Hybrizon xui van Achterberg & Liu, 2019

Liu, Jing-Xian, van Achterberg, Cornelis, Zheng, Bo-Ying & Yang, Qi-Meng, 2019, Hybrizon Fallen (Hymenoptera, Ichneumonidae, Hybrizontinae) in China, Journal of Hymenoptera Research 72, pp. 11-26 : 11

Hybrizon xui van Achterberg & Liu sp. nov.

Figs 23-29

Hybrizon juncoi : Konishi et al. 2012: 21, 22.

Type material.

Holotype, ♀ (ZJUH), "NE China: Shandong, Shanghe County, Ji’nan, Xushang, Dong Balizhuang, 36°16'4"N, 117°9'10"E, Malaise trap, 24-30.ix.2018, Jia-He Yan & Qi-Meng Yang", Paratypes (ZJUH, RMNH): 40 ♀, same data as holotype, of which 1 ♀ (ZJUH) additionally labelled “201901120”, because the molecular sequences originate from this specimen.

Differentiating diagnosis.

The new species is similar to the SW Palaearctic H. juncoi (Ceballos, 1957), because of the largely glabrous basal cell of the fore wing, vein 1-M of fore wing as dark as vein 2-CU1 of fore wing, ivory scutellum (except medio-anteriorly), larger body size and anterior notaulic area of mesoscutum more or less ivory or brownish. Konishi et al. (2012) included Korean specimens of this species under H. juncoi , but H. juncoi has the hind basitarsus about 4.5 times longer than wide (both sexes; 5.6-6.8 times in H. xui ), vein r of fore wing issued comparatively far removed from base of pterostigma (distance to base of pterostigma about equal to length of vein r; much less so in H. xui ), propodeum distinctly rugose-granulate (granulate and partly smooth in H. xui ), vein 1-M comparatively short (fig. 41 in van Achterberg 1999), resulting in a transverse disco-submarginal cell lower than subdiscal cell (vein 1-M medium-sized, resulting in a disco-submarginal cell as high as subdiscal cell in H. xui ) and penultimate segment of maxillary palp enlarged ( Fig. 8 ; small in H. xui ). According to the molecular analyses it is distinctly separated from H. hei and H. buccatus ( Figs 30 , 31 ); unfortunately, molecular data of its most closely relative ( H. juncoi ) are yet unknown.

Molecular data.

MN168195 (28S) and MN260327 (CO1).

Description.

Holotype, ♀, length of body 4.2 mm, of fore wing 3.1 mm.

Head. Antenna with 13 segments and 0.9 times as long as fore wing, length of third segment 1.4 times fourth segment, length of third, fourth and penultimate segments 5.3, 3.8 and 3.3 times their width, respectively; pedicellus slightly shorter than and as wide as scapus; penultimate segment of maxillary palp small compared to apical segment ( Fig. 26 ); face rugulose-granulate medio-dorsally and remainder largely smooth; maximum width of face 1.4 times its minimum width ( Fig. 27 ); frons smooth and shiny but near antennal sockets depressed and rugulose; length of eye 6.8 times temple in dorsal view; temples directly narrowed behind eyes; vertex shiny and superficially granulate; OOL:diameter of ocellus:POL = 3:5:7; length of malar space 1.3 times basal width of mandible, concave and largely smooth, posteriorly granulate.

Mesosoma. Length of mesosoma 1.2 times its height; mesoscutum strongly shiny and smooth, only anteriorly with few punctures and notauli absent ( Fig. 28 ); scutellum strongly convex (protruding up to dorsal level of mesoscutum or above) and shiny, smooth ( Figs 26 , 28 ); mesopleuron shiny and largely smooth; mesosternal sulcus narrow and smooth; metapleuron shiny and granulate; metanotum obtusely protruding dorsally; propodeum granulate, but medially and posteriorly with some rugae or carinae and interspaces largely smooth.

Wings. Fore wing: marginal cell comparatively wide ( Fig. 24 ); basal cell of fore wing largely glabrous, with 18 setae ( Fig. 24 ); vein r nearly vertical and issued comparatively close to base of pterostigma ( Fig. 24 ); vein 1-R1 0.6 times length of pterostigma; vein 1-M moderately curved and medium-sized, resulting in a disco-submarginal cell as high as subdiscal cell.

Legs. Hind coxa finely granulate; in lateral view length of femur, tibia and basitarsus of hind leg 6.9, 6.8 and 5.6 times their width, respectively; spurs of hind tibia 0.35 and 0.40 times hind basitarsus.

Metasoma. Length of first tergite 3.4 times its apical width, shiny, smooth (also laterally), medially with shallow elongate depression, subapically widened and its spiracles slightly protruding; second tergite with spaced striae basally and some superficial micro-sculpture medially; remainder of metasoma smooth and shiny; hypopygium with long bristly setae ( Fig. 29 ); second tergite with sharp lateral crease; length of setose part of ovipositor sheath 0.08 times fore wing and 0.26 times second metasomal tergite.

Colour. Dark brown; mouthparts (including mandible) and tegulae white; scapus, and scutellum (except medio-anteriorly) ivory; scutellum distinctly contrasting with dark brown mesoscutum medio-posteriorly ( Fig. 28 ); mesoscutum antero-laterally, pronotum, mesosternum, mesopleuron dorsally and ventrally, anterior half of fourth tergite and legs yellowish brown; pedicellus entirely brown and distinctly contrasting with pale scapus ( Figs 26 , 27 ), remainder of antenna largely dark brown; veins and pterostigma largely dark brown; vein 1-M of fore wing as dark as vein 2-CU1 of fore wing or nearly so; wing membrane subhyaline.

Variation. Length of body (3.2-)3.6-4.5 mm, of fore wing 2.6-3.7 mm; maximum width of face 1.3-1.4 times its minimum width; basal cell of fore wing with 10-24 setae; anteriorly notaulic area of mesoscutum ivory or brownish yellow, rarely dark brown; in lateral view length of hind basitarsus 5.4-6.6 times its maximum width; pedicellus entirely brown or dark brown, rarely pale yellowish ventrally; apical half of fourth tergite dark brown to brownish yellow; hind leg brownish yellow to brown. One paratype has a transverse groove subbasally on the second tergite.

Distribution.

China (Shandong).

Etymology.

Named in commemoration of the much too early deceased hymenopterist Prof. Dr Zai-Fu Xu (South China Agricultural University, Guangzhou; ix.1965 - vi.2017) for his great contributions to our knowledge of the Chinese Hymenoptera .

Figures

Figures 23 - 29. Hybrizon xui sp. nov., ♀, paratype 23 habitus, lateral aspect 24 wings 25 hind tarsus, lateral aspect 26 head and mesosoma lateral aspect 27 head, anterior aspect 28 head and mesosoma, dorsal aspect 29 ovipositor and ovipositor sheath, lateral aspect.

Figures 1 - 8. 1 - 3 Hybrizon buccatus (de Brebisson) ♀, Bulgaria, Brodilovo, but 3 of ♀ from Netherlands, Nunspeet 4, 5 H. flavofacialis Tobias, female, China, Hunan, Yuanjiang 6, 7 H. ghilarovi Tobias: 6 of ♀, China, Hunan, Yuanjiang and 7 of ♀, Bulgaria, Brodilovo 8 H. juncoi (Ceballos), ♀, Spain, Estepona 1, 4, 6 basal half of fore wing 2, 3, 5 hind basitarsus lateral 7 ovipositor and sheath lateral 8 palpi anterior. From van Achterberg (1999) and van Achterberg et al. (2013).

Figures 30, 31. RAxML result analysis of 28 S and COI sequences. Numbers in parentheses are GenBank numbers.