Trachyusa punctata, 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 : 414-416

Trachyusa punctata sp. nov.

Figs 9–10

Type material. Holotype, ♀ ( ZJUH), “ [SE China:] Zhejiang, Anji, Mt. Longwang , 26.vi.1996, Zhao Weichun, No. 963922.” Paratypes: 1♀ ( ZJUH), Zhejiang, Qingliangfeng , 21–23.ⅴ.2012, Yan Chengjin, No. 201202712 ; 1♀ ( NWUX), NW China: Shaanxi, Xunyangba, Ningshan , c. 1300 m, vii.2014, 33°33’N 108°32’N, Jiangli Tan ; 1♀ ( RMNH), NW China: Shaanxi, Mt. Nangong Nat. Park , Langoa, Ankang, swept, N32.29°, E109.06°, 9.vi.2016, 1000–2000 m, Jiangli Tan ; 1♂ ( NWUX), NW China: Shaanxi, Liping Nat. Forest Park, along road between Hongchenxia-Sicheng , 32°47’N 106°40’E, c. 1490 m, 21.vi.2015, Jiangli Tan .

Diagnosis. Body brownish with middle lobe of mesoscutum darker than mesopleuron( Fig.9 ); head comparatively cubic in dorsal view; eye in lateral view 1.2 × higher than wide; frons flat and smooth ( Fig. 10J ); vertex rather convex ( Fig. 10I ); OOL:diameter of ocellus:POL= 10:5:6; face as wide as high, rather evenly convex, with some long setae and rugose ( Fig. 10J ); clypeus semicircular and medium-sized, rather flat, with some punctures ( Fig. 10J ); first and third teeth of mandible small, middle (= second) tooth wide and acute, distinctly longer than lateral teeth and with orthogonal protuberance on its upper margin ( Figs 10L, 10M ); notauli long, punctate and extending to middle of mesoscutum, anteriorly near notauli distinctly punctate and with long setae ( Fig. 10D ); medio-posterior depression medium-sized to long, groove-shaped ( Fig. 10D ); surface of propodeum densely and coarsely reticulate-rugose, areola absent ( Fig. 10E ); pterostigma elliptical, vein r issued from behind middle of pterostigma, vein r 0.4–0.5 × width of pterostigma ( Fig. 10A ); hind coxa rugose ( Fig. 10D ); setose part of ovipositor sheath 0.06 × as long as fore wing (total visible sheath 0.1 times), flattened and setose basally and 0.14 × as long as hind tibia ( Fig. 10G ).

Description. Holotype, ♀, length of body 3.8 mm, of fore wing 3.7 mm.

Head. Comparatively cubic and shiny in dorsal view ( Fig. 10I ), width of head 1.5 × its medial length; antenna with 32 antennomeres, bristly setose, first flagellomere (including annellus) 1.2 × longer than second flagellomere ( Fig. 10H ); length of first, second and penultimate flagellomere 5.0, 4.3 and 2.3 × their width, respectively ( Fig. 10H ); maxillary palp incomplete; eye in dorsal view 1.8 × as long as temple ( Fig. 10I ); eye in lateral view 1.2 × higher than wide ( Fig. 10J ); frons flat and smooth ( Fig. 10J ); vertex rather convex; OOL:diameter of ocellus:POL= 10:5:6; face as wide as high, rather evenly convex, with some long setae and rugose ( Fig. 10J ); clypeus semicircular and medium-sized, rather flat, with some punctures ( Fig. 10J ); length of malar space 0.3 × 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 2.5 × its maximum width ( Figs 10L, 10M ).

Mesosoma. Length of mesosoma 1.8 × its height ( Fig. 10C ); pronope round, large and deep ( Fig. 10I ); side of pronotum smooth except medio-anteriorly and posteriorly indistinctly crenulated ( Fig. 10C ); epicnemial area crenulated anteriorly, remainder smooth; precoxal sulcus distinctly crenulated medially but shallow so anteriorly and posteriorly ( Fig. 10C ); remainder of mesopleuron smooth; pleural sulcus crenulated; episternal scrobe small, deep and linear; metapleuron densely and coarsely reticulate-rugose, with a round small pit anteriorly ( Fig. 10C ); notauli long and punctate, extending to middle of mesoscutum, mesoscutum near notauli anteriorly distinctly punctate and with conspicuous long setae; medio-posterior depression rather long, groove-shaped ( Fig. 10D ); mesoscutum slender and 1.3 × longer than wide; scutellar sulcus crenulated, with one longitudinal carina and several short carinae, and lateral part 3.0 × wider than its maximum length ( Fig. 10D ); surface of propodeum densely and coarsely reticulate-rugose, areola absent ( Fig. 10F );

Wings ( Fig. 10A ). Pterostigma elliptical, 5.0 × longer than its maximum width, vein r issued near middle of pterostigma, vein r 0.5 × as long as maximum width of pterostigma; r:3-SR:SR1 = 5:20:63; cu-a postfurcal; 1- CU1:2-CU1 = 3:20; first subdiscal cell absent; 2-SR:3-SR:r-m = 25:20:9; m-cu interstitial. Hind wing: M+CU: 1-M: 1r-m = 20:16:8; m-cu absent.

Legs. Hind coxa rugulose; tarsal claws rather robust; length of femur, tibia and basitarsus of hind leg 4.4, 8.4 and 6.7 × their width, respectively; apical appendages of first-fourth hind tarsal segments absent ( Fig. 10N ).

Metasoma. Length of first tergite 1.1 × as long as its maximum width, basal width 1.5 × its apical width, and maximum width of second tergite 1.3 × its length; first–fourth metasomal tergites distinctly granulate except posterior margins of third and fourth tergites; setose part of ovipositor sheath 0.06 × as long as fore wing (total sheath 0.1 times), flattened and setose basally and 0.14 × as long as hind tibia ( Fig. 10G ).

Colour. Brownish ( Fig. 9 ); head black; mesosoma and metasoma (except anterior margins of tergites) dark brown; mesopleuron and anterior margins of all tergites orange brown; first and second flagellomere and legs yellowish; pterostigma and veins brown; wing membrane slightly infuscated.

Variation. Body length: 2.3–4.0 mm, length of fore wing 2.6–3.8 mm; width of head 1.5–1.7 × medial length of head; length of vein r of fore wing 0.4–0.5 × width of pterostigma; medio-posterior depression of mesoscutum of paratypes from Shaanxi comparatively long and narrow; paratype from Xunyangba has nearly entire mesoscutum yellowish brown and antenna with 26 antennomeres. Male has length of fore wing 2.6 mm, and of body 2.2 mm, pterostigma strongly widened (compared to female), antenna with 30 antennomeres, and only middle lobe of mesoscutum dark brown.

Comparative Diagnosis. The new species can be distinguished from T. aurora (Haliday) primarily by the presence of conspicuous long setae on the mesoscutum and distinct punctures near the anterior course of the notauli (in contrast to the indistinct granulation seen in T. aurora ). Additionally, the vein r is 0.4–0.5 × the length of the maximum width of the pterostigma (compared to 0.2–0.3 × in T. aurora ). The new species also differs from T. indrik Belokobylskij, 1998 , T. vasilisk Belokobylskij, 1998 , and T. whartoni Yao, 2015 by its less transverse head, which is 1.5–1.7 × wider than long medially (as opposed to 1.7–2.2 × in the latter three species), and the presence of distinct punctures anteriorly near the notauli (which are absent in the latter three species).

Etymology. Named “ punctata ” because of the distinct punctures of the mesoscutum anteriorly: “ punctum ” is Latin for “small hole”.

Figures

FIGURE 9. Trachyusa punctata sp. nov., ♀, holotype, habitus, lateral aspect.

FIGURE 10. Trachyusa punctata sp. nov., ♀, holotype. A, fore wing; B, hind wing; C, mesosoma, lateral aspect; D, mesosoma, dorsal aspect; E, propodeum and metasoma, dorsal aspect; F, propodeum and first–third metasomal tergites, dorsal aspect; G, ovipositor and 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.