Xyela Dalman 1819
Creators: name: Blank, Stephan M.
name: Shinohara, Akihiko
name: Altenhofer, Ewald
Publisher: name: Zenodo
Year: 2013
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Hymenoptera
Xyelidae
Xyela

description: Xyela Dalman, 1819   
 Pinicola Brébisson [reported by Blainville], 1818: 116–117, type species: Pinicola julii Brébisson, 1818, by monotypy, preoccupied by Pinicola Vieillot, 1807 or 1808 in Vieillot 1807 –1809: tome 1, p. iv, tab. 1 fig. 13 (Aves: Fringillidae).   
 Mastigocerus [also spelled: Mastigocère] Latreille, 1818: 451 (unavailable name); Taeger & Blank 1996: 255 (nomenclature).   
 Mastigocera Berthold, 1827: 442 (unavailable name).   
 Mastigoceras Klug: Thomson 1871: 341 (misspelling).   
 Xyela Dalman, 1819: 122–124, type species: Xyela pusilla Dalman, 1819, by subsequent designation of Curtis 1824: 30.   
 Pinicolites Meunier, 1920: 896, type species: † Pinicolites graciosus Meunier, 1920, by monotypy.   
 Xyela subgen. Pinicolites: Rasnitsyn 1997: 2 (status changed).   
 Tritokreion Schilling in Schummel, 1826: 43, type species: Xyela pusilla Dalman, 1819, by subsequent designation of Blank et al. 2009: 72.   
 Tritokriton: Dalla Torre 1894: 458 (misspelling).   
 Tritocreion: Konow 1905: 22 (misspelling).   
 Neoxyela Curran, 1923: 20, type species: Neoxyela alberta Curran, 1923, by monotypy; Ross 1937: 106–107 (junior synonym of Xyela).   
 Xyelatana Benson, 1938: 34, type species: Xyela longula Dalman, 1819, by original designation; Burdick 1961: 322 (junior synonym of Xyela).   
 Xyela subgen. Mesoxyela Rasnitsyn, 1965: 491, 497–498, 512–513, type species: Xyela (Mesoxyela) mesozoica Rasnitsyn, 1965, by original designation.   
 Xyela subgen. Xyela section Alpigenixyela Rasnitsyn, 1971: 194, name for X. alpigena group of Rasnitsyn (1965) (unavailable name due to missing designation of type species, Art. 13.3., ICZN 1999).   
 Xyela subgen. Xyela section Concavixyela Rasnitsyn, 1971: 194, type species: Xyela concava Burdick, 1961, by monotypy.   
 Xyela subgen. Xyela section Desertixyela Rasnitsyn, 1971: 194: type species: Xyela deserti Burdick, 1961, by monotypy.   
 Xyela subgen. Xyela section Linsleyixyela Rasnitsyn, 1971: 193, name for X. linsleyi group of Rasnitsyn (1965) (unavailable name due to missing designation of type species, Art. 13.3., ICZN 1999).   
 † Xyela subgen. Xyela section Magnixyela Rasnitsyn, 1971: 193, name for X. magna group of Rasnitsyn (1965) (unavailable name due to missing designation of type species, Art. 13.3., ICZN 1999).   
 Xyela subgen. Xyela section Minorixyela Rasnitsyn, 1971: 194, name for X. minor group of Rasnitsyn (1965) (unavailable name due to missing designation of type species, Art. 13.3., ICZN 1999).   
 Remarks. Xyela Dalman, 1819 is the type genus of Xyelidae Newman, 1834, which was originally spelled Xyelites by Newman (1834: 408). André (1881) recognized that the description of Pinicola Brébisson, 1818 predates that of Xyela, and he treated the latter name as a synonym. Consequently he also introduced the familygroup name Pinicolidae André, 1881 (pp. 465–466) to replace Xyelides since at that time family-group names were usually based on the stem of the valid name of the type genus concerned. The name Pinicola had already been used by Vieillot (1807 –1809) for the valid description of a genus of birds. This description has been wrongly dated to 1805 (e.g., by Hellmayr 1938, Blank et al. 2009), but the proper publication date of Pinicola in Vieillot’s work, which was printed in 12 consecutive issues, is 1.12.1807 (Browning & Monroe 1991, Banks & Browning 1995) or 1808 (Peterson 2013). Pinicola Vieillot makes Pinicola Brébisson a junior homonym. Due to this homonymy, Pinicolidae André is not available (ICZN 1999, Art. 39). The stem Xyel- of the junior name Xyela has to be used for the formation of relevant family-group names. The validity and availability of the other genus-group names associated with Xyela were discussed by Blank et al. (2009).   
 Xyela can be recognized with help of the key by Blank (2002). Imagines are distinguished from other Xyelidae by the combination of the following characters: vein Sc of the fore wing closely adpressed to vein R (Fig. 4); ovipositor elongate (Figs 6, 95–120); antennal flagellum longer than synantennomere 3, comprising 9 antennomeres (Figs 6–7); maxillary palp enlarged, particularly palpomere 3 (Figs 6–7, smaller in X. helvetica, X. longula, X. lugdunensis); evident tergal grooves present; surface coriaceous (except for the Nearctic X. deserti); wings without setae. The Nearctic X. lata D.R. Smith, 1990 disagrees with this concept. It has a narrow cell present between veins Sc and R, a comparatively short antennal filament and unlike other Xyela species a shiny surface sculpture (Smith 1990, Rasnitsyn 1995). Xyela lata has therefore been placed in Xyela (Pinicolites), while all other extant species are classified with Xyela (Xyela) (Rasnitsyn 1997, Blank et al. 2009, Taeger et al. 2010). A key for larvae of Xyelidae, which allows identification on genus level, was published by Smith (1967).   
 Rasnitsyn (1965) distinguished within the extant fauna a number of species groups based on his own studies and on the work of Burdick (1961). The julii group and the longula group only include species distributed in Eurasia. Subsequently, Rasnitsyn (1971) fused with the julii group the bakeri group, in which he originally included the Nearctic X. bakeri Konow, 1898 and the West Palearctic X. graeca and X. menelaus. In our barcoding analysis, X. bakeri imagines and larvae collected from Pinus sabiniana from California are placed at 10.07 % interspecific distance next to X. menelaus (Fig. 23, intraspecific variation ca 2 %). But this seemingly large divergence might merely result from insufficient consideration of additional species distributed in the New World. The alpigena group, linsleyi group and minor group contain species distributed both in Eurasia and in the Nearctic according to Rasnitsyn (1965). In our treatise on Eurasian Xyela species, leaving the Nearctic species out of consideration, these groups are named the alpigena group, lugdunensis group (for linsleyi group) and curva group (for minor group). Rasnitsyn’s concava group (Concavixyela) and deserti group (Desertixyela) include only Nearctic species. The meridionalis group and the rasnitsyni group, which are defined in this study, are not associated with one of the groups recognized by Rasnitsyn. The use of species group names is here intended as an informal aid in sorting species taxonomically, although some of the groups that include more than a single species might be monophyletic. The diagnosis for each species group precedes a list of the included species below.   
  Key to the Eurasian Xyela species    
 1 Female............................................................................................ 2   
 – Male............................................................................................. 31   
 2 (1) Tip of valvula 3 acutely pointed, without defined sensilla field (Figs 86–87, 95, 104). Ovipositor sheath very long, fore wing 0.90–1.35 times longer than ovipositor sheath.............................................................. 3   
 – Tip of valvula 3 narrowly or widely rounded, bearing defined sensilla field (Figs 88–94, 96–103, 105–120). Ovipositor sheath shorter, fore wing at least 1.45 times longer than ovipositor sheath 5   
 3 (2) Article 3 of maxillary palp 1.45–1.65 times longer than scape, wider than synantennomere 3. Ovipositor sheath compressed, in medial section, combined width of both valvulae 3 in lateral view ca 3.5 times wider than in dorsal view. Dorsal edge of valvula 3 sloping down to acute tip, ventral edge almost straight (Fig. 2, 104). Vein 2r-m meeting Rs proximal to furcation of Rs1 and Rs2 from Rs. Northeastern China (Jilin), Russian Far East (Primorskiy Kray), South Korea (Fig. 22)..............................................................................  Xyela rasnitsyni Blank & Shinohara, sp. nov.  ♀   
 – Article 3 of maxillary palp 0.70–0.90 times as long as scape, narrower than synantennomere 3. Ovipositor sheath in medial section diamond-shaped in cross section, combined width of both valvulae 3 in medial section in lateral view ca 1.2 times width in dorsal view. Both dorsal and ventral edge of valvula 3 evenly narrowing to tip (Figs 86–87). Vein 2r-m mostly meeting Rs1 distal to furcation of Rs1 and Rs2 from Rs. West Palearctic species....................................... 4   
 4 (3) Ovipositor sheath ca 3.4 mm long, valvula 3 2.9–3.1 times longer than valvifer 2, 11.5–12.0 times longer than wide at base (Fig. 86). Fore wing 1.20–1.35 times longer than ovipositor sheath. Male unknown. Subalpine zone of Austria and Switzerland (Fig. 19)..................................................................  Xyela helvetica (Benson, 1961)  ♀   
 – Ovipositor sheath 4.1–5.6 mm long, valvula 3 3.6–4.2 times longer than valvifer 2, 13.5–16.5 times longer than wide at base (Fig. 95). Fore wing 0.90–1.10 times longer than ovipositor sheath. Lowlands and mountainous regions of Europe, southwards to the Alps and neighboring mountain ranges (Fig. 20)...............................  Xyela longula Dalman, 1819  ♀   
 5 (2) Ovipositor strikingly short (Figs 89, 103): valvula 3 of ovipositor sheath 0.85–0.90 as long as valvifer 2, fore wing 3.3–3.5 times longer than ovipositor sheath. Taiwan (Fig. 12).........................  Xyela meridionalis Shinohara, 1983  ♀   
 – Ovipositor longer: valvula 3 of ovipositor sheath at least 1.35 times longer than valvifer 2, fore wing at most 2.8 times longer than ovipositor sheath 6   
 6 (5) Valvula 3 diamond-shaped in cross section, dorsal and ventral edge parallel in medial portion, narrowing in distal 0.10–0.15 to round tip (Fig. 88, 96). Article 3 of maxillary palp 1.10–1.20 times as long as scape, about as wide as synantennomere 3. France, Hungary (Fig. 21).................................................  Xyela lugdunensis Berland, 1943  ♀   
 – Valvula 3 either strongly compressed and medially parallel-sided (Figs 92, 105–120), or diamond-shaped in cross section and wedge-shaped over complete length (Figs 90, 97–102). Article 3 of maxillary palp more than 1.30 times longer than scape, wider than synantennomere............................................................................. 7   
 7 (6) Valvula 3 wedge-shaped, dorsal and ventral outline steadily narrowing toward round tip (Figs 90, 97–102), medial portion diamond-shaped in cross-section, width about equal in lateral and dorsal view. Pale membranous triangle at base of valvula 3 several times longer on ventral edge than wide at base, distally often extending to preapical region of valvula.............. 8   
 – Valvula 3 of ovipositor sheath knife-shaped (Fig. 92, 105–120), strongly compressed, medial part of valvula 3 in lateral view 3–4 times wider than combined width of both valvulae 3 in dorsal view, dorsal edge sloping down to round apex, ventral edge almost straight. Pale membranous triangle of valvula 3 about as long on ventral edge as wide at base................. 13   
 8 (7) Valvula 3 2.30–2.60 times longer than valvifer 2. East Palearctic species........................................ 9   
 – Valvula 3 1.90–2.20 times longer than valvifer 2. West and East Palearctic species................................ 10   
 9 (8) Fore wing 1.55–1.70 times longer than ovipositor sheath. Wings almost clear. Article 3 of maxillary palp completely pale. Mesoscutellum usually with large yellow spot, seldom completely black. Eastern East Palearctic: Russian Far East (Primorskiy Kray), South Korea (Fig. 10)....................................  Xyela koraiensis Blank & Shinohara, sp. nov.  ♀   
 – Fore wing (1.75–)1.85–2.00 times longer than ovipositor sheath. Wings slightly infuscate. Article 3 of maxillary palp more or less infuscate in proximal half. Mesoscutellum usually black, sometimes indistinctly yellow in middle. Eastern East Palearctic: subalpine zone of Japan (Hokkaido, Honshu), Russia (Kamchatka) (Fig. 9).......  Xyela kamtshatica Gussakovskij, 1935  ♀   
 10 (8) West Palearctic species............................................................................... 11   
 – East Palearctic species............................................................................... 12   
 11 (10) Valvula 3 1.75–1.95 times longer than valvifer 2 (Fig. 97). Kidney-shaped spots and black stripes along frontal furrows fusing (ca. 75 % of specimens; pale specimen illustrated in Fig. 28). Subalpine zone of Austria, Germany, Switzerland (Fig. 8)................................................................................  Xyela alpigena (Strobl, 1895)  ♀   
 – Valvula 3 (1.90–)1.95–2.20 times longer than valvifer 2 (Fig. 100). Kidney-shaped spots separated from black stripes along frontal furrows by yellow (ca. 75 % of specimens; dark specimen illustrated in Fig. 34). Mountains of Bulgaria (Fig. 8)................................................................................  Xyela peuce Blank, sp. nov.  ♀   
 12 (10) Ovipositor sheath 2.55–2.80 mm, valvula 3 9.0–9.5 times longer than wide basally (Fig. 101), fore wing 1.75–1.90 times longer than ovipositor sheath. Wings slightly infuscate. Valvifer 2 pale brown basally and infuscate distally. Central East Palearctic (possibly also in western part): Russia (Irkutskaya Obast), Mongolia (Hentiyn Nuruu) (Fig. 9).................................................................................................  Xyela sibiricae Blank, sp. nov.  ♀   
 – Ovipositor sheath 1.90–2.25 mm, valvula 3 6.5–8.0 times longer than wide basally (Fig. 102), fore wing 1.95–2.05 times longer than ovipositor sheath. Wings pale. Valvifer unicolorous pale brown. Eastern East Palearctic: Russian Far East (Primorskiy Kray), South Korea (Fig. 10)..............................................  Xyela ussuriensis Rasnitsyn, 1965  ♀   
 13 (7) Posterior claws with subapical tooth (often very feeble). Valvula 3 evenly and distinctly curved downwards, often black (Figs 118–120). Valvula 2 of ovipositor with more or less evident alternating dark and pale pattern in distal half (Fig. 124)..... 14   
 – Posterior claws without subapical tooth. Valvula 3 usually straight, sometimes indistinctly bent downwards in species with long ovipositor, often pale brown, sometimes dark brown, never black (Figs 105–117). Valvula 2 of ovipositor evenly pale brown............................................................................................. 17   
 14 (13) Head yellow with dark pattern (Fig. 42)................................................................. 15   
 – Head black, or brown with dark brown or black pattern (e.g., in faded collection specimens; Figs 44, 46).............. 16   
 15 (14) Antennomere 4 6.0–7.5 times longer than wide distally. Fore wing 2.15–2.30 times longer than ovipositor sheath. European part of Mediterranean area, central and western Europe, Turkey (Fig. 11)..................  Xyela curva Benson, 1938  ♀   
 – Antennomere 4 4.0–5.0 times longer than wide distally. Fore wing 1.95–2.05 times longer than ovipositor sheath. China (Fujian, Hong Kong) (Fig. 12)...................................................  Xyela exilicornis Maa, 1949  ♀   
 16 (14) Ovipositor 1.7–1.9 mm (Fig. 119), fore wing 3.7–4.6 mm long. Japan (Honshu) (Blank et al. 2005, fig. 3)..........................................................................................  Xyela japonica Rohwer, 1910  ♀   
 – Ovipositor 1.5–1.7 mm (Fig. 120), fore wing 3.3–3.7 mm long. East Asian mainland: northeastern China (Jilin), South Korea (Blank et al. 2005, fig. 3)........................................  Xyela occidentalis Blank & Shinohara, 2005  ♀   
 17 (13) East Palearctic species............................................................................... 18   
 – West Palearctic species............................................................................... 24   
 18 (17) Ovipositor sheath 1.20–1.85 mm long, if up to 2.00 mm then Japanese species................................... 19   
 – Ovipositor sheath 1.90–2.60 mm long and species from Asian mainland........................................ 23   
 19 (18) Wings brown infuscate. Ovipositor sheath 1.80–2.00 mm long (Fig. 115). Subalpine zone of Hokkaido, Japan (Fig. 9)....................................................................  Xyela pumilae Blank & Shinohara, sp. nov.  ♀   
 – Wings clear or slightly infuscate. Ovipositor sheath usually shorter than 1.80 mm long, sometimes up to 1.95 mm (X. variegata). Species distributed below subalpine zone 20   
 20 (19) Japan. [Identification often doubtful.]................................................................... 21   
 – South Korea, expected for neighboring regions of East Asian mainland........................................ 22   
 21 (20) Fore wing (?2.30–)2.40–2.55 times longer than ovipositor sheath (Fig. 111). Japan (Honshu) (Blank et al. 2005, fig. 4).........................................................................  Xyela tecta Blank & Shinohara, 2005  ♀   
 – Fore wing 2.00–2.30(–?2.40) times longer than ovipositor sheath (Fig. 112). Japan (Honshu) (Blank et al. 2005, fig. 5)...............................................................................  Xyela variegata Rohwer, 1910  ♀   
 22 (20) Fore wing 2.10–2.40 times longer than ovipositor sheath (Fig. 106). Head yellow with dark pattern varying from pale brown to dark brown: frons brown with wide dark brown stripes along frontal furrows, dark brown medial spot, sometimes paler with medial spot surrounded by yellow (Figs 54–55), seldom frons completely dark, kidney-shaped spots on vertex usually fusing with brown pattern of frons anteriorly. South Korea (Blank et al. 2005, fig. 4).....  Xyela densiflorae Blank & Shinohara, 2005  ♀   
 – Fore wing 1.70–2.00 times longer than ovipositor sheath (Fig. 114). Frons and vertex with a large dark black to brown spot, kidney-shaped spots, stripes along frontal furrows and medial frontal spot usually not discernable (Figs 66–67). South Korea (Blank et al. 2005, fig. 5). [See Blank et al. 2005 for material from Vietnam with pale face and only with dark kidney-shaped spots and ocellar-postocellar area.]........................................  Xyela par Blank & Shinohara, 2005  ♀   
 23 (18) Valvula 3 2.15–2.25 times longer than valvifer 2, valvula 3 7.5–9.0 times longer than wide basally (Fig. 116). OOL: POL = 1.65–2.00: 1. China (Fujian, Hong Kong, Jiangsu) (Fig. 12).............................  Xyela sinicola Maa, 1947  ♀   
 – Valvula 3 2.00–2.15 times longer than valvifer 2, valvula 3 6.5–8.0 times longer than wide basally (Fig. 109). OOL: POL = 1.30–1.70(–2.00): 1. In East Palearctic eastwards to Mongolia, widely distributed in West Palearctic (Fig. 17; see also couplet 28)........................................................................  Xyela julii (Brébisson, 1818)  ♀   
 24 (17) Head dark brown or black, sometimes vertex with pale brown stripes (Figs 58, 64, 78). High montane and subalpine species (usually above 1,500 m altitude)........................................................................ 25   
 – Face usually with rich yellow pattern, sometimes predominantly yellow, at least with large yellow stripes on vertex (Figs 50–52, 60, 62, 79). Species of lowland and montane regions (usually between 0–1,000 m altitude), rarely in subalpine zone 27   
 25 (24) Vertex usually completely black, seldom with indistinct brown spots (Fig. 64). Valvula 3 1.75–2.00 times longer than valvifer 2 (Fig. 113). Fore wing 2.00–2.15 times longer than ovipositor sheath. Distance between posterior ocelli often narrow, OOL: POL = 1.60–2.10: 1. Central and eastern European Alps, westwards to Switzerland (overlapping there with X. uncinatae), neighboring low mountain ranges in Bulgaria and Slovakia (Fig. 19)...................  Xyela obscura (Strobl, 1895)  ♀   
 – Vertex usually with distinct pale brown to brown spots or stripes. Valvula 3 1.95–2.25 times longer than valvifer 2. Fore wing 1.60–2.05 times longer than ovipositor sheath. Distance between posterior ocelli often wide, OOL: POL = 1.40–1.85: 1..... 26   
 26 (25) Fore wing 1.60–1.80 times longer than ovipositor sheath. Ovipositor sheath usually longer than 2.3 mm, usually valvula 3 brown and valvifer 2 pale brown (Fig. 108). Albania, Greece (Fig. 16)................  Xyela heldreichii Blank, sp. nov.  ♀   
 – Fore wing 1.80–2.05 times longer than ovipositor sheath. Ovipositor sheath usually shorter than 2.3 mm, valvifer 2 and valvula 3 similarly colored (Fig. 117). Western Alps (France, Switzerland), Pyrenees (Andorra, Spain) (see also couplet 28; Fig. 19)..........................................................................  Xyela uncinatae Blank, sp. nov.  ♀   
 27 (24) Valvula 3 6.5–8.0 times longer than wide basally.......................................................... 28   
 – Valvula 3 4.0–6.0 times longer than wide basally.......................................................... 29   
 28 (27) Fore wing 1.60–1.90 times longer than ovipositor sheath (Fig. 109). Widely distributed from 0–1,000 m altitude in northern and central West Palearctic (occasionally at higher altitude), in Mediterranean region at 1,400–1,700 m altitude, in East Palearctic eastwards to Mongolia (see also couplet 23; Fig. 17)  Xyela julii (Brébisson, 1818)  ♀   
 – Fore wing 1.80–2.05 times longer than ovipositor sheath (Fig. 117). Pale form of X. uncinatae (see also couplet 26). Subalpine zone of western Alps (France, Switzerland) and Pyrenees (Andorra, Spain) (Fig. 19)  Xyela uncinatae Blank, sp. nov.  ♀   
 29 (27) Valvifer 2 pale brown, valvula 3 dark brown (Fig. 105). Wings slightly infuscate. Face medially diffusely pale brown up to eye margins, darker than yellow stripe on vertex between kidney-shaped spot and upper eye margin, along frontal furrows little darker brown without clearly defined stripes, brown medial spot of frons present and weakly contrasting (Fig. 50). Lateral face of posterior coxae dark brown. Male unknown. Croatia (Fig. 13)...................  Xyela altenhoferi Blank, sp. nov.  ♀   
 – Valvifer 2 and valvula 3 similarly pale brown or yellow (Figs 107, 110). Wings clear. Medial part of face similarly yellow as stripe on vertex between kidney-shaped spot and upper eye margin, face often with strongly contrasting dark brown medial spot and stripes along frontal furrows (Figs 51–52, 62). Lateral face of posterior coxae usually yellow or pale brown. Identification often doubtful 30   
 30 (29) Valvula 3 (?4.5–)4.8–5.8 times longer than wide basally, valvula 3 (?1.60–)1.70–2.00 times longer than valvifer 2, ovipositor sheath (1.45–) 1.60–1.80 mm long (Fig. 107), fore wing 1.90–2.35(–2.55?) times longer than ovipositor sheath. Northern part of Mediterranean Basin and adjacent areas, on Balkans northwards to Vienna Basin (Fig. 15).................................................................................................  Xyela graeca J.P.E.F. Stein, 1876  ♀   
 – Valvula 3 4.0–4.5(–?4.8) times longer than wide basally, valvula 3 1.35–1.70(–?1.80) times longer than valvifer 2, ovipositor sheath 1.30–1.65(–?1.70) mm long (Fig. 110), fore wing (2.25?–)2.40–2.80 times longer than ovipositor sheath. Northern part of Mediterranean Basin and adjacent areas, on Balkans northwards to Vienna Basin (Fig. 18)....................................................................................................  Xyela menelaus Benson, 1960  ♀   
 31 (1) Posterior claws without subapical tooth. Medial lobe of valviceps strongly protruding, proximal lobe 0.60–0.80 times as wide as medial lobe. Lateral lamella of valviceps distinct, strongly oblique (Figs 141–152). Face yellow or pale brown at least along eye margin, vertex with yellow stripe (e.g., Figs 53, 61), frons often more or less brown or black (e.g., Figs 57, 81) 32   
 – Posterior claws with subapical tooth (often very feeble). Proximal lobe of valviceps at least 0.90 times as wide as medial lobe, often wider than medial lobe (Figs 126–140). Lateral lamella of valviceps vertical or slightly oblique (Fig. 126–139), sometimes indistinct or absent (Figs 126–127, 140). Either face yellow with brown and black pattern (e.g., Figs 25, 29), or head predominantly dark (at least face with eye margin continuously dark, Figs 45, 47) 44   
 32 (31) East Palearctic species............................................................................... 33   
 – West Palearctic species............................................................................... 39   
 33 (32) Upper edge of proximal lobe of valviceps almost parallel to longitudinal axis of valviceps, straight or slightly concave (Figs 141, 144, 148, 150).................................................................................. 34   
 – Upper edge of proximal lobe of valviceps sloping down toward valvular stalk proximally, more or less convex (Figs 149, 152, 147).............................................................................................. 37   
 34 (33) Medial lobe of valviceps 1.10–1.25 times as wide as distal lobe (Figs 144, 148).................................. 35   
 – Medial lobe of valviceps 1.30–1.50 times as wide as distal lobe. Identification without additional geographic information often doubtful (Figs 141, 150).............................................................................. 36   
 35(34) Wings brown infuscate. Tip of longer distal filament of valviceps reaching 0.55–0.65 of width of distal lobe of valviceps (Fig. 148). Stripes along frontal furrows and medial spot of frons black. Subalpine zone of Hokkaido, Japan (Fig. 9)..........................................................................  Xyela pumilae Blank & Shinohara, sp. nov.  ♁   
 – Wings almost clear. Tip of longer distal filament of valviceps reaching 0.65–0.75 of width of distal lobe of valviceps (Fig. 144). Stripes along frontal furrows and medial spot of frons often dark brown. East Palearctic eastwards to Mongolia, widely distributed in West Palearctic (see also couplet 42; Fig. 17)  Xyela julii (Brébisson, 1818)  ♁   
 36 (34) Proximal vertical edge of medial lobe of valviceps straight or slightly concave (Fig. 150). Japan (Honshu) (Blank et al. 2005, fig. 4)  Xyela tecta Blank & Shinohara, 2005  ♁   
 – Proximal vertical edge of medial lobe of valviceps concave (Fig. 141). South Korea (Blank et al. 2005, fig. 4)...........................................................................  Xyela densiflorae Blank & Shinohara, 2005  ♁   
 37 (33) Proximal lobe of valviceps 0.18–0.22 times as long as valviceps (Fig. 149). China (Fujian, Hong Kong, Jiangsu) (Fig. 12).................................................................................  Xyela sinicola Maa, 1947  ♁   
 – Proximal lobe of valviceps 0.24–0.33 times as long as valviceps (Figs 147, 152)................................. 38   
 38 (37) Valviceps (1.30–)1.40–1.45 times longer than wide, proximal lobe 0.60–0.65 times as wide as medial lobe. Median longitudinal sclerotization of valviceps usually distinct (Fig. 152). Japan (Honshu) (Blank et al. 2005, fig. 4)..........................................................................  Xyela variegata Rohwer, 1910  ♁   
 – Valviceps 1.45–1.65 times longer than wide, proximal lobe of valviceps 0.65–0.70 times as wide as medial lobe. Median longitudinal sclerotization of valviceps usually indistinct (Fig. 147). South Korea (Blank et al. 2005, fig. 4).......................................................................................  Xyela par Blank & Shinohara, 2005  ♁   
 39 (32) Longer distal filament of valviceps 0.85–1.05 times as long as width of distal lobe of valviceps. Distal edge of medial lobe of valviceps gradually ascending (Fig. 142, 145). Lateral side of posterior coxae predominantly yellow, more or less dark at base. Face predominantly yellow, stripes along frontal furrows often inconspicuous (Figs 53, 63)........................ 40   
 – Longer distal filament of valviceps 0.55–0.75 times as long as width of distal lobe of valviceps. Distal edge of medial lobe of valviceps steeply ascending (Fig. 143–144, 146, 151). Lateral side of posterior coxae predominantly brown or dark brown. Stripes along frontal furrows usually wide and conspicuous or face predominatly brown (Figs 59, 61, 65, 81). [Species very similar in color and morphology; identification often impossible without information on collection site like altitude, geographical position, available Pinus species.]................................................................... 41   
 40 (39) Proximal lobe of valviceps with upper edge converging with longitudinal axis of valviceps, proximal edge evenly rounded. Excision of lower edge 0.16–0.22 times as deep as width of medial lobe, medial lobe 1.35–1.55 times wider than distal lobe. Distal flagella usually longer, longer flagellum reaching (0.90–)0.95–1.05 of width of distal lobe (Fig. 142). Northern part of Mediterranean Basin, northwards to Lower Austria (Fig. 15)......................  Xyela graeca J.P.E.F. Stein, 1876  ♁   
 – Proximal lobe of valviceps with upper edge almost parallel to longitudinal axis of valviceps, proximally abruptly turning down to truncate vertical edge. Excision of lower edge 0.23–0.27 times as deep as width of medial lobe, medial lobe 1.15–1.30(–1.35) times wider than distal lobe. Distal flagella usually shorter, longer flagellum reaching 0.85–0.90(–0.95) of width of distal lobe (Fig. 145). Northern part of Mediterranean Basin, northwards to Lower Austria (Fig. 18)....  Xyela menelaus Benson, 1960  ♁   
 41 (39) OOL: POL = 1: (1.30–)1.40–1.75. Altitudinal distribution from lowland to subalpine zone........................ 42   
 – OOL: POL = 1: (1.50–)1.60–1.90 and altitudinal distribution exclusively subalpine.............................. 43   
 42 (41) Synantennomere 3 640–810 µm long. Hypopygium usually yellow, paler than preceding sterna. Stripes along frontal furrows 1.0–1.5 times as wide as ocellar diameter (Fig. 59). On stands of Pinus heldreichii. Mountains of Albania and Greece above 1,500 m altitude (Fig. 16)..................................................  Xyela heldreichii Blank, sp. nov.  ♁   
 – Synantennomere 3 540–600(–650) µm long. Hypopygium usually brown to dark brown, color similar to that of preceding sterna. Stripes along frontal furrows often wide and fusing with medial spot, at least wider than 2 times ocellar diameter (Fig. 61). On stands of Pinus sylvestris. Widely distributed from 0–1,000 m altitude in northern and central West Palearctic (occasionally at higher altitude), in Mediterranean region at 1,400 –1,700 m altitude, in East Palearctic eastwards to Mongolia (see also couplet 35; Fig. 17).......................................................  Xyela julii (Brébisson, 1818)  ♁   
 43 (41) On stands of Pinus mugo. Central and eastern European Alps, westwards to Switzerland (overlapping there with X. uncinatae), mountain ranges in Bulgaria and Slovakia (Fig. 19)..................................  Xyela obscura (Strobl, 1895)  ♁   
 – On stands of Pinus uncinata. Western European Alps (France, Switzerland), Pyrenees (Fig. 19)................................................................................................  Xyela uncinatae Blank, sp. nov.  ♁   
 44 (31) Valviceps without lateral lamella (Fig. 126) or lateral lamella indistinct and oblique (Fig. 140)...................... 45   
 – Valviceps with distinct lateral lamella, vertical or slightly oblique (Figs 128–139)................................ 46   
 45 (44) Medial lobe broadly rounded, situated almost in middle of valviceps, 1.05–1.15 times wider than distal lobe. Excision of lower edge of valviceps 0.16–0.23 times as deep as width of medial lobe (Fig. 126). Lowland and mountainous regions of Europe, southwards to the Alps and neighboring mountain ranges (Fig. 20). [Unknown male of X. helvetica from subalpine zone of Austrian and Swiss Alps (Fig. 19) possibly similar.].................................  Xyela longula Dalman, 1819  ♁   
 – Medial lobe roundly protruding, situated in proximal quarter of valviceps, 1.60–1.65 times wider than distal lobe. Excision of lower edge of valviceps 0.30 –0.31 times as deep as width of medial lobe (Fig. 140). Northeastern China (Jilin), Russian Far East (Primorskiy Kray), South Korea (Fig. 22).......................  Xyela rasnitsyni Blank & Shinohara, sp. nov.  ♁   
 46 (44) Dorsal edge of proximal lobe of valviceps strongly curved, proximal section more or less concave (Figs 128–135). Proximal lobe often wider than medial lobe. Lateral lamella usually narrow (seldom as wide as in Figs 128), proximal and distal weakly edge s-shaped...................................................................................... 47   
 – Dorsal edge of proximal lobe of valviceps weakly curved, evenly concave throughout (Figs 136–139). Proximal lobe of valviceps usually narrower, at most as wide as medial lobe. Lateral lamella of valviceps wide, proximal edge convex and distal base concave........................................................................................... 54   
 47(46) Article 3 of maxillary palp 1.15 times as long as scape. Proximal lobe of valviceps 0.90 times as wide as medial lobe (Fig. 128). Medial lobe with 28–30 cone-like sensillae. France, Hungary (Fig. 21).......  Xyela lugdunensis (Berland, 1943)  ♁   
 – Article 3 of maxillary palp 1.25–1.65 times as long as scape. Proximal lobe of valviceps 0.95–1.10 times as wide as medial lobe (Figs 129–135). Medial lobe with 8–30 cone-like sensillae (only 8–15 sensillae in specimens with article 3 of maxillary palp 1.25–1.30 times as long as scape).................................................................. 48   
 48 (47) Excision of lower edge of valviceps ca 0.27 as deep as width of medial lobe. Medial lobe ca 1.25 times wider than distal lobe and tip of longer distal filament reaching ca 0.95 of width of distal lobe (Fig. 135). Taiwan (Fig. 12)........................................................................................  Xyela meridionalis Shinohara, 1983  ♁   
 – Excision of lower edge of valviceps 0.11–0.23 as deep as width of medial lobe. Medial lobe at least 1.30 times (usually 1.50–1.75 times) wider than distal lobe or tip of longer distal filament reaching at most 0.90 of width of distal lobe (Figs 129–134).... 49   
 49 (48) Wings slightly infuscate. Medial lobe of valviceps 1.50–1.75 times wider than distal lobe (Figs 129–130, 132–133)..... 50   
 – Wings clear. Medial lobe of valviceps 1.25–1.45 times wider than distal lobe (Figs 131, 134)....................... 53   
 50 (49) Stripes along frontal furrows in middle at most as wide as ocellar diameter, often fading (Figs 29, 35). West Palearctic species.................................................................................................. 51   
 – Stripes along frontal furrows in middle at least 2 times wider than ocellar diameter, sometimes frons predominantly black (Figs 31, 37). East Palearctic species........................................................................ 52   
 51 (50) Valviceps 1.45–1.50 times longer than wide, medial lobe with 22–30 cone-like sensilla (Figs 3, 129). Stripes along frontal furrows often fading (Fig. 29). Subalpine zone of Austria, Germany, Switzerland (Fig. 8)  Xyela alpigena (Strobl, 1895)  ♁   
 – Valviceps 1.55–1.60 times longer than wide, medial lobe with 14–15 cone-like sensilla (Figs 132). Stripes along frontal furrows continuous (Fig. 35). Mountains of Bulgaria (Fig. 8)  Xyela peuce Blank, sp. nov.  ♁   
 52 (50) Valviceps 1.30–1.40 times longer than wide, medial lobe 1.70–1.75 times wider than distal lobe, proximal lobe 0.19–0.23 times as long as valviceps (Figs 130). Mesoscutellum black. Article 3 of maxillary palp yellow, proximal half more or less infuscate. Eastern East Palearctic: subalpine zone of Japan (Hokkaido, Honshu), Russia (Kamchatka) (Fig. 9)...................................................................  Xyela kamtshatica Gussakovskij, 1935  ♁   
 – Valviceps 1.45–1.50 times longer than wide, medial lobe 1.50–1.55 times wider than distal lobe, proximal lobe 0.14–0.15 times as long as valviceps (Fig. 133). Mesoscutellum with large yellow spot. Article 3 of maxillary palp yellow or pale brown. Central East Palearctic (possibly also in western part): Russia (Irkutskaya Obast), Mongolia (Hentiyn Nuruu) (Fig. 9)...............................................................................  Xyela sibiricae Blank, sp. nov.  ♁   
 53 (49) Hypopygium as dark brown as other sterna, seldom a little paler. Medial lobe of valviceps 1.40–1.45 times as wide as distal lobe (Fig. 131). Eastern East Palearctic: Russian Far East (Primorskiy Kray), South Korea (Fig. 10).................................................................................  Xyela koraiensis Blank & Shinohara, sp. nov.  ♁   
 – Hypopygium pale brown to yellow, preceding sterna significantly darker. Medial lobe of valviceps 1.30–1.40 times as wide as distal lobe (Fig. 134). Eastern East Palearctic: Russian Far East (Primorskiy Kray), South Korea (Fig. 10)......................................................................................  Xyela ussuriensis Rasnitsyn, 1965  ♁   
 54 (46) Pale colored species: head yellow with pale brown to black pattern (Fig. 43).................................... 55   
 – Predominantly dark colored species: head black or brown with dark brown to black pattern (Figs 45, 47).............. 56   
 55 (54) Lower edge of valviceps with evenly rounded excision, excision 0.15–0.21 times as deep as width of valviceps (Fig. 136). European part of Mediterranean area, central and western Europe, Turkey (Fig. 11)..........  Xyela curva Benson, 1938  ♁   
 – Lower edge of valviceps with triangular excision, excision 0.30–0.33 times as deep as width of valviceps (Fig. 137). China (Fujian, Hong Kong) (Fig. 12)..................................................  Xyela exilicornis Maa, 1949  ♁   
 56 (54) Valviceps 1.45–1.50 times longer than wide, proximal lobe 0.20–0.22 times as long as valviceps (Fig. 138). Japan (Honshu) (Blank et al. 2005, fig. 3)  Xyela japonica Rohwer, 1910  ♁   
 – Valviceps 1.55–1.70 times longer than wide, proximal lobe (0.22–)0.25–0.30 times as long as valviceps (Fig. 139). East Asian mainland: northeastern China (Jilin), South Korea (Blank et al. 2005, fig. 3)...  Xyela occidentalis Blank & Shinohara, 2005  ♁   Species accounts  
 The following sections present detailed descriptions of morphology, nomenclature and ecology of the Eurasian Xyela species. Xyela densiflorae, X. par, X. tecta, X. variegata (members of the julii group) and X. japonica and X. occidentalis (curva group) from China (Jilin), Japan (Honshu) and South Korea have been treated by Blank et al. (2005) and only short summaries are included here. The host plant relationships for all Xyela species have been summarized in Tab. 2 on page 65.
description: Published as part of Blank, Stephan M., Shinohara, Akihiko & Altenhofer, Ewald, 2013,  The Eurasian species of  Xyela  (Hymenoptera, Xyelidae): taxonomy, host plants and distribution , pp. 1-106 in Zootaxa 3629 (1) on pages 13-18, DOI: 10.11646/zootaxa.3629.1.1, http://zenodo.org/record/5261330