Trachionus Haliday, 1833

Cui, Qian, van Achterberg, Cornelis, Tan, Jiang-Li & Chen, Xue-Xin, 2015, The genus Trachionus Haliday, 1833 (Hymenoptera, Braconidae, Alysiinae) new for China, with description of four new species, ZooKeys 512, pp. 19-37: 20-21

publication ID

http://dx.doi.org/10.3897/zookeys.512.9759

publication LSID

lsid:zoobank.org:pub:DF784B4C-E834-4A50-A0BF-D07CB72BD009

persistent identifier

http://treatment.plazi.org/id/3F23C003-831C-676C-B21E-136BD235B549

treatment provided by

ZooKeys by Pensoft

scientific name

Trachionus Haliday, 1833
status

 

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 × 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 –0.8× 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).

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:

Key to Chinese species of Trachionus   Haliday

Kingdom

Animalia

Phylum

Arthropoda

Class

Insecta

Order

Hymenoptera

Family

Braconidae

Loc

Trachionus Haliday, 1833

Cui, Qian, van Achterberg, Cornelis, Tan, Jiang-Li & Chen, Xue-Xin 2015
2015
Loc

Planiricus

Perepechayenko 2000
2000