Exechia trunciseta Lindemann, 2021

Lindemann, Jon Peder, Soli, Geir & Kjaerandsen, Jostein, 2021, Revision of the Exechia parva group (Diptera: Mycetophilidae), Biodiversity Data Journal 9, pp. 67134-67134 : 67134

Exechia trunciseta Lindemann sp. n.

Materials

Type status: Holotype. Occurrence: catalogNumber: TSZD-JKJ-111562 ; recordedBy: T. Saigusa; individualCount: 1; sex: male; lifeStage: adult; preparations: Pinned, with genitalia in glycerine in separate microvial; Location: country: Bhutan; stateProvince: Thimpu District; locality: East of Dochhu La ; verbatimElevation: 2700 m; decimalLatitude: 27.487778; decimalLongitude: 89.762222; Event : eventDate: 1993-08-16; Record Level: collectionCode: KUEC

Description

Male: Wing length 3.3 mm. Colouration (Dry specimen). Head, face and clypeus dark brown; labellum yellow; palpus yellow with segments 4 and 5 pale brown. Antenna with scape and pedicel yellow; flagellum dark brown, basal half of first flagellomere yellow. Scutum dark brown with yellow anterolateral margin; lateral sclerites and propleura brown; halteres whitish-yellow. Legs yellow. Abdomen dark brown, tergites II-III with a yellow laterodorsal area. Terminalia brown with MB dark brown (Fig. 40 b). Head. Frons and vertex covered with short, brown setae. Clypeus covered with pale setae. Thorax. Scutum covered with short, brown setae. Legs. Fore leg with tibia 0.72 times length of first tarsomere. Mid-tibia with 23 anterior, 5 posterodorsal, 11 posterior and 3 posteroventral bristles. Hind tibia with 10 anterodorsal, 5 posterodorsal and 5 posterior bristles. Abdomen. Tergites covered with brown setae. Terminalia (Fig. 40). Each part of divided tergite IX with about 4 setae, most apical seta stout. Apicoventral margin of each gonocoxite forming short protrusion between the GL and hypandrium, each with 2 very stout setae, most apical seta distinctly truncated. GL (Fig. 40 a, b) about one-third of gonocoxite width, apex with 2-3 relatively stout setae. Aedaegal guides elongate and apically acute, converging (Fig. 40 a). Hypandrium covered with about 6 setae, with apical pair very short, length about half GL length (Fig. 40 a, b). Hypandrial lobe with each branch elongate, slender, evenly tapered, apex acute. Gonostylus (Fig. 40 c) with DB elongate and apically rounded; baso-internally forming small lobe, extending interiorly; evenly covered with relatively stout seta on dorsal side, except on most basal part and on internal lobe; apically with about 4 very stout and apically truncated setae. VB apically acute with 1 elongated seta on apex and 4 smaller setae further down, one distinctly wider than the others. IB apically with 1 seta on apex and row of 4 setae on elevation one-sixth from apex. MB wide, elongate, apex acute, baso-internally forming short distinctly right-angled process, apico-internally with row of 4 elongated setae, all about as long as MB length.

Female: Unknown

Diagnosis

Distinguished from E. crassiseta by the shape of the medial gonostylus branch (Fig. 40 c); from other species in the E. parva group in having the dorsal gonostylus branch basolaterally forming a short lobe and apically with a row of 4 stout truncated setae (Fig. 40 c), in combination with a dark medial gonostylus branch (Fig. 40 b), apically with a row of 4 elongated setae, all about as long as the medial gonostylus branch length (Fig. 40 c).

Etymology

From Latin truncatus, truncated and seta, bristle, relating to the shape of the seta on posteroventral margin of the gonocoxites and on apical margin of the dorsal lobe of the gonostylus.

Distribution

Oriental, Nepal (2700 m a.s.l., Fig. 19 )

Biology

Unknown.

Figures

Figure 19. Distribution map of species in the E. parva group occurring in the eastern Himalayas (Oriental Region), based on localities from studied material, type material and DNA-barcoded material. Different species are represented by individual colours. Altitudes are indicated in shades from grey (lowland) to white (mountains).