Not dissected. Oviscape yellow, contrasting with remainder of abdomen, dark brown. Tip of cerci rounded.

Male. Unknown.

Type-material examined. Holotype female, MZPW: “ Santa Inéz \(Ecuad. [ Ecuador])\ R. Haensch S.”; “ Type ” [red label]; “ Megalothoraca \undulosum\Type Enderl. ♀ [handwritten]\ Dr. Enderlein det. 1912” ( Fig. 59). The holotype is well preserved, with no damage, except left wing missing ( Figs 54–55); oviscape and cerci exposed ( Fig. 60).

Distribution. Ecuador.