Eurytoma acutibialis Yang, Liu & Cao 2023, sp. nov.
Creators: name: Liu, Huihui
name: Cao, Liangming
name: Wang, Xiaoyi
name: Xin, Xuebing
name: Bao, Yingxia
name: Yang, Zhongqi
Publisher: name: Zenodo
Year: 2023
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Hymenoptera
Eurytomidae
Eurytoma
Eurytoma acutibialis

description: 3.2 Eurytoma acutibialis Yang, Liu & Cao, sp. nov. (Figs 22–37)   
 Diagnosis. The new species is close to the previous species, E. truncatumi Yang, Liu & Cao, sp. nov., but can be separated from the latter by following: antenna yellowish brown (vs. with antenna black); malar sulcus nearly straight and before and behind it with a smooth and shining area (Fig. 28) (vs. with malar sulcus distinctly curved and without such a smooth and shining area (Fig. 2)); marginal vein long with length 1.67 times of post marginal vein and 2.0 times of stigmal vein (vs. with marginal vein 1.38 times of post marginal vein, and 1.64 times of stigma vein); forewing with basal cell open below (Fig. 25) (vs. forewing with basal cell closed below with hairs (Fig. 7)); hind tibia with 6–7 stout and long yellowish bristles on dorsal edge (vs. hind tibia with 5 such bristles); male with petiole length 1.4 times of its hind coxa (vs. with petiole 1.16 times as long as hind coxa).   
 Description. Female. Resembles to E. truncatumi Yang, Liu & Cao, sp. nov. Length 2.6–3.2 mm (Holotype 2.9 mm).   
 Head (Figs 20–23, 28). In dorsal view, temple 0.26 times as long as eye; POL 2.16 times of OOL. In front view, head 1.26 times as broad as high; frons with breadth 1.7 times of eye height; scrobal depression deep and its lateral and upper margins carinated; narrow and smooth longitudinal band under scrobes to clypeus lower margin (as in E. truncatumi Yang, Liu & Cao, sp. nov.) only indicated in lower half of face (Fig. 23); malar sulcus nearly straight with length 0.75 times of eye height; before and behind malar sulcus with a smooth and shining area (Fig. 28). Antennal scape extending out of top of scrobal depression slightly and reaching nearly vertex (Fig. 23), its shape cylindrical with length 4.3 times of breadth and expanding medially (Figs 21, 28); pedicel small and conical in form; combined length of pedicel plus flagellum 1.13 times of head breadth and 1.2 times of mesoscutum breadth; flagellum with 1 anellus, 5 funicle segments and 3 claval segments; all funicle segments elliptical in shape with length greater than breadth (Fig. 28); relative measurements (length/ breadth) of flagellum segments as follows: pedicel 18/14, anellus 3/6, funicle segment f1 32/20, f2 30/22, f3 30/22, f4 30/22, f5 30/22, clava segment c1 22/22, c2 20/21, c3 23/18; clava blunt apically with length longer than distal 2 funicle segments combined (56: 50); each funicle and clava segments covering distinct hairs as well as sparse longitudinal sensillae.   
 Mesosoma (Figs 20–22, 26–27). In dorsal view, mesosoma similar to E. truncatumi Yang, Liu & Cao, sp. nov., but different from following: pronotum rectangular and 2.3 times as broad as long medially; metanotum carinated as W-formed; propodeum having base of wide median furrow finely rugose except anterior half in medial part with about 8 larger punctures aligned in 2 lines (Figs 22, 27); hind femur with about 18 long hairs along its lower margin; bristles on hind tibia longer and denser than in E. truncatumi Yang, Liu & Cao, sp. nov., in which 6–7 stout and long bristles with yellowish in color particularly distinct (Fig. 24).   
Wings (Figs 20–21, 25). Wings hyaline. Forewing 2.14 times as long as broad, with very sparse and short setae on disc; in basal cell only having 3 setae and cell open below, basal setal line complete with 7 setae (Fig. 25); cubital setal line absent and thus speculum open below; marginal vein long with length 1.67 times of post marginal vein and 2.0 times of stigmal vein.  
 Metasoma (Figs 20–21). In dorsal view, metasoma compressed, but obviously bulged laterally with length 2.1 times of breadth; its breadth 0.9 times of mesoscutum and 1.04 times as long as mesosoma; others resemble those of E. truncatumi Yang, Liu & Cao, sp. nov.   
Color. Body black; antenna brownish yellow except pedicel blackish brown; all coxae and most parts of femora black as body; trochanters, distal 1/4 of femora, tibiae and tarsi yellow, but tibiae brown medially; wings hyaline with submarginal and stigmal veins pale yellow brown and marginal vein yellowish white. Pilosity on body white.  
 Male (Figs 29–37). Resembles to E. truncatumi Yang, Liu & Cao, sp. nov. Body length 1.6–2.6 mm, relatively smaller than female. Body color varied: some individuals black except legs with trochanter and tibia brownish yellow, and tarsus nearly white; some individuals blacked dorsally and yellowish in lower half, antenna, all legs and petiole lutescents. Head in dorsal view 3.4 times as broad as long medially; POL 2.5 times of OOL. Malar sulcus nearly straight and before and behind malar sulcus with a smooth and shining area as in female (Fig. 33). Pronotum 1.86 times as broad as long; mesoscutum with breadth 1.45 times of length and 1.33 times as long as pronotum. Relative length measurements of head, mesosoma, petiole and gaster in leteral view as follows: 18: 45: 17: 28. Hind leg with tibia having dense bristles and particularly with 6–7 stout and long yellowish bristles (Fig.36). Wings as in Fig. 35. Petiole length 3.5 times of its breadth and finely rugose dorsally, its length 1.4 times of hind coxa and 0.6 times of gaster (Figs 34, 36, 37). Antenna as in Fig. 32; 5 funicle segments with very distinct long whorls of hairs; relative length/breadth measurement of scape, pedicel, funicle segment 1, 2, 3, 4, 5 and claval segment 1, 2, 3 as follows: 20/7, 5/4, 15/6, 15/6,15/6, 15/6, 14/6, 12/5, 8/4,4/3,4/2; each funicle and clava segment with a line of longitudinal sensillae.   
Variation. Some female specimens with antenna yellow, some dark brown and few even black (individuals emerged in summer generation); some female specimens with body dorsal dark brown and other parts yellow or yellowish brown. Some males with lower half and ventral parts of body slightly brown yellow.  
Etymology. The specific epithet is derived from the distinguished stout and long bristles on dorsal edge of hind tibia.  
 Material examined. Holotype ♀, reared from seed of Acer truncatum damaged by Bradybatus sp. collected from the Daiqingtala Natural Reserve, Horqinright-middle Banner, Xing’an League, Inner Mongolia, China, 2 May 2023. Paratypes. 11♀ 4♂, the same data as holotype; 21♀ 2♂, the same data as holotype, but emerged on 5 May 2023; 1♀ 2♂, 4 January 2022; 2♀ 1♂, 24 January, 2022; 2♀ 1♂, 8 February 2022; 3♀, 14 February 2022; 2♀, 8 May 2022; 2♀, 20 August 2021; the collecting location of all above paratypes was the same as holotype. Other specimens examined. 426♀ 165♂, kept in three vials and emerged from 28 April to 10 May 2023, the collecting location as holotype.   
Distribution. China (Inner Mongolia).
description: Published as part of Liu, Huihui, Cao, Liangming, Wang, Xiaoyi, Xin, Xuebing, Bao, Yingxia & Yang, Zhongqi, 2023, Two new species of Eurytoma (Hymenoptera: Eurytomidae), parasitoids of Bradybatus sp. (Coleoptera: Curculionidae) damaging seeds of Acer truncatum in China, pp. 264-276 in Zoological Systematics 48 (3) on pages 270-275, DOI: 10.11865/zs.2023305, http://zenodo.org/record/10941934