Macrostomus montanus Rafael & Marques 2019, sp. nov.
Creators: name: Rafael, José Albertino
name: Marques, Dayse Willkenia Almeida
Publisher: name: Zenodo
Year: 2019
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Diptera
Empididae
Macrostomus
Macrostomus montanus

description: Macrostomus montanus sp. nov.
(Figs 6 A–N, 7A–E)
urn:lsid:zoobank.org:act: 9EB41EDC-134E-4C71-802C-6A6E9ACDB185
Diagnosis. Gena and postgena with setae somewhat stout; wing almost entirely hyaline, slightly brown infuscate at apex of costal cell, pterostigma and apex of cell r 2+3; last section of vein M 4 longer than vein dm-m; cell dm somewhat acute; tergite 8 short with distal sinus; epandrium with posterodorsal lobe longer than anterodorsal lobe, with longer setae more concentrated posteriorly on posterodorsal lobe; posterior cercus inwardly curved, trifid, apparently glabrous; hypandrium well sclerotized, slightly wider medially at level of posterior longer setae.
Description. Holotype ♂ (Fig. 6A). Body length 3.5 mm; wing length 3.2 mm. Head dichoptic. Frons shiny black, slightly wider than anterior ocellus width. Two pairs of proclinate ocellar setae, posterior pair weaker. Face narrower than frons width, same as anterior ocellus width. Postcranium shiny black, entirely and sparsely gray pruinose. Inner vertical seta stouter than outer vertical seta, latter subequal in length to uniseriate postocular row of setae; 2–3 pairs of dorsal occipital setae. Gena with 3 setae and postgena with 2 somewhat stout setae. Antenna velvety black with postpedicel short pubescent. Proboscis shiny, brown basally, yellow apically. Palpus black. Thorax shiny black, gray pruinose. Thoracic chaetotaxy: 4 antepronotals; 1 postpronotal stout and 2 minutes; 4 dorsocentrals (right row with 5); 1 presutural supra-alar; 1 postsutural supra-alar; 1 postalar stout, 1 minute; 4 proepisternals weak; 1 notopleural stout and 1 weak; 2 pairs of scutellars, outer pair slightly weaker; 7 laterotergitals. Legs yellow with distal 3/4 of fore tibia, apex of mid femur, entire mid tibia, distal half of hind femur, entire hind tibia, all tarsi brown to black. Legs longer setae: fore tibia with 1 sub-basal and 1 median anterodorsal slightly longer; mid femur with 1 subapical anterior slightly longer; mid tibia with alternating anterodorsal and posterodorsal equally spaced; hind femur with 1 anterior subapical; hind tibia (Fig. 6A) with 4–5 slender dorsal and hind tarsomere 1 with 1 longer median dorsal seta. Wing (Fig. 6A) almost entirely hyaline, slightly brown infuscate at apex of costal cell, pterostigma and apex of cell r 2+3. Veins M 1 and M 2 weaker and apex of CuA+CuP evanescent. Last section of vein M 4 longer than vein dm-m. Cell dm somewhat acute. Halter light yellow. Abdomen (Fig. 6B) shiny black; tergites 1–3 with longer setae posteriorly. Tergite 8 (Fig. 6C) with distal sinus. Sternite 8 (Fig. 6D) with distinct saddle-shaped projection posterodorsally and deep basal sinus. Tergite 8 articulated with sternite 8 somewhat horizontally (Fig. 6E). Epandrium (Fig. 6F) with posterodorsal lobe longer than anterodorsal lobe, with longer setae more concentrated posteriorly on posterodorsal lobe; anterodorsal cleft minute, inconspicuous (smaller seta on Fig. 6F); anteroventral cleft distinct (stronger seta on Fig. 6F). Anterior cercus (Figs 6G, J) small in lateral view, well sclerotized, with longer setae dorsally and posteriorly; when viewed anteriorly (Fig. 6H) emitting mesially large and flat cercal bridge connected medially; cercal bridge expanded posteriorly and fused with upper hypoproctal lobe when viewed dorsally (Fig. 6I). Median cercus (Fig. 6J) somewhat cup-shaped with longer setae dorsally. Posterior cercus (Fig. 6J) inwardly curved, trifid, apparently glabrous. Ventral projection of cercus (Fig. 6K) horizontally placed, distally expanded and setose. Dorsal lobe of hypoproct somewhat inconspicuous, fused with cercal bridge expansion of anterior cercus; ventral lobe of hypoproct distinctly setose, placed between setose lobes of ventral projection of cercus and cercal bridge of anterior cercus. Hypandrium (Figs 6L, M) well sclerotized, almost same width throughout, slightly wider medially at level of posterior longer setae; distally with two pairs of curved hooks, distal pair stouter. Ejaculatory apodeme (Fig. 6L) tetralamellar, all lamella subequal. Phallus (Fig. 6L) slightly longer than hypandrium.
Female. Frons wider than width of anterior ocellus, wider than in male. Face slightly narrower than frons, approximately as wide as width of anterior ocellus. Wing distinctly more infuscated at costal and distal margins (Fig. 7A). Tergite 8 (Figs 7B, C) wider basally in lateral view; with shallow basal sinus and deep distal sinus in dorsal view. Sternite 8 (Figs 7B, D, E) highly modified; in lateral and ventral views widened distally and with ventral subapical small translucid protuberance. Genital fork (Figs 7D, E) T-shaped with arms upwardly directed. Genital chamber (Fig. 7D, E) well sclerotized, wide, U-shaped, with basal protuberance upwardly directed.
Geographical records. Bolivia (La Paz).
Type material examined. HOLOTYPE ♂, paratype ♀, on same pin: “ BOLIVIA, La Paz, Chulumani, cloud forest, above 2000 m [eters]”; “ In copula, Chulumani, 5.iv. [19]79”; “QR code: NHMUK 010664427 ”; “Holot ♂ Parat ♀ Macrostomus montanus Rafael & Marques ” (Fig. 6N) (NHMUK). PARATYPES: Bolivia: same data as holotype, except 2.iv. [19]79, QR code: NHMUK 0 10864440 (1♂, NHMUK); NHMUK 0 10664353 (1♀, INPA); NHMUK 0 10664429 (1♀, NHMUK); NHMUK 0 10664436 (1♀, NHMUK); NHMUK 0 10664441 (1♀, NHMUK); NHMUK 0 10664442 (1♀, INPA); same data, except 25.iii. [19]79, NHMUK 0 10664430 (1♀, NHMUK, dissected); La Paz, Sarampionim [sic], 23.ii.2005, Arm. Malaise, J. Rodriguez (1♀, CBF).
Holotype condition. Good. Left hind leg lost; right hind leg glued on piece of white card; abdomen not dissected.
Etymology. From the Latin montanus = mountain and refers to the high elevation where the specimens were collected.
Variation. One specimen (QR code: NHMUK 010864440) with three pairs of ocellar setae; the additional anterior pair slightly longer than posterior pair.
Remarks. Macrostomus montanus sp. nov. is tentatively included in the M. limbipennis species-group, however, it differs mainly by having epandrium with posterodorsal lobe longer than the anterodorsal lobe. In the key presented by Rafael & Cumming (2012), this species runs to couplet 3 separating M. limbipennis (Bezzi) from M. penai Rafael & Cumming, but it differs from the first species by male tergite 8 not humped and from the second species by all cercal lobes shortened (versus elongate and upwardly directed in M. penai), posterior lobe of epandrium longer than anterior lobe (versus same length) and by female sternite 8 with a ventral subapical small translucid protuberance (versus absent), genital fork T-shaped with arms upwardly directed (versus small rod, without lateral arms), genital chamber wide, U-shaped, well sclerotized (versus membranous).
description: Published as part of Rafael, José Albertino & Marques, Dayse Willkenia Almeida, 2019, Five new species of Macrostomus Wiedemann and a checklist of Empididae (s. str.) (Diptera) from Bolivia, pp. 251-275 in Zootaxa 4567 (2) on pages 259-261, DOI: 10.11646/zootaxa.4567.2.3, http://zenodo.org/record/2594934