Trachyusa Ruthe 1854
Creators: name: Zhu, Jiachen
name: Achterberg, Cornelis Van
name: Chen, Xuexin
Publisher: name: Zenodo
Year: 2025
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Hymenoptera
Braconidae
Trachyusa

description: Key to species of the genus Trachyusa Ruthe
1 Body slender in lateral view (Figs 9, 11, 13, 15); mesoscutum in dorsal view longer than its maximum width (Figs 10D, 12D, 14D, 16C); antenna longer than body length................................................................ 2
- Body stout in lateral view; mesoscutum in dorsal view shorter than wide; antenna as long as or shorter than body length... 7
2 Mesoscutum with conspicuous long setae and anteriorly near notauli with some distinct punctures (Fig. 10D); head less transverse in dorsal view, 1.5–1.7 × wider than long medially (Fig. 10I); pterostigma of ♀ less robust, vein r 0.4–0.5 × as long as maximum width of pterostigma (Fig. 10A); China (Shaanxi, Zhejiang)........................ T. punctata sp. nov.
- Mesoscutum only with medium-sized setae medio-anteriorly and anteriorly near notauli smooth; head usually distinctly transverse (except in T. aurora), 1.7–2.2 × wider than long medially (Figs 12I, 14I, 16H); if 1.5–1.7 × then pterostigma of ♀ robust, vein r 0.2–0.3 × as long as its maximum width........................................................ 3
3 Head less transverse in dorsal view, 1.5–1.7 × wider than long medially; with some indistinct granulation near notauli; vein m-cu of fore wing interstitial or nearly so; [NW European T. nigrothoracica van Achterberg & O’Connor, 1990, is provisionally considered to be a melanistic form of T. aurora]; Europe, East Palaearctic (Far East Russia, Korea)................................................................................................... T. aurora (Haliday, 1838)
- Head more transverse, 1.7–2.2 × wider than long medially (Figs 12I, 14I, 16H); area near notauli smooth; vein m- cu of fore wing antefurcal or postfurcal (Figs 12A, 14A, 16H).......................................................... 4
4 Notauli smooth and almost reaching middle of mesoscutum (Fig. 12D), medio-posterior depression short and shallow (Fig. 12D); [precoxal sulcus short, reduced near posterior edge of mesopleuron (Fig. 12C)]; China (Guizhou)................................................................................................. T. microporosa sp. nov.
- Notauli distinctly sculptured, at least so anteriorly (Fig. 14D); if sculpture of notauli reduced then medio-posterior depression long and posteriorly rather deep......................................................................... 5
5 Medio-posterior depression of mesoscutum short; precoxal sulcus long, wide and distinctly developed near posterior edge of mesopleuron; vein m-cu of fore wing slightly postfurcal; East Palaearctic (Far East Russia)... T. indrik Belokobylskij, 1998
- Medio-posterior depression of mesoscutum long (Fig. 14D); precoxal sulcus short, absent near posterior edge of mesopleuron (Fig. 14C); vein m-cu of fore wing slightly antefurcal (Fig. 14A)............................................... 6
6 Mesosoma and metasoma black or dark reddish brown (Figs 14D–F); pterostigma of ♂ (compared to ♀) strongly widened; first flagellomere 3.5–4.3 × longer than its apical width (Fig. 14H); hind coxa more or less sculptured (Figs 14C); notauli narrowly sculptured (Figs 14D); [head 1.7–1.9 × wider than long medially]; Russia (Far East), China (Guizhou, Shaanxi)..................................................................................... T. vasilisk Belokobylskij, 1998
- Mesosoma and metasoma brownish yellow (Figs 16C–E), but apex of metasoma and propodeum (especially of ♂) more or less darkened; pterostigma of ♂ (compared to ♀) moderately widened; first flagellomere 4.5–5.8 × longer than its apical width (Fig. 16G); hind coxa smooth (Fig. 15); notauli often more extensively sculptured (Fig. 16C); [head 1.7–2.3 × wider than long medially]; China (Guizhou, Hebei, Liaoning, Shaanxi, Zhejiang)............................. T. whartoni Yao, 2015
7 Notauli on posterior half of mesoscutal disc deeply impressed; mesoscutum black; first metasomal tergite usually slenderer (Fig. 15 in van Achterberg & O’Connor 1990); Central Europe.............................. T. szepligetii Papp, 1967
- Notauli on posterior half of mesoscutal disc at most shallowly impressed; mesoscutum brownish yellow; first tergite rather robust (Fig. 14 in van Achterberg & O’Connor 1990); Central Europe....................... T. bucephala Papp, 1967
description: Published as part of 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, pp. 401-438 in Zootaxa 5569 (3) on page 413, DOI: 10.11646/zootaxa.5569.3.1, http://zenodo.org/record/14734162