Tropidopsilus orientalis Kawai & Chemyreva, 2025

Tropidopsilus orientalis Kawai & Chemyreva , sp. nov.

Figs 4A–F View FIGURE 4 , 5A–D View FIGURE 5

Type material. Holotype: 1♀ ( ELKU), Japan, Honshu, Aichi Pref., Toyota, Takiwaki , ( MT), 24–30 VI 2002, K. Yamagishi leg. Palatypes: 1♂ ( ELKU), 1♀ ( NBC), same locality as holotype, 5–11 VIII 2002, K. Yamagishi leg., 1♀ ( NBC), Japan, Honshu, Aichi Pref., Seto , Misawa , ( MT), 22–31 VII 2003, K. Yamagishi leg.

Differential diagnosis. Distance between toruli as long as diameter of torulus ( Fig. 4C View FIGURE 4 ); female antenna weakly incrassate apically with F1 shorter than F2 and F3 measured together; all flagellomeres cylindrical, longer than wide in lateral and dorsal view; male F1 with keel and emargination extending to 0.4 of segment length; pronotal collar visible in dorsal view; scutellar disc not humped and without posterior mesoscutellar sulcus ( Fig. 4F View FIGURE 4 ); mesopleuron without epicnemial and subalar bridges, with distinct epicnemial pit ( Fig. 4D View FIGURE 4 ); metascutellum without spine medially; parastigma, marginal vein and radial cell almost equal to each other; Т2 anteriorly smooth, without medial furrow and lateral impression ( Figs 4F View FIGURE 4 , 5A View FIGURE 5 ).

Description. Female (holotype). Body length except ovipositor 2.6 mm, wing length 2.0 mm. Meso- and metasoma testaceous, head brown and legs yellowish.

Head. Head in dorsal view wider than long (32: 21), wider than mesosoma (32: 27), in frontal view slightly wider than high (32: 31). OOL: POL: LOL=7: 4: 3. Occipital flange very narrow, smooth. Epistomal sulcus distinct. Tentorial pits large. Clypeus convex and faintly rugulose, semicircular, with straight ventral margin, wider than high (15: 13). Pleurostomal distance as long as shortest distance between eye and longer than width of clypeus. Labrum exposed, semicircular. Face including antennal shelf below toruli, rugulose in frontal view. Toruli separated from each other by furrow, distance between toruli as long as diameter of torulus. Eye setose, its largest diameter much longer than malar space (40: 7) in lateral view.

Antenna. Scape slightly curved with simple apical rim. Outer side of scape smooth and bare. Inner side of scape setose. Flagellum gradually thickened toward apex. F8–F13 slightly wider than F1–F7. Ratios of length to maximal width of each flagellomeres in dorsal view: F1 60: 10; F2 45: 10; F3 40: 10; F4 35: 12; F5 35: 12; F6 30: 12; F7 28: 12; F8 26: 15; F9 26: 15; F10 23: 15; F11 23: 15; F12 23: 15; F13 38: 15. Ratios in lateral view: F1 24: 4; F2 180: 4; F3 14: 4; F4 14: 4; F5 14: 4; F6 12: 4; F7 10: 4; F8 10: 5; F9 8: 6; F10 8: 6; F11 8: 6; F12 8: 6; F13 14: 6. Pubescence of antennae heterogeneous, with intermittent long erect setae scattered through denser shorter setae.

Mesosoma. Mesosoma convex, longer than wide (41: 27) and higher than wide (11: 10). Pronotal shoulder prominent, with sharp prominent epomia. Lower and lateral branch of epomia complete. Pronotal collar vertical, with transverse carina between pronotal shoulders. Lateral part of pronotum impressed and smooth, dorsal and posterior areas of lateral part of pronotum covered by scattered setae. Anterior scutellar pit deep with long setae posteriorly, anteriorly open (not margined), with straight and distinct posterior margin ( Fig. 4F View FIGURE 4 ). Scutellar disc large, convex, smooth, with long setae. Axillar depressions smooth, with a pair of verriculate tubercles. Mesopleuron smooth, bare medially and pubescent dorsally and ventrally; epicnemial pit deep, with sharp edge postero-dorsally. Metascutellum with strong median carina and lower lateral carina. Propodeum transverse. Dorsal area of propodeum covered by long setae. Median keel of propodeum simple; plica disappear in anterior one-third, produced into a tooth posteriorly; lateral longitudinal carina of propodeum complete, produced into a small tooth posteriorly ( Fig. 4D View FIGURE 4 ). Submetapleural carina present. Metapleuron laterally with two almost fused large depressions: upper depression with a few scattered setae inside, lower depression bearing three vericulate tubercles. Nuchal area, ventral side of metapleura (between meso- and metacoxa in lateral view) and base of metacoxa each with a pair of verriculate tubercles.

Wing. Fore wing with distinct costal, subcostal, basal, marginal, postmarginal, stigmal and radial veins. Marginal vein slightly shorter than radial cell (5: 6) and as long as parastigma.

Metasoma. Petiole cylindrical, 3.7 times as long as its maximum width in dorsal view, with irregular longitudinal striation and covered with numerous tufts of setae ventrally. Gaster with seven clearly differentiated tergites and five sternites. T2 anteriorly without medial furrow and lateral impression, remainder of T2 as well as following segments smooth. All tergites with sparse, scattered setae. S2 not humped anteriorly, covered with long setae. S3–S6 short, with long setae. S7 elongate and compressed, with long setae. Ovipositor long and exposed, slightly longer than length of T2 (38: 37).

Variation. Females (n=3). Body length, except ovipositor, (only specimens with border between petiole and T2 base not bent) 2.4–2.6 mm. Maximum width of eye 5.7–6.3 times longer than malar space. Marginal vein 0.8–1.0 times longer than radial cell and 1.0–1.3 times longer than parastigma. Petiole length 3.4–4.0 times longer than its maximum width. Length of exposed part of ovipositor 0.8–1.0 times longer than length of T2.

Male. Body length 2.5 mm. Similar to female except following characters: head in frontal view as long as height, in dorsal view wider than mesosoma (15: 13); malar space longer than that of female, 0.4 times as long as largest diameter of eye; pleurostomal distance shorter than shortest distance between eyes; flagellum 12-segmented, filiform; F1–F11 gradually shortened toward apex; radial cell slightly shorter than marginal vein (9: 10); marginal vein longer than parastigma (20: 17); petiole 3.1 times as long as maximum width in dorsal view; sternites with eight differentiated segments; tip of aedeagus bifurcate. Ratios of length to maximum width of each flagellomeres in dorsal view: F1 56: 10; F2 48: 10; F3 43: 10; F4 43: 10; F5 38: 10; F6 38: 10; F7 34: 10; F8 34: 10; F9 30: 10; F10 30: 10; F11 30: 10; F12 43: 10, in lateral view: F1 22: 4; F2 18: 4; F3 17: 4; F4 17: 4; F5 16: 4; F6 14: 4; F7 12: 4; F8 12: 4; F9 12: 4; F10 12: 4; F11 10: 4; F12 16: 4.

Comparative diagnosis. The new species differs from Tropidopsilus laticeps in the following characters: mesopleuron without epicnemial and subalar bridges (with both bridges in T. laticeps ); scutellar disc longer than anterior scutellar pit (shorter in T. laticeps ) and moderately convex (strongly convex in T. laticeps ); median carina of metascutellum not forming a spine (forming a long spine in T. laticeps ); radial cell as long as marginal vein (shorter than marginal vein in T. laticeps ). The new species is very close to Tropidopsilus rubra (Buhl) and differs from it only in the following: pronotal collar visible in dorsal view and mesonotum moderately convex (pronotal collar not visible dorsally, mesonotum strongly convex in T. rubra ); posterior mesoscutellar sulcus absent (present in T. rubra ); median carina of metascutellum not forming a spine (with a short spine in T. rubra ); base of T2 smooth (with longitudinal furrow in T. rubra ).

Etymology. The name of this species is the Latin adjective orientalis , meaning “eastern”.

Distribution. Japan (Honshu; Aichi).

Biology. Host unknown. The two Malaise traps were located in different deciduous secondary forest ( Fig. 6 View FIGURE 6 ).