Thrypticus bolevensis, Kejval & Pollet, 2024

Kejval, Zbyněk & Pollet, Marc, 2024, Long-legged flies (Diptera: Dolichopodidae) in the Czech Republic- 2. Corindia and Thrypticus, Zootaxa 5432 (3), pp. 411-424 : 415-417

Thrypticus bolevensis sp. nov.

( Figs 5–10 , 12 )

Type locality. Czech Republic, Plzeň-Bolevec, NW bank of Velký bolevecký rybník (pond), 49°46′39″N 13°23′37″E, altitude 310 m.

Material examined. HOLOTYPE ♂ ( Fig. 12 ), labelled: “CZ-Bocc 6246, 18.7.2023 PLZEŇ-Bolevec, V. Bolevecký rybník (pond banks), 310 m, Z. Kejval leg. 49°46′39″N 13°23′37″E ” ( NMPC) . PARATYPES: 3 ♂, same data as holotype, except: 2.6.2022, 49°46′33.5″N 13°23′27″E ( NMPC) ; 1 ♂ “CZ-Bocc 6246, 3.8.2023 PLZEŇBolevec, Senecký rybník (pond bank), Eleocharis , ca 325 m, Z. Kejval leg. 49°47′07″N 13°23′31″E ” ( NMPC) .

Description. Male (holotype). Body length 1.7 mm; wing length 1.5 mm, 0.5 times as wide as long.

Head. Vertex, frons and face metallic green to bluish green, very thinly dusted; face at its narrowest about 0.8 times as wide as length of clypeus, and slightly wider than postpedicel length; ocellar and outer vertical bristles black; upper postocular bristles mostly brownish and short, with five lowermost markedly longer and pale yellowish; palpus brownish black, with several short black apical bristles; proboscis brown. Antenna entirely black, scape bare dorsally, pedicel with subapical crown of short dark bristles, postpedicel subcircular, slightly wider than long; aristalike stylus apical, dark, microscopically pubescent, slightly shorter than eye size, and with rather delicate apex.

Thorax. Mesonotum shiny metallic bluish green, including pleura and scutellum, slightly violet dorso-medially; dorsum and pleura very thinly dusted and lacking obvious pattern; scutellum finely rugose. Most thoracic bristles brownish; field of setulae dorso-laterally, extending to transverse suture; about 6 pairs of short acrostichal bristles, increasing in size/length posteriorly; 5 pairs of dorsocentral bristles, increasing markedly in size/length posteriorly; other thoracic bristles (all paired): 1 tiny white proepisternal, 1 tiny anterior postpronotal, 2 notopleural, 1 basal external postpronotal, 1 sutural intra-alar, 1 supra-alar, and 1 postalar bristles; scutellum with only one pair of strong median bristles (no lateral setulae).

Legs. Coxae I and III dark, metallic green, II somewhat paler, brownish, and only slightly shiny; trochanters yellowish to brown, with trochanter III paler. All femora largely dark, metallic green with narrow yellow base and apical part yellow on apical third/half on inner side. All tibiae dark, brownish, somewhat paler on inner side. All tarsi dark, brownish black. Vestiture of legs mostly brownish to black, only coxae with pale yellowish bristles; coxa III with two lateral bristles. Femur I with tiny posterior preapical bristle; femur II with distinct posterior and much shorter anterior preapical bristle. Tibia I void of any distinct bristles; tibia II with weak anterodorsal bristle in basal third.All legs unmodified. Ratio of femur/tibia/tarsomeres 1–5 in leg I: 8.9/8.9/4.0/1.7/1.3/1.0/1.6; leg II: 8.3/8.6/4.8/ 2.5/1.5/1.0/1.5; and leg III: 7.8/8.0/2.6/3.2/1.6/1.0/1.1. Wing. Hyaline, with dark veins; shape oval, posterior margin in basal half distinctly convex, with obsolete anal lobe; veins R 4+5 and M 1 parallel, very gently curved posteriorly but almost straight in apical third; lower calypter whitish with pale brownish setae. Halter with yellow knob and partly dark shaft. Abdomen. Tergites metallic bluish green, shiny; vestiture pale brownish, marginal bristles at least twice as long as discal setae; sternites dark, partly metallic green. Epandrium largely brownish black, except for pale brownish to yellowish tip and epandrial lobes; epandrial lobes ( Fig. 6 ) fused and of different lengths, each bearing one strong apical seta. Cercus ( Fig. 5 ) pale yellowish brown, elongate, with simple, straight and rounded apical process, slightly exceeding apex of surstylus in lateral view. Surstylus ( Fig. 5 ) largely pale yellowish brown, with distinctly darker, black terminal part, moderately wide in lateral view and narrowly produced apically, nearly evenly ovoid in ventral view ( Fig. 6 ); ventral margin of surstylus in lateral view with 5 paired bristles (3 minute pairs and another 2 much longer and robust), two of which articulated on distinct protrusions, with distal pair of robust bristles pointing mediad ( Figs 5, 6 ); apex of surstylus obliquely subtruncate and bluntly pointed. Hypandrium ( Figs 7–10 ) and phallus brownish; hypandrium with distinct ventral swelling, sharply angular in lateral view, formed by three laterally flattened protrusions (indicated in Fig. 8 ); tip of phallus with rather sharply angular ventral projections.

Female. Unknown.

Variation. Body length (♂): 1.6–1.8 mm; anterodorsal bristle of tibia II present (weak) to indistinct.

Differential diagnosis. Thrypticus bolevensis sp. nov. is characterized by coloration (entirely black antennae, largely dark legs, partly yellowish brown hypopygium), scutellum with single pair of strong marginal bristles (lacking also any minute setulae), oval shape of wings and mainly by shape and setation of the male hypopygial appendages. It may resemble Thrypticus intercedens and T. pollinosus by some male characters, e.g. apically rather rounded or at most subtruncate surstylus (in lateral view, any apical excavation lacking) and more prominent ventral swelling of hypandrium, but differs from these (and all other) species by the angular ventral margin of the surstylus (in lateral view, Fig. 5 ), with two pairs of distinct protrusions bearing bristles.

Etymology. Named after the type locality (Plzeň-Bolevec, Bolevecké rybníky ponds).

Distribution. Czech Republic.

Ecology. All specimens were swept on or near pond banks, either directly from Eleocharis palustris or from littoral vegetation with a conspicuous presence of this or related plants ( Figs 1, 2 ). The following monocotyledon genera and species were also present, mostly in larger quantities: Bolboschoenus maritimus (Linnaeus) , Carex spp. , Phragmites australis , Juncus spp. , and Schoenoplectus lacustris .

Figures

FIGURES 5–10. Thrypticus bolevensis sp. nov. (paratype). 5, terminal part of hypopygium, lateral view; 6, same, ventral view; 7, hypandrium, lateral view; 8, same, dorsal view; 9, phallus, lateral view; 10, phallus, detail of its apex, lateral view. Scale (0.2 mm): A—Figs 7–9, B—Figs 5, 6; (0.1 mm): C—Fig. 10.

FIGURES 11–14. 11–13, Thrypticus habitus, lateral view. 11, T. atomus Frey (female, Horšovský Týn); 12, T. bolevensis sp. nov. (male, holotype); 13, T. cuneatus (Becker) (male, Plzeň-Bolevec); 14, T. atomus (Horšovský Týn, female ovipositor). All photos by Z. Kejval. Scale (1 mm)—Figs 11–13; (0.1 mm)—Fig. 14.

FIGURES 1–4. Collecting sites in Bohemia (Czech Republic) for Thrypticus species. 1, 2, Plzeň-Bolevec, NW banks of Velký bolevecký rybník, at extremely low (June 2022) and artificially raised water level (July 2023), with abundant Eleocharis palustris, Juncus spp. and Phragmites australis; 3, 4, Kateřina, Soos NNR, salt marshes with extensive Schoenoplectus tabernaemontani stands. All photos by Z. Kejval.