Dibrachys liaoi 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 : 135-136

Dibrachys liaoi Jiao & Xiao sp. n. Figs 29-32

Diagnosis.

The new species belongs to Dibrachys s. str., and the mainly differences with Dibrachys microgastri ( Bouché) as follows: Dibrachys liaoi sp. n. slightly blue-greenish, clypeal margin with two sharp teeth, Fu1 to Fu4 length slight longer than its width respectively, Fu5 and Fu6 quadrate, gaster 1.8 × as long as broad; but in Dibrachys microgastri ( Bouché), body yellow-green, clypeal margin with two blunt teeth, Fu1 to Fu5 quadrate, Fu6 transverse, gaster 2 × as long as broad.

Description.

Holotype. Female. Body (Figs 29, 30) length 2.2 mm. Head and mesosoma dark green, with metallic reflection; gaster brown and with metallic reflection basally. Antennae dark brown except scape and pedicel yellowish brown; mandible brown; legs yellowish brown except coxae brown; fore wing slightly infumate, wing venation yellowish brown.

Head in frontal view (Fig. 31), width 1.24 × height; frons with dense reticulation; lower face flat, reticulation on lower face same as that on frons; eye height 0.7 × head height, eyes separated by 1.09 × eye height; antennal scrobe deep, extending upwards but not reaching anterior ocellus. Antennal insertion on lower ocular line, distance from upper margin of torulus to lower margin of anterior ocellus 2.35 × distance from lower margin of torulus to clypeal margin; clypeus with longitudinal sculpture, only small area smooth; clypeal margin protruded, emarginate in middle with two sharp teeth; oral fossa width 0.46 × head width. Head in lateral view, malar sulcus inconspicuous, eye height 3.3 × malar space. Antennal scape 0.81 × as long as eye height, not reaching lower margin of anterior ocellus; length of pedicel and flagellum combined shorter than head width (0.84 ×); pedicel in lateral view 2.6 × as long as broad; anelli transverse; Fu1 to Fu4 slightly longer than broad respectively, Fu5 and Fu6 quadrate; each funicular segment with one row of longitudinal sensilla; clava slightly clavate, 2.43 × as long as broad, micropilosity only limited to apex of third clava segment. Head in dorsal view 1.89 × as wide as long; vertex convex, occipital carina strong; eye length 2 × temple length; POL 1.64 × OOL.

Head 1.31 × as broad as thorax. Mesosoma 1.38 × as long as broad. Pronotum with raised reticulation, pronotal collar slightly narrower than mesoscutum (0.86 ×); middle length of pronotum almost 1/9 as long as length of mesoscutum; collar not margined anteriorly, posterior margin of collar with a smooth band. Mesoscutum 1.86 × as broad as long, with regular and dense reticulation; notauli incomplete and unconspicuous. Scutellum convex, 1.09 × as broad as long, frenal line absent; reticulation same as on mesoscutum but slightly large on posterior part of scutellum. Propodeum (Fig. 32) medially ½ as long as scutellum; plica complete; median carina incomplete, occasionally with one or two short longitudinal ridge which interrupted in the middle; nucha short and smooth, separated with middle part of propodeum by a transverse shallow depression; spiracles elongate, 2 × as long as broad, separated by the width of spiracles from hind margin of metanotum; area below spiracles with finely reticulation. Fore wing 2.25 × as long as broad, without marginal fringe; basal vein with sparse setae, basal cell bare; speculum only stretched to 1/3 base of marginal vein; upper surface of costal cell bare, lower surface with a one complete row of setae and distal 1/3 with some scattered setae; submarginal vein 2.33 × as long as marginal vein; marginal vein 1.67 × as long as postmarginal vein; stigmal vein as long as postmarginal vein, slightly curved.

Petiole invisible dorsally. Gaster (Fig. 29) long ovate, 1.8 × as long as broad, 1.3 × as broad as thorax width; surface of each tergite coriaceous; Gt1 covering 1/3 length of gaster, posterior margin of Gt1 cambered, median with an obvious hollow; following tergites with posterior margin straight; gaster terminal acute.

Male. Body length 2.1 mm; head and thorax blue-green; antenna light brownish except clava slightly dark, other segments yellow; legs yellow to yellowish brown except coxae concolorous with body; fore wing yellowish brown; gaster brown, with a yellow transverse bright ribbon at 1/3 base of gaster.

Material examined.

Holotype: China: ♀, Beijing: Miyun Reservoir, 40.29°N, 116.50°E, 18.VII.1983, ex. pupae of Dendrolimus tabulaeformis , leg. Ju-Wen Wu. Paratypes: China: 1♂, 2♀, same data as holotype; 2♀, Beijing: Miyun Reservoir, 20.VII.1983, ex. pupae of Dendrolimus tabulaeformis , leg. Ju-Wen Wu; 5♀, Beijing: Huairou, 15.VI.1982, ex. Illiberis pruni , leg. Mr. Jin; 1♀, Beijing: Songshan, 26.VIII.1984, ex. Illiberis pruni ; 4♀, Beijing: Changping, 15.VI.1981, ex. Locastra muscosalis , leg. Zhen-Hua Liu; 1♀, Beijing: Yuanmingyuan Imperial Garden, 18.VII.1984, ex. larvae of Lymantria dispar , leg. Mu-Zong Cheng; 6♀, Beijing: Yuanmingyuan Imperial Garden, 2.VI.1984, ex. larvae of Lymantria dispar , leg. Ding-Xi Liao; 4♂, 5♀, Beijing: Mentougou, late July of 1983, ex. Prothesia similes xanthocampa, leg. Sui-Hua Zhao; 1♀, Beijing: Qingbaichang, leg. Ding-Xi Liao.

Etymology.

In memory of professor Ding-xi Liao in China.

Hosts.

Larvae of Illiberis pruni Dyar, Illiberis nigra Leech ( Lepidoptera : Zygaenidae ), Lymantria dispar (L.) ( Lepidoptera : Noctuoidea) and Porthesia similis (Fueszly) ( Lepidoptera : Lymantridae ), pupae of Dendrolimus tabulaeformis Tsai et Liu, Dendrolimus superans (Butler) ( Lepidoptera : Lasiocampidae ), Illiberis ulmivora Graeser, Pseudopanolis flavimacula Inaba ( Lepidoptera : Noctuidae ), Rogas dendrolimi (Matsumura) ( Hymenoptera : Braconidae ) and Tenthredinidae sp..

Distribution.

China (Liaoning, Beijing, Hebei, Shanxi, Shandong, Gansu, Qinghai).