Xyela lugdunensis ( Berland, 1943 )

Blank, Stephan M., Shinohara, Akihiko & Altenhofer, Ewald, 2013, <strong> The Eurasian species of <em> Xyela </ em> (Hymenoptera, Xyelidae): taxonomy, host plants and distribution </ strong>, Zootaxa 3629 (1), pp. 1-106 : 58-61

Xyela lugdunensis ( Berland, 1943)

Xyelatana lugdunensis Berland, 1943: 90–91 , ♀, type locality: France, Lyon .

Xyela lugdunensis: Rasnitsyn 1965: 492 , 514 (combination with Xyela ).

Xyela nigroabscondita Haris & Gyurkovics, 2011: 140–141 , ♂, type locality: Hungary, Szeged, Újszeged, Népliget; syn. nov. Xyela curva: Chevin & Tussac 1992: 62 (misidentification).

Description. Female. Color. Head yellow with black and brown pattern: two dark brown to black stripes along the frontal furrows 2.0–3.5 times as wide as ocellar diameter, meeting black ocellar and postocellar area, black longitudinal spot in middle of frons present, isolated or fusing dorsally; kidney-shaped spots on vertex separate from or fusing with black postocellar area ( Fig. 26 ). Antennae brown, a little paler below. Thorax dorsally brown or black, more or less with pale pattern on pronotum, mesonotal lobes and mesoscutellum. Tegulae pale and infuscate in middle, mesepisternum largely pale brown. Abdominal terga brown to black, lateral parts of terga 8 and 9+10 partly paler, valvifer 2 and valvula 3 brown or black, membrane between valvifer 2 and valvula 3 pale, valvula 3 sometimes with small pale ventral margin up to the preapical portion ( Figs 88 , 96 ). Legs brown to dark brown, femora with more or less distinct longitudinal dark stripes, posterior coxae dark brown with distal 0.3–0.5 of the ventral side pale. Wing membrane, venation and pterostigma brownish infuscate.

Morphology. Fore wing 4.9–5.4 mm long, 1.50–1.65 times longer than ovipositor sheath, vein 1r-m usually present and 20–140 µm long ( Fig. 5 ; one specimen with 130 µm long vein Rs+M on right wing), position of 2r-m variably proximal or distal with respect to the furcation of Rs. Synantennomere 3 1.00– 1.13 mm long, antennomere 4 290–330 µm long and 8.5–10.0 times longer than wide distally. Article 3 of maxillary palp 440–480 µm long, 1.10–1.25 times longer than scape and about as wide as synantennomere 3. OOL: POL = 1.85–2.00: 1. Ovipositor sheath 3.10–3.40 mm long, valvula 3 2.35–2.50 times longer than valvifer 2 and 10.0–11.0 times longer than wide at base ( Figs 88 , 96 ). Valvula 3 of ovipositor sheath diamond-shaped in cross section, pale membranous area triangular in basal 0.2 of valvula 3, sometimes extending up to preapical region as narrow ventral pale margin, valvula parallel-sided in the middle, in distal 0.1 dorsal and ventral edge narrowing to round tip, tip with a defined sensilla field directed laterally and bearing 5–6 setae. Ovipositor slightly curved downwards. Valvula 1 of ovipositor compressed, aulax terminating almost at tip, dorsal edge sloping down and ventral edge sloping up to tip, distal 0.1 more sclerotized, with 8–10 wide-spaced annuli (basal oblique and distal 3–4 perpendicular), ventral edge with ca 4 shallow serrulae, olistether with 7–8 setae. Left and right valvulae 2 fused along dorsal edge up to distal 0.1. Valvula 2 almost parallel-sided, medial and preapical part with ca 6 shallow, regularly spaced prominences bearing 1–2 sensilla campaniformia each (similar to alpigena but less sclerotized), in distal 0.1 with smooth dorsal margin evenly tapering toward tip and with ca 9 oblique annuli. Posterior tibia 1.15–1.25 mm long, all claws with delicate subapical tooth.

Male. Color. Similar to dark female specimens. Face and vertex predominantly dark brown to black ( Fig. 27 ). Dorsal side of thorax black. Hypopygium yellow.

Morphology. Fore wing 4.7 mm long, 1r-m 60–80 µm long. Synantennomere 3 1000 µm long, antennomere 4 350 µm long and 10.5 times longer than wide distally. Article 3 of maxillary palp 450 µm long, ca 1.15 times longer than scape and about as wide as synantennomere 3. OOL: POL = 1.90: 1. Longitudinal apodeme of basiparamere curved, basal portion in lateral position, harpe ca 0.90 times as long as wide in lateral view. Lower ergot on valvular stalk present, small. Valviceps 1.40–1.45 times longer than wide on medial lobe, lateral lamella slightly oblique with proximal edge convex and distal base weakly s-shaped, proximal lobe of penis valve 0.30–0.35 times as long as valviceps and 0.90 times as high as medial lobe, excision on lower edge asymmetric, 0.10–0.15 as deep as width of medial lobe, valviceps on medial lobe 1.40 times wider than on distal lobe, 2 distal flagella present, tip of longer flagellum reaching 0.85 width of distal lobe ( Fig. 128 ). Valviceps without median longitudinal sclerotization, medial lobe evenly rounded, with 28–30 cone-like sensilla mainly along proximal to distal upper edge, upper edge between medial and distal lobe with numerous setae. Posterior tibia ca 1.15 mm long, all claws with delicate subapical tooth.

Type material. Holotype ♀: “ Lyon ”; “Museum Paris Coll. J. de Gaulle 1919”; “ Xyela Julii Bréb. ”; “ Xyelatana lugdunensis Berl. L. Berland det. 1943”; [red letters:] “Type”; [red:] “Holotypus ♀ Xyelatana lugdunensis Berland, 1943 det. S. M. Blank 1999”; “ Xyela lugdunensis ( Berland, 1943) ♀ det. S. M. Blank 1999”. Left anterior leg and right flagellum missing. MNHN .

Xyela nigroabscondita . Holotype ♀: “A”; “Szeget: Népliget”; “ 2011 III. 14 Gyurkovics H.”; [label with red frame:] “ Holotypus sp. n. ♀ Xyela nigroabscondita Haris & Gyurkovics ”; “ Xyela lugdunensis ( Berland, 1943) det. S.M. Blank 2012”. Tips of antennal filaments broken, fragments glued to cardboard label. SCMK . Paratypes: 1♀ 1♂ HNHM (studied) , 1♀ 1♂ SCMK .

Host plant. Ο Pinus nigra Arn.

Geographic distribution. France, Hungary ( Fig. 121 ).

Remarks. Among the European taxa, Xyela lugdunensis is distinguished from the similar X. alpigena by shorter maxillary palps (article 3 1.10–1.25 times longer than scape in lugdunensis / 1.70–1.80 in X. alpigena females, 1.40–1.50 in males) and longer ovipositor (fore wing 1.60–1.65 times longer than ovipositor / 1.90–2.05). The penis valve of the male is similar to that of X. meridionalis and of members of the X. alpigena group. Most of these species have the proximal lobe of the valviceps 0.95–1.10 times wider than the medial lobe (0.90 in X. lugdunensis ) except for X. peuce , but which has 14–15 cone-like sensilla on the medial lobe (28–30). Members of the X. alpigena group have the medial lobe of the valviceps 1.50–1.75 timed wider than the distal lobe (1.40 in X. lugdunensis ) except for X. ussuriensis (1.30–1.40) in which the proximal lobe is 1.00-1.05 times as wide as the medial lobe (0.90 in X. lugdunensis ). Penis valves of species associated with the X. curva group have a similarly wide lateral lamella, but the distal edge is concave (weakly s-shaped in X. lugdungensis ), and the proximal lobe of the valviceps is evenly rounded (roundly bulging and proximally descending). Blank (2002), who had only the female X. lugdunensis holotype on hand, tentatively placed the species in the X. alpigena group because of similar structure of the ovipositor sheath. Now the preparation and mounting of valvula 2 of the ovipositor sheath has revealed that it is not wedge-shaped like in the X. alpigena group, but medially parallel-sided and narrowing to the tip in the distal 0.1. This was not apparent from the dry specimen.

The sexes have been associated with help of the type series of X. nigroabscondita from Hungary. Haris & Gyurkovics (2011) observed copulations among these specimens. Additional support comes from the comparatively short maxillary palps, extensive dark pattern of the frons strongly contrasting with the yellow color, and the infuscate wings.

Judging from the holotype and two paratypes of X. nigroabscondita and the few specimens from France including the holotype of X. lugdunensis studied here, these two taxa are synonyms. Morphometric features of the specimens from Hungary fall within or immediately adjoin the variability range of specimens collected in France. For example, the relative length of maxillary palpomere 3 is 1.10–1.20 times longer than the scape in specimens from France and 1.20–1.25 in specimens from Hungary (1.26–1.42 according to Haris & Gyurkovics 2011). The holotype of X. lugdunensis was collected in 1919 and has faded brown, which explains differences in the color of the ovipositor sheath and the wings, which are respectively predominantly black and grey in more fresh specimens. However, the black pattern of the Hungarian specimens is generally more extensive. Haris & Gyurkovics (2011) stated the “anterior mesonotal lobes [are] without any spot”, but actually the holotype has large spots on these lobes and on the mesoscutellum, and a paratype female inconspicuous spots on the mesonotal lobes. The “white triangular-shaped spot on [the] base of valvula 3 ( Fig. 6 ) is a characteristic feature of the new species [ X. nigroabscondita ]” according to Haris & Gyurkovics (2011), but actually a similar white spot is present in X. alpigena and other species of the associated species group. Haris & Gyurkovics (2011) stated that the “total length of [the] body with valvula 3: total length without valvula 3 is 1.54 max. 1.56 (54–56%) in the new species [ X. nigroabscondita ], but 1.95 in Xyela lugdunensis (95%!)”. Morphometric comparison with the body length has turned out as an unreliable character in other Xyela species due to variable inclination of head and prothorax and due to shrinking. The absolute length of valvula 3 is similar among French (2.20–2.35 mm) and Hungarian specimens (2.40 µm) as well as the relative length of the fore wing compared to the ovipositor length (1.55–1.65: 1 / 1.50–1.55: 1). Minute differences in the shape and inflection of the ovipositor sheath between X. nigroabscondita (figs 4, 6 in Haris & Gyurkovics 2011) and X. lugdunensis (figs 3, 5) cannot be followed, since they may depend on different shrinkage of mounted specimens with dehiscent (holotype of X. lugdunensis ) or closed ovipositor sheath (holotype of X. nigroabscondita ). Haris & Gyurkovics (2011) stated that “RS+M vein [is] missing in the new species [ X. nigroabscondita ] ( Fig. 4 and 12 )” and that “it is true for all 5 specimens (males and females).” Actually in the holotype veins Rs+M / Rs / M are practically interstitial on the right side, and a female paratype has a 40 µm long Rs+M on the left and a 130 µm long 1r-m on the right fore wing. In specimens from France a more or less long vein 1r-m is present. In females the position of vein 2r-m with respect to the furcation of vein Rs1 and Rs2 from Rs is variable and not suitable to distinguish X. lugdunensis and X. nigroabscondita . In the holotype of X. lugdunensis and a female from Ecully 2r-m meets Rs2 0–65 µm beyond the furcation (asymmetric in both specimens and not “interstitial” as stated by Haris & Gyurkovics 2011 for the holotype of X. lugdunensis ), in the holotype of X. nigroabscondita 90–130 µm beyond, and in a female paratype of X. nigroabscondita 210–260 µm before the furcation. Left and right wing of a second female from Ecully is asymetric in this respect (left: 60 µm before, right: 130 µm beyond). In the single male the of 2r-m fusion is 60–80 µm before the furcation.

Although all known specimens of X. lugdunensis were collected outside the native distribution range of Pinus nigra ( Fig. 21 ), circumstances of collection indicate this pine species to be the host plant. General presence of P. nigra in the Hungarian plain is also indicated by the occurrence of X. curva , X. graeca and X. menelaus there ( Figs 11 , 15 , 18 ). The type series of X. nigroabscondita was collected “on the ground amongst leaf-litter and fallen twigs” below “some isolated black pine trees ( Pinus nigra )” in the city park of Szeged ( Haris & Gyurkovics 2011). The specimen recorded by Chevin & Tussac (1992) was collected in a yellow pan trap ca 10 m distant from a small P. nigra wood (H. Tussac, personal communication). This pine is also demonstrably present in Ecully, where two female X. lugdunensis and two female X. curva were collected. Larvae of X. curva are known to be associated with P. nigra as the host.

A female from Cabrerets was misidentified as X. curva by Chevin & Tussac (1992). In France X. lugdunensis appears to have only a small distribution range, as the specimens were collected at most ca 300 km apart from each other in the environs of the Massif Central. The recent record from Szeged in Hungary has been a surprise and raises the question, why X. lugdunensis has been observed so seldom, while the putative host, Pinus nigra , has a wide distribution and was studied extensively in the course of our work.

Together with the Nearctic X. linsleyi Burdick, 1961 and X. styrax Burdick, 1961 , Rasnitsyn (1965) placed X. lugdunensis in his X. linsleyi group. His view cannot be confirmed, because the characters presented do not include unequivocally derived states for such an association: the lack of serrulae on valvula 2 of the ovipositor is the ground plan condition of Xyela ; a short article 3 of the maxillary palp, narrowly rounded tip of valvula 3, and curved ovipositor are of minor weight, because they occur homoplastically in other species groups, too.

Figures

FIGURE 11. Records of Xyela curva (480 specimens from 67 collection sites) and natural distribution of the host plant, Pinus nigra (solid line, combined from Meusel et al. 1965 and Barbéro et al. 1998). Additional record included for Sicily (Turrisi 2007).

FIGURE 12. Records of Chinese and Taiwanese Xyela species, X. exilicornis (5 specimens from 2 collection sites), X. meridionalis (4 specimens from 1 collection site) and X. sinicola (10 specimens from 4 collection sites), and natural distribution of their supposed host plants, Pinus massoniana (solid line, according to Kindel (1995) and P. morrisonicola (dashed line, according to Mirov 1967).

FIGURE 15. Records of Xyela graeca (553 specimens from 53 collection sites) and natural distribution of the host plant, Pinus nigra (solid line, combined from Meusel et al. 1965 and Barbéro et al. 1998).

FIGURE 18. Records of Xyela menelaus (311 specimens from 20 collection sites) and natural distribution of the host plant, Pinus nigra (solid line, combined from Meusel et al. 1965 and Barbéro et al. 1998).

FIGURE 21. Records of Xyela lugdunensis (7 specimens from 4 collection sites) and natural distribution of the supposed host plant, Pinus nigra (solid line, combined from Meusel et al. 1965 and Barbéro et al. 1998).

FIGURES 24–41. Color pattern of head of Xyela species: X. longula group, X. lugdunensis group, X. alpigena group, X. meridionalis group. Legend: HT—holotype; LT—lectotype; PT—paratype. Legend for Fig. 25: kss—kidney-shaped spot; mfs—medial frontal spot; sff—stripe along frontal furrow.

FIGURES 86–94. Ovipositor sheath, sensilla pattern and sensilla plate (spl) at the apex of the ovipositor sheath. 86, Xyela helvetica. 87, X. longula, arrows indicate the modified hairs at apex of valvula 1. 88, X. lugdunensis. 89, X. meridionalis. 90–91, X. alpigena. 92–93, X. curva. 94, X. densiflorae.

FIGURES 95–104. Ovipositor sheaths of Xyela species. All figures at same scale. Legend: HT—holotype; PT—paratype.

FIGURES 2–5. Measurements and terminology of wing venation (see explanations on pp. 8–10). 2, Xyela rasnitsyni (paratype), ovipositor sheath (embedded in glycerine and therefore valvula 3 a little wider compared to dry, pinned specimens). 3, X. alpigena, penis valve. 4, X. curva, wings. 5, X. lugdunensis (paratype of X. nigroabscondita), fore wing.

FIGURES 126–135. Penis valves of Xyela species: X. longula groups, X. lugdunensis group, X. alpigena group, X. meridionalis group. 127, tentatively identified male of from Tence (France: Auvergne, MNHN), see text. 128, paratype of X. nigroabscondita.

FIGURES 121–125. Distal section of ovipositors. 121, Xyela longula. 122, X. alpigena. 123, X. occidentalis (paratype). 124, X. curva. 125, X. rasnitsyni (paratype). Arrowheads in Figs 123–124 indicate preapical small tooth on dorsal edge of valvula 1.

FIGURES 6–7. Habitus of Xyela. 6, X. curva, female. 7, X. meridionalis, male.