Exechia repanda Johannsen, 1912

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 repanda Johannsen, 1912

Exechia repanda Johannsen, 1912: 73 ♂♀ ( Johannsen 1912)

Materials

Type status: Holotype. Occurrence: catalogNumber: TTG-TBB-2048 ; recordedBy: O. A. Johannsen; individualCount: 1; sex: Male; lifeStage: adult; preparations: Pinned, with genitalia in glycerine in separate microvial; Location : country: USA; stateProvince: New York; municipality: Ithaca ; Event : eventDate: 1894-08-28; Record Level : institutionCode: CUIC Type status: Other material. Occurrence: catalogNumber: BIOUG17656-D06 ; recordedBy: BIObus 2013; individualCount: 1; sex: female; lifeStage: adult; preparations: Pinned, with genitalia in glycerine in separate microvial; Location : country: Canada; stateProvince: Nova Scotia; locality: Kejimkujik National Park , Eel Weir Road ; verbatimElevation: 96 m; decimalLatitude: 44.3482; decimalLongitude: -65.189; Event : samplingProtocol: Malaise Trap; eventDate: 2013-06-22; habitat: Wetland; fieldNotes: 2 malaise traps |mostly sunny|bog; Record Level: institutionCode: CBG Type status: Other material. Occurrence: catalogNumber: BIOUG31032-H11 ; recordedBy: Mary-Ann Mitchler; individualCount: 1; sex: female; lifeStage: adult; preparations: Pinned , with genitalia in glycerine in separate microvial; Location : country: Canada; stateProvince: Manitoba; municipality: Winnipeg ; locality: Oakenwald School ; verbatimElevation: 232 m; locationRemarks: EQP-CLL-551; decimalLatitude: 49.8459; decimalLongitude: -97.139; Event : samplingProtocol: Malaise Trap; eventDate: 2016-09-30; Record Level: institutionCode: CBG Type status: Other material. Occurrence: catalogNumber: BIOUG03446-H05 ; recordedBy: Tyler Peters; individualCount: 1; sex: male; lifeStage: adult; preparations: Pinned , with genitalia in glycerine in separate microvial; Location : country: Canada; stateProvince: Ontario; locality: Point Pelee National Park , Cactus Field ; verbatimElevation: 168 m; decimalLatitude: 41.939; decimalLongitude: -82.516; Event : samplingProtocol: Malaise Trap; eventDate: 2012-07-04; habitat: Mixed Habitat; fieldNotes: Cedar / Savannah; Record Level: institutionCode: CBG Type status: Other material. Occurrence: catalogNumber: BIOUG27568-B05 ; recordedBy: BIO Collections Staff; individualCount: 1; sex: male; lifeStage: adult; preparations: Pinned, with genitalia in glycerine in separate microvial; Location: country: Canada; stateProvince: Ontario; municipality: Mississauga; locality: CRH Canada , 2391 Lakeshore Rd W ; verbatimElevation: 87 m; locationRemarks: Site 3; decimalLatitude: 43.491; decimalLongitude: -79.618; Event: samplingProtocol: Intercept Trap; eventDate: 2015-10-15; habitat: Grassland; fieldNotes: 1 Intercept Trap |windy, sunny|grass, thistle; Record Level: institutionCode: CBG Type status: Other material. Occurrence: catalogNumber: BIOUG08568-B05 ; recordedBy: Barb Maschke; individualCount: 1; sex: Male ; lifeStage: adult; preparations: Pinned , with genitalia in glycerine in separate microvial; Location : country: Canada; stateProvince: Ontario; municipality: Perth East ; locality: Mornington Central School ; verbatimElevation: 380 m; locationRemarks: EQP-CLL-556; decimalLatitude: 43.614; decimalLongitude: -80.885; Event : samplingProtocol: Malaise Trap; eventDate: 2013-10-04; Record Level: institutionCode: CBG Type status: Other material. Occurrence: catalogNumber: BIOUG05522-E07 ; recordedBy: Stacey Fraser; individualCount: 1; sex: Male ; lifeStage: adult; preparations: Pinned , with genitalia in glycerine in separate microvial; Location : country: Canada; stateProvince: Ontario; municipality: Guelph ; locality: St. James Catholic School ; locationRemarks: EQP-CLL-592; decimalLatitude: 43.5596; decimalLongitude: -80.234; Event : samplingProtocol: Malaise Trap; eventDate: 2013-04-03; Record Level: institutionCode: CBG

Description

Male (n = 3): Body length 3.0-3.2 mm. Wing length 2.4-2.6 mm. Colouration (Dry specimen). Head, face and clypeus dark brown; labellum pale brown to yellow; palpus yellow. Antenna with scape and pedicel yellow; flagellum pale brown, basal half of first flagellomere pale. Thorax with scutum brown, sometimes anterior and lateral margin paler; lateral sclerites pale brown to brown; propleura yellow to pale brown; halteres whitish-yellow. Legs whitish-yellow. Abdomen brown, tergites II-III slightly paler than the rest or sometimes a distinct pale area covering lateral part of tergite II and anterolateral part of tergite III. Terminalia yellow to pale brown. Head. Frons, vertex and clypeus covered with pale setae. Antenna 1.83-1.93 times as long as length from vertex to ventral margin of clypeus; flagellomeres slightly longer than broad, with sixth flagellomere 1.0-1.1 times as long as wide. Thorax. Scutum covered with pale setae. Legs. Fore leg with tibia as long as first tarsomere. Mid-tibia with 20-22 anterior, 2-3 posterodorsal, 7 posterior and (n = 1) 1 posteroventral bristles. Hind tibia with 8-7 anterodorsal, 5 posterodorsal and 4 posterior bristles. Wings. Vein r-m 2.7-3 times longer than stem of M-fork. Abdomen. Tergites covered with pale setae. Terminalia (Figs 2 b, 31 a, b, c). Each part of divided tergite IX with about 7-9 setae, most apical seta stout. GL (Fig. 31 a, b) with length 0.5-0.54 of gonocoxite width; apico-internal margin slightly angled exteriorly; basal half or third covered with setae; apex with 3-4 setae. Aedaegal guides short with acute apex. Hypandrium covered with 9-13 setae, with apical pair reaching about half of GL (Fig. 31 a). Each part of hypandrial lobe narrow, apical half somewhat widened. Gonostylus (Fig. 31 c) with DB 2.3-2.4 times longer than broad, curved interiorly; apical lobe well defined, apex rounded; evenly covered with setae on dorsal side, except on the most apical part; external margin forming a distinct angle, with row of 4-5 elongate setae. VB round, 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 (n = 3): Body length 3.1-3.3 mm. Wing length 2.4-2.8 mm. Colouration (Dry specimen). Head, face and clypeus dark brown; labellum yellow to pale brown; palpus yellow. Antenna with scape and pedicel yellow; flagellum brown, basal part of first segment pale. Thorax with scutum dark brown, sometimes anterior and lateral margin paler; lateral sclerites brown; propleura yellow to brown; halteres whitish-yellow. Legs whitish-yellow. Abdomen brown to dark brown, tergites II-VI with pale lateral areas extending dorsally at anterior fifth to third of tergites III and IV, forming two more or less distinct pale bands. Terminalia pale brown. Head. Frons, vertex and clypeus covered with pale setae. Antenna 1.7-1.8 times as long as length from vertex to ventral margin of clypeus; flagellomeres quadrate or longer than broad, with sixth flagellomere 1.0-1.2 times as long as wide. Thorax. Scutum covered with pale setae. Legs. Fore leg with tibia (n = 2) 1.1-1.13 as long as first tarsomere. Mid-tibia with (n = 1) 20 anterior, (n = 1) 3 posterodorsal and (n = 1) 5 posterior bristles. Hind tibia with (n = 1) 6 anterodorsal, (n = 1) 4 posterodorsal and (n = 1) 4 posterior bristles. Wings. Vein r-m 1.5-2.8 times longer than stem of M-fork. Abdomen. Tergites covered with pale to pale brown setae. Terminalia (Fig. 31 d, e). Cerci with apical segment half as long as basal segment. Tergite VIII with apicolateral margin slightly angular, not distinctly protruding (Fig. 31 d). Sternite VII with apicoventral margin evenly rounded, sometimes with medial part very slightly protruding. Sternite VIII (Fig. 31 e) with hypogynal valves separated by narrow cleft with depth about one-fifth of sternite VIII length; apical seta about 0.6-0.65 of sternite VIII length. Gonapophysis IX with basolateral part expanding in a relatively obtuse angle; spermathecal eminence trilobed, in ventral view appearing cross-shaped; apex with 8 small setae.

Diagnosis

Distinguished from E. subrepanda in having the dorsal gonostylus branch only 2.3-2.4 times longer than broad and with the external row of setae covering one-third to half of the total dorsal gonostylus branch length (Fig. 31 c); from E. neorepanda in having the dorsal gonostylus branch more curved interiorly and with the external margin forming a more distinct angle (Fig. 31 c); from E. curvata in having the dorsal gonostylus branch with exterior margin forming a less protruding angle, with external row of setae covering one-third to half of the total dorsal gonostylus branch length (Fig. 31 c), in combination with the gonocoxal lobes more elongate; from other species in the E. parva group by the dorsal gonostylus branch 2.3-2.4 times longer than broad (Fig. 31 c), in combination with the gonocoxal lobes covered with setae on basal half or less and with the apico-internal margin slightly angled exteriorly (Fig. 31 a).

Distribution

Nearctic, Canada, USA (Fig. 13 )

Biology

Adults collected in grassland, savannah and wetland habitats.

Taxon discussion

The species is very close to E. neorepanda and E. subrepanda and species determination should be conducted with care or by use of DNA barcoding. It has also been reported from Chokotka, East Russia ( Polevoi and Barkalov 2017), but we have not considered these occurrences due to the risk of confusion with E. neorepanda or E. subrepanda . We assume that previous records of E. repanda in the West-Palaearctic Region constitute records of E. neorepanda .

Notes

Holotype in rather poor condition - both wings and left legs mounted on slide. Antennae almost intact (one tip lost). Terminalia in fairly good condition - transferred to glycerine in microvial and associated with pinned specimen.

Figures

Figure 13. Distribution map of species in the E. parva group occurring in the Nearctic 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).