The genus Trachionus Haliday, 1833 (Hymenoptera, Braconidae, Alysiinae) new for China, with description of four new species Author Cui, Qian Author van Achterberg, Cornelis Author Tan, Jiang-Li Author Chen, Xue-Xin text ZooKeys 2015 512 19 37 http://dx.doi.org/10.3897/zookeys.512.9759 journal article http://dx.doi.org/10.3897/zookeys.512.9759 1313-2970-512-19 DF784B4CE8344A50A0BFD07CB72BD009 Taxon classification Animalia Hymenoptera Braconidae Trachionus Haliday, 1833 Figs 1, 2-10, 11, 12-21, 22, 23-32, 33, 34-42, 43-46 Trachionus Haliday, 1833: 265; Dalla Torre 1898 : 198 (as synonym of Chelonus Panzer, 1806; Chelonus mandibularis attributed to Haliday, and this undescribed species was synonymized (p. 204) with Chelonus maculator (Dahlbom, 1833)); Shenefelt 1973 : 839 (id.); Marsh 1979 a: 231 (id.); van Achterberg 1997 : 81 (as valid genus). Type species (by original designation): " Chelonus mandibularis " (= Sigalphus mandibularis Nees, 1816). Aenone Haliday, 1833: 267 (nom. nud.; not Aenone Lamarck, 1818), 1838 : 214; Shenefelt 1974 : 1109; van Achterberg 1997 : 81 (synonymy with Trachionus Haliday). Aenone Curtis, 1837: 123 (not Aenone Lamarck, 1818); van Achterberg 1997 : 81 (synonymy with Trachionus Haliday). Type species (by present designation): Sigalphus mandibularis Nees, 1816. Oenone Haliday, 1839: 3 (not Oenone Lamarck, 1818); Shenefelt 1974 : 1109; van Achterberg 1997 : 81 (synonymy with Trachionus Haliday). Type species (designated by Haliday 1840 ): Sigalphus mandibularis Nees, 1816. Symphya Foerster, 1863: 273; Shenefelt 1974 : 1109-1111; Marsh 1979 : 217; van Achterberg 1997 : 81 (synonymy with Trachionus Haliday). Type species (by original designation): Sigalphus mandibularis Nees, 1816. Anarmus Ruthe (in Brischke), 1882: 138; Shenefelt 1974 : 1109; van Achterberg 1997 : 81 (synonymy with Trachionus Haliday). Type species (by van Achterberg 1997 ): Sigalphus mandibularis Nees, 1816. Planiricus Perepechayenko, 2000: 30 (as subgenus of Trachionus ). Type species (by original designation): Sigalphus hians Nees, 1816. Diagnosis. Vein r-m of forewing absent; mandible exodont, with 3-5 teeth or small lobes and second tooth of mandible acute (Figs 7, 17, 28, 30, 39); forewing vein 1-SR longer than 3 x width of vein and distinctly longer than parastigma (Figs 1-2, 11-12, 22-23, 33-34); clypeus transverse (Figs 7, 17, 28, 39) and epistomal suture narrow (subgenus Planiricus Perepechayenko) or as wide as convex part of clypeus and deep (subgenus Trachionus Haliday); ocelli normal (subgenus Planiricus Perepechayenko) or strongly protruding (subgenus Trachionus Haliday); pronope absent; metanotum distinctly and acutely protruding dorsally (Figs 4, 14, 25, 36); anterior half of sternaulus (below the precoxal sulcus) present or absent, only in subgenus Trachionus Haliday posterior half of sternaulus wide and coarsely crenulate; combined length of second and third metasomal tergites of female 0.6 -0.8x total length of metasoma, these tergites at least partly sculptured (Figs 5-6, 15-16, 26-27, 37, 42); fourth and fifth metasomal tergites smooth and of female more or less retracted (Figs 16, 27, 42). Figure 1. Trachionus acarinatus sp. n., male, holotype, habitus lateral. Figures 2-10. Trachionus acarinatus sp. n., male, holotype. 2 wings 3 head and mesosoma lateral 4 mesosoma dorsal 5 metasoma dorsal 6 metasoma lateral 7 head anterior 8 head dorsal 9 hind leg 10 detail of metanotal spine. Figure 11. Trachionus albitibialis sp. n., female, holotype, habitus lateral. Figures 12-21. Trachionus albitibialis sp. n., female, holotype. 12 wings 13 head and mesosoma lateral 14 mesosoma dorsal 15 metasoma dorsal 16 metasoma lateral 17 head anterior 18 head dorsal 19 antenna 20 hind leg 21 detail of metanotal spine. Figure 22. Trachionus brevisulcatus sp. n., female, holotype, habitus lateral. Figures 23-32. Trachionus brevisulcatus sp. n., female, holotype. 23 wings 24 head and mesosoma lateral 25 mesosoma dorsal 26 metasoma dorsal 27 metasoma lateral 28 head anterior 29 head dorsal 30 head lateral 31 hind leg 32 detail of metanotal spine. Figure 33. Trachionus mandibularoides sp. n., female, holotype, habitus lateral. Figures 34-42. Trachionus mandibularoides sp. n., female, holotype. 34 wings 35 head and mesosoma lateral 36 mesosoma dorsal 37 metasoma dorsal 38 detail of metanotal spine 39 head anterior 40 head dorsal 41 hind leg 42 metasoma lateral. Biology. Ovo-larval koinobiont parasitoids of Phytobia spp. ( Agromyzidae ) boring in or near the cambium layer in branches of shrubs and trees ( Greene 1914 ; Clausen 1954 ; van Achterberg et al. 2012 ). Notes. Up to 1997 the interpretation of the genus Trachionus had been problematical, not the least because of the synonymy with the genus Chelonus by Dalla Torre (1898) . It is contradicted by the clear original diagnosis by Haliday (1833) : "Areolae cubitales 2; mandibulae hiantes 4-dentes". If the diagnosis of the genus is combined with the diagnosis of the group ("Abdominis segmenta coalita postica retracta. Chelonus") then it is clear that it can only apply to the tribe Dacnusini (because of the exodont mandibles) and to the genus Aenone Curtis, 1837 (because of the Chelonine-like metasoma), a junior homonym and, therefore, unavailable. In 1997 van Achterberg clarified the position of the genus Trachionus and synonymized Trachionus with Symphya Foerster, the oldest available name for the group in current use that time. All four species from China belong to the subgenus Planiricus Perepechayenko (= Trachionus hians -group) because they have the epistomal suture much narrower than the clypeus and the sternaulus is absent or is only anteriorly shallowly developed as punctate area. Trachionus is similar to two Palaearctic genera, Epimicta Foerster, 1863, and Parasymphya Tobias, 1998, because of the presence of the pronotal spine, and the sculpture and shape of the second and third metasomal tergites. These taxa can be separated as follows:
Parasymphya Tobias, 1998
Parasymphya dentata
717283961627427172830398182940 Agromyzidae Phytobia 2
31324355 -615-1626-27374215-61115-162226- 274142536717283912111222233334 Trachionus Haliday, 1833
Epimicta Foerster, 1863
Key to Chinese species of Trachionus Haliday
363536 Trachionus mandibularoides sp. n.
42441425 2
510446 Trachionus acarinatus sp. n.
2632254345 3
283045312425 Trachionus brevisulcatus sp. n.
174320131414 Trachionus albitibialis sp. n.
Figure 43-46. 43 Trachionus albitibialis sp. n., female, holotype 44 Trachionus mandibularoides sp. n., female, holotype 45 Trachionus brevisulcatus sp. n., female, holotyp 46 Trachionus acarinatus sp. n., male, holotype 43-46 mandible lateral.