Megalothoraca species are large (8.0–12.4 mm), with thorax well developed and wing generally longer than body, mid and hind legs long and slender, fore leg generally conspicuously more robust than the others (at least in males), and abdomen oval. Males and females of the included species are unique in lacking spine-like seta on the posteroventral surface of the mid and hind femora; mid femur with only one anteroventral spine-like seta and hind femur with one or two such setae (e.g. Fig. 40); vein R₂₊₃ with two conspicuous curves on apical third (Figs 16, 48, 57), and medial spurious vein short (Fig. 48) (absent in M. flava Enderlein, 1912). Additionally, Megalothoraca males have costal vein conspicuously bowed anteriorly and thickened on medial portion (unmodified in females) (Figs 5, 18, 22), thorax distinctly well developed, setae on the fore and mid coxae stout (Fig. 7) and hind coxa setulose on posterior surface (males of other Richardiinae genera have unmodified costal vein, thorax proportional to the rest of body, unmodified setae on the coxae and hind coxa bare posteriorly – also setulose in Setellia Robineau-Desvoidy, 1830).

The following features of Megalothoraca are shared with Euolena egregia (Gerstaecker, 1860) and species of Bathachophtalmum Hendel, 1911: antero- and posteroventral spine-like setae on fore femur distinctly more numerous and robust than on mid and hind femora; palpus straight. Moreover, species of Megalothoraca are similar to species of Batrachophthalmum, Euolena Loew, 1873 (in part) and Hemixantha Loew, 1873 (in part) in the male terminalia with medial surstylus bilobed at apex, and prensiseta long and inserted preapically on inner margin. Species of Megalothoraca can be easily differentiated by the venation of their wing, thorax well developed, number and thickness of the spine-like setae on mid and hind femora and the presence of setulae on hind coxa, as described above.

The general morphology of Megalothoraca species is quite regular, and the chaetotaxy of the head and especially the thorax is very similar among species. The main characteristics used to distinguish them are the coloration of the body and the wing spots. Since all species were described based on either male or female specimens and no species is known from both sexes, it is not possible to ascertain whether there is sexual dimorphism. Megalothoraca undulosa (Enderlein, 1912), M. ferruginea (Enderlein, 1912), and M. rosalyae sp. nov., (known only from females) lack a lobe on the costal vein; have narrower medial band on the wing, lack anterior spine-like setae on the fore and mid coxae, and their thorax is not as well developed as the thorax of males (M. pterodontida Hendel, 1911 and M. flava).

Megalothoraca ferruginea, M. flava, M. pterodontida, M. rosalyae sp. nov., M. undulosa.

Large species, length 8.2–12.4 mm, commonly with wing longer than body (except in M. ferruginea). Robust body, with general colour yellow (Fig. 5) or reddish brown (Fig. 1) to dark brown (Figs 15, 31, 55), generally non-metallic (except abdomen of M. rosalyae sp. nov., Fig. 30). Head. In dorsal view, slightly narrower than thorax; in frontal view, wider than high. Eye oval, higher than wide. Vertex, in frontal view, straight (Figs 10, 58) or slightly concave (in M. rosalyae sp. nov., Fig. 32). Frons not protruded anteriorly (Figs 9, 19, 34). Ocellar triangle slightly elongate, anterior ocellus inserted on dorsal third or fourth of frons; bright, non-pollinose; convex, contoured by a weak (or stronger in M. rosalyae sp. nov., Figs 32, 33) cavity. Lunule developed. Antennal bases narrowly separated by less than width of scape; scape slightly elongate, almost as long as pedicel. First flagellomere short, at most 2.5 times longer than high. Arista long pubescent. Clypeus well developed. Palpus elongate and linear, base, mid region and apex similar in width (Figs 9, 19). Postcranium, in lateral view, distinctly more developed on ventral two-thirds (Figs 9, 19, 34). Chaetotaxy: setae long and robust; ocellar seta present or absent, orbital and genal setae present, postocellar and postgenal setae absent, outer vertical seta distinctly longer and thicker than inner vertical seta, with alveolus robust and elevated (e.g. Figs 10, 32, 33). Thorax. Especially in males, thorax distinctly well developed and robust (Figs 5, 15). Scutum elongated, gradually widened posteriorly (Figs 3, 13, 37, 54), with two longitudinal and parallel excavated rows, distinctly visible (e.g. Figs 37, 38); setulae sparsely and randomly distributed; weakly pollinose. Scutellum bare. Subscutellum developed. Prosternum, proepimeron, metasternum, and metapleuron bare. Katatergite not setulose, sparsely pollinose. Metathoracic spiracle conspicuously setulose at posterior margin. Postmetacoxal bridge completely sclerotized. Chaetotaxy: very reduced in number, scapular seta, postpronotal seta (except in M. rosalyae sp. nov.), presutural supra-alar, postsutural surpa-alar, intra-alar, proepimeral and katepisternal setae absent; postalar seta present, robust; one dorsocentral and one scutellar setae stout; posterior notopleural seta distinctly stouter and longer than anterior notopleural seta; postalar seta developed, robust. Legs. Elongate. Males with fore (Fig. 7) and mid coxae with one robust anterior apical spine- like seta; females without these spines, only with long setae. Fore femur distinctly (in males, e.g. Figs 5, 15) or slightly (in female, e.g. Figs 39, 40) thicker than mid and hind femora (except in M. ferruginea, similar in thickness), with stout antero- and posteroventral spine- like setae (generally number in left and right femora varies in the same specimen), and more numerous than on mid and hind femora (e.g. Figs 15, 21, 39, 40). Mid and hind legs slender and long (Figs 1, 5, 15, 31). Mid and hind femora sparsely setulose, without posteroventral spine-like seta, mid femur with only one anteroventral spine-like seta (e.g. Fig. 1), and hind femur with one (e.g. Figs 1, 15) or two spine-like setae (e.g. Fig. 40). Hind coxa setulose on posterior surface in males, bare in females. Hind femur without anterodorsal preapical seta. Wing (Figs 16, 18, 22, 48, 57). Long, generally longer than body length, 8.0–13.8 mm. Pattern conspicuous, including basal, medial and apical marks (Fig. 22, each mark indicated). Males with costal vein conspicuously bowed anteriorly and thickened at their medial portion in males, unmodified in females. (Figs 18, 48). Veins bare. Vein R₂₊₃ with two conspicuous or inconspicuous (in M. rosalyae sp. nov., Fig. 48) curves in apical third; with short postmedial spurious vein (absent in M. flava). Veins R₄₊₅ and M converging apically. Vein r-m at distal third to fifth of cell dm. Vein A₁+CuA₂ long, becoming weaker towards margin. Alula and anal lobe well developed. Abdomen. Dark brown (e.g. Figs 20, 54), sometimes with blue sheen (Fig. 30); metallic or non-metallic; smooth, non-punctate, and sparsely pollinose or shining. Shape oval (Fig. 41), syntergite 1+2 with base about one third as wide as apex, and with one or two pairs of preapical laterodorsal setae. Female sternites and terminalia (only female of M. rosalyae sp. nov. was dissected and examined, Figs 42–47, 49–53). Sternite 1 present, setulose (Fig. 42). Sternites 3–5 with short basal apodemes (Figs 44–46). Sternite 6 with basal round hole (Fig. 47). Oviscape short, almost as wide as long (Fig. 53). Eversible membrane poorly sclerotized, with distal half covered with oblique rows of multidentate scales. Tergite and sternite 8 with pair of rows of moderately long setulae in distal two-thirds. Tip of cerci rounded (Figs 49, 50). Two subglobose spermathecae strongly sclerotized. Male sternites and terminalia (only male of M. pterodontida was dissected and observed, Figs 23–29). Sternite 1 present and setulose (Fig. 23). Sternites without basal apodemes (Figs 23–27). Spiracles 6 and 7 present. Epandrium densely setulose, globose (Fig. 28), in lateral view, higher than wide (Fig. 29). Cerci, in lateral view, developed, and globose, densely setulose (Fig. 29). Medial and lateral surstyli similar in length. Lateral surstylus without preapical projection. Medial surstylus with a submedial anterior rounded projection; bilobate apically; with long and acuminate preapical prensiseta.

Colombia, Ecuador, Peru, Bolivia (new record).

Megalothoraca ferruginea, known from a female specimen, is the only species within genus with head and thorax entirely reddish brown, fore and mid coxae, fore and mid femora pale brown (Figs 1, 3) (black in M. undulosa and most other species, except yellow in M. flava).

Holotype female, MZPW: Measurements (in mm): body length 8.20 (8.50 according to Enderlein 1912: 106); wing length 8.00 (8.25 according to Enderlein 1912: 106). Head (Figs 1, 3). Extremely damaged, especially oral region and eyes, ratios not measured, and some parts not observed. Anterior ocellus inserted on posterior third of frons. Reddish brown, except ocellar triangle and vertex brown. Vertex in frontal view straight, not concave. Frons and postcranium sparsely whitish and brownish pollinose, respectively. Antenna brownish. Clypeus, palpus, gena and prementum missing. Ocellar seta slightly longer than orbital seta; inserted at same level. Thorax (Figs 1, 3). Entirely reddish brown, with scutellum, subscutellum and mediotergite slightly darker. Scutum 1.33 times longer than wide. Postpronotal seta absent. Legs (Fig. 1). Fore coxa, trochanter, and femur yellowish orange; mid and hind coxae, trochanters, and femora reddish brown; all tibiae brown; all tarsomeres yellowish. Fore and mid coxae without anterior spine. Femora similar in thickness. Left fore femur with two anteroventral and three posteroventral spine-like setae, and right fore femur with two antero- and posteroventral spine-like setae; setae different in size, occupying apical half of femur. Fore and mid coxae without spine-like seta. Mid and hind femora with one stout preapical anteroventral spine-like seta; stouter than those on fore femur. Hind coxa bare on posterior surface. Wing (Fig. 1). Generally hyaline except for the following marks: cell bc yellowish; faint and diffuse brownish basal band from vein R₁ at level of costal break, passing on base of bifurcation between R₂₊₃ and R₄₊₅, and on vein bm-cu; oblique yellow area in cell r₁, from costal break reaching medial band; incomplete and narrow medial brown band, from costal margin to vein CuA₁, passing on spurious vein and on vein r-m, with irregular margins; and wider and conspicuous apical brown spot, faint in cell m, with proximal margin irregular, almost straight. Vein R₂₊₃ from apical third equally twice sinuous. Spurious vein faint and short, at same level of vein r-m. Vein M, distal to vein r-m, sinuous and curved towards R₄₊₅. Vein r-m at distal third of cell dm length. Halter with stem brownish and knob brown. Abdomen (Figs 1, 3). Entirely dark brown, except contrasting tergite 5 yellowish orange. Tergites brown setulose, very sparsely whitish pollinose. Syntergite 1+2 with two pairs of weak preapical laterodorsal setae. Sternites 1–4 brownish, sternite 5 yellowish orange. Female terminalia (Fig. 4). Not dissected. Oviscape reddish yellow. Tip of cerci rounded.

Male. Unknown.

Holotype female, MZPW: “Santa Inéz\(Ecuad. [Ecuador])\R.Haensch S.”; “Type” [red label]; “Phlebacrocyma\ferrugineum\Type Enderl. ♀ [handwritten]\Dr. Enderlein det. 1912” (Fig. 2). The holotype is pinned, in poor condition (Figs 1, 3): head damaged, with eyes, oral and genal regions, and postcranium ventrally missing, right anterior region of anepisternum and katepisternum with a hole; oviscape, apex of segment 8, and cerci exposed (Fig. 4).

Figures 1–4. 

Megalothoraca ferruginea, holotype female, MZPW: (1) habitus lateral; (2) labels; (3) habitus dorsal; (4) oviscape, part of segment 8, and cerci. Photographs 1 and 3 were provided by Dominika Mierzwa, MZPW. Scale bars: 1, 3, 4 = 0.2 mm, 2 = 0.5 mm.

Ecuador.

Megalothoraca flava, known only from a male, is distinct by having thorax and legs entirely yellow (Fig. 5) (other species are brownish, brown or black), spurious vein in R₂₊₃ absent, and apical brown spot not completely homogenous, with faint hyaline areas on cells r₂₊₃ and r₄₊₅.

Holotype male, MZPW: Measurements (in mm): body length 12.4 (11.75 according to Enderlein 1912: 105); wing length 13.8 (13.5 according to Enderlein 1912: 105). Head (Figs 9–11). Head width-to-height ratio 1.36. Frons-to-head ratio 0.33. Frons width-to-height ratio 0.72. Ocelli-distance ratio 2.14; anterior ocellus inserted at dorsal third of frons (Figs 10, 11). Brown, except prementum, palpus, and posterior half of postcranium yellow (Fig. 9). Vertex, in frontal view, straight. Frons sparsely whitish pollinose. Parafacial, gena and ventral two-thirds of postcranium, especially at contour eye and extending to occipital foramen, densely whitish pollinose. Vertex and dorsal third of postcranium bright. Postcranium sparsely brown setulose. Orbital and outer vertical areas, extended to vertex, slightly tumescent and bright (Fig. 11). Ocellar seta present, longer than orbital seta, and inserted at same level. Thorax (Figs 5, 9). Entirely yellow. Scutum 1.54 times longer than wide. Postpronotal seta absent. Legs (Figs 5, 7–9). Entirely yellow. Fore (Figs 7, 8) and mid coxae with strong anterior spine-like seta. Fore femur thicker than mid and hind femora. Left fore femur with five anteroventral and three posteroventral spine-like setae, and right fore femur with six anteroventral and three posteroventral spine-like setae; setae different in size, occupying apical two-thirds of anteroventral surface and apical third of posteroventral surface of femur. Mid and hind femora with one preapical anteroventral spine-like seta, thinner than those on fore femur. Hind coxa setulose on posterior surface. Wing. Generally hyaline except for the following marks: conspicuous brown basal band from vein R₁, from base of bifurcation between R₂₊₃ and R₄₊₅ to vein bm-cu, distinctly wider in cell r₁; wide medial brown band, from costal vein to vein M, wider at distal margin in cell r₁, but not reach apical spot, and more diffuse in cell dm, with proximal and distal margins irregular; apical brown spot, as wide as medial band, with diffuses hyalines areas in cells r₂₊₃ and r₄₊₅, very faint in cell m, with proximal margin irregular. Vein R₂₊₃ from apical third equally twice conspicuous and shortly sinuous. Spurious vein absent. Vein M, distal to vein r-m, sinuous and curved towards R₄₊₅. Vein r-m at distal fifth of cell dm. Halter pale brown. Abdomen. Brown with metallic reflexes, except basal half of syntergite 1+2 and tergite 5 reddish brown. Tergites sparsely and shortly brownish setulose, non pollinose. Syntergite 1+2 with one pair of robust and one pair of weak preapical laterodorsal setae. Sternites brown. Male terminalia. Not dissected. Epandrium and cerci brownish yellow.

Female. Unknown.

T

Holotype male, MZPW: “Santa Inéz\(Ecuad. [Ecuador])\R.Haensch S.”; “Type” [red label]; “Megalothoraca\flava\Type Enderl. ♂ [handwritten]\Dr. Enderlein det. 1912” (Fig. 6). The holotype is pinned and relatively well preserved, with no part missing; scutum, scutellum, and median region of costal vein of left wing damaged (Fig. 5).

Ecuador.

Figures 5–11. 

Megalothoraca flava, holotype male, MZPW: (5) habitus lateral; (6) label; (7) spine-like seta on fore coxa, in detail; (8) fore femur, anterior view; (9) head and thorax, lateral; (10) head, frontal; (11) head, dorsal. Scale bars = 0.5 mm.

Megalothoraca pterodontida, known from male specimens, is recognized by body mostly dark brown (Figs 13–15); medial band of wing wide, complete from costal to posterior margins, and with a rounded hyaline area anterior to vein M in cell dm, band continuous in cell r₁ reaching apical spot (Figs 13, 16). Here, M. hendeli is recognized as a junior synonym of M. pterodontida since there are no significant differences between the three syntype of M. hendeli (Figs 20–22) from Ecuador and the holotype of M. pterodontida (Figs 12, 14, 16) from Peru.

Holotype male (Figs 12, 14, 16, 18), HNHM: Measurements (in mm): body length 11.5 (12.0 according to Hendel 1911a: 396); abdomen length 4.1 (4.0 according to Hendel 1911a: 396); wing length 13.3 (13.0 according to Hendel 1911a: 396). Head (Fig. 14). Head width-to-height ratio 1.31. Frons-to-head ratio 0.39. Frons width-to-height ratio 0.98. Ocelli-distance ratio 2.8; anterior ocellus inserted at dorsal third of frons. Dark brown, with ocellar triangle and vertex almost black; clypeus and prementum dark brown, palpus brown. Vertex, in frontal view, straight. Frons and face sparsely brownish pollinose. Parafacial, gena, and ventral two-thirds of postcranium, especially at contour eye and extending to occipital foramen, densely whitish pollinose. Vertex and dorsal third of postcranium bright. Postcranium sparsely black setulose. Scape and pedicel dark brown, flagellomere and arista slightly paler. Orbital and outer vertical areas, extended to vertex, slightly tumescent and bright. Ocellar seta present, longer than orbital seta, and inserted at same level. Thorax (Fig. 14). Entirely reddish dark brown, with postpronotal lobe and notopleuron densely whitish pollinose. Scutum 1.41 times longer than wide. Postpronotal seta absent. Legs (Fig. 14). All coxae, trochanters, and fore femur reddish dark brown; all tarsomeres yellow; fore tibia, mid and hind femora at basal fourth and apical fifth, mid and hind tibiae at basal third brownish, remainder of mid and hind femora and of tibiae yellowish orange. Fore and mid coxae with strong anterior spine-like seta. Fore femur distinctly thicker than mid and hind femora. Left fore femur missing, right fore femur with seven anteroventral and four posteroventral spine-like setae; setae distinctly different in size, occupying apical three-fourths of anteroventral surface, and apical two-thirds of posteroventral surface of femur. Mid and hind femora with one preapical spine-like seta, thinner than those on fore femur. Hind coxa setulose on posterior surface. Wing (Figs 16, 18). Generally hyaline except for the following marks: cell bc yellow and cell c slightly yellowish; faint and diffuse brownish basal band from vein R₁, from base of bifurcation between R₂₊₃ and R₄₊₅ to vein bm-cu; yellow area in cell r₁ from costal break to proximal margin of medial spot; complete wide brown medial band, from costal vein to posterior margin and continuous in cell r₁, reaching apical spot, with a rounded hyaline area anterior to vein M in cell dm, with proximal and distal margins irregular; and apical brown spot, as wide as medial band, very faint in cell m, with proximal margin rounded. Vein R₂₊₃ from apical third equally twice conspicuous and shortly sinuous. Spurious vein faint, slightly distal to vein r-m. Vein M, distal to vein r-m, sinuous and curved towards R₄₊₅. Vein r-m at distal fifth of cell dm. Halter pale brown. Abdomen. Tergites brown (Fig. 14), sparsely and shortly brown setulose, sparsely whitish pollinose, denser at basal half of syntergite 1+2. Syntergite 1+2 with one pair of strong preapical laterodorsal setae. Sternites dark brown. Holotype not dissected, sternites visualized from one non-type specimen from Peru (ZMHB) (Figs 23–27): sternites without basal apodeme. Sternite 1 (Fig. 23) relatively well developed, one-third of sternite 2 length, convex at apex and almost straight at apex, densely short setulose, setulae similar in length. Sternite 2 (Fig. 24) divided into two plates, twice longer than wide, densely short setulose, setulae similar in length. Sternite 3 (Fig. 25) sub rectangular, with base straight and narrower, twice longer than wide, setulae different in size. Sternites 4 (Fig. 26) sub quadrate, as long as wide, with long and short setulae. Sternite 5 (Fig. 27) sub rectangular, slightly wider than long, with short setulae medially, and long setulae at margin. Male terminalia. Holotype not dissected, one non-type specimen from Peru (ZMHB) dissected (Figs 28, 29). Epandrium and cerci brown. Spiracles 6 and 7 presents, similarly developed. Epandrium long setulose. Cerci, in lateral view, developed, and globose, densely setulose. Medial and lateral surstyli similar in length. Lateral surstylus lateral flattened laterally, without preapical projection. Medial surstylus distinctly wider at basal half; bilobate apically, preapical lobe smaller than apical lobe. Distiphalus with ribbons weakly setulose, apex without set of setae, and with plate poorly sclerotized.

Female. Unknown.

Megalothoraca pterodontida Hendel, holotype male, HNHM: “Cagon\Peru (1000 m.)”; “Megalothoraca\pterodontida\typus” [handwritten]; “TYPUS” [red label] (Fig. 17) (HNHM). Specimen pinned, and in excellent condition, with no part missing, except by the left fore leg from femur; just a little dust attached at body; wing well stretched (Figs 12 (left side), 14). Megalothoraca hendeli Enderlein, syntypes male, MZPW: “Santa Inéz\(Ecuad. [Ecuador])\R. Haensch S.”; “Type” [red label]; “Megalothoraca\hendeli\Type Enderl. ♂ [handwritten]\Dr. Enderlein det. 1912” (1 male). Specimen well preserved, with no damage, with outstretched wings (Figs 20–22). Comments: In the original description, Enderlein (1912) did not designate any specimen as the holotype, nevertheless this specimen has a red label attached to it, where “Type” is written, and the other two specimens have yellow labels written “co-type”. Revision of this species have never been provided before, then all specimens must be considered syntypes. “Santa Inéz\(Ecuad. [Ecuador])\R. Haensch S S.”; “Co = Typus” [yellow label]; “Megalothoraca\hendeli\Type Enderl. ♂ [handwritten]\Dr. Enderlein det. 1912” (2 males). Both specimens are well preserved, with no damage.

Peru. Cagón, 1000 m [without date and collector], det. Kertész (1 male, HNHM); Department Cuzco, Callanga river, i. Thale des Piñipini [valley], 1900, 1500m, Garlepp col., det. Enderlein (2 males, ZMHB); Bolivia. [La Paz] Mapiri [without date and collector], det. Enderlein, 1919[?] (1 male, ZMHB).

Legs. The specimen from Bolivia has the fore coxa with anterior seta stout, but not as spine-like seta. The number of antero- and posteroventral spine-like on fore femur can moderately vary in greater or lesser number than on the holotype. Wing. Non-type material from Bolivia (Fig. 13) and syntypes of M. hendeli (Fig. 22, indicated with black arrow) have the extension between medial band and apical spot, in cell r₁, with a hyaline area anterior to first sinuosity of vein R₂₊₃. Besides, the material from Bolivia has the medial band in cell dm incomplete, not reaching the vein dm-cu, and hyaline area of cell dm, anteriorly to vein M, opened (Fig. 13, indicated with black arrow). Abdomen. Paler (e.g. non-type from Peru, ZMBH) or darker (e.g. syntypes of M. hendeli) than holotype, with tergites reddish brown to dark brown.

Ecuador, Peru, and Bolivia (new record).

Figures 12–19. 

Megalothoraca pterodontida: (12, 14, 16–18) Holotype male, HNHM; (13, 15, 19) Non-type male, ZMHB. (12) Photo of box with holotype (left) and non-type material (right) male from HNHM; (13) habitus dorsal; (14, 15) habitus lateral; (16) wing; (17) labels; (18) wing, costal vein in detail; (19) head, lateral. Scale bars: 14–17 = 2.0 mm, 19 = 1.0 mm.

Figures 20–22. 

Megalothoraca hendeli, syntype male, MZPW, new synonymy of M. pterodontida: (20) habitus dorsal; (21) habitus ventral; (22) wing. Photographs 20 and 21 were provided by Dominika Mierzwa, MZPW. Abbreviations: A. Apical spot; B. Basal band; M. Medial band. Scale bars = 2.0 mm.

Figures 23–29. 

Megalothoraca pterodontida, non type male, ZMHB, drawing lines: (23–27) sternites, ventral: (23) sternite 1; (24) sternite 2; (25) sternite 3; (26) sternite 4; (27) sternite 5; (28, 29) epandrium, medial and lateral surstyli, and cerci; (28) posterior view; (29) lateral view. Scale bars = 0.2 mm.

Megalothoraca rosalyae sp. nov., known from a female specimen, can be recognized by general dark brown (almost black) color of the thorax (Figs 31, 37), except postpronotal lobe paler, reddish brown (Fig. 38), and abdomen dark blue, distinctly metallic (Fig. 30), ocellar seta absent and postpronotal seta present; two anterodorsal spine-like setae on mid femur (Fig. 40), and sinuosity of vein R₂₊₃ smother, asymmetrically twice sinuous (Fig. 48).

Holotype female, CEUA: Measurements (in mm): body length 8.57; wing length 8.80; abdomen length 3.47. Head (Figs 32–36). Head width-to-height ratio 1.33. Frons-to-head ratio 0.35. Frons width-to-height ratio 0.90. Ocelli-distance ratio 1.81; anterior ocellus inserted at dorsal fourth of frons (Figs 33, 36). Frons dark brown on dorsal third and with polished appearance, reddish brown on ventral two-thirds and velvety appearance (Figs 32, 22); densely whitish pollinose. Lunule brown (Fig. 32). Face, gena, and postcranium dark brown, almost black (Figs 32, 34, 36). Parafacial reddish brown (Fig. 32). Vertex, in frontal view, concave (Fig. 32). Face sparsely whitish pollinose. Gena and postcranium on ventral two-thirds, especially at contour eye and extending to occipital foramen, densely whitish pollinose (Figs 34, 36). Vertex and postcranium on dorsal third bright. Postcranium sparsely black setulose. Antenna dark brown, except base of flagellomere slightly paler. Clypeus, palpus and prementum dark brown. Orbital and outer vertical area extended to vertex, distinctly tumescent and bright (Figs 32, 33). Orbital and outer vertical setae missing, visible only alveoli, distinctly marked (Figs 33, 35). Ocellar seta absent. Thorax (Figs 37, 38). Dark brown, almost black, except postpronotal lobe brown, with anatergite, mediotergite, and postmetacoxal bridge densely whitish pollinose. Scutum 1.33 times longer than wide. Postpronotal seta present (missing, visible only alveolus). Legs (Figs 39, 40). Entirely dark brown, with hind tarsomeres slightly paler. Fore and mid coxae without anterior spine-like seta. Fore femur slightly thicker than mid and hind femora. Left fore femur with one preapical antero- and posteroventral spine-like seta, and right fore femur with one preapical anteroventral and two posteroventral, on apical third, spine-like setae; setae similar in size. Mid and hind femora with one and two anteroventral preapical spine-like setae, respectively; similar in thickness with those on fore femur. Hind coxa bare on posterior surface. Wing (Fig. 48). Generally hyaline except for the following marks: cell bc brownish; basal band discontinuous in an irregular brown spot in cell r₁ between costal break and base of bifurcation between R₂₊₃ and R₄₊₅, and faint brown spot on vein bm-cu; complete narrow brown medial band, from costal to posterior margin of wing, wider in cell r₁, with irregular margins; wider brown apical spot, faint in cell m, with proximal margin irregular. Vein R₂₊₃ twice asymmetric and inconspicuously sinuous, proximal curve beginning from medial region, and distal curve shorter and more conspicuous. Spurious vein conspicuous, at same level of vein r-m. Vein M, distally to vein r-m, almost straight and inclined towards R₄₊₅. Vein r-m at distal two-fifths of cell dm. Halter whitish. Abdomen (Figs 30, 41–47). Tergites dark blue, with metallic blue reflexes (Fig. 30); sparsely and shortly whitish setulose, not pollinose, except basal third of syntergite 1+2 distinctly whitish pollinose (Fig. 41). Sternites dark brown (brown when dissected), densely setulose (Figs 42–47), sternites 3–5 with basal apodeme (Figs 44–46). Sternite 1 (Fig. 42) relatively well developed, one-third of sternite 2 size, semicircular, densely short setulose, setulae similar in length. Sternite 2 (Fig. 43) divided into two plates, twice longer than wide, densely short setulose, setulae similar in length. Sternite 3 (Fig. 44) subrectangular, twice longer than wide, with long and short setulae. Sternites 4 (Fig. 45) and 5 (Fig. 46) spatulate, as long as wide (at largest width) (Fig. 45), and wider than long (Fig. 46), respectively, with long and short setulae. Female terminalia (Figs 49–53). Oviscape dark brown, with paler central apical mark (Fig. 53). Taenia brownish, slightly less sclerotized than oviscape; two-fifths oviscape length (Fig. 53). Eversible membrane as long as taenia, with denticles on basal half. Sternite and tergite 8 ciliated, except basally, similar in length (Figs 49, 51). Sternite 8 0.84 mm long. Tip of cerci rounded and base slightly concave centrally, vaguely resembling a heart shape (Figs 49, 50). Setae on cercus (Fig. 50): two long basal setae, one ventral and one more lateral dorsal; ventrally two very short postmedial setae; two long preapical setae, more apical one shorter; and very short and thin setulae distributed on cerci (Fig. 50, visible only alveoli of these setulae). Two spherical and strongly sclerotized spermathecae, one slightly larger than other (Fig. 52).

Male. Unknown.

Holotype female, CEUA: “Colombia, Antioquia, Bolivar\Vereda la Mina, Bosques\cercanos a la mina, 1900m.\5.80358ºN 76.0691ºW, Manual\24.iv.2011. E. Garcias col. CEUA”; “Holotype (♀) CEUA\Megalothoraca rosalyae\Wendt & Marinoni, 201_” [red label] (CEUA). Specimen pinned, in excellent condition, with no damage (Figs 30, 31); almost setae on head and thorax missing (visible only alveoli); left wing detached and mounted between cover slips; abdomen dissected and stored in plastic microvial with glycerine.

Colombia.

The epithet honors the Brazilian dipterist Rosaly Ale-Rocha, in recognition of her extensive contributions to the taxonomy of Diptera.

Figures 30–40. 

Megalothoraca rosalyae sp. nov., holotype female, CEUA: (30) habitus dorsal; (31) habitus lateral; (32–36) head: (32) frontal; (33) laterofrontal, dorsal region, in detail; (34) lateral; (35) dorsal, ocellar triangle, in detail; (36) dorsal, general view; (37) thorax, dorsal; (38) thorax, lateral; (39) fore femur, posterior view; (40) mid and hind femur, anterior view. Scale bars: 30, 31 = 2.0 mm, 32, 34, 36–40 = 1.0 mm.

Figures 41–53. 

Megalothoraca rosalyae sp. nov., holotype female, CEUA: (41) Line drawing of abdomen, dorsal; (42–47) sternites, ventral: (42) sternite 1; (43) sternite 2; (44) sternite 3; (45) sternite 4; (46) sternite 5; (47) sternite 6; (48) wing (spurious vein in detail, left side); (49–51) cerci and segment 8: (49) general view, ventral; (50) in detail, ventral; (51) general view, lateral; (52) spermatechae; (53) oviscape, taenia, eversible membrane, segment 8, and cerci. Scale bars: 41, 48, 53 = 1.0 mm, 42–47, 49, 51, 52 = 0.2 mm.

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).

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 R₁ at level of costal break, from base of bifurcation between R₂₊₃ and R₄₊₅ to vein bm-cu; oblique brownish yellow area in cell r₁ from costal break to medial band; incomplete and very narrow brown medial band, from costal margin to vein CuA₁, 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 R₂₊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 R₄₊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.

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).

Ecuador.

Figures 54–60. 

Megalothoraca undulosa, holotype female, MZPW: (54) habitus dorsal; (55) habitus lateral; (56) habitus ventral; (57) wing; (58) head, frontal; (59) label; (60) oviscape. Photographs 54 to 56 provided by Dominika Mierzwa, MZPW. Scales bar: 54–57 = 2.0 mm, 59 = 5.0 mm.

Megalothoraca teleopsis Hennig, holotype male, SDEI: “S. Antonio\Columbia”; “coll. [collector] Fassl” [handwritten]; “Holotypus” [red label]; “HOLOTYPUS” [red label] (Fig. 62). The holotype is pinned, in poor condition, very damaged: eyes, flagellomeres, left fore and mid legs, right hind leg, and left wing missing; head and abdomen glued to the thorax (Figs 61, 63); apex of abdomen damaged (Fig. 61). Bratrachophtalmum quimbaya Carvalho, Wolff & Wendt, holotype male, CEUA: ♂ “COLOMBIA. Risaralda. Pereira./Santuario de Flora y Fauna Otún-/Quimbaya Trampa VSR bosque/Mayo 2001 Grupo de Entomologia/CEUA 12796” (CEUA). The holotype is pinned, and in excellent condition, with no damage. Paratype male, DZUP: ♂ labelled identical to the holotype (DZUP).

Colombia.

Synonyms and new combinations

Megalothoraca teleopsis was described by Hennig (1938b) as the first and only species within the genus with stalked eyes, and Carvalho et al. (2011) described an enigmatic stalk-eyed fly from Colombia – Batrachophthalmum quimbaya. Upon comparing the types of both species, we did not find any morphological differences to distinguish them (Figs 1–3 and see Carvalho et al. 2011: figs 6–10). Therefore, B. quimbaya is herein considered a junior synonymy of M. teleopsis. Additionally, although M. teleopsis has features similar to other species of Megalothoraca (thorax developed, setae on fore femur distinctly stouter than on mid and hind femora, mid and hind legs longer and more slender than fore leg), those features are also common among species of Batrachophthalmum and Euolena (in part).

Megalothoraca teleopsis and Batrachophthalmum rufiventre Hendel, 1911 type species of the genus, share several characteristics, then here we transfer M. teleopsis to Batrachophthalmum, based on: as well B. rufiventre, M. teleopsis has the mid and hind femora with rows of weak spine-like setae on antero- and posterodorsal surfaces, and contrasting with the mid and hind femora of the other species of Megalothoraca, which have one (sometimes two) stout spines only on anteroventral surface. Also, M. teleopsis has vein R₂₊₃ without spurious vein and sinuous just before margin (Fig. 64), as in B. rufiventre (see Carvalho et al. 2011: figs 1, 2), and differing from species of Megalothoraca which have vein R₂₊₃ with two conspicuous preapical curves and a small postmedial spurious vein (e.g. Figs 16, 22, 57).

Batrachophthalmum species are recognized by the following combination of characteristics: head wider than high, especially in males; arista densely pubescent; all femora with spine-like setae on antero- and posteroventral; setae on fore femur distinctly more robust than those on mid and hind femora; hind coxa bare on posterior surface; costal vein of male with no modification, R₂₊₃ without spurious vein, with only one tender sinuosity on apical third sinuous just before margin; r-m at distal three-fourths of cell dm.

Figures 61–65. 

(61–64) Batrachophthalmum teleopsis, holotype male, SDEI: (61) habitus lateral; (62) labels; (63) habitus frontal; (64) wing; (65) Batrachophthalmum quimbaya (= B. teleopsis), paratype male, DZUP, hind leg, anterior view. Scale bars: 61, 63–65 = 1.0 mm, 62 = 0.5 mm.