Bracon (Glabrobracon) longistriatus, Li & He & Chen, 2020

Li, Yang, He, Jun-hua & Chen, Xue-xin, 2020, The subgenera Glabrobracon Fahringer, Lucobracon Fahringer and Uncobracon Papp of the genus Bracon Fabricius (Hymenoptera, Braconidae, Braconinae) in China, with the description of eleven new species, Deutsche Entomologische Zeitschrift 67 (2), pp. 209-252 : 209

Bracon (Glabrobracon) longistriatus sp. nov. Figs 7 , 8

Type material.

Holotype. ♀, China, Heilongjiang Prov., Yichun, 1985, Jin Liyuan, No. 864358 ( ZJUH). Paratypes. 12♀♀9♂♂, China, Heilongjiang Prov., Yichun, 1985, Jin Liyuan, No. 864365, 864737, 864740, 864739, 864358 (17 specimens) ( ZJUH); 26♀♀28♂♂, China, Heilongjiang Prov., Yichun, 1985.VII, Jin Liyuan, No. 851834 (20 specimens) (host Pissodes nitidus Roelofs), No. 864359 (21 specimens), 864303 (4 specimens), 864296 (5 specimens); 4♀♀5♂♂, China, Heilongjiang Prov., Yichun, 19??, Jin Liyuan, No. 850134 (9 specimens) (host Pissodes sp.) ( ZJUH).

Diagnosis.

This new species is very similar to B. (G.) instabilis Marshall, 1897, but can be separated from the latter by the following characters: in dorsal view, temples gradually narrowed behind eyes and length of eye 1.4 × temple (temples strongly narrowed behind eyes and length of eye more than twice as long as temple in B. (G.) instabilis ); first metasomal tergite (except median area), second tergite (but infuscate medially) reddish-yellow, third tergite sometimes reddish-yellow basally (metasomal tergites often entirely blackish-brown); legs yellow and only claws dark brown (legs blackish-brown with yellow or yellowish-brown pattern); first metasomal tergite 1.0-1.1 × longer than its apical width (1.2-1.4 times).

Description.

Holotype, ♀, length of body 3.0 mm, of fore wing 3.2 mm, of ovipositor sheath 1.1 mm.

Head. Antenna incomplete, only remaining are scapus and pedicel; malar suture indistinct, with some short setae; clypeus height: inter-tentorial distance: tentorio-ocular distance = 2: 11: 6; clypeus sparsely short setose; eye not emarginate (Fig. 8g ); face largely smooth, except for a few weak punctures and with sparse short setae (Fig. 8g ); eye height: shortest distance between eyes: head width = 12: 16: 31; frons smooth, slightly concave behind antennal sockets, with a rather weak median groove (Fig. 8h ); vertex smooth, with sparse short setae; shortest distance between posterior ocelli: minimum diameter of elliptical posterior ocellus: shortest distance between posterior ocellus and eye = 8: 5: 8; temples subparallel immediately behind eyes (Fig. 8h ).

Mesosoma. Length of mesosoma 1.6 × its height (Fig. 8c ); notauli relatively deeply impressed anteriorly, shallow posteriorly (Fig. 8d ); mesoscutum largely smooth except for a few weak punctures posteriorly, with sparse setae posteriorly (Fig. 8d ); scutellar sulcus deep, wide, with crenulae (Fig. 8d ); scutellum smooth, with dense setae posteriorly; metanotum moderately convex medially (Fig. 8d ); propodeum largely smooth, with a short medio-longitudinal carina posteriorly and sparsely setose medially, with dense long setae laterally (Fig. 8d ).

Wings. Fore wing (Fig. 8a ): SR1: 3-SR: r = 19: 9: 5; 1-SR+M more or less straight, 1.3 × longer than 1-M; 2-SR: 3-SR: r-m = 13: 18: 9; m-cu straight, 1.7 × longer than 2-SR+M; angle between 1-SR and C+SC+R about 80°; cu-a more or less interstitial. Hind wing (Fig. 8b ): SC+R1: 2-SC+R: 1r-m = 19: 3: 8.

Legs. Length of fore femur: tibia: tarsus = 25: 27: 31; length of hind femur: tibia: basitarsus = 24: 35: 14; length of femur, tibia and basitarsus of hind leg 3.7, 7.0 and 4.7 × their maximum width, respectively; hind tibial spurs 0.3 and 0.4 × as long as hind basitarsus.

Metasoma. Length of first tergite 1.1 × its apical width; first tergite concave medio-basally, median area convex and with some striae (Fig. 8j ); lateral grooves of first tergite moderately narrow, with sparse and weak crenulae (Fig. 8j ); second tergite largely with striae, but laterally and posteriorly smooth (Fig. 8e ); median length of second and third tergites about equal; second metasomal suture moderately narrow, crenulate, weakly curved medially (Fig. 8e ); third to seventh tergites smooth (Fig. 8e ); ovipositor sheath 0.3 × as long as fore wing.

Colour. Largely blackish-brown (Fig. 7 ); pedicel apically, mandible (except for apically black brown) and legs (but claws dark brown) yellow (Figs 7 , 8f, g ); first metasomal tergite (but median area blackish-brown), second tergite (but medio-anteriorly blackish-brown) yellowish-brown (Fig. 8e, j ); ovipositor sheath black (Fig. 7 ); wing membrane pale yellow, pterostigma yellow and veins dark brown (Fig. 8a, b ).

Variation. Length of body of female 3.0-4.5 mm, of fore wing of female 3.1-4.2 mm and of ovipositor sheath 1.0-2.0 mm; antenna of female with 28 segments; apical antennal segment acute, 2.6 × longer than its maximum width; first flagellomere 2.0 × longer than wide, 1.1 and 1.2 × longer than second and third, respectively, the latter being 1.6 × longer than wide; length of mesosoma 1.4-1.6 × its height; length of first tergite 1.0-1.1 × its apical width; ovipositor sheath 0.3-0.5 × as long as fore wing; third metasomal tergite sometimes basally yellowish-brown; pterostigma and veins yellowish-brown to dark brown.

Male. Length of body of male 2.3-3.3 mm, of fore wing of male 2.0-2.9 mm; metasomal tergites sometimes uniformly black brown.

Biology.

The type series has been reared from Pissodes sp. and Pissodes nitidus Roelofs ( Coleoptera: Curculionidae ).

Distribution.

China (Heilongjiang).

Etymology.

Named after the largely striate median area of the first metasomal tergite and the second tergite: “longus” is Latin for “long” and “striata” is Latin for "with striae".

Figures

Figure 7. Bracon (Glabrobracon) longistriatus sp. nov., ♀, holotype, habitus lateral.

Figure 8. Bracon (Glabrobracon) longistriatus sp. nov., ♀, holotype. a. Fore wing; b. Hind wing; c. Mesosoma, lateral view; d. Mesosoma, dorsal view; e. Metasoma, dorsal view; f. Hind leg, lateral view; g. Head, front view; h. Head, dorsal view; i. Head, lateral view; j. First metasomal tergite, dorsal view.