Euurobracon acuminatus, 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 : 384-385

Euurobracon acuminatus sp. nov.

( Figs 1 . a–i)

Holotype: Length of body 14.0 mm, fore wing 13.0 mm, ovipositor 15.0 mm.

Head. Antennae with 61 flagellomeres, terminal flagellomere slightly acute at apex, and approximately as long as wide basally, first flagellomere 1.67 and 1.92× longer than second and third respectively, the latter being approximately as long as wide maximally. Inter-tentorial distance: tentorio-ocular distance = 15: 7. 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. 1 e). Head widest across eyes ( Fig. 1 f). Shortest distance between eyes: width of head = 9: 16. Length of head behind eye: horizontal length of eye = 0.69: 1. Frons densely setose immediately behind the antennal sockets except for the vicinity of the mid-longitudinal sulcus. POL: diameter of posterior ocellus: shortest distance between posterior ocellus and eye = 14: 10: 31.

Mesosoma. Mesosoma approximately 1.72× longer than high ( Fig. 1 d). Mesosoma shiny and glabrous, with sparse and short setae, and sometimes more densely laterally. Mesoscutum strongly convex at middle, and notauli only impressed at the front part of the mesoscutum. Propodeum with sparse but long setae ( Fig. 1 c).

Wing. Fore wing: vein SR1: 3-SR: r = 92: 61: 11. vein 1-SR+M slightly curved near middle, and approximately as long as 1-M; vein m-cu straight, 2.73× longer than 2-SR+M; vein 2-SR: 3-SR: r-m = 33: 62: 32; vein 3-CU1 strongly expanded along its posterior third. Hind wing: vein 2-SC+R transverse and strongly reclivous; vein 1r-m 1.46× longer than SC+R1.

Leg. Length of fore femur: tibia: tarsus = 72: 88: 98. Antero-lateral aspect of fore tibia densely and evenly covered with thick setae. Fore basitarsus 2.8× longer than maximally wide. Length of hind femur: tibia: basitarsus = 72: 107: 43. Hind basitarsus 8.2× longer than wide.

Metasoma. First metasomal tergite approximately 1.1× longer than maximally wide, with a mid-longitudinal depression extending posteriorly behind level of the dorsal carinae ( Fig. 1 h). Second metasomal tergite approximately 1.6× wider than long, usually with a pair of well-developed pits medially on either side of the midline ( Fig. 1 i). Second metasomal suture rather shallow but distinct and complete. Third metasomal tergite with antero-lateral areas; and transverse median groove rather shallow, but also with a pair of well-developed pits medially on either side of midline. Fourth and fifth metasomal tergites completely glabrous, with sparse hairs. Ovipositor 1.15× length fore wing.

Color. Body mainly dark yellow. First metasomal tergite black brown, but with the raised median area yellow. Second metasomal tergite black brown. Third and fourth metasomal tergites with anterior margins black brown. Hind tarsi and ovipositor sheath black. Wing membrane yellow patterned distally with grey brown and brown.

Variation. Female: Length of body 13.0 mm, fore wing 13.0 mm, ovipositor 15.0 mm. Length of head behind eye: horizontal length of eye = 0.71: 1. Mesosoma 1.75× longer than high. Length fore wing vein SR1: 3-SR: r = 92: 57: 13. Length fore wing vein 2-SR: 3-SR: r-m = 32: 63: 31. Hind wing vein 1r-m 1.67× longer than SC+R1.

Specimens examined. Holotype, ♀, Xiashu, Jiangsu, 1926. V. 3, collector unknown (ZJUH). Paratype: 1♀, Xiashu, Jiangsu, 1926. V. 3, collector unknown (ZJUH).

Biology. Unknown.

Distribution. China (Jiangsu).

Etymology. From Latin “ acuminatus ” meaning for subacute, referring to the terminal flagellomere slightly acute at apex.

Diagnosis. This species is similar to Euurobracon xuthus sp. nov., but can be separated from the latter by: length of head behind eye: horizontal length of eye = 0.69–0.71: 1 (the latter 0.92: 1); fore wing vein 2-SR+M relatively short, and vein m-cu 2.73× longer than 2-SR+M ( Fig. 1 a) (the latter 1.94×); first metasomal tergite with a mid-longitudinal depression extending posteriorly behind the level of the dorsal carinae ( Fig. 1 h) (the latter with the raised median area usually simple); and hind wing membrane yellow patterned distally with grey-brown or brown ( Fig. 1 b) (the latter light yellow uniformly).

Figures

FIGURE 1. Euurobracon acuminatus 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.