Exechia curvata 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 curvata Lindemann sp. n.

Materials

Type status: Holotype. Occurrence: catalogNumber: BIOUG05015-F10 ; recordedBy: Becky Nichols; individualCount: 1; sex: male; lifeStage: adult; preparations: Pinned (Dried from HMDS); Location : country: United States; stateProvince: Tennessee; locality: Great Smoky Mountains National Park , Twin Creeks Science and Education Center ; verbatimElevation: 559 m; decimalLatitude: 35.6859; decimalLongitude: -83.4986; Event : samplingProtocol: Malaise Trap; eventDate: 2012-10-30; Record Level: institutionCode: CBG Type status: Paratype. Occurrence: catalogNumber: BIOUG00965-E09 ; recordedBy: James Sones; individualCount: 1; sex: female; lifeStage: adult; preparations: Pinned (Dried from HMDS); Location : country: Canada; stateProvince: Ontario; locality: Leeds and Grenville , Elizabethtown-Kitley , 4452 Rowsome Rd. , Elizabethtown ; verbatimElevation: 112 m; locationRemarks: MT-2; decimalLatitude: 44.621; decimalLongitude: -75.773; Event : samplingProtocol: Malaise Trap; eventDate: 2010-10-14; habitat: Temperate mixed forest; Record Level: institutionCode: CBG Type status: Paratype. Occurrence: catalogNumber: BIOUG05033-B01 ; recordedBy: Becky Nichols; individualCount: 1; sex: female; lifeStage: adult; preparations: Pinned (Dried from HMDS); Location : country: United States; stateProvince: Tennessee; locality: Great Smoky Mountains National Park , Twin Creeks Science and Education Center ; verbatimElevation: 559 m; decimalLatitude: 35.6859; decimalLongitude: -83.4986; Event : samplingProtocol: Malaise Trap; eventDate: 2012-12-06; Record Level: institutionCode: CBG Type status: Paratype. Occurrence: catalogNumber: BIOUG21858-G11 ; recordedBy: CSC; individualCount: 1; sex: female; lifeStage: adult; preparations: Pinned (Dried from HMDS); Location : country: Canada; stateProvince: Ontario; locality: Thousand Islands National Park ; verbatimElevation: 91 m; decimalLatitude: 44.453; decimalLongitude: -75.865; Event : samplingProtocol: Malaise Trap; eventDate: 29-Sep-2014; habitat: Mixed habitat; fieldNotes: Shoreline transition area (from emergent typha marsh to mixed forest edge); T1; Record Level: institutionCode: CBG Type status: Paratype. Occurrence: catalogNumber: BIOUG16127-C09 ; recordedBy: Claire Gulliver; individualCount: 1; sex: female; lifeStage: adult; preparations: Pinned (Dried from HMDS); Location : country: Canada; stateProvince: Ontario; locality: London ; verbatimElevation: 259 m; locationRemarks: EQP-CLL-589; decimalLatitude: 43.03; decimalLongitude: -81.271; Event : samplingProtocol: Malaise Trap; eventDate: 03-Oct-2014; Record Level: institutionCode: CBG

Description

Male (n = 1): Body length 3.2 mm. Wing length 2.8 mm. Colouration (Dry specimen). Head, face and clypeus dark brown; labellum dark brown; palpus yellow. Antenna with scape and pedicel yellow; flagellum pale brown, basal half of first flagellomere pale. Thorax with scutum dark brown, anterior and lateral margin paler; lateral sclerites and propleura brown; halteres whitish-yellow. Legs whitish-yellow. Abdomen dark brown with pale lateral area confined to ventral margin of tergite II and basolateral part of tergite III. Terminalia yellow. Head. Vertex, frons and clypeus covered with pale setae. Antenna 1.9 times as long as length from vertex to ventral margin of clypeus; flagellomeres longer than broad, with sixth flagellomere 1.2 times 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 20 anterior, 4 posterodorsal, 10 posterior and 3 posteroventral bristles. Hind tibia with 6 anterodorsal, 5 posterodorsal and 3 posterior bristles. Wings. Vein r-m 2.22 times longer than stem of M-fork. Abdomen. Tergites covered with pale setae. Terminalia (n = 2, Fig. 23 a, b, c). Each part of divided tergite IX with about 7-8 setae, most apical seta stout. GL with length 0.42-0.48 gonocoxite width, apico-internal margin slightly angled exteriorly, basal third covered with setae, apex with 3 setae (Fig. 23 a, b). Aedaegal guides short with acute apex. Hypandrium covered with about 12 setae, with the apical pair reaching about half of the GL (Fig. 23 a, b). Hypandrial lobe with each part apically slightly widened. Gonostylus (Fig. 23 c) with DB about 2.4 times longer than broad, distinctly 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 and slightly protruding angle, with row of 4 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 = 4): Body length 2.6-2.8 mm. Wing length 2.4-2.5 mm. Colouration (Dry specimen). Head, face and clypeus dark brown; labellum and palpus yellow. Antenna with scape and pedicel yellow; flagellum pale brown, basal half of first flagellomere pale. Thorax with scutum brown to dark brown; lateral sclerites brown; propleura brown; halteres whitish-yellow. Legs whitish-yellow. Abdomen brown to dark brown, tergites II-VI with pale lateral areas extending dorsally at anterior fourth to third of tergite III and anterior third to half of tergite IV, forming two distinct pale bands. Terminalia pale brown. Head. Vertex, frons and clypeus covered with pale setae. Antenna 1.75-1.9 times as long as length from vertex to ventral margin of clypeus; flagellomeres slightly longer than broad, with sixth flagellomere (n = 2) 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 20-24 anterior, (n = 3) 3 posterodorsal, (n = 3) 6-8 posterior and 1-3 posteroventral bristles. Hind tibia with (n = 3) 6-7 anterodorsal, 4 posterodorsal and 3-4 posterior bristles. Wings. Vein r-m 2.0-2.2 times longer than stem of M-fork. Abdomen. Tergites covered with brown setae on dark areas and pale setae on pale areas. Terminalia (Fig. 23 d, e). Cerci with basal segment 0.6 times as long as basal segment. Tergite VIII with apicolateral margin forming distinctly protruding angle (Fig. 23 d). Sternite VIII (Fig. 23 e) with hypogynal valves separated by narrow cleft with depth about one-sixth of sternite VIII length; apical seta 0.6-0.67 of sternite VIII length. Gonapophysis IX with basolateral part expanding in relatively obtuse angle; spermathecal eminence trilobed, in ventral view appearing cross-shaped; apically with about 8 small setae.

Diagnosis

Distinguished from E. repanda , E. subrepanda and E. neorepanda in having the dorsal gonostylus branch more curved and with external margin forming a distinct protruding angle, with the external row of setae covering only about one sixth of the total dorsal gonostylus branch length (Fig. 23 c), in combination with the gonocoxal lobe length only 0.42-0.48 times the gonocoxite width (Fig. 23 a, b); from other species in the E. parva group in having the dorsal branch about 2.4 times longer than broad (Fig. 23 c), in combination with the gonocoxal lobe covered with setae on about the basal third, with the apico-internal margin slightly angled exteriorly (Fig. 23 a, b).

Etymology

From Latin curvus, curved, relating to the shape of the dorsal branch of the gonostylus.

Distribution

Nearctic, Canada, USA (Fig. 13 ).

Biology

Adult collected in temperate mixed forest.

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).