Bracon (Bracon) tenuicornis Wesmael 1838
Creators: name: Papp, Jenő
name: Xviii, Budapest
Publisher: name: Zenodo
Year: 2012
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Hymenoptera
Braconidae
Bracon
Bracon tenuicornis

description: Bracon (Bracon) tenuicornis Wesmael, 1838
Fig. 47 A-K
Braco tenuicornis Wesmael, 1838: 42 ♀ (type material: 1 ♀), type locality: “environs de Bruxelles ” (Belgium), ♀ holotype (“J’ai pris une seule femelle de cette espèce...” Wesmael l.c., present designation) in the Royal Belgian Institute of Natural Sciences, Brussels; examined.
Braco tenuicornis – Szépligeti 1901: 184 (in key, in Hungarian); 1904 (1901): 160 (in key, in German) ♀. Bracon (Orthobracon) tenuicornis –Fahringer1927:271,273(♀),281 (♁)(in key) and425 (redescription) ♀ ♁, assigned to “Section Orthobracon ”. — Telenga 1936: 162 (♀, in key), 249 (redescription) (in Russian) and 365 (in key, in German) ♀ ♁. — Shenefelt 1978: 1648 (literature up to 1971).
Bracon (Bracon) tenuicornis – Tobias 1986: 129 (in key, in Russian). — Tobias & Belokobylskij 2000: 138 (in key, in Russian). — Papp 2008: 1753 (in key).
Designation of the ♀ holotype of Bracon tenuicornis (Fig. 47 A-H)
(First label, printed) “ Coll. Wesmael ”; (second label, printed) “2043”; (third label) “ Braco ♀ / tenuicornis mihi” (handwriting) / “dét. C. Wesmael ” (printed); (fourth label, printed) “ Type ”; (fifth label, with my handwriting) “ Belgique / Bruxelles / VIII leg. Wesmael ” (above), “test J. Papp / 1987” (reverse); sixth label is the holotype card (labels 5-6 attached by me). Holotype is in good condition: (1) micropinned, pin thick hence mesoscutum almost invisible; (2) flagelli apically deficient.
Material examined
12 ♀♀ + 1 ♁ from six countries: SCOTLAND: 1 ♀. THE NETHERLANDS: 2 ♀♀ from two localities. GERMANY: 2 ♀♀ from one locality. SWEDEN: 1 ♀. HUNGARY: 3 ♀♀ + 1 ♁ from three localities. BULGARIA: 2 ♀♀ from two localities.
Redescription of the ♀ holotype of Bracon tenuicornis (Fig. 47 A-H)
LENGTH. Body 3.1 mm long.
ANTENNAE. Antennae deficient, left antenna with 30 and right antenna with 24 antennomeres (according to the original descripion antenna with 31 antennomeres). First flagellomere clearly twice and 28th flagellomere 1.8 times as long as broad.
HEAD. In dorsal view less transverse (Fig. 47A), 1.7 times as broad as long, eye 2.2 times longer than temple, temple constricted, occiput weakly excavated. Horizontal diameter of oral opening somewhat longer than shortest distance between opening and compound eye (cf. Fig. 40D). Head polished.
MESOSOMA. In lateral view 1.6 times as long as high, polished. Propodeum polished, above lunule with short carina and above it surface uneven (Fig. 47B).
LEGS. Hind femur 2.8 times as long as broad medially (Fig. 47C). Claw downcurved, basal lobe large as in Fig. 47D.
WINGS. Forewing about as long as body. Pterostigma (Fig. 47E) four times as long as wide and issuing r proximally from its middle, r as long as width of pterostigma. Second submarginal cell long, 3-SR 1.3 times longer than 2-SR, SR1 straight, twice as long as 3-SR and reaching tip of wing; 1-R1 just 1.5 times as long as length of pterostigma. First discal cell less high, 1-M 1.7 times as long as m-cu, 1-SR-M bent and 1.3 times longer than 1-M (Fig. 47F).
TERGITES. First tergite (Fig. 47G) 1.3 times as long as broad behind, beynd pair of spiracles faintly broadening, margin of scutum crenulated, scutum posteriorly and tergite laterally from scutum rugoserugulose. Second tergite transverse, three times as broad behind as long and as long as third tergite; suture between tergites 2-3 feebly bisinuate and finely crenulated. Second tergite medially rugose, laterally rugulo-granulo-uneven, further tergites with weakening sculpture. Ovipositor sheath just shorter than hind tibia, hind end of ovipositor sheath and ovipositor as in Fig. 47H.
COLOUR. Antenna dark brown, scape basally, pedicelle entirely and first flagellomere again basally testaceous. Head and tergites brownish black, mesosoma black. Oral organs and clypeus yellow. Tegula yellow with brownish suffusion. Legs yellow, coxae 2-3 basally blackish, fifth tarsomere light brownish. Second tergite latero-posteriorly with a pair of little yellow maculae. Sternites yellow with brownish pattern. Wings hyaline, pterostigma and veins yellow.
Variable features of the ♀ (12 ♀♀) (Fig. 47 I-K)
Body 2.8-3.2, usually 3-3.1, mm long. Antenna with (20-)25-30 antennomeres. Penultimate flagellomere 1.6-1.8 times as long as broad. Temple in dorsal view somewhat more constricted (Fig. 47I). Propodeum with a carina and medially rugulose (Fig. 47J). Hind femur 2.8-2.9 times, rarely 4.1 times, as long as broad medially. First tergite more broadening posteriorly, i.e. somewhat longer than broad behind (Fig. 47K). Sculpture beyond first tergite rugulos to granulose. Dark colour either more or less extended, or tergites brown and head + mesosoma black to blackish.
Description of the ³ (1 ³)
Similar to the ♀. Body 2.2 mm long. Antenna with 26 antennomeres. Metasoma from fourth tergite smooth and shiny. Body black, legs yellow.
Host
COL. Scolytidae: Phloeophthorus scarabaeoides Bernard.
Distribution
Europe (so far known in six countries)
Taxonomic position
Bracon tenuicornis is nearest to B. orbus Papp (Papp 1981; Hungary) albeit the latter species is ranged in the subgenus Glabrobracon, the two species are similar to each other and are distinguished by a few features:
1 (2) Metasoma from second tergite with weakening sculpture (subgeneric difference of Bracon s. str., Fig. 47G). Head in dorsal view 1.7 times as broad as long, temple constricted (Fig. 47A, I). Second tergite as long as third tergite (Fig. 47G). Forewing: second submarginal cell less long, 3-SR 1.3 times longer than 2-SR (Fig. 47E). Propodeum medially either uneven or (less usually) with a mediolongitudinal carinula (Fig. 47B, J) .................................................... B. (B.) tenuicornis Wesmael, 1838
2 (1) Metasoma less sculptured: second tergite (♀) or second and third tergites (♁) rugo-rugulose, further tergites polished (subgeneric difference of Glabrobracon, Fig. 23H). Head in dorsal view 1.6 times as broad as long, temple rounded (Fig. 23G). Second tergite somewhat longer than third tergite (Fig. 23H). Forewing: second submarginal cell long, 3-SR 1.5-1.6 times longer than 2-SR (Fig. 30F). Propodeum polished, around lunule with short rugulae(cf. Fig.3C) .................. B. (Gl.) orbus Papp, 1981
description: Published as part of Papp, Jenő & Xviii, Budapest, 2012, A revision of the Bracon Fabricius species in Wesmael's collection deposited in Brussels (Hymenoptera: Braconidae: Braconinae), pp. 1-154 in European Journal of Taxonomy 21 on pages 97-100, DOI: 10.5852/ejt.2012.21, http://zenodo.org/record/3858161