Trachyusa microporosa, Zhu & Achterberg & Chen, 2025

Zhu, Jiachen, Achterberg, Cornelis Van & Chen, Xuexin, 2025, A revision of five genera of Alysiini (Hymenoptera, Braconidae, Alysiinae) from China, with description of five new species, Zootaxa 5569 (3), pp. 401-438 : 416-418

Trachyusa microporosa sp. nov.

Figs 11–12

Type material. Holotype, ♀ ( ZJUH), “ [SE. China:] Guizhou, Kuankuangshui , 4.vi.2010, Tang Pu, No. 201002964”.

Diagnosis. Body (except most of mesosoma) dark brown ( Fig. 11 ); eye in lateral view 1.3 × higher than wide ( Fig. 12K ); frons flat and smooth; vertex rather convex; OOL:diameter of ocellus:POL= 7:3:4; face 1.2 × wider than high, rather evenly convex, with some long setae and punctures ( Fig. 12I ); clypeus semicircular and medium-sized, rather flat, with some punctures ( Fig. 12J ); length of malar space 0.35 × basal width of mandible; first and third teeth of mandible small, middle (= second) tooth wide and acute, distinctly longer than lateral two tooth and with orthogonal protuberance on upper margin( Figs 12L, 12M ). notauli only impressed anteriorly, smooth and narrow and absent posteriorly, medio-posterior depression small ( Fig. 12D ); mesoscutum largely glabrous; mesoscutum slender and 1.1 × longer than wide ( Fig. 12D ); surface of propodeum densely and coarsely reticulate-rugose, areola absent ( Fig. 12E ); pterostigma elliptical; vein r 0.4 × width of pterostigma; cu-a of fore wing postfurcal ( Fig. 12A ); hind coxa smooth ( Fig. 12D ); setose part of ovipositor sheath 0.05 × as long as fore wing (total sheath 0.09 times), flattened and setose basally and 0.15 × as long as hind tibia. ( Fig. 12G ).

Description. Holotype, ♀, length of body 2.7 mm, of fore wing 2.5 mm.

Head. Comparatively transverse and shiny in dorsal view ( Fig. 12I ), width of head 1.7 × its lateral length; antenna with 29 antennomeres, bristly setose but basally less so, first flagellomere (including annellus) 1.2 × longer than second flagellomere, length of first, second and penultimate flagellomere 5.0, 4.3 and 2.3 × their width, respectively ( Fig. 12H ); length of maxillary palp 1.2 × height of head; eye in dorsal view 1.5 × as long as temple ( Fig. 12I ); eye in lateral view 1.3 × higher than wide ( Fig. 12K ); frons flat and smooth; vertex rather convex; OOL:diameter of ocellus:POL= 7:3:4; face 1.2 × wider than high, rather evenly convex, with some long setae and punctures; clypeus semicircular and medium-sized, rather flat, with some punctures ( Fig. 12H ); length of malar space 0.35 × basal width of mandible; first and third teeth of mandible small, middle tooth wide and acute, distinctly longer than lateral teeth and with orthogonal protuberance on its upper margin; medial length of mandible 1.9 × its maximum width.

Mesosoma. Length of mesosoma 1.7 × its height; pronope round, large and deep; side of pronotum smooth but medio-anteriorly and posteriorly indistinctly crenulated ( Fig. 12I ); mesoscutum with lateral carina in front of tegulae ( Fig. 12C ); epicnemial area smooth but crenulated ventrally; precoxal sulcus indistinctly crenulated medially and absent anteriorly and posteriorly ( Fig. 12C ); remainder of mesopleuron smooth; pleural sulcus crenulated; episternal scrobe small, linear and connected with pleural sulcus; metapleuron densely and coarsely reticulate-rugose, with a round small pit present anteriorly ( Fig. 12C ); notauli only impressed anteriorly, smooth and narrow, medio-posterior depression of mesoscutum small ( Fig. 12D ); mesoscutum largely glabrous; mesoscutum slender and 1.1 longer than wide; scutellar sulcus crenulated and lateral part 3.3 × wider than its maximum length ( Fig. 12D ); surface of propodeum densely and coarsely reticulate-rugose, areola absent ( Fig. 12E );

Wings ( Figs 12A–B ). Pterostigma elliptical; r:3-SR:SR1 = 3:16:63; vein r 0.44 × width of pterostigma; cu-a postfurcal; 1-CU1:2-CU1 = 1:10; first subdiscal cell absent; 2-SR:3-SR:r-m = 15: 10:6; m-cu distinctly antefurcal. Hind wing: M+CU: 1-M: 1r-m = 20:17:6; m-cu absent.

Legs. Hind coxa smooth; tarsal claws rather robust; length of femur, tibia and basitarsus of hind leg 4.2, 10.1 and 6.3 × their width, respectively; apical appendages of first-fourth hind tarsal segments absent ( Fig. 12C ).

Metasoma. Length of first tergite 1.2 × its apical width, maximum width of second tergite 1.2 × its length; first–fourth tergites distinctly granulate except for smooth posterior margins of third and fourth tergites; setose part of ovipositor sheath 0.05 × as long as fore wing (total 0.09 times), flattened and setose basally and 0.15 × as long as hind tibia ( Fig. 12G ).

Colour. Dark brown ( Fig. 12H ); mesosoma and anterior half of the mesopleuron yellowish; antenna and legs (except tarsal claw) yellowish brown.

Comparative diagnosis. The new species differs from T. indrik Belokobylskij, 1998 , T. vasilisk Belokobylskij, 1998 , and T. whartoni Yao, 2015 by its smooth notauli, which almost reach the middle of the mesoscutum, and a short, shallow medio-posterior depression. In contrast, these three species possess distinctly sculptured notauli, and if the sculpture is reduced, the medio-posterior depression is long and rather deep towards the posterior.

Etymology. Named “ microporosa ” because of the small and short medio-posterior depression of the mesoscutum: “ micro ” is Greek for “little” and “ poros ” is Greek for “pit”.

Figures

FIGURE 11. Trachyusa microporosa sp. nov., ♀, holotype, habitus, lateral aspect.

FIGURE 12. Trachyusa microporosa sp. nov., ♀, holotype. A, fore wing; B, hind wing; C, mesosoma, lateral aspect; D, mesosoma, dorsal aspect; E, propodeum and first metasomal tergite, dorsal aspect; F, propodeum and metasoma, dorsal aspect; G, ovipositor sheath, lateral aspect; H, basal antennomeres of antenna, lateral aspect; I, head, dorsal aspect; J, head, anterior aspect; K, head, lateral aspect; L, mandible, full view on first and second teeth; M, mandible, full view on third tooth; N, hind leg, lateral aspect.