Megaxyela euchroma Stephan M. Blank & Katja Kramp & David R. Smith & Yuri N. Sundukov & Meicai Wei & Akihiko Shinohara 2017, sp. nov.
Creators: name: Stephan M. Blank
name: Katja Kramp
name: David R. Smith
name: Yuri N. Sundukov
name: Meicai Wei
name: Akihiko Shinohara
Publisher: name: Zenodo
Year: 2017
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Hymenoptera
Xyelidae
Megaxyela
Megaxyela euchroma

description: Megaxyela euchroma Blank, Shinohara & Wei sp. nov.
urn:lsid:zoobank.org:act:63EF6069-E728-4107-8DC2-F02C9081880A
Figs 1F, 3A–3K, 11A, 12A, 13A
Megaxyela sp. 3 – Shinohara et al. 2017: fig. 15 (phylogenetic analysis).
Diagnosis
This species is unique upon the black head bearing narrow yellow lines along inner and outer orbits and a linear yellow spot on vertex (Fig. 3A–B, D, F–G), and the presence of ctenidia along the annuli of the ovipositor (Figs 1F, 12A). It is separated from other Eurasian species by the metallic blue shine of dark colored body parts (Fig. 3A–G), the laterally black terga 2–4 (Fig. 3A–E; only the ventral margins of the terga bear a narrow longitudinal white line ventrally, Fig. 3C, E), the almost completely black valvula 3 of the ovipositor sheath (Fig. 11A), the black hypopygium of the male (Fig. 3E), and the large and irregular teeth of the upper edge of the valviceps (Fig. 13A).
Etymology
The species name is a noun derived from ancient Greek ευ- (eu-, beautiful) and χρωμα (chroma, color).
Type material
HolotypeCHINA: ♀: “CSCS14007 [..., Chinese characters for Kaishan Laodian, Mt. Tianmushan, Linan, Zhejiang Province], E119°26′05″ N30°20′33″ 1142 m 2014.IV.8 [..., Chinese characters for the collectors Nie Haiyan & Hu Ping] CH3COOC2H5”, [red:] “HolotypeMegaxyela euchromasp.n. det. SMBlank & AShinohara 2015”; “ DEI-DISHym 22554 ” (CSCS).
ParatypesCHINA: 2 ♀♀, same site as holotype, 4–5 Apr. 2015, Li Zejian leg. (LSAF); 1 ♀, same site as holotype, 8 Apr. 2014, Liu Ting and Yu Xingjie leg., CSCS14008 / DEI-DISHym 22555 (CSCS); 1 ♀, same site, 9 Apr. 2014, Liu Ting and Yu Xingjie leg., CSCS14010 / DEI-DISHym 22556 (CSCS); 1 ♂, same site, 10 Apr. 2014, Liu Ting and Yu Xingjie leg., CSCS14012 / DEI-DISHym 22557 (CSCS); 1 ♀, 2 ♂♂, same site as holotype, 11 Apr. 2015, Li Zejian leg., CSCS); 3 ♀♀, same site, 16 Apr. 2014, Nie Haiyan and Hu Ping leg., CSCS14026 / DEI-DISHym 22558–22560 (CSCS, SDEI, YUIC); 1 ♀, 1 ♂, same site, 16 Apr. 2014, Liu Ting and Yu Xingjie leg., CSCS14027 / DEI-DISHym 22561–22562, (CSCS); 1 ♂, same site, 1150 m, 4 Apr. 2015, A. Shinohara leg., DEI-DISHym 22515 (SDEI) (specimen used for barcoding); 1 ♀, same site, 8 Apr. 2014, A. Shinohara leg., DEI-DISHym 22512 (NSMT); 1 ♂, same site, 9 Apr. 2014, A. Shinohara leg., DEI-DISHym 22513 (NSMT) (specimen used for barcoding); 1 ♂, 1 ♀, same site, 11 Apr. 2015, A. Shinohara leg., DEI-DISHym 22514, DEI-DISHym 22516 (NSMT); 1 ♀, same site, 15 Apr. 2014, A. Shinohara leg., DEI-DISHym 22511 (NSMT); 3 ♀♀, same site, 16 Apr. 2014, A. Shinohara leg., DEI-DISHym 22509–22510 and 22355 (latter specimen used for barcoding) (NSMT, SDEI).
Description
Female
COLOR. Body black with white, yellow white and red brown pattern, black parts with blue tinge (Fig. 3A– B). Head black with three yellow white lines, one on vertex posterior of eye, one along dorsal half of inner orbits, one along ventral half of outer orbits and along ventral edge of eye; clypeus along anterior margin, labrum, mandibles and most of other mouthparts red brown to white (similar to Fig. 3F–G).Antenna black. Tegula, dorsolateral corner and narrow lateroventral margin of pronotum yellow white. Abdominal terga 1–8 with narrowly white distal margins, lateroventral portions of terga 2–7 with continuous 50–100 µm wide white stripe along ventral margin (Fig. 3C). Abdominal sterna 2–7 broadly white along lateral and distal margins (Fig. 3C). Valvifer 2 of ovipositor red brown in basal half, black in distal half, valvula 3 black with brown tip, membrane in between valvifer 2 and valvula 3 white (Fig. 11A). Fore and mid legs red brown, coxae predominantly black from bases, trochanters partly white. On hind leg, basal third of coxa laterally black, distal portion red brown, trochanter and trochantellus white, femur predominantly red brown in basal half, predominantly black in distal half, tibia black, tarsus white, tarsomere 1 weakly infuscate in basal third (Fig. 3A–C, H–I). Wings weakly brown stained, venation brown, pterostigma black (Fig. 3D–E), sometimes brown (Fig. 3A–B, immature specimens?).
MORPHOLOGY. Body 11.3–13.1 mm, fore wing 14.1–14.6 mm long. POL: OOL: OCL = 1.0: 1.6–1.8: 1.8–2.0. Interantennal distance 0.9–1.0 × as wide as distance between torulus and eye margin, malar space 0.4–0.5 × as wide as interantennal distance. Eye 1.3–1.4 × as long as wide, frons at dorsal edge of antennal toruli 1.6 × as wide as maximum diameter of eye. Synantennomere 3 (4.0–) 4.5–4.9 mm, filament 0.9–1.1 mm, with 7–8 articles (9 in one specimen). Article 3 of maxillary palp 0.5–0.6 mm. Ovipositor sheath 2.5–2.7 mm, valvula 3 1.4–1.6 × as long as valvifer 2, valvula 3 2.0–2.1(–2.2) × as long as wide. On hind leg, femur (4.5–) 4.9–5.2 mm, tibia (5.4–) 5.9–6.5 mm, tarsus (4.3–) 4.6–5.2 mm, tarsomere 1 4.2–4.4 × as long as wide, longer distal spur of tibia 0.4–0.5 × as long as tarsomere 1, subapical tooth of claw stout and little shorter than apical tooth. Head dull, medial part of frons and vertex minutely areolate, lateral parts of frons rugose, gena minutely areolate (Fig. 3F and 3G). Inner orbit and ventral half of gena with carina, on inner orbit partly obscured by generally rugose structure. Mesonotum minutely areolate, posterio-medial part of medial lobes of mesoscutum and lateral parts of mesoscutellum rugulose. Mesepisternum minutely areolate, dull, with scattered 20 µm large pits. Metatarsomere 1 dorsally almost glabrous, laterally sparsely setose, lateroventrally with some stout setae up to 150 µm, ventrally densely setose, setae about 100 µm long (Fig. 3H–I). Pulvilli present on metatarsomeres 1–4, on tarsomere 1 pulvillus 70–100 µm long, on tarsomere 4 200–230 µm (Fig. 3H– J). Valvula 3 of ovipositor sheath convex dorsally and ventrally in basal and medial sections, preapically weakly concave, setae up to 250 μm long scattered mainly along dorsal and ventral margins (Fig. 11A). Ovipositor about 2.1 mm long, weakly curved ventrally, valvula 1 and valvula 2 without bulbous areas (Fig. 12A). Valvula 1 in distal 0.6 with annuli, basal annuli sigmoid, distal annuli weakly oblique, annuli with ctenidia composed of minute denticles, ventral edge in distal 0.3 bearing serrulae, cypsellae between distal 6 serrulae deep (Figs 1F, 11A). Valvula 2 in distal 0.4 with annuli, basal annuli weakly curved, distal annuli straight, annuli with ctenidia, denticles larger than those on valvula 1, dorsal edge of valvula 2 indented between annuli.
Male
COLOR. Similar to female (Fig. 3D–G, K). Subgenital plate and genitalia black.
MORPHOLOGY. Body 9.4–10.2 mm, fore wing 11.9–12.3 mm long. POL: OOL: OCL = 1.0: 1.5–1.8: 1.6–1.9. Interantennal distance 0.9–1.0 × as wide as distance between torulus and eye margin, malar space 0.4–0.5 × as wide as interantennal distance. Eye 1.3–1.4 × as long as wide, frons at dorsal edge of antennal toruli 1.6–1.7 × as wide as maximum diameter of eye. Synantennomere 3 4.0– 4.4 mm, filament (0.8–) 0.9–1.1 mm, with 7–8 articles. Article 3 of maxillary palp 0.5 mm long. On hind leg, femur 4.1–4.4 mm, tibia 5.1–5.3 mm, tarsus 4.2–4.5 mm, tarsomere 1 4.7–5.3 × as long as wide, longer distal spur of tibia 0.40 × as long as tarsomere 1. Claws and microsculpture similar to female. Setation of metatarsus less dense than in female (Fig. 3K). Subgenital plate bluntly pointed at apex. Valviceps of penis valve distally evenly rounded, basal 0.4 of upper side expanded to a roundly angular lobe, upper edge of valviceps distal of lobe weakly concave, with large, irregular teeth. Distal half of valviceps in upper and medial portion with long setae, distal of middle in lower portion with dense assemblage of short, conical setae (Fig. 13A).
Remarks
Megaxyela euchroma sp. nov. is characterized by a number of unique characters (see Diagnosis). All other East Asian species are completely white on the ventral portion and partly on the dorsolateral portion of terga 2–3 or 2–4. In these cases, the white band on terga 2–3 or 2–4 is much wider than on the subsequent terga. The head is more extensively yellow or red brown, at least on the gena in M. gigantea, M. pulchra sp. nov. and M. togashii, or the eye is completely surrounded by black except for the malar space in M. parki. Megaxyela euchroma sp. nov. and M. parki share the white metatarsus, which is black in the other East Asian species.
With respect to the white pattern of the terga, M. euchroma sp. nov. is similar to the North American M. alisonae, M. bicoloripes, M. inversa sp. nov. and M. tricolor (Smith & Schiff 1998). Megaxyela alisonae and M. bicoloripes have a white metatarsus similar to M. euchroma sp. nov., while M. tricolor has a black metatarsus. In the Nearctic species, a yellow white pattern on the orbits and the vertex, similar to that of M. euchroma sp. nov., is absent. Megaxyela alisonae and M. bicoloripes bear an extensive red brown pattern on thorax and abdomen, which is absent in M. euchroma sp. nov. Megaxyela inversa sp. nov. differs in the shape of the ovipositor sheath, which is straight dorsally in the basal and the medial sections, vs convex in M. euchroma sp. nov.
The analysis of the COI sequences supports the monophyly of the studied specimens by a bootstrap of 100%. The maximum intraspecific variation is 0.3%. The nearest neighbor, M. fulvago sp. nov., is placed at a distance of 12.7% (Fig. 2).
All the available adults were found on the undergrowth of open forests during cloudy weather. There were Juglans trees nearby and new shoots of leaflets were beginning to grow.
description: Published as part of Stephan M. Blank, Katja Kramp, David R. Smith, Yuri N. Sundukov, Meicai Wei & Akihiko Shinohara, 2017, Big and beautiful: the Megaxyela species (Hymenoptera, Xyelidae) of East Asia and North America, pp. 1-46 in European Journal of Taxonomy 348 on pages 10-13, DOI: 10.5852/ejt.2017.348, http://zenodo.org/record/1042663