Bracon (Lucobracon) quadratus sp. nov. Figs 21, 22

Type material.

Holotype. ♀, China, Liaoning Prov., Dalian, 4.IX.1991, Lou Juxian, No. 975849 (ZJUH). Paratypes. 2♀♀, same data as holotype, No. 975951, 975890 (ZJUH).

Diagnosis.

This new species is very similar to B. (L.) grandiceps Thomson, 1892, but can be separated from the latter by the following characters: fore wing vein 1-SR+M 1.5 × longer than vein 1-M (1.8 × in B. (L.) grandiceps); hind femur 3.4 × longer than maximum width (2.5 times); propodeum smooth along medio-longitudinal carina (rugose along medio-longitudinal carina); tergites yellow with third to sixth tergites with a brown medial spot, respectively (uniformly dark brown).

Description.

Holotype, ♀, length of body 3.3 mm, of fore wing 2.6 mm, of ovipositor sheath 1.5 mm.

Head. Antenna short, approximately as long as head and mesosoma, with 26 segments; apical antennal segment slightly acute, 2.1 × longer than its maximum width (Fig. 22k); first flagellomere 1.4 × longer than wide, 1.2 and 1.3 × longer than second and third, respectively, the latter being 1.1 × longer than wide; malar suture rather weak, with some short setae; clypeus height: inter-tentorial distance: tentorio-ocular distance = 2: 12: 5; clypeus sparsely short setose; eye not emarginate (Fig. 22g); face smooth, with some long setae laterally (Fig. 22g); eye height: shortest distance between eyes: head width = 11: 16: 28; frons smooth, nearly not concave behind antennal sockets, with a weak median groove (Fig. 22h); vertex smooth, with sparse short setae; shortest distance between posterior ocelli: minimum diameter of elliptical posterior ocellus: shortest distance between posterior ocellus and eye = 4: 3: 7; temples subparallel behind eyes (Fig. 22h).

Mesosoma. Length of mesosoma 1.8 × its height (Fig. 22c); notauli only impressed anteriorly (Fig. 22d); mesoscutum smooth, with sparse short setae along imaginary notaulic courses (Fig. 22d); scutellar sulcus deep, moderately wide, with crenulae (Fig. 22d); scutellum smooth, with dense short setae posteriorly; metanotum moderately convex medially (Fig. 22d); propodeum largely smooth, except for a short medio-longitudinal carina posteriorly and sparsely setose medially, with dense long setae laterally (Fig. 22d).

Wings. Fore wing (Fig. 22a): SR1 not reaching tip of wing; SR1: 3-SR: r = 27: 16: 6; 1-SR+M more or less straight, 1.5 × longer than 1-M; 2-SR: 3-SR: r-m = 3: 4: 2; m-cu straight, 1.6 × longer than 2-SR+M; angle between 1-SR and C+SC+R about 80°; cu-a more or less interstitial. Hind wing (Fig. 22b): SC+R1: 2-SC+R: 1r-m = 14: 4: 5.

Legs. Length of fore femur: tibia: tarsus = 16: 20: 23; length of hind femur: tibia: basitarsus = 22: 32: 11; length of femur, tibia and basitarsus of hind leg 3.4, 8.0 and 5.5 × their maximum width, respectively; hind tibial spurs 0.4 and 0.5 × as long as hind basitarsus.

Metasoma. Length of first tergite 1.2 × its apical width; first tergite concave medio-basally, median area convex and largely rugose but posteriorly smooth (Fig. 22i); lateral grooves of first tergite moderately wide, with sparse weak crenulae (Fig. 22i); second tergite largely smooth but medio-basally weakly rugose (Fig. 22e); median length of second and third tergites approximately equal; second metasomal suture narrow, largely smooth but with a few weak crenulae, more or less straight medially (Fig. 22e); third to seventh tergites smooth (Fig. 22e); setose part of ovipositor sheath 0.6 × as long as fore wing.

Colour. Largely yellow (Fig. 21); antennal segments apical half brown, scapus and pedicel yellowish-brown (Figs 21, 22j, k); eye, mandible apically, scutellum posteriorly, metanotum medially, claws and ovipositor sheath blackish-brown (Figs 21, 22d, f); third to sixth metasomal tergites each with a brown spot medially (Fig. 22e); wing membrane pale infuscate, pterostigma dark brown and veins yellowish-brown to dark brown (Fig. 22a, b).

Variation. Length of body of female 3.3-4.1 mm, of fore wing of female 2.3-3.1 mm and of ovipositor sheath 1.4-1.6 mm; length of mesosoma 1.7-1.8 × its height; antenna uniformly blackish-brown; setose part of ovipositor sheath 0.5-0.6 × as long as fore wing.

Biology.

Unknown.

Distribution.

China (Liaoning).

Etymology.

Named after the square brown and medial spot of fourth and fifth metasomal tergites: “quadratus” is Latin for “square” .