Trachionus polongongius, Geng & Zheng, 2022

Geng, Jun-Ling & Zheng, Min-Lin, 2022, A new species of Trachionus Haliday (Hymenoptera: Braconidae: Alysiinae) from China, Zootaxa 5219 (1), pp. 97-100 : 97-100

Trachionus polongongius sp. nov.

Figs 1–11 .

Type material. Holotype, female [Southwest of China] Tibet, Motuo, Bononggong , 24.vii.2014, Ling-fei Peng . Paratype: 1♀, same data as holotype .

Description. Female (holotype). Body length 2.9 mm; fore wing length 2.8 mm.

Head. Antenna almost as long as body, 29-antennomeres, first flagellomere 1.25× longer than second flagellomere, first, second, median (fourteenth flagellomere) and penultimate flagellomeres 2.3, 2.0, 1.3 and 1.6× as long as wide, respectively; width of head 2.5× its median length, smooth and shiny dorsally, sparsely setose; frons relatively flat and smooth; eye in dorsal view 1.7× longer than temple; stemmaticum distinctly convex, posterior ocellus oval and relatively big, OOL: diameter of ocellus: POL = 40:14:13; area between antennal sockets rugose and punctured, shiny; face somewhat elevated medio-dorsally, more or less shiny and densely punctulate, with upward pointing long setae and somewhat dense close to eye; epistomal suture narrow and deep, densely crenulate ( Fig.2 ); clypeus transverse, more or less convex, densely punctulate dorsally and smooth ventrally; mandible 1.6× as long as its maximum width, strongly rugose and with many long seta on its basal half part; mandible extremely close to eye, length of malar space 0.1× basal width of mandible; mandible hardly widened apically, first and third tooth triangular and somewhat obtuse, second tooth longest and quite acute, ventral tooth as long as first or third tooth and relatively slender; maxillary palp 5-segmented, 0.9× height of head.

Mesosoma. Length of mesosoma 1.4× its height; side of pronotum almost entirely coarsely punctate, and strongly crenulate on the anterior side of this area; epicnemial area largely rugose-punctuate; precoxal sulcus wide and complete, strongly rugose-crenulate; dorsal half of pleural sulcus narrow and finely crenulate, ventral half of pleural sulcus wide and strongly crenulate; episternal scrobe wide and coarsely punctuate; anterior half of sternaulus wide and coarsely rugose, posterior half of sternaulus present as two longitudinal rows of coarse punctations; remainder of mesopleuron smooth; mesosternal sulcus wide and coarsely rugose; metapleuron strongly reticulate-rugose; mesoscutum mostly strongly rugose-punctuate, moderately distributing with backward pointing setae, only its lateral lobes glabrous, smooth and shiny medially; median groove of mesoscutum and notauli rather indistinct due to the very coarsely rugose-punctate surface; scutellar sulcus deep, with 3 longitudinal carinae, 0.45× as long as scutellum; scutellum convex, very coarsely rugosepunctate, sparsely and evenly setose on its anterior half, somewhat densely setose posteriorly; metanotal spine distinctly protruding above level of scutellum; propodeum almost vertically lowered posteriorly in lateral view and postero-laterally with somewhat protruding carinae, its surface coarsely foveolate-punctate, median carina present as a narrow areola on its horizontal part and indiscernible on vertical part ( Fig. 5 ).

Wings. Pterostigma sub-elliptical, 4.0× as long as wide, 0.85× as long as vein 1-R1; 1-R1 8.9× as long as vein 2-R1; vein r issued nearly from middle of pterostigma; r:2-SR:3-SR+SR1=4:8:25; vein SR1 slightly curved; 1-CU1:2- CU1=2:17; M+CU1:1-M:m-cu=38:16:11; first subdiscal cell closed; 3-CU1:CU1b=5:3; vein m-cu distinctly antefurcal; vein 1-CU1 widened. Hind wing: M+CU:1-M:1r-m=14:6:7; intersection of vein cu-a and 1-1A arcuate; m-cu absent.

Legs. Hind coxa mainly smooth; all femora somewhat widened; length of femur, tibia and basitarsus of hind leg 3.1, 6.3 and 4.8× their width, respectively.

Metasoma. Length of first tergite almost equal to its apical width, somewhat convex medially, its surface coarsely punctuate and with about 10 longitudinal coarse striae, dorsal carinae converging medially and united in distinct median carina; second united third tergites punctuate-striate, carapace-like and wholly hiding apical tergites ( Fig.9 ); apex of carapace without carinae or striae, just present as a granular coriaceous area ( Fig.10 ); side of carapace acutely protruding ventrally on about three-quarter part and nearly forming a right angle in this area ( Fig.10 ); ovipositor sheath apically acute and bending somewhat upward; hypopygium large and apically acute.

Colour. Body mainly black; scapus and pedicellus of antenna reddish brown, remainder of antennomeres black; mandible black; palpi yellowish; tegula reddish yellow; pterostigma and veins of fore wing dark brown; legs mainly dark yellow except tarsi dark brown; ovipositor dark yellow, its sheath dark brown.

Male: unknown.

Host: unknown.

Etymology. The species name is derived from the Chinese name of the collecting place: “Bolonggong” village of Motuo County, Tibet Autonomous Region, China.

Distribution. Only known from Tibet (Southwest Palaearctic China)

Remarks. This new species is similar to Trachionus kotenkoella (Perepechayenko) , but differs from it as follows: 1) epistomal suture distinctly and densely crenulate (epistomal suture not crenulate in T. kotenkoella ); 2) side of carapace acutely protruding ventrally on about threequarter part and nearly forming a right angle in this area (side of carapace very gently protruding ventrally and at most form a very obtuse angle in this area for T.kotenkoella ); 3) apex of carapace without carinae or striae, just present as a granular coriaceous area (apex of carapace with sharp carinae in T.kotenkoella ).

Figures

FIGURE 1. Trachionus polongongius sp. n., female, holotype. Habitus lateral.

FIGURES 2–11. Trachionus polongongius sp. n. 2. head (frontal view); 3. head (dorsal view); 4. head (lateral view) 5. propodeum (dorsal aspect); 6. metasoma (dorsal aspect, showing first tergite); 7. mesosoma (dorsal aspect); 8. mesosoma (lateral aspect); 9. metasoma (dorsal aspect, showing tergites beyond T1); 10. metasoma (lateral view); 11. wings