Megaxyela gigantea Mocsáry, 1909

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, European Journal of Taxonomy 348, pp. 1-46 : 16-19

Megaxyela gigantea Mocsáry, 1909

Figs 5A–H , 11C , 12E , 13C, G–H

Megaxyela gigantea Mocsáry, 1909: 39 (♀, type locality: Russia, Khabarovskiy Kray, Kazakevichevo). Megaxyela mikado Sato, 1930: 4–5, figs a–b (♀, type locality: South Korea, Suwon, Kazan).

Megaxyela mikado – Takeuchi 1937: 25 (synonymy with M. gigantea ).

Megaxyela gigantea – Shinohara 1992: 785–789 (description, distribution, hosts, references), 794–795 (key), figs 1A–B, 2A–B, 2E, 3A–C, 4A, 4F–G.

Type material

Lectotype (here designated)

RUSSIA: ♀, lectotype of Megaxyela gigantea , “ Ussuri Kasakewitsh [= Khabarovskiy Kray, Kazakevichevo , 48.27° N, 134.77° E] 1907 Korb ”; “ Megaxyela gigantea det. Mocsáry”; [rectangular red label without inscription]; “ Megaxyela gigantea Mocs. ”; [red:] “ Lectotype Megaxyela gigantea Mocsáry, 1909 Det. A. Shinohara 1997 ”, in perfect condition ( HNHM). The lectotype corresponds well with Shinohara’s (1992) characterization of the species.

Paralectotypes

RUSSIA: 1 ♀, same collecting data as lectotype (HNHM), Mocsáry (1909) described M. gigantea from an unknown number of females.

SOUTH KOREA: 1 ♀, holotype of Megaxyela mikado, “ Suigen [= Suwon , 37.28° N, 127.02° E], Chosen [= Korea], Apr. 24., 1927, coll. K. Sato ”; “ 270” , “Type of Megaxyela mikado Sato”, “ Megaxyela gigantea Mocs. det. K. Sato, XI–1957 ”, “ DEI-GISHym 22350 ” , left wings missing (NSMT). The holotype of M. mikado is a comparatively dark female of M. gigantea with a large dark brown spot on ocellar area and vertex. Terga 2–4 bear white stripes laterally, which are of equal width (see figure in Sato 1930; Shinohara & Smith 1979: fig. 13, in synonymy with M. gigantea ). The synonymy first proposed by Takeuchi (1937) is here confirmed.

Additional material examined or reported in literature

NORTH KOREA: 1 ♀, P’yŏngan-pukto [“Pyongah Prov. N”], Mt. Myohyang , 40.02° N, 126.33° E, 23 May 1985, Vojnits & Zombori leg. ( HNHM).

RUSSIA: 1 ♀, Primorskiy Kray, Voroshilovskiy rayon, southern slopes of Sikhote Alin, on river Suputinka [“Fluss Suputinka, S. Abhänge von Sichota-Alin”], 43.77° N, 131.90° E, 20 Jun. 1937, T. Samoylov leg. ( NHRS).

SOUTH KOREA: 4 ♀♀, 51 ♂♂ (including DEI-GISHym 708), Chollanam-do, Mt. Nogodan, Mts. Chirisan , 35.30° N, 127.53° E, 1220 m alt., 4–5 Jun. 1996, A. Shinohara leg. ( NSMT) ; 1 ♀, Kangwondo, Mirugam (Pugdaesa), Mt. Odaesan , 37.80° N, 128.57° E, 1300 m alt., 30 May 1991, A. Shinohara leg. (NSMT) ( Shinohara 1992) ; 1 ♀, same locality, 27 May 1998, A. Shinohara leg. (NSMT) ; 1 ♂ (specimen DEI-GISHym 18507 used for barcoding), same locality, collected from Juglans ? mandshurica, 1 Jun. 2002, A. Shinohara leg. (NSMT) ; 5 ♀♀, 5 ♂♂, Kyonggi-do, Suwon [“ Suigen ”], 37.283° N, 127.017° E, 12 May 1932, S. Fujii leg. (CIS, NSMT, USNM) ( Shinohara 1992) ; 2 ♀♀, 4 ♂♂, same locality, 14 May 1932, S. Fujii leg. (NSMT, USNM) ( Shinohara 1992) ; 5 ♀♀, Seoul [“ Keijo ”], 37.57° N, 127.00° E, 11 May 1935, K. Sato leg. (NSMT) ( Shinohara 1992) ; 2 ♀♀, Seoul, Ch’ongnyangni [“ Seiryori ”], 37.58° N, 127.05° E, 6 May 1934, H. Doi leg. (UOP) ( Shinohara 1992).

Description

See Shinohara (1992) and Figs 5A–B, E , 11C (ovipositor sheath).

Female

Ovipositor about 2.7 mm long, weakly curved ventrally, valvula 1 and valvula 2 bulbous distal of middle, without ctenidia ( Fig. 12E ). Pulvilli absent on article 1 of metatarsus, present on article 4 and 50 µm long, presence ambiguous for articles 2–3 ( Fig. 5F–G ).

Male

See Figs 5C–D, H , 13G–H . Valviceps of penis valve distally parabolically rounded, basal quarter of upper side expanded to a round lobe coiled laterally, medial 0.3–0.8 of upper edge with one or two shallow elevations and numerous small teeth. Distal 0.7 of valviceps with long setae, most dense in medial lower portion ( Fig. 13C ).

Host plant

Saito (1941), Ko (1969) and Xiao (2006) reported Juglans ailanthifolia Carrière (cited as J. sieboldiana Maxim.), J. mandshurica Maxim., J. regia L. (including the synonym J. sinensis [C. DC.] Dode), Pterocarya rhoifolia Sieb. & Zucc., and P. stenoptera C. DC. All recorded hostplant associations of M. gigantea need confirmation, because they can also refer to the new species M. pulchra sp. nov.

In South Korea, A. Shinohara captured a male of M. gigantea together with 3 ♀♀, 2 ♂♂ M. pulchra sp. nov. from the same J.? mandshurica tree at end of May and beginning of June 2002.

Remarks

Megaxyela gigantea is similar to species with the terga 2–3 or 2–4 laterally extensively white (dorsally black in M. euchroma sp. nov. and in the Nearctic species except for M. major ). It is unique among the East Asian species in the predominantly red brown head (predominantly black in M. parki , pale yellow color and less extensive in M. togashii ) bearing a large infuscate spot on face and vertex (completely red brown in M. fulvago sp. nov.), which does not extend to the antennal toruli ventrally (spot extending to toruli in M. pulchra sp. nov.). As in M. fulvago sp. nov., the surface of the face is minutely areolate and bears scattered, shallow, 50 µm large pits (face rugose in other East Asian species at least laterally). The dorsal side of terga 2–4 is white laterally for 0.15–0.20 × the tergal width in M. gigantea and M. fulvago sp. nov., whereas the white marks are generally narrower in M. parki or narrower at least on tergum 4 in M. pulchra sp. nov. and M. togashii .

The single specimen studied genetically is placed within the group, which otherwise comprises M. fulvago sp. nov., but we interpret this placement as an artefact caused by the very short sequence length of M. gigantea . Morphological results indicate two separate species.

Figures

Fig. 5. Megaxyela gigantea Mocsáry, 1909. A – B. Habitus dorsal / lateroventral (♀, holotype of M. mikado, DEI-GISHym 22350, NSMT). C – D. Habitus dorsal / lateroventral (♂, 18507, NSMT). E. Head frontal (♀, holotype of M. mikado, 22350, NSMT). F – G. Metatarsus lateral / ventral (♀, holotype of M. mikado, 22350, NSMT). H. Metatarsus ventral (♂, 18507, NSMT).

Fig. 11. Species of Megaxyela Ashmead, 1898, ovipositor sheaths. A. M. euchroma Blank, Shinohara & Wei sp. nov. (holotype, DEI-GISHym 22554, CSCS). B. M. fulvago Blank, Shinohara & Wei sp. nov. (5752, NSMT). C. M. gigantea Mocsáry, 1909, holotype of M. mikado Sato, 1930 (22350, NSMT). D. M. inversa Blank & D. R. Smith sp. nov., paratype (22356, USNM). E. M. langstoni Ross, 1936, holotype (30821, INHS). F. M. parki Shinohara, 1992 (18510, NSMT). G. M. pulchra Blank, Shinohara & Sundukov sp. nov., holotype (18501, NSMT). H. M. togashii Shinohara, 1992, holotype (22352, NSMT). Images not to the same scale.

Fig. 12. Species of Megaxyela Ashmead, 1898, ovipositors. A. M. euchroma Blank, Shinohara & Wei sp. nov., paratype, DEI-GISHym 22510 (NSMT). B – C. M. fulvago Blank, Shinohara & Wei sp. nov., paratype (5752, NSMT). C. Complete valvula 2 (incident light) and tip of valvula 2 (insert, transmitted light). D. M. inversa Blank & D. R. Smith sp. nov., paratype (22356, USNM). E. M. gigantea Mocsáry, 1909, holotype of M. mikado Sato, 1930 (22350, NSMT). F. M. parki Shinohara, 1992, paratype (18510, NSMT). G. M. pulchra Blank, Shinohara & Sundukov sp. nov., paratype (22348, NSMT). H. M. togashii Shinohara, 1992 (22353, NSMT). The images in B and H have been flipped horizontally.

Fig. 13. Species of Megaxyela Ashmead, 1898, penis valves (A – F) and genitalia capsules (G – I). A. M. euchroma Blank, Shinohara & Wei sp. nov. (DEI-GISHym 22513, NSMT). B. M. fulvago Blank, Shinohara & Wei sp. nov. (5239, NSMT). C. M. gigantea Mocsáry, 1909 (708, NSMT). D. M. parki Shinohara, 1992 (710, NSMT). E. M. pulchra Blank, Shinohara & Sundukov sp. nov. (18503, NSMT). F. M. togashii Shinohara, 1992 (22521, NSMT). G – H. M. gigantea, genitalia capsule in dorsal / ventral view (18507, NSMT). I. M. pulchra sp. nov., genitalia capsule in dorso-posterior view (22349, NSMT). Arrow heads in Fig. 13 H – I indicate lobe of upper side of valviceps coiled laterally. Images not to same scale.