Chorebus (Chorebus) densepunctatus, Burghele

Zheng, Min-Lin & Chen, Jia-Hua, 2017, The dacnusine genus Chorebus Haliday (Hymenoptera: Braconidae: Alysiinae) from China, Zootaxa 4294 (2), pp. 170-180 : 171-173

ChorebuS (ChorebuS) denSepunctatuS Burghele, 1959

( Fig. 1 A–H)

Chorebus densepunctatus Burghele, 1959: 121 –126; Griffiths, 1968: 63 –152; Shenefelt 1974: 1044. Chorebus (Chorebus) densepunctatus: Tobias et al., 1986: 7 –231.

Material examined. 1 female, Huanggang mountain, Fujian Province, China, 28.vi.1982, coll. Yihua Liu ; 2 males, Fushi Town , Yongding County, Fujian Province, China, 9.vi.1986, coll. Hong Zhang ; 2 males, Erliping , Wuyi mountain, Fujian Province, China, 23.viii.1993, coll. Jianquan Yang ; 1 female, Jiulongkeng , Guangze County, Fujian Province, China, 25.vii. 2002, coll. Lianxi Gao ; 1 female and 7 males, Huangshikeng , Qingliu County, Fujian Province, China, 29.viii.2010, coll. Jianquan Yang and Junjie Guo ; 1 female, Mudanjiang national forest park, Heilongjiang Province, China, 19.vii. 2011, coll. Xiaohui Dong .

Description. Female. Body 2.0 mm long.

Head. Antenna with 21 flagellomeres, densely setose; first flagellomere distinctly longer than other flagellomeres, 1.2× and 1.6× as long as second and third flagellomere, respectively; first, tenth and penultimate flagellomeres 4.0×, 2.5× and 2.4× as long as wide, respectively. In dorsal view, head 1.4× as broad as long. Occipital almost completely bare. Eye 0.8× as long as temple. Ocellus small, OOL:OD:POL=22:5:13. In frontal view, eyes distinctly convergent below. Face densely pubescent. Clypeus somewhat protruding. Mandible ( Fig. 1 C, 1D) relatively slender, with three teeth (third tooth hardly visible); first tooth very short and obtuse, second tooth quite long and pointed.

Mesosoma. Mesosoma 1.5× as long as high, almost entirely covered with granulose sculpture ( Fig. 1 F, 1H). Sides of pronotum almost glabrous. Propleuron densely pubescent. Mesoscutum ( Fig. 1 H) densely pubescent except two lateral lobes relatively sparsely pubescent; notaulus almost invisible; medio-posterior depression of mesoscutum only form a very small and shallow depression. Precoxal sulcus represented by a well-defined smooth linear groove, which extends virtually for the entire length of the mesopleuron. Median part of metanotum somewhat dorsally protruding, not beyond the scutellum. Propodeum sparsely pubescent on its anterior half and densely pubescent on its posterior half, and with a distinct median longitudinal carina extending posteriorly to the one-third part of propodeum from its base. Metapleuron ( Fig. 1 F) with dense pubescence forming a distinct rosette around a swelling on its lower half.

Wings ( Fig. 1 G). Pterostigma relatively thin. Vein r arises somewhat before the middle of pterostigma, 1.5× as long as the maximal width of pterostigma and almost perpendicular to the outer margin of pterostigma. Vein cu-a distinctly antefurcal. Vein CU1b relatively strong except its weak lower tip, almost as long as vein 3-CU1. Vein M+CU of hind wing 1.1× as long as vein 1-M.

Legs. Hind coxa with a conspicuous tuft of matted pubescence on its posterior margin. Hind tibia and tarsus almost equal in length. Hind basitarsus and telotarsus equal in length, 0.7× as long as third tarsomere.

Metasoma. First tergite ( Fig. 1 E) strongly widened towards its apex, about 1.1× as long as its apical width, almost glabrous, and longitudinally striated. Remaining tergites smooth and hardly setose. Second and third tergites equal in length. Ovipositor hardly projecting beyond the apical tergite in the retracted position.

Colour. Head mainly black; antenna dark brown; mandible yellow except edge of teeth reddish-brown; clypeus dark reddish-brown; labrum yellow; maxillary and labial palp pale yellow. Mesosoma black; tibiae yellowishbrown, tarsi brown, femorae yellow, coxae of front and mid legs yellow, coxa of hind leg mainly brown. First metasomal tergite black; remaining tergites dark brown; ovipositor sheath black.

Variation. Antenna with 20–21 flagellomeres, major colour of body from reddish-brown to black.

Male. Similar to female. Body length 2.1–2.2 mm, antenna with 21–25 flagellomeres.

Biology. Known as endoparasitoids of Hydrellia griseola (Fallen) (Burghele 1960) .

Distribution. China (North Palaearctic and Oriental, first record), Hungary, Romania, Ukraine.

Remarks. Chorebus (Chorebus) densepunctatus is quite similar to other two species C.(C.) scabrifossa Stelfox and C.(C.) striola Stelfox in subgenus Chorebus s.str. as their mesosomal sculpturing is mainly and densely granulose, but can be easily distinguished as follows: precoxal sulcus represented by a well-defined smooth linear groove (precoxal sulcus distinctly rugose in C.(C.) scabrifossa ); second metasomal tergite smooth (sculptured in C.(C.) striola ) ( Tobias et al. 1986).

Figures

FIGURE 1 (A – H). Chorebus (Chorebus) densepunctatus Burghele, rec. nov., ♀, A. head (frontal view); B. head (dorsal view); C. mandible (view on last tooth); D. mandible (maximum view on 1 st tooth); E. first metasomal tergite (dorsal aspect); F. mesosoma (lateral aspect); G. fore and hind wings; H. mesonotum (dorsal aspect).