Pseudexechia endybalensis Polevoi, 2023

Polevoi, A. V. & Potapova, N. K., 2023, New data on the fungus gnats (Diptera: Keroplatidae, Mycetophilidae) of Yakutia with description of three new species, Far Eastern Entomologist 478, pp. 1-22 : 16-18

Pseudexechia endybalensis Polevoi , sp. n.

https://zoobank.org/NomenclaturalActs/ BD78E0BA-B135-4BC7-9DCC-717857DA190C

Figs 22–25

TYPE MATERIAL. Holotype – ♂, Russia, Yakutia , mouth of River Endybal , 65.621° N, 130.277° E, 730 m, 1.VIII 2015, A. Popov leg. [ ZISP, INS _DIP_ 0001010].

DIAGNOSTIC CHARACTERS. Medium-sized brown species with, yellow legs and transparent wings. Belongs to trisignata group ( Kjaerandsen, 2009). Resembles Pseudexechia tuomikoskii Kjaerandsen, 2009 by the structure of male terminalia, but distinguished by the following characters ( Figs 22–25 ): hypandrial lobe with medial projections not protruding beyond the apex of the lobe; tip of dorsal branch not whitish, ventral branch of gonostylus with small subtriangular apical projection and strong ventrolateral blunt (not fan-tipped) setae; hypoproct truncate apically (cf. Kjaerandsen, 2009: Fig. 8 A–C ).

DESCRIPTION. Male. Head dark brown. Three ocelli in a shallow triangular arrangement. Lateral ocellus almost touching the margin of compound eye. Face and clypeus dark brown, mouthparts and palpi yellow. Antenna dark brown except yellow scape, pedicel and basal half of the first flagellomere. Fifth flagellomere about as long as broad.

Thorax. Mesonotum brown, thinly dusted. Scutellum brown. Pleurae brown except antepronotum, proepisternum and area around prothoracic spiracle. Laterotergite with few setae posteriorly, mediotergite bare. Halter yellow.

Wing. Length 3.29 mm. Veins brownish. Costa not produced beyond the tip of R5. Sc short, ends in R1. M-stem 1.06 as long as r-m. Base of posterior (M 4 -CuA) fork lies distally to base of M1-M2 fork. R1 and R5 setose, other veins bare.

Legs (partly missing). Coxae, trochanters, femorae, tibiae and tarsi yellow. Mid tibia with 3 longer and 17 shorter a, 3 pd and 3 p. Ratio of tibia to basitarsus for mid leg: 1.18. Tibial spurs yellow.

Abdomen brown with brownish hairs.

Terminalia brown. Gonocoxite slightly longer than wide, with deep funnel shaped apical excavation, bearing numerous strong setae along mesial margin ( Fig. 22 ). Hypandrial lobe subovate, median projections not produced beyond the apicolateral corners ( Fig. 24 ). Gonostylus ( Fig. 25 ): dorsal branch widely rounded apically, more or less uniformly sclerotized; dorsointernal branch forming a lamellate fan; ventral branch shaped as rounded spatula, with slightly protruding angular tip, ventrolaterally with 5 blunt-tipped setae; internal branch forming, striated cushion; anterior branch subrectangular, projecting caudally. Tergite 9 ( Fig. 23 ) wide, with strong median suture. Pseudocercus long, setose. Cercus forming setose ovate knob. Hypoproct relatively long, truncate apically.

DISTRIBUTION. So far known only from the type locality in the North-East Yakutia .

HABITAT AND BIOLOGY. Collected in herb rich meadow in Chosenia stand. Larval biology unknown.

ETYMOLOGY. The Species epithet refers to the type locality, Endybal River.

Figures

Figs 22–25. Male terminalia of Pseudexechia endybalensis sp. n. 22 – ventral view; 23 – tergite 9; 24 – hypandrial lobe; 25 – gonostylus, mesial view. Abbreviations: hl – hypandrial lobe; hp – hypoproct; mphl – median projection of hypandrial lobe; vbg – ventral branch of gonostylus. Scale bar = 0.2 mm.

Figs 8–10. Male terminalia of Macrorrhyncha nocticolor sp. n. 8 – ventral view; 9 – lateral view; 10 – dorsal view. Scale bar = 0.2 mm.