Pediobius bisulcatus Cao & Zhu

Cao, Huan-Xi, Salle, John La & Zhu, Chao-Dong, 2017, Chinese species of Pediobius Walker (Hymenoptera: Eulophidae), Zootaxa 4240 (1), pp. 1-71 : 11-12

1. Pediobius bisulcatus Cao & Zhu , sp. n.

( Figs 1 , 33 a)

Diagnosis. Scutellum with two deep sublateral grooves that join posteriorly to form a U-shaped groove; smooth inside and striate outside the U-shaped groove ( Figs 1 a, 1c). Petiole with two setae that subequal in length on each side. Gaster subcircular, much shorter than mesosoma, with Gt6 about 6× as broad as long and Gt7 nearly invisible; Gt1 of female occupying about 2/5 length of gaster ( Fig. 1 a), but hardly reaching mid-length of gaster in male ( Fig. 1 c). Fore wing with an infuscate area below STV ( Figs 1 d, 1f).

Female. Body length 1.7–1.8mm. Body small, slender.

Body metallic blue green. Face with slightly metallic green reflections. Scape and pedicel metallic blue-green, flagellum with blue-green reflections. Legs with coxae, femora and tibiae metallic blue-green; first three tarsomeres pale white, and apical tarsomere dark brown ( Fig. 1 h); metatibial spur white.

Antenna with 3-segmented funicle and 2-segmented clava, and funicle clearly separated from clava ( Fig. 1 g). Scape not reaching median ocellus. Pedicel longer than broad, shorter than F1 and nearly as broad as F1. Flagellum setose; funicular segments longer than broad, subequal in width and decreasing slightly in length; C1 longer than broad, C2 slightly narrower than C1 and with a distinct terminal spine. Relative measurements of scape: pedicel: F1: F2: F3: C1: C2 = 2.1: 1.0: 0.9: 0.8: 0.7: 0.7: 0.6. Face strongly reticulate above toruli, except sculpture slightly weaker between frontofacial sutures; much more finely reticulate below toruli except for a strongly reticulate subround area below each torulus ( Fig. 33 a). Toruli inserted above lower margin of eyes. Scrobal grooves meeting at frontofacial sutures. Interscrobal space with sharp projection. Frontofacial sutures diverging at an obtuse angle of about 100° ( Fig. 33 a).

Head in dorsal view strongly transverse, more than 3× as broad as long (5.6: 1.5). Vertex with long setae, strongly but finely reticulate. Frons and occiput slightly emarginate, and median length of vertex short. Ocelli arranged in a right-angle triangle. POL longer than OOL (1.2: 1.0). Occiput only weakly margined between the posterior ocelli, with a long seta on each side of occipital carina ( Fig. 1 a).

Pronotal collar smooth, and with anterior carina. Mesoscutum strongly and finely reticulate; both pairs of setae very long and the posterior pair situated on MLM. Notauli distinct and in posterior two-thirds merging to groovelike inner margins of deep, narrow and smooth notaular depressions. Posterior margin of MLM emarginate slightly, separated from base of scutellum by a distinct, narrow, semicircular hole. Axilla reticulate. Scutellum slightly longer than broad (3.0: 2.7), distinctly narrowed anteriorly; convex with two deep sublateral grooves joining posteriorly to form a U-shaped groove, and smooth inside and striate outside the U-shaped groove ( Fig. 1 a); setae on scutellum very long, as long as those on MLM. Dorsellum short and polished, with two small, irregularly sculptured lateral foveae, polished between two lateral foveae; slightly protruding in an obtuse angle apically. Propodeum with submedian carinae fused in anterior third and distinctly raised to form a crest against dorsellum, but strongly diverging straight backwards over posterior two-thirds; submedian area distinctly longer than broad (1.7: 1.0) and smooth; plicae subparallel; callus with 4 setae. Lateral panel of pronotum and prepectus reticulate; acropleuron, mesepisternum and mesepismeron polished; transepimeral sulcus, pleural suture and transepisternal sulcus deep and distinct; transepimeral sulcus curved in upper on third and straight in lower two thirds ( Fig. 1 b).

Petiole subquadrate (1.4: 1.3), strongly reticulate with a longitudinal median ridge and two short lateral ridges in anterior third and with two long white setae at each side, which subequal in length. Gaster short, subcircular (5.0: 5.0), much shorter than mesosoma (5.0: 6.5); Gt1 occupying about 2/5 length of gaster, weakly reticulate, with posterior margin protruding slightly apically and converging at sides ( Fig. 1 a); Gt6 much broader than long, about 6× as broad as long (3.6: 0.6), and Gt7 nearly invisible.

Fore wing setose, with a large infuscate area below STV ( Fig. 1 f); speculum small and closed below; PMV long, slightly longer than STV. Relative measurements of SMV: MV: PMV: STV= 2.5: 7.3: 1.0: 0.9. Metatibial spur straight, very short, almost as long as width of tibia, not reaching apex of basal tarsomere ( Fig. 1 h).

Male. Body length about 1.5 mm. Similar to female, except as follows. Body more vividly green, with strong coppery reflections. Scape hardly reaching median ocellus ( Fig. 1 e). Flagellum much longer and more setose than for female, all flagellomeres subequal in length and separated by short petioles. Petiole without a longitudinal median edge but with two transverse edges. Gt1 relatively longer, though hardly reaching mid-length of gaster ( Fig. 1 c).

Etymology. This species is named for the U-shaped groove on its scutellum, from Latin bi = two and sulcus = sulcus.

Material examined. Holotype ♀, CHINA, Hainan, Wuzhishan, Wuzhi Mountains , 26.IV.1984, coll. Chang- Fang Li ( IZCAS) . Paratypes: 2♂, same data as the holotype ; 1♀, CHINA, Fujian, Huanggang Mountains , 27.VI.1980, coll. Jing-Wei Zhao ( IZCAS) ; 1♀, Huanggang Mountains , 27.VI.1980, coll. Xiu-Fu Zhao ( IZCAS) ; 1♀, Huanggang Mountains , 12.IX.1981, coll. Ju-Chang Huang ( IZCAS) ; 1♀, Huanggang Mountains , VI. 1982, coll. Jian-Fei Xu ( IZCAS) ; 2♀, CHINA, Guangxi, Jinxiu, Shengtang Mountains , 28–29.VI.2000, coll. Chao-Dong Zhu ( IZCAS) .

Biology. Unknown.

Distribution. CHINA: Fujian, Guangxi, Hainan.

Remarks. Two females of P. bisulcatus collected in Guangxi Province, China, have the scutellum more polished than that of holotype, which nearly polished outside the U-shaped groove. Pediobius bisulcatus and P. elongatus are similar to P. alcaeus not only in the characters listed in the diagnosis of the alcaeus -group, but also the sublateral grooves of the scutellum joining posteriorly, which distinguish them from all other alcaeus -group species. In addition, P. bisulcatus is characterized by its unusually broad Gt6 that is 6× as broad as long. Based on comparison with three females of P. alcaeus determined by Z. Bouček, P. bisulcatus differs from P. alcaeus mainly by the following characters: fore wing with an infuscate area below STV, petiole with two setae on each side, and gaster subcircular and almost as long as mesosoma. Besides the main differences given in the key, P. bisulcatus differs from P. elongatus in having the ocelli arranged in a right-angle triangle, whereas they are arranged in an obtuse-angle triangle in P. elongatus .

Figures

FIGURE 1. Pediobius bisulcatus Cao & Zhu, sp. n. a: female, body in dorsal view; b: female, body in lateral view; c: male, body in dorsal view; d: male, body in lateral view; e: male, head with antenna in front view; f: female, fore wing; g: female, antenna; h: female, hind leg. Scale bar: a – e, 0.5 mm; f, 0.4 mm; g, 0.1 mm; h, 0.2 mm.

FIGURE 33. Pediobius spp., head in front view. a: Pediobius bisulcatus Cao & Zhu, sp. n., female; b: Pediobius elongatus Cao & Zhu, sp. n., female; c: Pediobius petiolapilus Cao & Zhu, sp. n., female; d: Pediobius prominentis Cao & Zhu, sp. n., female; e: Pediobius narangae Sheng & Wang, 1994, female; f: Pediobius tortricida Cao & Zhu, sp. n., female; g: Pediobius saulius (Walker, 1839), female; h: Pediobius saulius (Walker, 1839), male. Scale bar: 0.5 mm.