Streblocera (Streblocera) necurvata Long, 2025

Streblocera (Streblocera) necurvata Long , sp. nov.

Figures 15 View FIGURE 15 , 16 View FIGURE 16 , 21 View FIGURE 21

Type material. Holotype, ♀, labelled “Euph. 391 ”, ( IEBR), NE Vietnam: Lang Son, Huu Lung , Huu Lien NR, forest, MT, 21°38’43’’N 106°21’41’E, 187 m, 15.ii.2024, PQ Mai, TD Duong.

Diagnosis. Small wasp, scapus without basal tooth-like; S. (S.) necurvata , sp. nov., is similar to S. (S.) curvata Belokobylskij , from Nepal, but differs from the latter by having: 1) Occipital carina incomplete medio-dorsally (vs occipital carina complete medio-dorsally in S. (S.) curvata ); 2) First metasomal tergite 1.8 × as long as its apical width [vs 2.3 × in S. (S.) curvata ]; 3) Length of scapus 6.6 × its maximum width [vs 9.0 × in S. (S.) curvata ]; and 4) Antenna with 16 antennomeres [vs 17–18 antennomeres in S. (S.) curvata ].

Description. Holotype, ♀; body length 2.0 mm, fore wing length 2.3 mm, ovipositor 0.3 mm ( Fig. 15 View FIGURE 15 ).

Head. Antenna with 16 antennomeres; length of scapus 6.6 × its maximum width ( Fig. 16E View FIGURE 16 ); scapus 1.8 × of head height; first flagellomere strongly curved, with hook apically, 5.5 × as long as its width medially and 2.75 × second flagellomere ( Fig. 16E View FIGURE 16 ); in dorsal view, occipital carina incomplete medio-dorsally ( Fig. 16A View FIGURE 16 ), width of head 1.55 × its median length, and 1.4 × width of mesoscutum (without tegulae); temple roundly narrowed behind eye; length of eye 1.3 × as long as temple; POL: OD: OOL= 3: 2.5: 6 ( Fig. 16A View FIGURE 16 ); eye 1.8 × as high as broad; in lateral view, transverse diameter of eye 1.1 × temple; in frontal view, diameter of antennal socket as long as distance between sockets; face width as long as length of face and clypeus combined, and 1.25 × height of eye; clypeus margin straight ( Fig. 16B View FIGURE 16 ); malar space 0.9 × as long as basal width of mandible, and 0.3 × as long as eye height; distance between tentorial pits 1.75 × distance from pit to eye margin; face and clypeus densely setose ( Fig. 16B View FIGURE 16 ); frons flat, smooth; temple and vertex polished smooth ( Figs 16A, C View FIGURE 16 ).

Mesosoma. In lateral view, length of mesosoma 1.6 × as long as its height; notauli narrow, punctate anteriorly, sparsely crenulated posteriorly ( Fig. 16D View FIGURE 16 ); prescutellar sulcus narrow, with one carina, 0.5 × as long as scutellum; mesoscutal lobes and scutellum smooth; pronotal side sparsely crenulate medially; smooth dorsally and ventrally; precoxal sulcus short, oblique, densely punctate ( Fig. 16F View FIGURE 16 ); mesopleuron smooth highly smooth; metapleuron sparsely rugose; propodeum without basal carina, smooth antero-laterally, with two sinuate-divergent rugosities baso-medially and sparse rugosities posteriorly ( Fig. 16G View FIGURE 16 ).

Wings. Length of fore wing 3.0 × its width; length of pterostigma 3.2 × its width, and 1.9 × vein 1-R1 ( Fig. 16I View FIGURE 16 ); vein r arising distinctly behind middle of pterostigma, 0.3 × as long as width of pterostigma, and 0.2 × vein 1-R1; vein 1-CU1: cu-a: 2-CU1 = 2.0: 2.5: 8.0; length of hind wing 4.2 × its width; 1-M: 1r-m: 2-SC+R = 3: 5: 5.

Legs. Length of hind femur, tibia and basitarsus 5.6, 11.7 and 8.7 × as long as their maximum width, respectively; hind basitarsus 0.4 × hind tibia, and 0.8 × second-fifth tarsus combined; fourth hind tarsus 0.75 × as long as fifth tarsus (without pretarsus).

Metasoma. Length of first tergite 1.8 × its apical width, apical width of first tergite 2.5 × its minimum width ( Fig. 16H View FIGURE 16 ); ovipositor 0.1 × fore wing, and 0.7 × first tergite; ovipositor flat, slightly curved upwards; first metasomal tergite sparsely rugose basally, striate medially, largely smooth apically ( Fig. 16H View FIGURE 16 ); the rest tergites highly smooth.

Colour. Head yellow; stemmaticum dark brown; eyes silver-grey; scapus and pedicel yellow; flagellum yellowish brown; all legs yellow; propleuron, mesopleuron and metapleuron yellow; mesoscutal lobes yellowish brown to brown; scutellum yellow; propodeum yellowish brown basally, yellow apically; first metasomal tergite brown, the remainder brownish yellow; ovipositor sheath brown; pterostigma pale yellow, darker ventrally; wing veins pale yellow; wing membrane hyaline.

Male. Unknown.

Host: Unknown.

Etymology. “ ne ” Latin meaning “not” and “curvata ”, in reference to it being close to but different from S. (S.) curvata Belokobylskij, 2000 , from Nepal.

Distribution. NE Vietnam: Lang Son province (Huu Lien NR) ( Fig. 21 View FIGURE 21 ).