Dibrachys golmudica Jiao & Xiao

Jiao, Tian-yang, Yao, Qin-ying & Xiao, Hui, 2017, Review of Dibrachys Foerster from China (Hymenoptera, Chalcidoidea, Pteromalidae), ZooKeys 656, pp. 123-149 : 133-135

Dibrachys golmudica Jiao & Xiao sp. n. Figs 23-28

Diagnosis.

The new species belongs to Dibrachys s. str., and the noticeable differences with other species of the subgenus by the following characters: in female, antennae with three anelli; the postmarginal vein being distinctly shorter than the stigmal vein (0.5 ×), and gaster being 2.5 × as long as broad.

Description.

Holotype. Female. Body length 2.2 mm (Figs 23, 24). Head and mesosoma black with bronze luster and metallic reflection. Gaster dark brown with metallic reflection basally. Antennal scape yellowish brown to light brown from base to apex, flagellum dark brown; legs yellowish brown except coxae concolorous with body and femora light brown; fore wing hyaline, without infumation, venation yellowish brown or yellowish.

Head in frontal view (Fig. 25) 1.24 × as wide as high; eyes with inner margins parallel, eye height 0.62 × head height, eyes separated by 1.26 × their height; lower face with weak striation, upper face with obvious regular reticulation; antennal scrobe deep, not reaching anterior ocellus. Antennal insertion on lower ocular line, distance from upper margin of torulus to lower margin of anterior ocellus 2.54 × distance from lower margin of torulus to lower margin of clypeus; clypeus with longitudinal striation on both sides, lower margin slightly protruded, emarginate in middle with two obtuse teeth; oral fossa 0.49 × as wide as head. Head in lateral view (Fig. 27) with malar sulcus conspicuous, eye height 1.5 × its broad and 2.83 × malar space. Antennal scape length 0.91 × eye height; length of flagellum and pedicel combined less than head width (0.88 ×); pedicel in lateral view 2.3 × as long as broad; antenna with 3 anelli, Fu1 and Fu2 distinctly transverse, Fu3 quadrate, Fu1 to Fu3 combined 0.78 × as long as pedicel; Fu4 longer than broad, Fu5 quadrate; each funicular segment with one row of sensilla; setae on funicle all decumbent; clava not distinctly clavate, 3.4 × as long as broad, micropilosity limited to apex of third clava segment. Head in dorsal view (Fig. 26), 2 × as wide as long; vertex convex, sculpture on vertex slightly smaller than sculpture on frons; occipital carina distinct; eye length 2.5 × temple length; POL 2.11 × OOL.

Head 1.24 × as broad as thorax. Mesosoma 1.6 × as long as broad. Pronotum 0.65 × as broad as mesoscutum, collar rounded, posterior band smooth. Mesoscutum 1.57 × as broad as long, with regular reticulation, in anterior half weakly reticulate and posterior half with deep reticulation; notauli distinct but not complete. Scutellum convex, 1.07 × as broad as long, frenal line absent; reticulation smaller than on mesoscutum, but regular and shallow. Propodeum medially ½ as long as scutellum, with fine, deep, dense reticulation; plica weak (Fig. 28), only visible basally and separated by 2 × medial length of propodeum; median carina incomplete; propodeum with short, slightly convex nucha having transverse striation; propodeal spiracles elongate, 2.67 × as long as broad. Fore wing 2.16 × as long as broad, without marginal fringe; setae pale, inconspicuous; basal vein and basal cell bare, upper surface of costal cell bare, lower surface with one complete row of setae and distally with some scattered setae; submarginal vein 2.75 × as long as marginal vein, marginal vein 2.63 × as long as stigmal vein, postmarginal vein shorter than stigmal vein (at most 0.5 ×); stigmal vein slightly curved.

Gaster spindle-shaped with apex pointed (Fig. 23), 2.5 × as long as broad; as wide as thorax; Gt1 covering 1/4 of gaster, with posterior margin cambered; tergites beyond Gt1 equal in length; ovipositor exserted.

Male. Head black except frons with yellowish-green, and antennae yellow; mesosoma black except thorax purplish laterally, legs yellow except coxae brown. Antennae with two distinctly transverse anelli, pedicel in lateral view 1.8 × as long as broad, each funicular segment longer than broad; gaster oval, apex not pointed.

Material examined.

Holotype. ♀, China: Qinghai: Golmud, Guolemude, 2880m, 36.26°N, 94.53°E, 14.IX.2001, leg. Chao-Dong Zhu. Paratype. 1♀, same data to holotype; 3♂, 6♀, Inner Mongolia: Ejin B., 11.VI.1981, ex. Dinorhopala on Populus diversifolia , leg. Hua-Qiang Shao.

Etymology.

Named after the location where the holotype was collection.

Hosts.

Specimens from Inner Mongolia were reared from Dinorhopala ( Coleoptera : Curculionidae ) on Populus diversifolia .

Distribution.

China (Inner Mongolia, Qinghai).