Euurobracon xuthus, Li, Yang, He, Jun-Hua & Chen, Xue-Xin, 2016

Li, Yang, He, Jun-Hua & Chen, Xue-Xin, 2016, The genus Euurobracon Ashmead (Hymenoptera, Braconidae, Braconinae) in China, with description of three new species, Zootaxa 4132 (3), pp. 383-392 : 389-391

Euurobracon xuthus sp. nov.

( Figs 3 a–i)

Holotype: Length of body 15. 5 mm, fore wing 14.5 mm, ovipositor 16.0 mm.

Head. Antennae with 61 flagellomeres, terminal flagellomere blunt at apex, and approximately as long as wide basally, first flagellomere 1.5 and 1.7× longer than second and third respectively, the latter being approximately as long as wide maximally. Inter-tentorial distance: tentorio-ocular distance = 2: 1. Clypeus smooth, shiny and glabrous, and clypeal guard hairs forming a single row. Face with sparse and long setae laterally but with the raised supraclypeal triangular area and the adjacent depressed areas ventrally, glabrous ( Fig. 3 e). Head widest across eyes ( Fig. 3 f). Shortest distance between eyes: width of head = 13: 23. Length of head behind eye: horizontal length of eye = 0.92: 1. Frons densely setose immediately behind the antennal sockets except for the vicinity of the midlongitudinal sulcus. POL: diameter of posterior ocellus: shortest distance between posterior ocellus and eye = 14: 13: 43.

Mesosoma. Mesosoma approximately 1.76× longer than high ( Fig. 3 d). Mesosoma shiny and glabrous, with sparse but long setae, and sometimes more densely laterally. Mesoscutum strongly convex at middle, and notauli only impressed at the front part of the mesoscutum. Propodeum densely and long setose ( Fig. 3 c).

Wing. Fore wing: vein SR1: 3-SR: r = 94: 65: 13; vein 1-SR+M slightly curved near middle, and approximately as long as 1-M; vein m-cu straight, 1.94× longer than 2-SR+M; vein 2-SR: 3-SR: r-m = 35: 71: 36; vein 3-CU1 strongly expanded along its posterior third. Hind wing: vein 2-SC+R transverse and strongly reclivous; vein 1r-m 1.41× longer than SC+R1.

Leg. Length of fore femur: tibia: tarsus = 79: 87: 99. Antero-lateral aspect of fore tibia densely and evenly covered with thick setae. Fore basitarsus 3.1× longer than maximally wide. Length of hind femur: tibia: basitarsus = 61: 92: 36. Hind basitarsus 7.8× longer than wide.

Metasoma. First metasomal tergite approximately 1.1× longer than maximally wide, dorsal carinae sublamelliform, the raised median area usually simple ( Fig. 3 h). Second metasomal tergite approximately 1.68× wider than long, usually with a pair of well-developed pits medially on either side of the midline, but without transverse median groove ( Fig. 3 i). Second metasomal suture rather shallow but distinct and complete. Third metasomal tergite with antero-lateral areas; with an obvious transverse median groove. Fourth and fifth metasomal tergites completely glabrous, with sparse hairs. Ovipositor 1.1× length of the fore wing.

Color. Body mainly yellow brown, metasomal tergites rather dark brown except first metasomal tergite with the raised median area yellow. Hind tarsi and ovipositor sheath ferruginous. Fore wing membrane yellow but with weakly yellow brown patterns near stigma. Hind wing membrane light yellow uniformly.

Male. Eyes much larger, concaved at middle. Shortest distance between eyes: width of head = 8: 35. Length of head behind eye: horizontal length of eye = 0.13: 1. POL: diameter of posterior ocellus: shortest distance between posterior ocellus and eye = 10: 9: 4. Body mainly yellow or yellow brown. First metasomal tergite dark brown at anterior and lateral area. Second and third metasomal tergites with anterior margins dark brown. Third to fifth metasomal tergites with transverse median grooves.

Specimens examined. Holotype, ♀, Chijiang, Jiangsu, 1923. IV. 18, O. Piel (ZJUH). Paratype: 1 6, Chijiang, Jiangsu, 1923. IV. 18, O. Piel (ZJUH).

Biology. Unknown.

Distribution. China (Jiangsu).

Etymology. From Latin “ xuthus ” meaning for pale yellow, referring to the hind wing membrane light yellow, and without black marking.

Diagnosis. This species is similar to Euurobracon impossibilis Dalla Torre, 1898 , but can be separated from the latter by the following: length of head behind eye: horizontal length of eye = 0.92: 1 (the latter 0.83: 1); fore wing membrane yellow but with weakly yellow brown patterns near stigma ( Fig. 3 a), and hind wing membrane light yellow uniformly ( Fig. 3 b) (the latter wing membrane moderate to dark brown except for a small clear window around fore wing vein 2-SR+M and a paler brown band just distal to fore wing vein 1-SR+M); and ovipositor relatively short, only 1.1× length fore wing ( Fig. 3 a) (the latter longer, 1.9–2.2× longer than fore wing).

Figures

FIGURE 3 Euurobracon xuthus sp. nov.: a. body, lateral view; b. hind wing; c. metanotum and propodeum, dorsal view; d. metanotum and propodeum, lateral view; e. head, frontal view; f. head, dorsal view; g. metasomal tergites, dorsal view; h. first metasomal tergite, dorsal view; i. second metasomal tergite, dorsal view. Scar bar 500 µm.