Mesoconius bipleuron, Marshall, 2019

Marshall, Stephen A., 2019, A revision of the genus Mesoconius Enderlein (Diptera, Micropezidae, Taeniapterinae), European Journal of Taxonomy 548, pp. 1-126 : 78-81

Mesoconius bipleuron sp. nov.

urn:lsid:zoobank.org:act:A2CC6797-7A50-428B-8A74-0B90D08C5AC5

Fig. 32

Etymology

The specific name refers to the bicoloured pleuron.

Material examined

Holotype

COLOMBIA • ♂; Cundinamarca, PNN Chingaza, Bosque Palacio ; 04°31ʹ N, 73°45ʹ W; 2930 m a.s.l.; 10–24 Nov. 2000; E. Raigoso leg.; IAVH.

Paratypes

COLOMBIA • 1 ♀; same collecting data as for holotype; IAVH • 1 ♂; same locality as for holotype; 5–17 Jan. 2001; L. Cifuentes leg.; IAVH • 1 ♀; same collecting data as for holotype; 17 Jan.–5 Feb. 2001; E. Niño leg.; IAVH • 1 ♀; same collecting data as for holotype; 4–16 Feb. 2001; E. Niño leg.; IAVH • 1 ♀; same collecting data as for holotype; 20 Dec. 2000 – 5 Jan. 2001; E. Niño leg.; IAVH • 1 ♀; same collecting data as for holotype; 6–21 Jul. 2000; E. Raigoso leg.; IAVH • 1 ♀; Boyacá, SFF Iguaque, Cerro Pan de Azucar ; 05°25ʹ N, 73°27ʹ W; 3300 m a.s.l.; 22 Aug.–12 Sep. 2001; P. Reina leg.; Malaise trap; IAVH • 1 ♀; Boyacá, SFF Iguaque, La Planada ; 05°25ʹ N, 73°27ʹ W; 2850 m a.s.l.; 13 Nov.–4 Dec. 2000; P. Reina leg.; MYCRO071-15 sequenced for CO1; DEBU .

Description

LENGTH. 15 mm.

COLOUR. Head black dorsally; face, clypeus and antenna brown; palpus orange; parafacials and gena silvery. Frontal vitta mostly velvety black. Thorax mixed orange and black, pleuron mostly black ventrally, microtrichose except shiny black middle of katepisternum; mostly shiny orange dorsally, orange part often extending ventrad through katepisternum, posterior margin of anepisternum microtrichose; scutum orange and bare laterally, middle of scutum with a broad microtrichose longitudinal band on a dark background; scutellum orange medially, brown laterally. Fore femur orange on basal half, black on distal half, tibia black, tarsomere 1 white dorsally, black ventrally, distal tarsomeres black (tarsomere 2 sometimes white basally). Mid and hind femora variable in colour, entirely reddish brown, brown with strong basal and middle black bands, or brown with partial basal and middle black bands. Mid and hind tibia brown, tarsus black. Wing uniformly lightly infuscated, with only a faint indication of a clearer discal band. Abdomen of female with orange tergites and oviscape, pleuron white, posterolateral corners of T2 black. Abdomen of male with tergites brown, except for pale T2–3; pleura 2 and 3 with black setulose patches.

HEAD. Epicephalon and paracephalon indistinctly striate, with dense white microtrichosity anteriorly and posteriorly, shiny in between. Frontal vitta slightly raised, very broad in front of ocelli, black part broadly rounded behind, but with a microtrichose tapered posterior extension; anterior part of vitta with velvety black part tapered and widely separated from anterior margin of frons, but vitta reaching anterior margin as a differentiated, parallel-sided, depressed strip (obvious or inconspicuous depending on the light). Lower frons dull, indistinctly microtrichose. Palpus relatively narrow, slightly curved upward and tapered towards apex. Postocellar bristles closely spaced and slightly divergent, inner and outer vertical bristles well developed; upper fronto-orbital large, inserted in shiny part of epicephalon, lower frontoorbital minute or absent.

THORAX. Scutum densely microtrichose dorsally, forming colour patterns described above; dorsocentral setulae minute, forming a sparse row; acrostichal setulae indistinct. Cervical sclerite subquadrate, with a vertical groove separating a large microtrichose posterior section from a bare anterior portion; central part of posterior portion of females with a large oval patch of dense microtrichia. Prosternum unusually bare and shiny, narrow and tapered anteriorly (unlike all congeners). Postpronotal lobe sparsely microtrichose, without setulae, area above postpronotal lobe with several long, fine, curved setulae. Dorsocentral bristle subequal to scutellar length. Scutellum with minute discal setulae and one pair of apical bristles (slightly longer than scutellum). Vertical row of katepisternal bristles golden. Katatergite evenly convex and microtrichose, without a conspicuous swelling or point. All coxae with an anteroventral tuft of long black setae.

ABDOMEN. Indistinctly petiolate, with a distinct constriction between T1 and T2; length of T1+2 1.3× that of T3; width of T1, posterior margin of T2 and anterior margin of T3 similar; posterior margin of T3 conspicuously broader.

FEMALE ABDOMEN. Oviscape relatively broad and short, subequal to T4–6. Bursa large, irregular; ventral receptacle extremely large, with a distinct head. Paired and single spermathecal ducts arising independently from bursa, single duct slightly thinner and shorter, with an elongate and tuberculate spermatheca (distally evaginated on dissected material). Paired spermathecal duct parallel-sided and uniformly textured, constricted at apex into two very short, narrow stems, each leading to an elongate oval, tuberculate spermatheca.

MALE ABDOMEN. Sternite 5 very small and pale, tapered anteriorly; S6 large, broad, setulose, setose and brown; S7 bare and narrow; right side of segment 7 with a small sclerite surrounding spiracle, pleuron not invaginated. Sternite 8 subequal to epandrium, partially fused with broad ventral lobe of S7 on left side, shiny anterodorsally in contrast to microtrichose anterior sclerites, micosetulose posteriorly and anteriorly. Epandrium setulose, long-setose posterodorsally. Ejaculatory apodeme small, smaller than epandrium; hypandrium with a scoop-like anterior margin; basal part of distiphallus long, mostly broadly sclerotized and parallel-sided, but distally upcurved, with sclerotized part strongly tapered; phallic bulb small and inconspicuous; phallus beyond phallic bulb very short, pale, with a clubbed apex.

Remarks

Mesoconius bipleuron sp. nov. is externally distinctive for its bicoloured pleuron and internally highly distinctive for the truncate distal distiphallus in the male and the enlarged sperm storage structures (spermathecae, ventral receptacle) in the female.

Figures

Fig. 32. Mesoconius bipleuron sp. nov. A. ♀ with unmarked tibiae. B. Typical ♀. C. Spermathecae and associated structures. D. Head, holotype, ♂, IAVH. E. Pleuron and abdominal base, holotype. F. Holotype, ♂. G–H. Male terminalia. Abbreviations: bdp = basal distiphallus; ddp = distal distiphallus; pb = phallic bulb; vr = ventral receptacle.