Mesembrina nigribasis, Kuchta, James S. & Savage, Jade, 2008

Kuchta, James S. & Savage, Jade, 2008, Revision of the new world fauna of Mesembrina Meigen (Diptera: Muscidae) with the description of a new neotropical species, Zootaxa 1689, pp. 29-50 : 46-48

Mesembrina nigribasis sp. nov.

Figs. 1 C, 1F, 1I, 5A–G.

Diagnosis: Large species, entirely black ( Fig. 1 C). Gena black pollinose. Thorax and abdomen with only black hairs, three dusted white lines on prescutum present. Only known species with wing base and calypters intensely black, M1 vein ending past wing apex ( Fig. 1 F). T2 of males not curved or elongated but with row of fine pv setae increasing in length towards apex ( Fig. 1 I).

Etymology: The name refers to the black wing base, a feature that distinguishes this species from all other members of Mesembrina .

Type material examined: Holotype ɗ – “ Costa Rica: Prov. San José: Pérez / Zeledón, P. N. Chirripó, Llano Bonito. / 2450m. 30 ENE 2000. B. Hernández. / Manual L S 378500 513200 #57131”; “ Holotype ɗ / Mesembrina nigribasis / Kuchta & Savage [red]” ( INBC).

Paratypes (all with a yellow label reading: Paratype [sex] / Mesembrina nigribasis Kuchta & Savage ): 5 ɗ same data as holotype (3 INBC, 1 CNC, 1 USNM); 3 ɗ, Prov. San Jose: Pérez Zeledón, Pque Nal Chirripó por Llano Bonito. 2200m. 29 JUL 2000. M. Alfaro. Manual L_S_512000_379300 # 58935 ( INBC); 2 ɗ, Prov. San Jose: Pérez Zeledón, Pque Nal Chirripó por Llano Bonito 2450m. 26 ENE 2000. A. Picado Manual L_S_378500_513200 #57038 ( INBC); 1 ɗ, Prov. San Jose: Pérez Zeledón, Pque Nal Chirripó. Monte Sin Fe. 3180m. 26 ENE 2000. M. Alfaro. Manual (red, libre) L S 377530 515340 #56271 ( INBC); 1 ɗ, C. Turrúbares, 1750m, 7 feb 1993. J.C. Saborío. L-N-197500, 484650, INBC / CRI 0 / 0 1192788 ( INBC); 5 ɗ, Prov. San José: F. Cementerio de la Máquina, 2100-5000 m, P. N. Chirripó, 2 mar 1993. F. Quesada, M. Segura. L-S- 378700, 512500 (4 INBC, 1 USNM); 2 ɗ, same data except M.A. Zumbado, L-S-378700, 512500 ( INBC); 2 ɗ, Heredia: Estac. Barva. Braulio Carrillo. N.P. 2500 m. Mar 1990. G. Rivera, 233400-523200 ( INBC); 1 Ψ, Prov Puntarenas: Coto Brus, Sendero a Cerro Echandi, 1er Campamento. 900m. 12 ABR 1998. E. Navarro. Manual _N_326500_571700 # 57375 ( INBC); 1 ɗ, Prov. Puntarenas: Coto Brus, P.Int. La Amistad, Estación Pittier, Fila Pitter, 2200m, 19 FEB 2002. M. Alfaro, Libre L_S_332800_579050 #63227 ( INBC); 5 ɗ, Prov. Puntarenas: Coto Brus, Send. entre Est. Tres Colinas y Laguna Seca. 2100-2500m. 19 JUL 2000. M. Alfaro. Libre. L_S_344300_565800 #63227 (2 INBC, 2 BMNH, 1 CNC); 2 ɗ, Prov. Puntarenas: Coto Brus, Z.P. Las Tablas, E.B. Las Alturas, S. Cerro Chai. 2100m. 13 ENE 2001. M. Alfaro. Manual. L_S_592150_32440 #61814 ( INBC); 3 ɗ, Prov. Puntarenas: Sendero a Cerro Echandi. 2600m. 13-14 ABR 1998. B. Gamboa. Colectado en una fila. L_S_329700_593100 #50725 ( INBC); 1 ɗ, Prov. Puntarenas: Est. Biologica Las Alturas, Send. a Cerro Chai. 1700m. 15 ABR 1998. E. Navarro. L_S_324100_591500 #51635 ( BUIC); 1 ɗ, Prov. Puntarenas: Zona Prot Las Tablas, Est Las Alturas, Cerro Chay. 2000m. 1 ABR 2000. M. Alfaro. Manual (red, libre) L S 324500 592100 #56447 ( BUIC).

Description: Male: body length 11.3–12.5mm.

Head: Background color black, parafacial dusted silver and gena black pollinose; eye sparsely haired; distance between eyes 1.0x–1.2x distance between the outer margins of the posterior ocelli; 6–8 fine black medioclinate fr and with abundant weaker medioclinate, proclinate or reclinate orb, tuft of short black setae posterior to ocellar triangle, 1 i vt and 1–2 convergent pavt; palpus dark reddish to black, 5.0x as long as wide; pedicel black, haired and with 2 setae more than 2.0x length of others; first flagellomere black, 4.0x as long as wide; basal half of arista thickened and often dark orange; prementum haired and glossy, 2.0–2.5x as long as wide

Thorax: Glossy black; covered in fine black hairs and setae, postpronotal lobes and medial portion of prescutum with silvery dust appearing as three distinct lines; anepimeron haired with a tuft of longer hairs on dorsal edge; dorsal thoracic bristles black and often nearly indistinguishable from surrounding hairs; anepimeron haired with a tuft of longer hairs on dorsal edge; 0 + 2 acr, anterior postsutural acr 0.75x length of posterior one, 0 + 1–2 dc, if 2 postsutural dc present, then anterior one weaker, 1 + 0 ial, 1 + 5–6 spal, 3 npl, 2 pal; anepisternum bare anteriorly; 0 a kepst, 1 p kepst; postpronotum haired, with 2–3 strong ppnl; scutellum glossy black sometimes reddish,1 pair of apical sctl, 8 pairs of lateral sctl.

Legs: Black, fifth tarsomere flattened on all legs; pulvilli large, 2.0x as long as wide; F1 with 1 row of equal pd on basal two-thirds, 1 row of p decreasing in size from base and 1 complete row of sub-equal v; F2 with 3–5 p in a group near apex; F3 with 1 row of sub-equal av and ad, apical third of av and ad rows stronger than basal sections; T1 with very fine and short a giving the surface a shiny brown look, 1 strong ad and 1 d near apex; T2 ( Fig. 1 I) with 1 strong ad located on apical third, 1 row of 5–8 strong p sub-equally spaced and 1 row of fine black pv on apical two-thirds increasing in length apically but of equal length on apical third; T3 with 1 d near apex and 1 long pd near midpoint; fore tarsomeres: 1>2>3>4<5; mid tarsomeres: 1>2>3>4<5; hind tarsomeres: 1>2>3>4<5, tarsomeres 1, 4–5 with very fine brown and short p giving the surface a shiny look and tarsomeres 2–3 with fine short yellowish p.

Wing: ( Fig. 1 F). Mostly clear with heavy black tinge on basal half; basicosta black; wing veins black on basal half, yellow medially, brown on apical half; M1 vein running parallel to wing margin on apical quarter of wing ending at or slightly before wing apex; alula with black tinge; calypters black.

Abdomen: Shiny black; densely covered in fine black hairs. Sternite 5 1.2x as long as wide ( Fig. 5 D).

Postabdomen: Epandrium wider than high ( Fig. 5 B); mesolobus higher than wide with outer ventral projection slightly longer than inner projection ( Fig. 5 B); surstylus short, lightly bent medially with apex ending abruptly with a straight edge in posterior view ( Fig.5 B), rounded in lateral view ( Fig.5 A); pregonite with base wide, projecting dorsally and apex slender, with 4 lateral setae ( Fig. 5 C); postgonite with base slightly concave and with several small lateral setae and apex rounded, 2.0x as high as width of base ( Fig. 5 C); epiphallus with apex forked, as long or slightly shorter than phallapodeme ( Fig. 5 C); apex of phallapodeme bulb-shaped ( Fig. 5 C); ejaculatory apodeme large and well sclerotized; lateral sclerites of distiphallus broad and weakly sclerotized, apical section with sparse spinules ( Fig. 5 C).

Female: body length 12mm (description based on a single specimen). Differs from male as follows:

Head: Distance between eyes 5.0x distance between the outer margins of the posterior ocelli, tuft of short setae posterior to ocellar triangle black, frontal vitta black, many fine setae sometimes present on frontal vitta; 1 pavt; 6 medioclinate fr, stronger anteriorly, 2 strong reclinate orb and numerous fine proclinate orb 0.5x the length of longer orb and not extending onto the parafacial.

Thorax: As in male.

Legs: T2 with 2 v on basal two-thirds.

Wing: As in male.

Abdomen: As in male.

Postabdomen: Anterior portion of tergite 8 split longitudinally into 2 rectangular parallel rods, posterior plate of tergite 8 with 8–9 robust sub-equal setae ( Fig. 5 E); anterior portion of sternite 8 split longitudinally into 2 club-shaped parallel plates, posterior plate of sternite 8 with 3 robust sub-equal setae ( Fig. 5 F); tergite 10 bare except for 2 pairs of strong setae on the posterior margin ( Fig. 5 E); cercus bare, cercal pegs small ( Figs. 5 E, 5F); spermathecae 2.0x as long as wide ( Fig. 5 G).

Distribution: NEOTROPICAL: Costa Rica: Heredia, Puntarenas, San Jose.

Remarks: This new species of Mesembrina represents a significant range extension for the genus as it is the only species found in the Neotropical Region. All specimens known to the authors have been collected at or above an altitude of 900m, with the majority found above 2000m.

Figures

FIGURE 1. Males of M. decipiens (A, D, G), M. latreillii (B, E, H) and M. nigribasis (C, F, I). A – C. Whole habitus, lat-

FIGURE 5. M. nigribasis. A. Male external genitalic structures, lateral view. B. Male external genitalic structures, posterior view. C. Male internal genitalic structures, lateral view. D. Male sternite 5, ventral view. E. Female apical portion of ovipositor, dorsal view. F. Female apical portion of ovipositor, ventral view. G. Female spermatheca.