Chorebus (Stiphocera) convexiclypeus, Zheng & Chen, 2017, Zheng & Chen, 2017

Zheng, Min-Lin & Chen, Jia-Hua, 2017, The dacnusine genus Chorebus Haliday (Hymenoptera: Braconidae: Alysiinae) from China, Zootaxa 4294 (2), pp. 170-180 : 177-179

ChorebuS (Stiphocera) convexiclypeuS , sp. nov.

( Fig. 4 A–I)

Type material. Holotype: female: Linzhi County, Tibet, China, 15.viii. 2012, coll. Wangzhen Zhang . Paratypes: 1 female and 1 male, Linzhi County, Tibet, China, 15.viii. 2012, coll. Wangzhen Zhang .

Description. Holotype, female. Body 3.4 mm long.

Head. Antenna with 33 flagellomeres; first flagellomere 1.2× as long as second flagellomere, 1.5× as long as third flagellomere; first and penultimate flagellomeres 5.0× and 1.8× as long as wide, respectively. Head in dorsal view transverse ( Fig. 4 B), 2.0× as broad as long. Temple somewhat swollen. Eye 0.7× as long as temple. OOL: OD: POL=12:3:4. Occipital with 3 rows of setae. Face 1.9× as high as wide, with a distinct median longitudinal carina on its upper half, densely pubescent (pubescence directed downward) except a glabrous median longitudinal area. Clypeus ( Fig. 4 A) strongly protruding, shield-like, with many pubescence. Mandible ( Fig. 4 C) with 4 teeth; first tooth relatively expanded upward; first and second tooth mostly equal in length and distinctly longer than other teeth; third tooth (additional tooth) relatively developed and distinctly separate to second tooth; fourth tooth only forming a weak obtuse protrusion. Maxillary palp relatively short.

Mesosoma. Mesosoma 1.5× as long as high. Pronotum with a relatively large pronope; sides of pronotum glabrous, mostly smooth (some rugosity on its posterior edge). Mesoscutum ( Fig. 4 D) mostly smooth and glabrous, only its anterior edge and anterior half of middle lobe densely and finely setose; notaulus absent on mesoscutal disk but impressed and crenulate on oblique anterior part of mesoscutum; medio-posterior depression of mesoscutum about 0.5× as long as mesoscutum, relatively deep and wide on its posterior half. Scutellum relatively protuberant, smooth, sparsely setose. Mesopleuron mostly smooth, shining and glabrous; precoxal sulcus deep, extends virtually half length of the mesopleuron, strongly crenulate. Below precoxal sulcus to mesosternum very densely setose. Propodeum ( Fig. 4 E) relatively wide and flat, entirely rugose, evenly covering with fine pubescence, without a median longitudinal carina. Median area of metanotum distinctly raised (not protruding beyond the level of scutellum). Metapleuron ( Fig. 4 G) rugose on its anterior and posterior area, only very slightly and finely punctured on its median area, entirely with dense pubescence directed towards hind coxa.

Wings. Pterostigma 5.7× as long as wide, 1.7× as long as vein 1-R1. Length of vein r equal to width of pterostigma. Posterior half of vein 3-SR+M somewhat curved. Subdiscal cell of fore wing closed ( Fig. 4 F).

Legs. Hind femur 5.0× as long as broad. Hind tibia and hind tarsus equal in length. Second tarsomere of hind tarsus 0.5× as long as its basitarsus. Third hind tarsomere 1.1× as long as its telotarsus ( Fig. 4 I).

Metasoma. First tergite ( Fig. 4 E) evenly widened towards its apex, 1.4× as long as its apical width, entirely rugose (more or less longitudinally), evenly covered with many fine setae (not concealed by rugosity). Tergites beyond first one smooth and shining, each with one transverse line of setae on its posterior area. Ovipositor projecting distinctly beyond the apical tergite in the retracted position, ovipositor sheath and hind basitarsus equal in length.

Colour. Head mainly black; antenna dark brown; median part of mandible reddish-yellow, teeth reddishbrown; clypeus black; labrum golden yellow; maxillary and labial palp yellow (distal segment of maxillary yellowish-brown). Mesosoma black; legs mainly reddish-yellow, tarsus brown, basal half of hind coxa dark brown, hind trochantellus brown, dorsal area of hind femur brown. First metasomal tergite black, remaining tergites dark brown; ovipositor sheath dark brown.

Variation. Body length 3.0– 3.4 mm; antenna with 30–33 flagellomeres.

Male. Similar to female. Body length 3.9 mm; antenna with 35 flagellomeres; pterostigma darker.

Biology. Unknown.

Etymology. The name is derived from the Latin words “convexi” (means “convex”) and “clypeus” which refers to the strongly convex clypeus.

Distribution. Only known from Tibet (Southwest Palaearctic China)

Remarks. This new species is close to Chorebus (Stiphocera) anita (Nixon) , but differs from the latter as follows: 1) clypeus strongly protruding, shield-like (not forming a shield-like protrusion in C.(S.) anita ); 2) first mandibular tooth distinctly expanded, additional tooth developed and obviously separate from second tooth (very slightly expanded, additional tooth only forming a small weak protrusion located at the base of ventral edge of second tooth in C.(S.) anita ); 3) hind tibia and hind tarsus equal in length (hind tarsus distinctly shorter than hind tibia in C.(S.) anita ).

Figures

FIGURE 4 (A – I). Chorebus (Stiphocera) convexiclypeus, sp. nov., ♀, A. head (frontal view, arrow indicates the strongly protrudeand shield-like clypeus); B. head (dorsal view); C. mandible; D. mesonotum (dorsal aspect); E. propodeum and first metasomal tergite (dorsal aspect); F. fore wing; G. mesosoma (lateral aspect); H. antenna (scapus, pedicellus, 1 st – 3 rdand last eight flagellomeres); I. hind tarsus