Spathius xui, Tang & Belokobylskij & Chen, 2015

Tang, Pu, Belokobylskij, Sergey & Chen, Xue-Xin, 2015, Spathius Nees, 1818 (Hymenoptera: Braconidae, Doryctinae) from China with a key to species, Zootaxa 3960 (1), pp. 1-132 : 126-129

Spathius xui sp. nov.

( Fig. 48 )

Description. Female. Body length 3.8 mm; fore wing length 2.1 mm.

Head. Antennae 26-segmented. Scape 1.8 × as long as its maximum width. First flagellar segment 5.5 × as long as its apical width, 1.25 × as long as second segment. Head width (dorsal view) 1.5 × median length. Head behind eyes (dorsal view) roundly narrowed; transverse diameter of eye 1.1 × length of temple. Ocelli medium-sized, arranged in triangle with base 1.1 × its sides; POL: Od: OOL = 10: 9: 25. Vertex almost entirely coriaceous. Frons entirely coriaceous, with coarse and curved striae. Eye glabrous, 1.5 × as high as broad. Malar space 0.4 × eye height and equal to basal width of mandible. Temple almost smooth. Face with very dense, fine and absolutely even transverse aciculation (like surface of gramophone record or CD); its width 1.1 × eye height and 1.1 × height of face and clypeus combined. Clypeal suture absent. Hypoclypeal depression rather small and round, its width 0.7 × distance from edge of depression to eye, 0.4 × width of face. Occipital carina complete dorsally, not joined with hypostomal carina being obliterated upper base of mandible.

Mesosoma. Length of mesosoma 2.2 × its height. Pronotal keel rather fine, its posterior branch almost fused medially with posterior margin of pronotum, anterior branch situated submedially on pronotum. Mesoscutum not highly and roundly elevated above pronotum; its median lobe convex anteriorly and without anterolateral corners. Mesoscutum densely granulate-reticulate, without striae and rugosity. Notauli anteriorly rather deep, wide, crenulate, almost completely absent in posterior half. Prescutellar depression rather shallow, short, with three carinae, rugulose-reticulate, 0.4 × as long as scutellum. Scutellum convex, with distinct lateral carinae, entirely distinctly and densely granulate. Mesopleuron rather widely reticulate-coriaceous. Subalar depression shallow, wide, and finely reticulate-striate. Precoxal sulcus distinct, narrow, straight, finely reticulate-crenulate, running along anterior 0.5 of lower part of mesopleuron. Propodeum with very small lateral tubercles. Propodeum with areas more or less distinctly delineated by rather fine carinae, rugose-reticulate with granulation and especially densely in anterior half; areola delineated by rather fine carinae, narrow and long, basal carina almost as long as anterior fork of areola.

Wings. Fore wing 4.5 × as long as wide. Vein r arising almost from middle of pterostigma. 3-SR: r: SR1 = 12: 2: 14. 2-SR vein almost entirely absent. Second submarginal cell not narrowed distally, its length 3.3 × maximum width, 1.5 × length of first subdiscal cell. Vein m-cu interstitial. Vein cu-a interstitial; Vein CU1a almost interstitial. Hind wing vein M+CU 0.5 × as long as vein 1-M. Vein m-cu interstitial, weakly curved towards base of wing.

Legs. Hind coxa densely granulate, without basoventral tooth and corner. Hind femur granulate-coriaceous, almost smooth below, 3.3 × as long as wide. Hind tibia apically without spines on outer side. Dorsal surface of hind tibia with rather short, sparse and semi-erect setae, their length 0.7–1.0 × maximum width of tibia. Hind tarsus 0.9 × as long as hind tibia. Hind basitarsus 0.6 × as long as second-fifth segments combined. Second segment of hind tarsus 0.45 × as long as basitarsus, as longer as fifth segment (without pretarsus).

Metasoma. Petiole (lateral view) weakly curved ventrally, dorsally weakly arched in basal third and straight in apical two-thirds, thickened in basal third; weakly widened in apical quarter (dorsal view), with spiracular tubercles in basal third, distinctly striate, distinctly rugulose between striae in anterior 0.7. Length of petiole 2.6 × its apical width (dorsal view), 1.6 × length of propodeum. Second tergite basally with separate laterotergite. Median length of second and third tergites combined 1.9 × basal width of second tergite, 0.9 × their maximum width. Second suture absent. Second and third tergites almost entirely with very dense and fine semi-circular aciculation. Fourth-fifth tergites with very fine coriaceous in basal halves and almost smooth in apical halves. Remaining tergites smooth. Ovipositor straight. Ovipositor sheath 1.8 × as long as petiole, 0.8 × as long as metasoma, as long as mesosoma, 0.55 × as long as fore wing.

Colour. Body light reddish brown, partly only yellow, metasoma in posterior half dark reddish brown. Antennae yellow to brown, distinctly infuscate apically. Palpi brown, apical segments of maxillary palpi weakly paler. Legs brownish yellow, partly yellow. Ovipositor sheath brownish yellow in basal 0.7 and black in apical 0.3. Fore wing distinctly and widely maculate; subbasal cell crossed by dark fascia before its narrowest part. Pterostigma dark brown, pale yellow in basal 0.4.

Male. Unknown.

Material examined. Holotype: female, China, Guangdong Prov., Yunan Tongledashan , 12–13.VIII.2003, Xu Zaifu, No. 20054357 ( ZJUH).

Comparative diagnosis. This new species is characterised by the absence of the vein 2-SR and the presence of excessively fine, very dense and absolutely even transverse aciculation on face. Spathius xui sp. nov. is similar to S. buonluoicus Belokobylskij , but differs in having the vein cu-a interstitial (distinctly antefurcal in S. buonluoicus ), propodeum with areola delineated by rather fine carina (without areola in S. buonluoicus ), vertex without striation (with fine transverse striation in S. buonluoicus ), and mesopleuron rather widely reticulate-coriaceous (smooth in S. buonluoicus ).

Etymology. This species is named in honour of Prof. Xu Zaifu, the collector of the holotype.

Distribution. China (Guangdong).

Figures

FIGURE 48. Spathius xui sp. nov. A, habitus, lateral aspect; B, head, dorsal aspect; C, head, frontal aspect; D, fore wing; E, mesosoma, lateral aspect; F, mesoscutum, dorsal aspect; G, metasoma, dorsal aspect. Scale bar 0.5 mm.