Megalothoraca pterodontida Hendel, 1911

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 : 5-9

Megalothoraca pterodontida Hendel, 1911

Figs 12–19, 23–29

Megalothoraca pterodontida Hendel, 1911a: 395 . Type locality: Peru, Cagon (1000m). Hendel 1911b: 52 (distribution, plate 3, figs 74, 75: habitus, head); Hennig 1938b: 9 (discussion); Aczél 1950: 43 (catalogue); Steyskal 1968: 5 (catalogue).

Megalothoraca hendeli Enderlein, 1912: 104 . Type locality: Ecuador, Santa Jnéz. Hennig 1938a: 121 (material list); Steyskal 1968: 5 (catalogue from Neotropical and United States). New synonymy.

Diagnosis and comments. 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 r 1 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.

Redescription. 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 spinelike 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 R 1, from base of bifurcation between R 2+3 and R 4+5 to vein bm-cu; yellow area in cell r 1 from costal break to proximal margin of medial spot; complete wide brown medial band, from costal vein to posterior margin and continuous in cell r 1, 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 R 2+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 R 4+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.

Type-material examined. 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 .

Aditional material. 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) .

Variation. 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 r 1, with a hyaline area anterior to first sinuosity of vein R 2+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.

Distribution. Ecuador, Peru, and Bolivia (new record).