Hybobathus persimilis ( Curran, 1930 ) Miranda, 2017

Miranda, Gil Felipe Gonçalves, 2017, Revision of the Hybobathus arx and Pelecinobaccha summa species groups (Diptera: Syrphidae), Zootaxa 4338 (1), pp. 1-43 : 17-20

Hybobathus persimilis ( Curran, 1930) comb. nov.

Fig. 6

Baccha persimilis Curran, 1930: 2 . Type locality: Brazil, Mato Grosso, Chapada. Lectotype male (AMNH). Hull, 1949: 96 (citation), 122 (key), 210 (fig. 93, abdomen); Thompson, 1974: 4 (lectotype designation).

Ocyptamus persimilis . Thompson et al. 1976: 24 (catalog citation).

Description. MALE ( Figs 6a, b, d & g–j ). Head. Yellow; face with sparse white microtrichosity, with black pile, absent medially. Gena with white pile. Lunule with central black marking and very narrow dorsal black vitta from central marking to the crease ventral to the frontal triangle. Frontal triangle with very small dark brown spot, and with black pile. Base of antenna protuberant. Vertical triangle with shiny white microtrichia, except on ocellar triangle, which is dull black, with several irregular rows of black pile, white posteriorly, ending dorsal to the anterior ocellus; ocellar triangle separate by its length from the posterior margin of the head. Eye contiguity shorter than the vertical triangle length. Eye with weak sub-triangular indentation on posterior margin positioned around the level of antennal insertions. Antenna with black pile; postpedicel with darkened dorsal 2/3. Occiput homogeneously covered by white microtrichia, with white pile, dorsal 1/3 with one row of flattened pile, ventral 2/ 3 with 2–3 rows, posterior row with longer and flattened pile. Thorax ( Figs 6a, b & d ). Scutum black, but yellow laterally from postpronotum to scutellum; mostly covered by white microtrichia, denser medially, except for medial pair of short vittate and sub-lateral pair of long vittate areas without microtrichia; pile long, white and erect, with anterior continuous row of longer pile densely arranged. Scutellum yellow, with slightly darker medial region, with long, black and erect pile; subscutellar fringe with long and white pile. Pleuron yellow, dark on anterior 1/3 of posterior anepisternum, ventral 1/2 of katepisternum, meron and postero-ventral margin of katatergum; white pilose (proepimeron, anterior and posterior anepisternum, dorsal and ventral katepisternum, with pile patches joining anteriorly, anterior anepimeron, katepimeron and metaepisternum), katatergum with long microtrichia giving it a ‘velvet’ appearance. Plumula white and of regular length. Calypter yellow, pile long and pale on margin of the ventral lobe and very short and dark on margin the dorsal lobe. Halter yellow, capitulum orange. Wing ( Figs 6a & b ). Hyaline, very slightly yellowish on bc, c, basal 1/2 of r1, and base of r; entirely microtrichose; alula hyaline, wide and convex, basally 1.5 times to apically 4 times as broad as c cell, entirely microtrichose. Legs ( Fig. 6b ). Pro- and mesolegs yellow with yellow pile, longer on postero basal margin of the femora, and dark anteriorly on mesocoxa and on several rows of longer pile on postero-apical 1/2 of the mesofemur. Metalegs mostly yellow, except light brown on most of metafemur and dark brown on a sub-apical small area, and metatibia dark brown except for base and apex, with mostly yellow pile but dark on a few pile of the metacoxa and on darker regions; metabasitarsomere 1/2 the length of the metatibia. Abdomen ( Fig. 6a ). Dark brown and petiolate, twice the length of the thorax. Tergite 1 yellow, except for dark brown apical margin, with long, yellow and erect pile, except a few dark ones on dark areas and mostly bare dorso-medially; sternite 1 yellow with long, yellow and erect pile. Tergite 2 rectangular and long, slightly compressed medially, twice longer than smallest width, with pair of fasciate yellow markings sub-apically; with long, yellow and erect pile, except black apically; sternite 2 as 1. Tergite 3 trapezoidal short, shorter than apical width and apical margin 1.5 times wider than basal margin, with a pair of central yellow vittae that reach the apical margin and a sub-lateral pair of short vittate markings that join to the central pair basally; pile long, black and appressed; sternite 3 mostly dark brown, except for yellow base, with long, yellow and erect pile. Tergite 4 rectangular, slightly wider than long; remaining characteristics as on 3; sternite 4 dark brown with long, black and appressed pile. Tergite 5 rectangular short, wider than long; remaining characteristics as on 4. Genitalia ( Figs 6g –j ). Cercus with 4 rows of pile; surstylus oval and elongated, in lateral and ventral views, with pile only on dorso-basal 1/2, with ventral setulae on apical 1/3 and a few on apical 1/2 of the ventro-lateral margin; subepandrial sclerite sub-rectangular, wider than long, slightly compressing on apical 1/2, apical indentation very short and with medial convexity between the connections to the surstyli, with quadrate basal indentation, forming a pair of truncated baso-lateral extremities. Hypandrium quadrate, in ventral view, slightly narrowing on apical 1/2, ventral notch extending on apical 3/4, with concave basal margin, and lateral indentations weak and positioned closer to base than middle; phallapodeme weakly sclerotized on basal 1/4; basiphallus drop-shaped, in ventral view, apical 1/2 much higher than the tapering basal 1/2, distiphallus with baso-lateral extensions that do not join ventrally, anterior sclerotized surface almost straight, tapering apically, with wider membranous area on apex with ventral pile, ventral surface completely membranous; postgonite large, with anterior margin presenting a distinct convexity on ventral 1/2 and straight dorsal 1/2, dorsal extremity with short acute projection, and ventral extremity with long acute projection, with pile on basal 4/5 of the ventral margin.

FEMALE ( Figs 6c, e, f & k–n ). Like male except for the following characters: Face with a narrow medial dark vitta and a pair of faint sub-medial dark vittae, vittae start from antennal insertions and end slightly ventral to the facial tubercle. Lunule dark brown dorsal to central marking until the crease. Frons with widening central dark vitta, with latero-apical extremities slightly extending, and connected to lunule color by narrow central dark vitta; with white microtrichosity concentrated medially from anteriorly to the ocellar triangle until the crease; bare on microtrichose area. Ocellar triangle separated by 1.75 times its length from the posterior margin of the head. Vertex covered in white microtrichosity, differently oriented postero-medially to ocellar triangle, and absent on ocellar triangle, which is dull black. Postpedicel dark on apico-dorsal 1/2. Dorsal occiput with a few black pile intermixed. Overall pile of scutum shorter, pile mostly black, except laterally and on anterior row, and anterior row interrupted medially. Overall pile on scutellum shorter; subscutellar fringe with very short, black and sparse pile. Wing dark yellow, paler on apical 1/3 of r1, apical 1/2 of r2+3, apical 2/3 of r4+5, anterior 2/3 of bm, most of dm, posteriorly on cup, and most of cua1. Abdomen 2.5 times longer than thorax. Tergite 1 dark brown on apical 1/2, with appressed, and mostly black, pile. Tergite 2 pile short, black and appressed; sternite 2 pile appressed. Tergite 3 central vittae slightly curving towards sides, slightly widening towards apex, and ending before the apex, sublateral markings longer and narrowing more apically, pile shorter; sternite 3 pile black and appressed. Tergite 4 as 3, except central vittae reach margin. Tergite 6 is 1/3 of the length of 5 and wholly dark. Genitalia ( Figs 6k–n ). Tergite 7 as four narrow sclerotized strips, the lateral ones joining basally to the medial ones, pilose on apical 1/2 and apico-lateral 2/3; sternite 7 membranous, wholly pilose, with some longer pile apico-laterally. Tergite 8 as a basal sclerotized fascia with long medial extension ending as a triangular apex, with a triangular indentation on basal margin, pilose on apical 1/2; sternite 8 with long, narrow, lateral sclerotizations, wholly pilose. Epiproct as pair of narrow, sclerotized, short strips, with very few pile apically, apodeme as long as the epiproct; hypoproct triangular and membranous, pilose. Cerci membranous, pilose, positioned apically and on a slightly perpendicular plane to the epiproct. Spermathecae not observed.

Variation. The male from Mexico (USNMENT01243063) has a larger central marking on the frontal triangle, paler metafemur, wider markings and longer sub-lateral vittae on the abdomen, and dark brown sternite 2.

Length. Body: male 11.4–13.4mm (n = 2), female 10.9mm; wing: male 9.5–10.3mm, female 9.1mm.

Distribution. Brazil (Distrito Federal, Mato Grosso), Mexico (Chiapas).

Prey records. This species has been reported preying on Tuthillia cognata Hodkinson, Brown & Burckhardt, 1986 ( Hemiptera , Psyllidae ) ( Pérez & Iannacone, 2009).

Comments. This species was a manuscript name of S. W. Williston that was first used by Curran (1930) ( Thompson 1974). This is the first time this species is formally described. The male description is based on the lectotype, except for the genitalia description that is based on a specimen from Mexico (USNMENT01243064). The male from this species can be distinguished from other species from this group by the scutum with long, erect, white pile (except H. obsoletus ), the wing mostly hyaline posteriorly, and the shorter abdominal segment 2. Furthermore, it can be distinguished from the closely related H. arx by the surstylus with pile only on the basodorsal 1/2, subepandrial sclerite with medial-apical convexity, and the ventral concavity on the anterior margin of the postgonite.

Even though the female assigned to this species has a distinct dark medial vitta on the face, mostly black pile on the scutum, and darker wings, it was the only specimen that had a similar short abdominal segment 2 and distribution, in the Brazilian ‘Cerrado’, as the lectotype. The facial coloration seems to vary inside the Hybobathus arx species group like in H. arx and H. obsoletus . Furthermore, the abdominal tergite 6 is completely devoid of markings, a distinct character from females from the related H. arx species. Thus, the distinguishing features of the female from the male are here considered as sexual dimorphism. The females can be further distinguished from the females of H. arx by the mostly dark tergite 6 and sternite 8 with heavier lateral sclerotized margins. However, this association should be considered as a tentative one until new specimens are collected and/or a molecular assessment can be performed.

Examined material. BRAZIL. [Mato Grosso], Chapada [1 ♂ lectotype Baccha persimilis , AMNH] . Distrito Federal, Planaltina , 24.ix–6.x.1985, leg. S.E. Miller (USNMENT01288163) [1 ♀, USNM] . MEXICO . Chiapas, Motozintla , 5.x.1976, leg. D.E. & J.A. Breedlove (USNMENT01243063) [1 ♂, USNM] .

Figures

FIGURE 6. Hybobathus persimilis (Curran, 1930) comb. nov. a. Male, holotype, habitus, dorsal (photo courtesy AMNH). b. Male, habitus, lateral. c. Female, habitus, dorsal. d. Male, scutum, lateral. e. Female, head, frontal. f. Female, abdominal segments 5 and 6, dorsal. g – j. Male genitalia: g. Epandrium, lateral. h. Hypandrium, lateral. i. Hypandrium, ventral. j. Epandrium, ventral. k – n. Female genitalia: k. abdominal segment 7, dorsal. l. abdominal segment 7, lateral. m. abdominal segment 8 and proctiger, lateral. n. abdominal segment 8 and proctiger, dorsal. bph: Basiphallus, conc: Concavity on the apical margin of the postgonite, conv: Apico-medial convexity of the subepandrial sclerite, crc: Cercus, drk: Dark marking on the face, ep: Epiproct, ind: Ventro-lateral indentation of the hypandrium, pgt: Postgonite, sscl: Subepandrial sclerite, s 2: abdominal segment 2, srs: Surstylus, tg 6: abdominal tergite 6, trvs: Transverse suture.