Coenosia metalleg, Patitucci & Couri & Mulieri, 2021

Patitucci, Luciano Damián, Couri, Marcia Souto & Mulieri, Pablo Ricardo, 2021, The killer flies Coenosia Meigen (Diptera: Muscidae) of southern South America: the Coenosia chaetosa species group with two new species, and notes on male terminalia patterns, Journal of Natural History 55 (23 - 24), pp. 1499-1519 : 1510-1513

Coenosia metalleg sp. nov.

Male. Length. Body: 2.71–3.22 mm, wing: 3.03–3.19 mm.

Head ( Figure 5 (a-b)). Frons black, fronto-orbital plate, parafacial and gena black with silver-grey pollinosity. Frons longer than wide, without frontal triangle. Gena with strong black hairs, and with height greater than the width of the postpedicel. Arista with its longest microtrichia shorter than its basal diameter.

Thorax ( Figure 5 (c)). Black without vittae; postpronotal lobe and lateral plates black with white-grey pollinosity. Chaetotaxy: acrostichal setae long and strong, the anterior presutural pair as long as the eaDC; dorsocentrals 1 + 3, with an aDC seta that is less than one third of the eaDC; intra-alars 1 + 2, posterior postsutural seta shorter; supra-alars 1 + 1. Katepisternum without setula.

Wing. Tegula black.

Legs. Coxae black with grey pollinosity and black setae. Trochanters yellow with black setae. Femora and tibiae metallic black, apex of all tibiae yellow, tarsi dark brown. Mid femur with 3–4 ventral setae, and 2 preapical setae on posterodorsal to posterior surface; mid tibia with one anterodorsal and one posterodorsal median setae, anterodorsal seta shorter and positioned below of the posterodorsal seta. Hind femur with a complete row of anterodorsal, a row of strong anteroventral setae on basal half, and a row of strong posteroventral setae on basal half, with two preapical setae (anterodorsal and posterodorsal); some specimens a short dorsal preapical seta.

Abdomen ( Figure 5 (d)). Black with brown pollinosity, without spots or central line, tergite 6 and epandrium metallic black. Epandrium globular. Sternite 5 similar in width and lenght, basal margin convex, apical margin strongly concave (‘U’ shape), with a depressed area at the base; lobes with a membrane on apical margin; setae concentrated on the lobes and extended to basal margin ( Figure 5 (e)).

Terminalia. Cercus metallic black, longer than broad without a constriction on apical third, sclerotised, setulose only on basal third (hair-like seta), with apical margin concave with two strong and wide sclerotised teeth ( Figure 5 (f-h)). Surstyli longer than broad, slightly curved towards at the distal tip towards cercus ( Figure 5 (g, i)). Hypandrium tubular, longer than wide. Aedeagus with phallapodeme straight, strongly sclerotised, and longer than hypandrium in lateral view; pregonite developed, kidney-shaped, ventrally fused with the hypandrium; postgonite developed; epiphalus slightly sclerotised, and distiphallus tubular with hairs on ventral surface, and slightly sclerotised at base ( Figure 5 (j-k)).

Female ( Figure 6 (a)). Length. Body: 3.75–4.0 mm, wing: 4.03–4.20 mm. Differs from male as follows: Legs. Femora and tibiae metallic black, the metallic colour in some specimens is not so evident. Mid femur with an anteroventral row of setae, 3–4 strong setae on anterior surface, and with 3–4 ventral setae on basal third. mid tibia with one anterodorsal and one posterodorsal median setae, anterodorsal seta longer and positioned below of the posterodorsal seta. Ovipositor: Segments longer than wide. Tergites 6, 7, and 8 with 2 long and parallel scletotized plates, plates on tergite 6 wider than in the others ( Figure 6 (b)); epiproct triangular, with hair-like setae, cercus longer than epiproct ( Figure 6 (d)). Sternites 6 and 7 as a long and rectangular plate; sternite 8 divided into 2 small and sclerotised plates each with 4–5 setae on distal margin ( Figure 6 (c)); hypoproct triangular, setulose, with several strong setae on distal margin ( Figure 6 (e)). Three spermathecae, ovoid shape.

Type material examined. Holotype male, pinned, labels: ‘Arg. Neuquén, P.N. Lanín / (Malaise open Bandurrias) 800m /40°08,728¨’ S, 71°30,826 ʹ W / 21-II-2011 Mulieri & Patitucci leg.’ print. on white paper; ‘MACN-En/34717’ print. on white paper . Paratypes: male, pinned, labels: ‘Arg. Neuquén, P.N. Lanín / Quillen 993 m ( Malaise 2)/39°31 ʹ 40’ S, 71°13 ʹ 13” W / I-2013 Olea, Mulieri & Patitucci leg .” print. on white paper; ‘MACN-En/34718’ print. on white paper; 2 females, pinned, labels: ‘ Arg. Neuquén, P.N. Lanín / Quillen 993 m ( Malaise 2)/39°31 ʹ 40’ S, 71°13 ʹ 13” W / I-2013 Olea, Mulieri & Patitucci leg.” print . on white paper; ‘MACN-En/34719-20’ print. on white paper. Two males, pinned, labels: ‘ Arg . Neuquén, Lagunas de/ Epulaufquen / 1502 m . a. s. l. transecta/ -36.815642, −71,064096 / 12-II -2018 Patitucci leg’. ( IFML) . Two females and one male, pinned, labels: ‘ Arg . Neuquén, P.N. Lanín / Seccional Bandurrias II-2011 / -40.144240, −71.342986 / Mulieri & Patitucci leg’ . print. on white paper ( MLP).

Other specimens examined. ARGENTINA: Chubut: PNLA: 2 females, 3 males, Cab . La Cascada, II-2013, −42.888499, −71.592376, Mulieri, Patitucci & Olea leg . ( MACN); 1 female, Lag . Futalaufquen , II-2013, −42.840982, −71.632934, Patitucci & Olea leg . ( MACN). Neuquén: ABM: 1 male, I-2013, −38.845457, −71.093002, Patitucci leg . ( MACN), Cerrro Chapelco , 103 females, 15 males, 1983, −40.197050, −71.298453, Gentili leg . ( IFML); ALE: 26 females, 3 males, 12-II-2018, −36.815.642, −71.084.096, Mulieri & Patitucci leg . ( MACN); PNL: 3 females, 2 males, Quillen, 11-I-2013, −39.3613, −71.2188, Mulieri, Patitucci & Olea leg . ( MACN); Villa Pehuenia : 5 females, 10/ 11-II-2018, −38.884503, −71.166194, Mulieri & Patitucci leg . ( MACN). Río Negro: PNNH: 3 females, Mallín, Playa Negra, II-2009,-41357809, −71571683, Garré & Montes de Ocaleg . ( MLP).

Distribution ( Figure 3 (c)). ARGENTINA: Chubut, Neuquén, Río Negro.

Etymology. The name refers to the striking black metallic colour of the legs.

Remarks. Coenosia metalleg sp. nov. is distinguished from its congeners by the following combination of characters: thorax and abdomen black without vittae or spots, coxae black, trochanters yellow, and femora and tibiae metallic black, mid tibia with one anterodorsal and one posterodorsal median setae, anterodorsal seta shorter and positioned below the posterodorsal seta, cercus metallic black, longer than broad with hair-like seta, and distiphallus with hairs on ventral surface In Stein’s key ( Stein 1911), C. metalleg runs to C. setiventris . These two species are distinguished by differences in the male terminalia of C. setiventris ( Couri and Pont 2020) , and their general colouration, particularly the colour of the legs. In Malloch´key ( Malloch 1934), C. metalleg runs to C. inaequalis , but the metallic black colour of the femora can separate it from C. inaequalis .

Figures

Figure 3. Geographical distribution. (a). Coenosia chaetosa Malloch. (b). Coenosia mallochi sp. nov. (c). Coenosia metalleg sp. nov. (Violet area: Central Chilean subregion; green area: Subantarctic subregion; black circle: new records; red square: previous distribution.).

Figure 5. Coenosia metalleg sp. nov. male. (a) Lateral view (Scale bar = 1 mm). (b) Head, frontal view. (c) Thorax, dorsal view. (d) Abdomen, dorsal view (Scale bar = 0.5 mm). (e) Sternite 5 (Scale bar = 0.2 mm). (f) Cercus and surstyli, posterior view. (g) Cercus, surstyli, and phallic complex, lateral view (Scale bar = 0.5 mm). (h) Detailed of distal tip of cercus (SEM). (i) Detailed of distal tip of surstylus (SEM) (Scale bar = 0.02 mm). (j) Phallic complex, lateral view. (k) Detailed of distal tip of phallic complex (SEM) (Scale bar = 0.05 mm). (Abbreviations: distiph, distiphallus; epiph, epiphallus; hypd, hypandrium; pgt, postgonite; phapod, phallapodeme; pregt, pregonite). Red arrow: hairs on ventral surface of hypandrium.

Figure 6. Coenosia metalleg, female. (a) Lateral view (Scale bar = 1 mm). (b) Terminalia dorsal view. (c) Terminalia ventral view (Scale bar = 0.5 mm). (d) Detail of epiproct. (e) Detail of hypoproct (Scale bar = 0.2 mm). (Abbreviations: st8, sternite 8).