Exechia rectiloba 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 rectiloba Lindemann sp. n.

Materials

Type status: Holotype. Occurrence : catalogNumber: TSZD-JKJ-102067 ; recordedBy: Jostein Kjaerandsen ; individualCount: 1; sex: male; lifeStage: adult; preparations: Pinned , with genitalia in glycerine in separate microvial; Location : island: Hokkaido; country: Japan; stateProvince: Hokkaido Prefecture; locality: Chitose-shi , Kokeno-domon Gallary beside Lake Shikotsu ; verbatimElevation: 279 m; decimalLatitude: 42.712; decimalLongitude: 141.321; Event: samplingProtocol: sweep net; eventDate: 2006-10-02; Record Level: institutionCode: TMU

Description

Male: Body length 3.2 mm. Wing length 2.8 mm. Colouration (Dry specimen). Head, face and clypeus brown; labellum and palpus yellow. Antenna with scape and pedicel yellow; flagellum pale brown, basal half of first flagellomere pale. Thorax with scutum brown, anterior and lateral margin paler; lateral sclerites and propleura brown; halteres whitish-yellow. Legs whitish-yellow. Abdomen brown with a pale area covering ventral and apicolateral margins of tergite II and ventral and basolateral margins of tergite III, in dorsal view appearing as a pale band narrowly broken medially. Terminalia yellow. Head. Frons, vertex and clypeus covered with pale setae. Antenna 1.8 times as long as length from vertex to ventral margin of clypeus; flagellomeres quadrate, with sixth flagellomere as long as wide. Thorax. Scutum covered with pale setae. Legs. Fore leg with tibia 1.05 times as long as first tarsomere. Mid-tibia with 26 anterior, 3 posterodorsal, 7 posterior and 2 posteroventral bristles. Hind tibia with 7 anterodorsal, 4 posterodorsal and 6 posterior bristles. Wings. Vein r-m 2.7 times longer than stem of M-fork. Abdomen. Tergites covered with long, pale setae. Terminalia (Fig. 30). Each part of divided tergite IX with about 6-8 setae, most apical seta stout. GL (Fig. 30 a, b) with length about 0.52 of gonocoxite width; apico-internal margin slightly angled exteriorly; basal tenth covered with setae; apex with 3 setae. Aedaegal guides short with acute apex. Hypandrium covered with about 13 setae, with apical pair reaching about half of the GL (Fig. 30 a, b). Hypandrial lobe with each branch slender, apical half somewhat widened. Gonostylus (Fig. 30 c) with DB about 2.2 times longer than broad, slightly curved interiorly; apical lobe well defined, about 0.22 of total DB length, apex acute; evenly covered with setae on dorsal side, except on the most apical part; external margin forming indistinct angle with row of 4 elongated setae. VB with 2 small setae. IB apically with 1 seta close to apex and pair of setae one-third from apex. MB apex acute, with 1 seta close to the base.

Female: Unknown.

Diagnosis

Distinguished from other species in the E. parva group in having the gonocoxal lobes extending almost without tapering, with only the basal tenth covered with setae (Fig. 30 a, b), in combination with the dorsal gonostylus branch only about 2.2 times longer than broad (Fig. 30 c) and the gonocoxal lobes with apico-internal margin slightly angled exteriorly (Fig. 30 a, b).

Etymology

From Latin rectus, straight and loba, lobe, relating to the shape of the gonocoxal lobes.

Distribution

East Palaearctic, Japan (Fig. 10 )

Biology

Unknown.

Figures

Figure 10. Distribution map of species in the E. parva group occurring in the East Palaearctic 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).