Megaxyela pulchra 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 pulchra

description: Megaxyela pulchra Blank, Shinohara & Sundukov sp. nov.
urn:lsid:zoobank.org:act:1079C626-6C18-4EC2-86DB-863D9F49E768
Figs 9A–I, 11G, 12G, 13E, I
Megaxyela gigantea – Zhelochovtsev & Zinovjev 1995: 396 (misidentification, partim). ― Lelej & Taeger 2007: 933 (misidentification, partim). ― Lelej 2012: 62 (misidentification, partim).
Megaxyela aff. gigantea – Sundukov 2009: 213 (record from Russia, Primorskiy Kray).
Megaxyela sp. 1 – Shinohara et al. 2017: fig. 15 (phylogenetic analysis). — Blank et al. 2017: 115
Diagnosis
Megaxyela pulchra sp. nov. is characterized by the following unique combination of characters: frons above the antennal toruli rugulose, head with black spot extending from postocellar area and vertex to the antennal toruli, pterostigma yellow brown and infuscate basally and anteriorly, pectus red brown, hypopygium of male red brown.
Etymology
The Latin adjective pulcher (fem. pulchra) indicates the beauty of this species.
Type material
HolotypeRUSSIA: ♀: “[vertically:] RU012 [horizontally:] RU [= Russia]: Primorskij Kraj: Ussuri Nature Reserve 43.644°N 132.346°E 150 m [alt.] 23. May 2016 leg. Kramp, Prous & Taeger ”; [red:] “HolotypeMegaxyela pulchrasp.n. det. SM Blank 2016”; “ DEI-GISHym 86249 (see ethanol coll.)”, specimen used for barcoding (pinned specimen in ZIN, right midleg in ethanol collection of SDEI).
Paratypes (11 ♀♀, 4 ♂♂)CHINA: 1 ♂, Hubei Sheng, Guanmenshan, Shennongjia, 31.43° N, 110.36° E, 21 May2010, A. Shinohara leg. (NSMT) (specimen DEI-GISHym 18504 used for barcoding); 1 ♂, Jilin Sheng, 43.00° N, 126.00° E, Jul. 1987 (CSCS); 1 ♀, Liaoning Sheng, 41.00° N, 123.00° E, 8 May 1958 (CSCS); 1 ♀, Shaanxi Sheng, Foping County, Daguping, 33.58° N, 107.77° E, 1320 m alt., 28. Apr. 2006, Mojun He leg. DEI-GISHym 22563 (CSCS); 1 ♀, Tibet Autonomous Region, Metok [“Motuo”, Mêdok], 29.32° N, 95.32° E, 1050 m alt., 9 Apr. 1980, Yingtao Jin leg. (CSCS).
RUSSIA: 1 ♀, Primorskiy Kray, Anisimovka, 43.17° N, 132.80° E, 26 May 1974, Berezantsev leg. (IBSS); 1 ♀, Primorskiy Kray, Lazovskiy Rayon, Lazo, 43.20° E, 134.15° N, 21–24 May 2008, V. Shokhrin leg. (IBSS); 1 ♀, Primorskiy Kray, Ussuri Nature Reserve, 43.67° N, 132.30° E, 23 May 1994, A. Lelej leg., DEI-GISHym 18501 (NSMT); 1 ♀, Primorskiy Kray, Voroshilovskiy Rayon, Suputinka River, 43.63° N, 132.10° E, 11 Jun. 1935, T. Samoylov leg. (ZIN).
SOUTH KOREA: 3 ♀♀, 2 ♂♂, Kangwon-do, Mirugam (Pugdaesa), Mt. Odaesan, 37.80° N, 128.57° E, 1300 m alt., collected from Juglans? mandshurica, 1 Jun. 2002, A. Shinohara leg. (NSMT) (including 1 ♀, 2 ♂♂ DEI-GISHym 18503, 22347, 22349 used for barcoding, also including DEI-GISHym 22346, 22348 illustrated in figures); 1 ♀, same locality, 31 May 1998, A. Shinohara leg. (NSMT).
Description
Female
COLOR. Body red brown with black and white pattern, black parts with bronze to blue tinge (Fig. 9A–C). Head brown, black spot of frons and vertex ventrally extending to toruli and leaving narrow stripe along inner orbits brown (Fig. 9F). Antenna black, narrow base of scape brown. Thorax with following parts black: Large medial spot on pronotum, complete dorsal side of mesothorax and metathorax, variable marks on dorsal corner of mesepisternum, metepimeron and metepisternum; mesopostnotum posteriorly and lateral mesonotal lobes with shared small brown spot laterally extending to mesoscutellum. Abdomen in dorsal view with continuous white bands laterally on terga 2–3 (each about 0.1 × as wide as tergal width), tergum 4 and 8 with narrower band or inconspicuously white, ventral portions of terga 2–4 and 8 completely white, of terga 5–7 black in dorsal half and white in ventral half, of tergum 9+10 brown (Fig. 9B–C). Sterna white, in two specimens on anterior margin of sterna 1–5 with pairs of black marks each about as wide as ocellar diameter (Fig. 9C), valvifer 2 and valvula 3 brown (tip of valvula 3 black only in holotype, Fig. 11G), membrane between valvifer 2 and valvula 3 pale. Legs brown with following black pattern: stripe on posterolateral margin of mesocoxa, dorsal, lateral and lateral third of ventral side of metacoxa, metafemur except for narrow base and fading stripe from base to middle along ventral side, metatibia and metatarsus. Wing hyaline and weakly brown stained, venation brown, pterostigma yellow brown with narrow base and anterior margin infuscate (Fig. 9A–B).
MORPHOLOGY. Body 10.8–13.4 mm, fore wing 14.9–16.0 mm long. POL: OOL: OCL = 1.0: 1.9–2.1: 1.9–2.0. Interantennal distance 1.0–1.1 × as wide as distance between torulus and eye, malar space 0.6–0.7 × as wide as interantennal distance. Eye 1.3–1.4 × as long as wide, frons at dorsal edge of antennal toruli 1.7–1.8 × as wide as maximum diameter of eye. Synantennomere 3 3.8–4.9 mm, filament 1.2–1.3 mm, with (8–)9–10 articles. Article 3 of maxillary palp 0.4–0.5 mm long. Ovipositor sheath 3.1–3.4 mm, valvula 3 1.5–1.6 × as long as valvifer 2, valvula 3 2.0–2.2 × as long as wide (Fig. 11G). On hind leg, femur 4.6–5.4, tibia 5.3–6.2 mm, tarsus 3.7–4.4 mm, tarsomere 1 4.0–4.3 × as long as wide, longer distal spur of tibia 0.6–0.7 times as long as tarsomere 1, subapical tooth of claw stout and slightly shorter than apical tooth (Fig. 9G–H). Head dull, medial part of frons and vertex minutely areolate, frons above toruli rugulose, gena coriarious. Inner and outer orbits with continuous carina, on inner orbit separating red brown stripe along eye from black spot of frons (Fig. 9F). Mesoscutum and mesoscutellum homogeneously, minutely areolate. Mesepisternum coriarious, shining, with shallow pits. Metatarsomere 1 sparsely setose dorsally and dorsolaterally, densely setose lateroventrally and ventrally, setae up to 200 µm long ventrally. Pulvilli absent on article 1 of metatarsus, present on articles 2–4, on article 4 pulvillus 70 µm long (Fig. 9G–H). Basal and medial sections of valvula 3 of ovipositor sheath convex dorsally, almost straight ventrally, preapical section concave on dorsal and ventral edge, medial to preapical section of dorsal margin and ventral margin with up to 150 μm long setae (Fig. 11G). Ovipositor about 2.8 mm long, weakly curved ventrally, valvula 1 and valvula 2 with bulbous areas close to middle, without ctenidia (Fig. 12G). Valvula 1 in distal 0.6 with very narrowly spaced, subparallel, straight, vertical annuli, ventral edge in distal 0.3 bearing very small serrulae. Valvula 2 in distal 0.6 with narrowly spaced annuli, distal 0.4 of dorsal edge of valvula 1 with small denticles.
Male
COLOR. Similar to female (Fig. 9D–E). Subgenital plate and genitalia red brown (Fig. 13I).
MORPHOLOGY. Body 10.2–10.9 mm, fore wing 12.7–13.4 mm long. POL: OOL: OCL = 1.0: 1.9–2.2: 1.8–2.0. Interantennal distance 1.0–1.1 × as wide as distance between torulus and eye margin, malar space 0.5–0.6 × as wide as interantennal distance. Eye 1.3–1.4 × as long as wide, frons at dorsal edge of antennal toruli 1.7–1.8 × as wide as maximum diameter of eye. Synantennomere 3 4.4–4.8 mm, filament (1.0–) 1.2–1.4 mm, with 9–11 articles (one male with left filament 1.2 mm long, 9 articles, right filament 1.0 mm long, 7 articles). Article 3 of maxillary palp 0.4–0.5 mm. On hind leg, femur 4.3–4.6 mm, tibia 5.2–5.5 mm, tarsus 4.4–4.6 mm, tarsomere 1 4.2–4.8 × as long as wide, longer distal spur of tibia 0.5 × as long as tarsomere 1. Claws, pulvilli and microsculpture similar to female (Fig. 9I). Subgenital plate bluntly pointed at apex. Valviceps of penis valve distally evenly rounded, basal 0.4 of upper side expanded to a round lobe coiled laterally (Fig. 13E), medial 0.4–0.8 of upper margin almost straight, with numerous small teeth. Distal 0.8 of valviceps with long setae, most dense on lower portion in medial 0.2–0.5 (Fig. 13E).
Host plant
In South Korea, A. Shinohara captured two females and three males from Juglans? mandshurica. Host records of J. ailanthifolia (cited as J. sieboldiana), J. mandshurica, J. regia (including the synonym J. sinensis), Pterocarya rhoifolia and P. stenoptera stated for Megaxyela gigantea by Saito (1941), Ko (1969) and Xiao (2006) might also contain the new species M. pulchra sp. nov.
Remarks
Among East Asian Megaxyela, this species is morphologically close to M. togashii. Both species have the frons above the antennal toruli rugulose (frons microareolate throughout in M. fulvago sp. nov. and M. gigantea) and extensively black (completely or largely red brown in M. fulvago sp. nov. and M. gigantea), valvula 3 2.0–2.2 × as long as wide (2.8–3.0 in M. parki), pterostigma infuscate basally and anteriorly (unicolorous yellow brown in M. fulvago sp. nov., M. gigantea and M. parki, completely black in M. euchroma sp. nov.), basal lobe of valviceps small and distally truncate, upper edge medially almost straight and lacking large teeth, long setae present on the lower portion in the medial 0.2–0.5 (basal lobe more prominent in M. euchroma sp. nov., M. fulvago sp. nov., M. gigantea and M. parki sp. nov., upper edge raised medially in M. gigantea, large teeth on the upper edge present particularly in M. euchroma sp. nov., long setae absent in medial portion of valviceps in M. euchroma sp. nov. and M. parki sp. nov.).
Megaxyela pulchra sp. nov. differs from the Nearctic species of Megaxyela, except for M. langstoni and M. major, and from the East Asian M. euchroma sp. nov. in the presence of a broad, continuous white band dorsolaterally and ventrally on terga 2–3. Such extensive white pattern on the basal terga is absent in most North American species, which at most bear a narrow white stripe along the ventral margin of the terga as observed in M. alisonae, M. bicoloripes and M. tricolor (Smith & Schiff 1998; Blank, unpublished data). Megaxyela pulchra sp. nov. differs from M. langstoni and M. major, for example, in the black metatarsus (yellow white in M. major) and in the stout valvula 3 of the ovipositor sheath (Fig. 11G; slender in M. major, see Smith & Schiff 1998: fig. 7).
Morphological differences between M. pulchra sp. nov. and M. togashii are faint: the mesoscutellum is homogeneously areolate and flat in M. pulchra sp. nov., but areolate in the middle, with a wide stripe along lateral and anterior margin rugose with areolate microsculpture in M. togashii; the distance between the toruli is 0.95–1.05 × as wide as the distance between torulus and eye margin in M. pulchra sp. nov. ♀ but 1.20 × in M. togashii ♀; the malar space is 0.6–0.7 × as wide as the distance between toruli in M. pulchra sp. nov. but 0.4 in M. togashii. The two species exhibit different tendencies of coloration: the face, ventral part of mesepisternum and mesosternum, and dorsal portion of tergum 4 are paler in M. pulchra sp. nov., while the posteriolateral ridge of the mesoscutal lateral lobe is paler in M. togashii. The subgenital plate of the male M. pulchra sp. nov. is red brown as in M. gigantea, whereas it is white in the male M. togashii.
The anterior margins of the sterna always bear a pair of large black marks in M. togashii. Such marks are absent in other Megaxyela (see Smith & Schiff 1998 for Nearctic species) except for M. pulchra sp. nov., whose female rarely bears small marks on the sterna. These spots are a putative apomorphy of the vicariant species M. pulchra sp. nov. from the East Asian mainland and M. togashii from Japan. Among Xyelidae, similar pairs of sibling species (or at least morphologically very similar species) with East-Asian mainland / Japanese vicariance have been observed among Xyela species associated with Japanese red pine, Pinus densiflora Siebold & Zuccarini (Blank et al. 2005).
The specimens studied genetically are supported by a bootstrap of 100%. The maximum intraspecific variation is 3.1%. The nearest neighbor, M. togashii, is placed at a minimum pairwise distance of 8.0%.
Zhelochovtsev & Zinovjev (1995), Lelej & Taeger (2007) and Lelej (2012) listed M. gigantea for the Russian Far East, but at least the female from Voroshilovskiy Rayon identified by A. Zinovjev refers to M. pulchra sp. nov. Sundukov (2009) noted a specimen from Lazo differing from M. gigantea, which is included as a paratype of M. pulchra sp. nov. here. The specimens published by Shinohara (1992) for South Korea all belong to M. gigantea.
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 26-30, DOI: 10.5852/ejt.2017.348, http://zenodo.org/record/1042663