Orthonevra sternolobosa Miranda, 2024

Miranda, Gil F. G., Soares, Matheus M. M. & Thompson, Christian, 2024, The Neotropical Orthonevra Macquart, 1829 (Diptera: Syrphidae), Zootaxa 5484 (1), pp. 1-78 : 65-67

Orthonevra sternolobosa Miranda sp. nov.

Fig. 36 . Map: Fig. 41

Diagnosis. The three narrow separate vittae on the scutum differentiates this species from most Orthonevra , and the narrow medial vitta on the scutellum separates it from the only other possible similar species, O. thompsoni .

Description. MALE. Head ( Fig. 36a–c ): metallic black, face with slight convexity in profile and ventral 1/4 slightly produced anteriorly as a convexity, strongly regulose except on ventral 1/4, shiny, pile white and not scale-like; with white microtrichose subtriangular macula laterally, positioned immediately ventral do antennal base and separated from it. Antenna dark without metallic reflections, scape paler, post-pedicel slightly pale dorsally; pedicel slightly more than twice the length of the scape, postpedicel oval elongated, slightly longer than the pedicel; pile black. Mala slightly produced apico-ventrally, slightly regulose. Gena shiny, smooth, and with white pile. Frontal triangle mostly smooth, narrowly regulose adjacent to eye margin, bare except for lateral row of white pile adjacent to eye margin. Vertical triangle isosceles triangle-shaped, 3 × longer than eye contiguity, with very short black pile posteriorly; ocellar triangle with a coarse texture, bare. Occiput not visible laterally on dorsal 1/3, homogeneously covered in white microtrichia which extends until dorsal to gena, with one row of very short black pile, pile becomes slightly longer and white on ventral 1/4. Eyes holoptic; with an anterior straight vitta and a sub-anterior and middle slightly sinuous vittae, and a medial fascia distinct until the middle vitta then inconspicuous posterior to that vitta, anterior vitta connects to the ends of the sub-anterior vitta, and dark on ventral 1/2 of posterior margin.

Thorax ( Fig. 36a, b ): metallic black-green, pile white, very short, appressed and sparsely distributed; scutum with three complete separate dark matte vittae with purple reflections, medial one divided in two on anterior apex, with a short narrow lateral vittate macula posterior to transverse sulcus; notopleuron metallic green; remaining of scutum covered by microsculpture; scutellum with medial matte black vitta extending from base to apex, as wide as medial vitta on scutum, pile inconspicuous. Pleuron wholly metallic, smooth on proepimeron, anteroventrally on anepisternum, anteriorly on katepisternum, and on katepimeron, remaining with a coarse texture, with densely distributed white microtrichia on proepisternum, with long white pile on antepronotum, ventral patch on katepisternum, dorsal to the posterior spiracle on the katatergum, and metasternum, with short pile on proepimeron, posterior anepisternum, dorsal patch on katepisternum, and anterior anepimeron, and very short on proepisternum. Dorsal lobe of calypter white with long white marginal pile, ventral lobe similar but pile 3 × longer than dorsal pile. Plumule white. Halter white.

Legs ( Fig. 36b ): metallic black, except yellow on apex of all femora, medial surface and basal 1/2 of protibia, basal 1/2 of mesotibia, basal 1/3 of metatibia, and first three tarsomeres of all legs; pro and metabasitarsomere swollen. Legs covered with short white pile, apex of mesotibia and mesotarsomeres with ventral black setulae, metafemur with ventral surface covered in black setulae.

Wing ( Fig. 36a, b ): with dark short vitta sub-apically on r1, and one vitta sub-apically (from end of R2+3 until posterior end of M1), with four short dark fascia (one in the middle of r2+3, two in the middle of r4+5 and one in the antero-middle of dm), wing apex slightly darker ( Fig. 36a ), stem vein and vein C yellow until crossvein h, mostly microtrichose, bare on small basal area of cell bm and immediately posterior to pseudovein on cup cell; basicosta with dense appressed white pile, with two more prominent setae apically. Alula 2 × the width of cell c.

Abdomen ( Fig. 36a, b ): metallic black-green, terga matte black microtrichose in large medial rectangular area, terminalia wholly metallic, pile sockets as small protuberances, pile black, appressed and very short, white laterally, longer laterally on terga 1 and 2; sterna with white pile; sternum 4 with a large extension on right side that is rounded apically.

Genitalia ( Fig. 36e–h ): surstylus bent in a right angle in the middle, with larger convex baso-dorsal portion and remaining narrower, curving gently on apical 1/2, with pile restricted to dorsal margin and apical 1/2 ( Fig. 36e ); cercus pedunculate, sub-triangular, dorsal corner more acute. Hypandrium sub-rectangular, with large rectangular notch ventrally ( Fig. 36f ); postgonite acute apically and with lateral lamina extending basal-dorsally until apex, fused to hypandrium, with sparse pile apically and a few pile baso-laterally; phallus rounded and with apical acute extension dorsally before the apex, then narrows ventrally to an acute apex, two-pronged medio-ventrally, and with small convexity before the base ( Fig. 36g, h ), basal tubular process short.

FEMALE. No females recorded.

Length. Body 5.20mm (n=1), wing 3.90mm (n=1).

Distribution. Ecuador ( Fig. 41 ).

Altitudinal range. 350m.

Etymology. The specific epithet is a combination derived from the name of the ventral abdominal sclerite [‘sternum’, not the Greek ‘sterno’ (chest)] + the Greek ‘lobos’ (elongated projection or protuberance), and should be treated as an adjective.

Comments. Similar to O. thompsoni sp. nov., see comments on mentioned species.

Type material examined: ECUADOR. Napo, Puerto Misahualli [ca 1°01'56.2"S 77°40'00.6"W], 350m, ??. ii.1983, M. Sharkey (male holotype sternolobosa CNC, JSS 42210) .

Figures

FIGURE 36. Orthonevra sternolobosa sp. nov., male. a–d. Habitus: a. Dorsal. b. Lateral. c. Head, oblique lateral view. d. Abdomen, apex, ventral (genitalia dissected). e–h. Genitalia: e. Epandrium, lateral view. f. Hypandrium, lateral view. g. Hypandrium, lateral view (separated portion). h. Hypandrium, dorsal view (separated portion).Abbreviations: btp: basal tubular process; cerc: cercus; epe: dorsal extension of the epandrium; mfe: middle fascia (eye); mve: middle vitta (eye); mvs: middle vitta (scutum); pg: postgonite; ph: phallus; sav: sub-anterior vitta; scl: scutellum; sur: surstylus; s4 pj: lobular projection of sternum 4; vt: vertical triangle.

FIGURE 41. Distribution map for Orthonevra flukei (sedman, 1964), O. gli sp. nov., O. hypnotica sp. nov., O. nitidula (Curran, 1925), and O. sternolobosa sp. nov.