Exechia columna 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 columna Lindemann sp. n.

Materials

Type status: Holotype. Occurrence: catalogNumber: TSZD-JKJ-111553 ; recordedBy: H. Shima; individualCount: 1; sex: male; lifeStage: adult; preparations: Pinned, with genitalia in glycerine in separate microvial; Location: country: Nepal; stateProvince: Province no. 1 (Kosi Zone); county: Sankhuwasabha District ; locality: Thudam ; verbatimElevation: 3500 m; decimalLatitude: 27.7500; decimalLongitude: 87.5333; Event : samplingProtocol: Malaise Trap; eventDate: 1972-07-02; Record Level: institutionCode: KUEC

Description

Male: Body length 3.9 mm. Wing length 3.2 mm. Colouration (Dry specimen). Head, face and clypeus dark brown; labellum dark brown; palpus whitish-yellow. Antenna with scape and pedicel yellow; flagellum pale brown, basal half of first flagellomere pale. Thorax with scutum pale brown, lateral margin paler; lateral sclerites brown; propleura brown; halteres whitish-yellow. Legs whitish-yellow. Abdomen dark brown, tergites II-III with a lateral pale area. Terminalia brown. Head. Frons and vertex covered with pale setae. Clypeus covered with only few (about 17) pale setae. Antenna long, 2.1 times as long as length from vertex to ventral margin of clypeus; flagellomeres longer than broad, sixth flagellomere 1.5 times as long as wide. Thorax. Scutum covered with pale setae. Legs. Fore leg with tibia 0.91 times as long as first tarsomere. Mid-tibia with 19 anterior, 4 posterodorsal, 7 posterior and 3 posteroventral bristles. Wings. Vein r-m 2.14 times longer than stem of M-fork. Abdomen. Tergites covered with pale brown setae. Terminalia (Fig. 21). Each part of divided tergite IX apically with about 4 setae, most apical seta stout. Gonocoxites with GL elongate, entirely covered with setae, apex with 2 short setae (Fig. 21 a, b). Aedaegal guides elongate and spathulate (Fig. 21 a). Hypandrium strongly extended distally, forming a large lobe that reaches far beyond apicoventral gonocoxal margin, covered with about 10 setae, with apical pair stout, reaching almost level of GL apex (Fig. 21 a, b). Hypandrial lobe with each branch elongate, narrow, apically rounded (Fig. 21 a). Gonostylus (Fig. 21 c) with DB forming a large distally projecting baso-external lobe; basal part rounded, abruptly tapered, apical part slender elongate, apex rounded; basodorsal part evenly covered with setae; baso-external lobe with 2 short stout setae on apex. VB small and apically rounded, with 2 setae, most apical seta on apex. IB with apical part slender and elongate; 1 seta on apex and row of 4 setae on elevated area close to middle. MB elongate; internal margin smooth; apically somewhat hollowed with small seta within hollow area close to apex.

Female: Unknown.

Diagnosis

Distinguished from E. serrae in having the gonocoxal lobe extended beyond the apex of the apical hypandrial setae (Fig. 21 a, b) and the medial gonostylus branch with internal margin smooth (Fig. 21 c); from other species in the E. parva group in having the hypandrium forming a distally-extended lobe reaching far beyond the apicoventral gonocoxal margin (Fig. 21 a, b) and the dorsal gonostylus branch with a large baso-external lobe with two apical setae (Fig. 21 c).

Etymology

From Latin Exechia columna , column, relating to the shape of the hypandrium forming a large distally-extended lobe.

Distribution

Oriental, Nepal (Fig. 19 )

Biology

Adult collected in the eastern Himalayas (3500 m a.s.l.).

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).