Xyela uncinatae Blank, 2013

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 : 52-54

Xyela uncinatae Blank , sp. nov.

Type locality: France, Alpes-de-Haute-Provence, Thorame-Haute .

Xyela obscura: Blank 2002: 208 , 227 (partly misidentified).

Description. Female. Color. Head predominantly dark, darkest specimens with head completely brown ( Fig. 78 ), in pale specimens face yellow along eye, on vertex and between postocellar area and kidney-shaped spot ( Fig. 79 ). Antenna brown dorsally and pale brown ventrally. Thorax dorsally brown, lateral mesonotal lobe, mesoscutellum and tegulae more or less pale. Mesepisternum largely pale brown. Abdomen brown, tergum 9+10 laterally and preapical sterna pale brown to yellow. Ovipositor sheath yellow, tip of valvula 3 infuscate preapically ( Fig. 117 ). Legs pale brown, coxae brown, femora more or less darkened on the upper side, distal tarsomeres darkened. Wings hyaline to little brown, venation pale.

Morphology. Fore wing 3.8–4.6 mm long, 1.80–2.05 times longer than ovipositor sheath, vein Rs+M 150–300 µm long, 2r-m meeting Rs proximal to furcation of Rs1 and Rs2. Synantennomere 3 590–760 µm long, antennomere 4 130–180 µm long and 3.5–4.5 times longer than wide distally. Article 3 of maxillary palp 450–540 µm long, (1.45–)1.55–1.75 times longer than scape and wider than synantennomere 3. OOL: POL = 1.40–1.75: 1. Ovipositor sheath (1.85–) 1.95–2.25 mm long, valvula 3 1.95–2.25 times longer than valvifer 2 and 6.5–8.0 times longer than wide at base ( Fig. 117 ). Valvula 3 of ovipositor compressed, pale membranous area about as long as basal width of valvula 3, dorsal edge of valvula 3 sloping down to round tip, distally with sensilla field exposed and directed caudally, bearing 3 setae. Ovipositor almost straight and compressed. Valvula 1 with aulax terminating distally, ventral edge sloping up to tip, with 13–14 oblique closely spaced annuli in distal quarter, without serrulae, olistether with 4–5 setae. Left and right valvulae 2 fused along dorsal edge in basal half. Valvula 2 with smooth dorsal margin, tapering in distal half, pale and evenly sclerotized, in distal 0.4 with single scattered sensilla campaniformia, in distal 0.05 with 5 indistinct oblique annuli. Posterior tibia 0.90–1,05 mm long, claws without subapical tooth.

Male. Color. Head yellow with black and brown pattern: frontal furrows at least with wide stripes meeting ocellar and postocellar spot and medial spot of frons present, kidney-shaped spots on vertex separate from black postocellar area in pale specimens but usually fused with frontal stripes anteriorly, often dark pattern fusing to a large dark brown or black spot ( Figs 80–81 ). Antennae pale brown. Thorax dorsally black, pronotum, mesonotal lobes and mesoscutellum sometimes pale brown, tegulae pale and brown in middle, mesepisternum largely pale brown. Abdomen including hypopygium brown. Legs pale brown, posterior coxae laterally brown, ventrally brown or more or less pale in distal half. Wing membrane almost hyaline, venation and pterostigma pale brown.

Morphology. Fore wing length 3.2–4.0 mm, 2r-m meeting Rs proximal to furcation of Rs1 and Rs2. Synantennomere 3 (520–)610–780 µm, antennomere 4 140–180 µm and 4.0–5.0 times longer than wide. Article 3 of maxillary palp 360–490 µm long, 1.30–1.50 times longer than scape and wider than synantennomere 3. OOL: POL = (1.50–)1.60–1.90: 1. Longitudinal apodeme of basiparamere curved, basal portion in lateral position, harpe about as long as wide in lateral view. Lower ergot on valvular stalk absent. Valviceps 1.45–1.65 times longer than wide on medial lobe, with distinct oblique lateral lamella, proximal lobe of penis valve 0.22–0.26 times as long as valviceps and 0.70–0.80 times as high as medial lobe, excision of lower edge 0.22–0.24 as deep as width of medial lobe, valviceps on medial lobe 1.15–1.20 times wider than on distal lobe, 2 distal flagella present, tip of longer flagellum reaching 0.55–0.70 width of distal lobe ( Fig. 151 ). Valviceps with median longitudinal sclerotization present, medial lobe almost symmetric and broad, with 5–9 cone-like sensilla along upper edge and scattered on lateral surface, upper edge between medial and distal lobe with 7–11 setae. Posterior tibia 0.75–0.90 mm long, claws without subapical tooth.

Type material. Holotype ♀: “F-04-Alpes H. P. [ France, Alpes-de Haute Provence], Thorame Haut , 28-V- [19]95, Noblecourt Rec [leg. T. Noblecourt]”; “ Xyela julii ♀ Noblecourt det: 95”; [red:] “Holotype ♀ Xyela uncinatae spec. nov. det. S. M. Blank 2000”. The holotype is a pale specimen (see below for variability). DEI . Paratypes: 37♀ 20♂, DEI, JLC, MNHN, MHNN, MZLS, MZLU, RMNH, TNC .

Etymology. The species name, a noun in genitive singular, has been chosen in accordance with the supposed host plant, Pinus uncinata .

Host plant. Ο Pinus uncinata Ramond.

Geographic distribution. Andorra, France, Spain, Switzerland ( Fig. 19 ).

Remarks. Xyela uncinatae is most similar to X. obscura in coloration, in ovipositor sheath morphology, and in the closely spaced posterior ocelli. In females the head is predominantly black or dark brown, but usually the vertex bears more or less distinct pale stripes in X. uncinatae , which are mostly absent or at least indistinct in X. heldreichii and X. obscura . The pale pattern of the head varies considerably in X. uncinatae: Among 25 females 4 have continuous yellow or pale brown stripes on the face along the eyes (pale form similar to julii ; see couplet 29 in the key), 10 have obvious brown stripes on the vertex (similar to pale X. obscura ), and 11 have the head completely dark brown (similar to dark X. obscura ). Morphological characters of the females overlap, but they are statistically different (U-test, n obscura = 13, n uncinatae = 16). On average the ovipositor is longer (U = 28, α <0.001), the relative length of valvula 3: valvifer 2 smaller (U = 20, α <0.001), and the relative length of fore wing: ovipositor larger (U = 54.5, α <0.05) in X. uncinatae than in X. obscura .

Male X. obscura and X. uncinatae resemble X. julii in the dark hypopygium. About 85–90 % will be distinguished from the latter by the closely spaced posterior ocelli. However, males of X. obscura and X. uncinatae cannot definitely be distinguished from each other. Males of X. uncinatae were associated with females using series collected by net and in Malaise traps in Thorame Haute, since this was the only female Xyela species found on this site.

Xyela uncinatae has not yet been reared, but the circumstances of collecting unequivocally indicate Pinus uncinata as the larval host plant. The French specimens were swept at ca 2,000 m altitude from cut grass below P. uncinata at the edge of a wood, which consisted only of this pine species and of larch (T. Noblecourt, personal communication). Other pine species can be excluded as host plants with high likelihood. Pinus mugo is almost absent from the Hautes-Alpes, and P. sylvestris is mostly restricted to warm places at lower altitude ( Chas 1994, Kindel 1995). In the Pyrenees P. mugo is absent, however, here P. sylvestris may be present in the subalpine zone ( Dupias 1987 a, Kindel 1995, Babéro et al. 1998).

There has been a long lasting controversial discussion about taxonomy and nomenclature of P. mugo , P. uncinata and P. rotundata . There is still no consensus on the treatment of mugo (krummholz, small seed cones with narrow apophyses) and uncinata (tree-shaped, large seed cones with prominent, hooked apophyses) as subspecies or two separate species. The two taxa hybridize extensively, giving the hybrid subspecies P. x rotundata . For practical reason mugo and uncinata are treated as species throughout this work following the taxonomic opinion and nomenclature presented by Earle (2011). Pinus uncinata is distributed in the western Alps, the Jura mountain range of Switzerland, the Pyrenees and the Spanish Sierra de Javalambre ( Meusel et al. 1965, Kindel 1995), although published data on the natural eastern distribution limit still differ among recent authors perhaps due to taxonomic problems ( Barbéro et al. 1998: fig. 8.8; Willis et al. 1998: fig. 5.1). It forms the montane to subalpine woodland in the western Alps at 1,200 –2,550 m and in the Pyrenees at 1,500 –2,000 m preferably on rocky places with limestone ( Chas 1994, Dupias 1987b, Kindel 1995, Lauber & Wagner 1998). Such a western distribution can also be demonstrated for Xyela uncinatae , which overlaps with the Eastern X. obscura in Switzerland.

Figures

FIGURE 19. Records of three West Palearctic, subalpine Xyela species, X. helvetica (2 specimens from 2 collection sites), X. obscura (221 specimens from 30 collection sites) and X. uncinatae (48 specimens from 9 collection sites) and natural distribution of the (supposed) host plants, Pinus mugo (solid line) and P. uncinata (dashed line, distribution of both pines according to Meusel et al. 1965). The distribution ranges of these pine species overlap in the Alps (see text). Additional literature record included for X. obscura from the Ukraine (Zombori & Ermolenko 1999).

FIGURES 66–85. Color pattern of head of Xyela species: X. julii group (part). Legend: HT—holotype; PT—paratype.

FIGURES 105–120. Ovipositor sheaths of Xyela species. All figures at same scale. Legend: HT—holotype; NT—neotype; PT—paratype.

FIGURES 146–156. Penis valves of Xyela species (X. julii group, part), and male external copulatory apparatus of Xyela in ventral and lateral view. 153–154, X. longula (penis valves removed). 155–156, X. curva (penis valves and volsellae removed). Legend: bpa—basiparamere, br—basal ring, gon—gonomacula, har—harpe, lap—lateral apodeme, vol—volsella. Figs 147, 150 and 152 reproduced from Blank et al. (2005).