Megaxyela, Ashmead in Dyar, 1898

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 : 33-36

publication ID	https://doi.org/10.5852/ejt.2017.348
publication LSID	urn:lsid:zoobank.org:pub:56D8BC29-3C29-4EE8-8633-B997784CA00A
DOI	https://doi.org/10.5281/zenodo.5698090
persistent identifier	https://treatment.plazi.org/id/03C587E2-FFF1-FFB3-FF15-FAB0FA92FC29
treatment provided by	Plazi (2017-11-06 16:40:52, last updated 2024-12-16 18:44:05)
scientific name	Megaxyela
status

Treatment

Identification key to the species of Megaxyela

1 a Valvula 3 of ovipositor sheath dorsally straight, ventrally evenly convex in basal and medial portion Fig. 11D View Fig. 11 ). b Ovipositor curved dorsally ( Fig. 12D View Fig. 12 ). Male unknown. USA (West Virginia) ……………… M. inversa Blank & D.R. Smith sp. nov.

– aa Valvula 3 of ovipositor sheath dorsally convex, ventrally various in shape ( Fig. 11A–C, E–H View Fig. 11 ; Smith & Schiff 1998: figs 7–11). bb Ovipositor curved ventrally ( Fig. 12A–B, E–H View Fig. 12 , Smith & Schiff 1998: figs 16–23, 26–27) ……2

2(1) a East Palaearctic and Oriental species …………………………………………………………3

– aa Nearctic species ………………………………………………………………………………8

3(2) a Tergum 8 red brown ( Fig. 8A, D View Fig. 8 ). b Eye surrounded by black except for red brown malar space ( Fig. 8F View Fig. 8 ). c Antenna red brown ( Figs 1D View Fig. 1 , 8A–D View Fig. 8 ). d Claw of hind leg with large subapical tooth ( Fig. 8F–G View Fig. 8 ). South Korea ( Fig. 14 View Fig. 14 ) ……………………………………………… M. parki Shinohara, 1992

– aa Tergum 8 black (e.g., Fig. 3A, D View Fig. 3 ), sometimes laterally and ventrally white (e.g., Figs 4A View Fig. 4 , 5A–D View Fig. 5 , 9C View Fig. 9 ). bb Eye at least narrowly lined with yellow or red brown on inner and outer orbits ( Figs 3F View Fig. 3 , 9F View Fig. 9 , 10C–D View Fig. 10 ) or face predominantly pale ( Figs 4G View Fig. 4 , 5E View Fig. 5 ). cc Dorsal side of antenna black. dd Claws bifid (e.g., Figs 3H–I View Fig. 3 , 4D View Fig. 4 , 5G View Fig. 5 ) ………………………………………………………4

4(3) a Metatarsus white, base of metatarsomere 1 black ( Fig. 3A–B, D–E, H–I, K View Fig. 3 ). b Terga 2–6 with narrow, evenly wide line along ventral margin ( Fig. 3C View Fig. 3 ), terga 2–4 laterally black in dorsal view ( Fig. 3A, D View Fig. 3 ). c Head black, inner and outer orbits with narrow yellow lines, vertex with linear yellow spot ( Fig. 3F–G View Fig. 3 ). d Pulvillus present on metatarsomere 1 ( Fig. 3I –K View Fig. 3 ). e Mesepisternum with indistinct pits between minutely areolate microstructure, dull. f Antennal filament composed of 7–8 (rarely 9) articles. g ♀: Ovipositor sheath black except for brown basal half of valvifer 2 ( Fig. 11A View Fig. 11 ). h ♀: Ovipositor with ctenidia along annuli ( Figs 1F View Fig. 1 , 12A View Fig. 12 ). i ♂: Hypopygium black ( Fig. 3E View Fig. 3 ). China (Zhejiang) ( Fig. 14 View Fig. 14 ) …………………… M. euchroma Blank, Shinohara & Wei sp. nov.

– aa Metatarsus black (e.g., Figs 4A–F View Fig. 4 , 5C–H View Fig. 5 ). bb Terga 2–3 or 2–4 with broad white band on dorsolateral and complete ventral portion, terga 3–5 or 4–5 less extensively white than preceding terga ( Figs 4A, E–F View Fig. 4 , 5A–D View Fig. 5 , 9A–E View Fig. 9 , 10A–B, E–F View Fig. 10 ). cc Head more extensively red brown or yellow, at least gena and face below antennal toruli pale ( Figs 4G View Fig. 4 , 5E View Fig. 5 , 9F View Fig. 9 , 10C–D View Fig. 10 ). dd Pulvillus absent on metatarsomere 1. ee Mesepisternum with distinct pits, smooth or with coriarious microstructure, more or less shining. ff Antennal filament composed of 9–10 articles (rarely fewer articles present on one antenna, check both antennae). gg ♀: Ovipositor sheath red brown, valvifer 2 sometimes white, valvula 3 sometimes infuscated along dorsal margin ( Fig. 11C, G–H View Fig. 11 ). hh ♀: Ovipositor without ctenidia along annuli ( Fig. 12B–C, G–H View Fig. 12 ). ii ♂: Hypopygium red brown ( Figs 4F View Fig. 4 , 5D View Fig. 5 , 9E View Fig. 9 ) or white ( Fig. 10F View Fig. 10 ) ……………………………5

5(4) a Head, prothorax and mesothorax red brown, without black ( Fig. 4A, E–G View Fig. 4 ). China (Hunan, Jiangsu, Zhejiang) ( Fig. 14 View Fig. 14 ) … M. fulvago Blank, Shinohara & Wei sp. nov.

– aa At least mesoscutum and usually vertex partly black (e.g., Figs 5A, C View Fig. 5 , 10A, E View Fig. 10 ) ……6

6(5) a At least ventral half of frons red brown ( Fig. 5E View Fig. 5 ). b Pterostigma unicolorous yellow brown ( Fig. 5A, C View Fig. 5 ). c Upper part of gena weakly imbricate, almost smooth, shining ( Fig. 5B View Fig. 5 ). d Microsculpture of frons above antennal toruli minutely areolate, similar to microsculpture of vertex, with few shallow pits ( Fig. 5E View Fig. 5 ). e Dorsal side of terga 2–4 with evenly wide, white lateral margins ( Fig. 5A, C View Fig. 5 ). North and South Korea, Russia (Primorskiy Kray) ( Fig. 14 View Fig. 14 ) …… M. gigantea Mocsáry, 1909

– aa Black spot of frons ventrally extending to antennal toruli ( Figs 9F View Fig. 9 , 10C–D View Fig. 10 ). bb Pterostigma yellow brown, narrow at base and anterior margin infuscate (e.g., Figs 9A View Fig. 9 , 10A View Fig. 10 ). cc Upper part of gena strongly imbricate, dull. dd Microsculpture of frons above antennal toruli rugulose, different from areolate microsculpture of vertex ( Figs 9F View Fig. 9 , 10C–D View Fig. 10 ). ee White lateral margin on dorsal side of tergum 4 narrower than on terga 2–3 or absent (e.g., Figs 9A–E View Fig. 9 , 10E View Fig. 10 ) ……………………………………………………………………………7

7(6) a Mesonotum black or with a small brown spot lateral to mesoscutellum ( Fig. 9A, D View Fig. 9 ). b Preapical sterna white ( Fig. 9B, E View Fig. 9 ), sometimes with pair of small black marks on anterior margin ( Fig. 9C View Fig. 9 ). c ♀: Thorax ventrally red brown ( Fig. 9B, E View Fig. 9 ). d ♀: Ovipositor sheath red brown, sometimes tip of valvula 3 black ( Fig. 11G View Fig. 11 ). e ♂: Hypopygium red brown ( Fig. 9E View Fig. 9 ). China (Jilin, Liaoning, Shaanxi, Tibet), South Korea, Russia (Primorskiy Kray) ( Fig. 14 View Fig. 14 ) …………………………………………… M. pulchra Blank, Shinohara & Sundukov sp. nov.

– aa Mesonotum black with yellow stripes along posterolateral ridge on mesoscutal lateral lobe ( Fig. 10A, E View Fig. 10 ). bb Sterna red brown to white, preapical sterna with pair of large black marks on anterior margin ( Fig. 10B, F View Fig. 10 ). cc ♀: Mesepisternum red brown, black spot in dorsal corner, black stripe along pectus, pectus largely black medially ( Fig. 10B View Fig. 10 ). dd ♀: Ovipositor sheath red brown with valvifer 2 ventrally yellow white, and valvula 3 with black stripe along dorsal margin ( Fig. 11H View Fig. 11 ). ee ♂: Hypopygium white ( Fig. 10F View Fig. 10 ). Japan (Hokkaido, Honshu, Shikoku ) ( Fig. 14 View Fig. 14 ) ……………… M. togashii Shinohara, 1992

8(2) a Metafemur, tegula and abdomen black, sterna with indistinctly pale posterior margins. b Tarsomeres (2–)3–5 of hind legs white. Canada (Ontario), USA (Indiana, Kansas, Massachusetts, Mississippi, Missouri, New York, Oklahoma, Pennsylvania) ………………………………………… M. aviingrata ( Dyar, 1898)

– aa Metafemur red brown, sometimes apex narrowly black (e.g., Smith & Schiff 1998, fig. 3). Tegula white. Sterna red brown and/or posterior margins of terga and sterna white. bb Metatarsus sometimes completely black (e.g., Smith & Schiff 1998: figs 14 and 15) ……9

9(8) a Head yellow and red brown, pronotum red brown ( Fig. 7A–C, G–I View Fig. 7 ). b Metatibia red brown or black, basal 0.2–0.4 white ( Fig. 7A–B, F–H View Fig. 7 ) ………………………10

– aa Head (except for clypeus, labrum, mouthparts, mandible) and pronotum black (e.g., Smith & Schiff 1998: fig. 3). bb Metatibia entirely black (e.g., Smith & Schiff 1998: fig. 3) ……………………………11

10(9) a Basal 0.3–0.5 of pterostigma black, distal portion red brown ( Fig. 7A–B View Fig. 7 ). b Dorsal side of terga red brown, terga 1(–2) medially more or less infuscate ( Fig. 7A View Fig. 7 ). c Basal 0.05–0.10 of metafemur yellow white ( Fig. 7B, F View Fig. 7 ). d Distal preapical metatibial spur reaches apex of metatibia ( Fig. 7B View Fig. 7 ), inner apical metatibial spur 0.5 × as long as metatarsomere 1 or longer ( Fig. 7D–E View Fig. 7 ). USA (Mississippi, Oklahoma, Texas) ……………………… M. langstoni Ross, 1936 sp. rev.

– aa Pterostigma uniformly red brown ( Fig 7G View Fig. 7 ). bb Dorsal side of terga 1–7 predominantly black ( Fig. 7G View Fig. 7 ). cc Basal 0.30–0.35 of metafemur yellow white ( Fig. 7H View Fig. 7 ). dd Distal preapical metatibial spur not reaching apex of metatibia ( Fig. 7H View Fig. 7 ), inner apical metatibial spur about 0.4 × as long as metatarsomere 1 ( Fig. 7J–K View Fig. 7 ). USA (Kansas, Oklahoma, Pennsylvania, Texas) ………………… M. major ( Cresson, 1880)

11(9) a Terga 1–7(–8) red brown, distal margins narrowly infuscate ( Smith & Schiff 1998: fig. 3). b Metatarsomere 1 stout, 4 × as long as wide, pilosity dorsally and ventrally dense ( Smith & Schiff 1998: fig. 15). USA (New York, Ohio) …………………………… M. alisonae D.R. Smith & Schiff, 1998

– aa Terga black, distal margins narrowly white. bb Metatarsomere 1 slender, 6–7 × as long as wide, pilosity dorsally sparse and ventrally dense (e.g., Smith & Schiff 1998: fig. 14) …………………………………………………………12

12(11) a Metatarsomeres (2–)3–5 white. b Ventral side of thorax and sterna red brown. c Alvula 2 less than 3.0 × as long as wide, 0.6 × as long as metatarsus ( Smith & Schiff 1998: fig. 10). USA (Michigan, Mississippi, Missouri, Pennsylvania,Virginia,West Virginia)……………… ……………………………………………………………… M. bicoloripes ( Rohwer, 1924)

– aa Metatarsus black. bb Ventral side of thorax and sterna black, sterna with white distal margins. cc Valvula 2 4.5 × as long as wide, about as long as metatarsus ( Smith & Schiff 1998: fig. 11). Canada (Ontario), USA (Connecticut, Illinois, Kansas, Missouri, West Virginia) ………… …………………………………………………………………… M. tricolor ( Norton, 1862)

References

Cresson E. T. 1880. Descriptions of new North American Hymenoptera in the collection of the American Entomological Society. Transactions of the American Entomological Society 8: 1 - 52.

Dyar H. G. 1898 a. Description of an unusual sawfly-larva belonging to the Xyelinae. Psyche 8: 212 - 214 [May 1898].

Mocsary A. 1909. Chalastogastra nova in collectione musei nationalis Hungarici. Annales historiconaturales Musei Nationalis Hungarici 7: 1 - 39.

Norton E. 1862. Notice of several new species of Tenthredinidae. Proceedings of the Entomological Society of Philadelphia 1 [1861 - 1863] (5): 143 - 144.

Rohwer S. A. 1924. A new sawfly of the family Xyelidae (Hymenoptera). Proceedings of the entomological Society of Washington 26: 215.

Ross H. H. 1936. A new pecan sawfly, Megaxyela langstoni n. sp. (Hymenoptera: Xyelidae). Entomological News 47: 131 - 132.

Shinohara A. 1992. The sawfly genus Megaxyela (Hymenoptera, Xyelidae) in East Asia. Japanese Journal of Entomology 60: 783 - 796.

Smith D. R. & Schiff N. M. 1998. The genera Macroxyela Kirby and Megaxyela Ashmead (Hymenoptera: Xyelidae) in North America. Proceedings of the Entomological Society of Washington 100: 636 - 657.

Figures

Fig. 1. Megaxyela Ashmead, 1898, morphological terminology. A. M. major (Cresson, 1880) (♀, paralectotype, DEI-GISHym 30823, ANSP), wings. B. M. parki Shinohara, 1992 (♀, 18509, NSMT), section of fore wing. C. M. euchroma Blank, Shinohara & Wei sp. nov. (♂, paratype, 22513, NSMT), penis valve. D. M. parki (♂, 710, NSMT), antenna. E. M. gigantea Mocsáry, 1909 (♀, holotype of M. mikado Sato, 1930, 22350, NSMT), ovipositor and ovipositor sheath, with indication of measurement of length of valvifer 2 (blue), valvula 3 (white), and width of valvula 3 (yellow). F. M. euchroma sp. nov. (♀, paratype, 22558, CSCS), section of ovipositor, white arrow heads indicating teeth of ctenidia on valvulae 1 and 2.

Fig. 3. Megaxyela euchroma Blank, Shinohara & Wei sp. nov. A – B. Habitus dorsal / lateral (♀, holotype, DEI-GISHym 22554, CSCS). C. Abdomen ventral, arrowheads indicating white stripe along ventral edge of terga (♀, 22511, NSMT). D – E. Habitus dorsal / lateroventral (♂, 22514, NSMT). F – G. Head, obliquely lateral / frontal, arrowheads indicating carina along inner orbit (♂, 22510, NSMT). H – K. Metatarsus, lateroventral (♀, holotype, 22554, CSCS), ventral (♀, 22510, NSMT), tarsomeres 1 – 2, ventral, arrowheads indicating small pulvilli (♀, 22509, NSMT), lateroventral (♂, 22513, NSMT).

Fig. 4. Megaxyela fulvago Blank, Shinohara & Wei sp. nov. A. Habitus lateral (♀, DEI-GISHym 5752, NSMT). B. Metatarsus lateral (♀, 5752, NSMT). C – D. Metatarsus lateral / ventral (♂, holotype, 5236, CSCS). E – F. Habitus dorsal / lateroventral (♂, holotype, 5236, CSCS). G. Head frontal (♂, 5239, NSMT).

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. 7. A – F. Megaxyela langstoni Ross, 1936, ♀ (A – C = holotype, DEI-GISHym 30821, INHS; D – F = 30822, USNM). G – K. M. major (Cresson, 1880), ♂, paratype (30823, ANSP). A – B. ♀, holotype, habitus dorsal / lateroventral. C. ♀, holotype, head frontal. D – E. ♀, metatarsus, lateral / ventral. F. ♀, abdomen lateroventral. G – H. Habitus dorsal / lateroventral. I. Head frontal. J – K. Metatarsus lateral / ventral.

Fig. 8. Megaxyela parki Shinohara, 1992. A – B. Habitus dorsal / lateroventral (♀, DEI-GISHym 18509, NSMT). C – D. Habitus dorsal / lateroventral (♂, 710, NSMT). E. Head frontal (♂, 710, NSMT). F – G. Metatarsus lateral / ventral, arrowheads indicate pulvilli (♀, 18509, NSMT). H. Metatarsus lateral (♂, 710, NSMT).

Fig. 9. Megaxyela pulchra Blank, Shinohara & Sundukov sp. nov. A – B. Habitus dorsal / lateroventral (♀, holotype, DEI-GISHym 86249, ZIN). C. Abdomen lateroventral, arrowheads indicating black anterolateral spots on sterna (♀, 18504, NSMT). D – E. Habitus dorsal / lateroventral (♂, 22349, NSMT). F. Head frontal (♀, holotype, 86249, ZIN). G – I. Metatarsus ventral (♀, 22346, NSMT), lateral (♀, 22346, NSMT), lateral (♂, 22349, NSMT).

Fig. 10. Megaxyela togashii Shinohara, 1992, ♀, holotype, DEI-GISHym 22352 (NSMT); ♂, 22354, (NSMT). A – B. Habitus dorsal / lateroventral (♀). C. Head frontal (♀). D – E. Habitus dorsal / lateroventral (♂). F. Head frontal (♂). G – H. Metatarsus lateral / ventral (♀). I – J. Metatarsus lateral / ventral (♂). Arrows in Fig. 10 B and 10 F indicate dark spots of abdominal sterna, arrowheads in H and J indicate minute pulvilli.

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. 14. Distribution of species of Megaxyela Ashmead, 1898 in East Asia. Records of M. togashii Shinohara, 1992 include reliable records published by Shinohara (1992, 2006), Tanaka (1999), Yamada (2000), Naito et al. (2004) and Shinohara et al. (2017). Other distribution data are based on examination of material in course of this work.