Apanteles transtergum Liu & Chen

Liu, Zhen, He, Jun-Hua & Chen, Xue-Xin, 2014, The grandiculus- and metacarpalis - group of the genus Apanteles Foerster, 1862 (Hymenoptera, Braconidae, Microgastrinae) from China, with descriptions of eight new species, Zootaxa 3765 (5), pp. 435-457 : 452-456

Apanteles transtergum Liu & Chen , sp. n.

Figure 10

Description. Female. Body length ca. 2.5 mm, fore wing length ca. 2.5 mm.

Head. A little rounded in dorsal view, 1.8× as wide as long and 1.2× as wide as mesoscutum. Eye in dorsal view 1.2× as long as temple. Temple shiny and distinctly thickly punctate, not constricted. Face about 0.8× as high as wide, relatively shiny, slightly convex with a narrow indistinct sulcus medially, shallowly punctate, less pubescent, inner margin of eyes subparallel. Apical margin of clypeus almost straight. Posterior almost tangent to the anterior ocellus touching the posterior pair, POL:OD:OOL=4.0:2.0:4.5. A sulcus extended from anterior ocellus to hind polished zone of vertex. Antenna about 0.8× as long as body length, penultimate antennomere cubic.

Mesosoma. Length to breadth and height 37.8:23.0:28.8. Disc of mesonotum relatively dull, densely heavily punctate, interspaces smaller than diameter of punctures. Scutellar sulcus slightly straight, narrow with carinae in between. Scutellum polished with relative shallow punctures all over. Propodeum dull, weakly rugose all over except big punctures anteriorly. Mesopleuron highly polished, its anterior half with shallow hair punctuation of even size.

Legs. Spines on outer side of hind tibia numerous but relatively dispersed. Spurs of hind tibia of equal size, almost 1/2 of basitarsus. Basitarsus of hind leg slightly shorter than tarsal segments 2–4.

Wings. Pterostigma 2.8× as long as its widest part. Vein 1-R1 (metacarp) 2/5 shorter than pterostigma, it is 2× as long as its distance from the apex of the marginal cell. Vein r arising from middle of pterostigma, shorter than width of pterostigma, vein r as long as vein 2-SR, indistinctly angled at their meeting, vein 2-M 5/6 length of vein 2-SR. 1st discal cell 1/3 wider than high. First submarginal cell of hind wing 2× wider than high. Vein cu-a straight and perpendicular to vein 1-1A. Vein 1-1A relatively long, 1/3 of fold of vannal lobe.

Metasoma. 1.3× as long as thorax (48.0:37.8). T1 narrowed to apex, basal width 1.5× hind width, and short, only 1.1× longer than basal width. Slightly concave at basal two-fifth, turned-over part shiny with close, numerous punctures, and weakly strigose except the convex polished zone apically. T2 subtriangular to transverse, curved into T3 medially, 3.5× wider than long in the middle. T3 2.1× as long as T2 (17.0:8.0). T2 shallowly punctate medially, and strigose laterally. Tergites after T2 relatively shiny, smooth, almost pubescent through. Hypopygium slightly longer than apex of abdomen. Ovipositor sheath 0.8× as long as hind tibia (20.0:26.0), relatively thick (as wide as tarsus segment 4).

Colour. Body black, except tergites posterior to T2 brownish. Palpi (except basal segment, anterior half of segment 2 of maxillary palpi and labial palpi brown) and spurs pale yellow. Tegulae, flagellum and ovipositor sheath evenly dark brown. Labrum, mandible reddish yellow. Legs bright reddish brown, except fore tibia, basal 1/ 3 of mid tibia and most of hind tibia reddish yellow. Wing membrane hyaline, vein 1-R1, C+SC+R and pterostigma brownish, r, 2-SR, 2-M and other veins light brown.

Variation. Body length 2.5–2.8 mm. T3–T4 with white hind, vein r and 2-SR distinctly angled at their meeting in paratype.

Male. Unknown.

Host. Unknown.

Material examined. Holotype: ♀, Mt. Xiaowutai, 1200m, Hebei, 2005. VIII.22, Zhang Hongying, No. 200608401. Paratype: 1♀, Mt. Xiaowutai, 1200m, Hebei, 2005. VIII.22, Zhang Hongying, No. 200608405.

Distribution. China (Hebei) ( Fig. 12 ).

Etymology. The specific name “ transtergum ” derives from the Latin noun “tergum” and prefix “trans”, referring to the transverse median field of T2+T3.

Remarks. This species is similar to A. olivierellae Wilkinson, 1936 , but can be separated from the latter in having vein 1-CU1 of fore wing 3/4 of vein 2-CU1 (the latter 1/2 or less); mesoscutum on the whole relatively dull, not highly polished as in A. olivierellae ; and vein 1-1A of hind wing about 1/3 of fold of vannal lobe (the latter half).

Figures

FIGURE 10. Apanteles transtergum Liu & Chen, sp. n. a propodeum and T 1 – 3, dorsal view b head, frontal view c hind wing d fore wing e mesonotum and scutellum, dorsal view f head, dorsal view g habitus, lateral view. Scale line = 0.5 mm.

FIGURE 12. Distribution map of metacarpalis - group of Apanteles species in China. •: Apanteles corvinus Reinhard, 1880; ♦: Apanteles cosmopterygivorus Liu & Chen, sp. n.; ♥: Apanteles dumosus Liu & Chen, sp. n.; ˔: Apanteles incurvus Liu & Chen, sp. n.; ˑ: Apanteles malleus Liu & Chen, sp. n.; ■: Apanteles metacarpalis (Thomson, 1895); •: Apanteles pelopea Nixon, 1973; ★: Apanteles transtergum Liu & Chen, sp. n.