Xyela peuce 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 : 25-26

Xyela peuce Blank , sp. nov.

Type locality: Bulgaria, Pirin Mountains , environs of Begovica mountain refuge.

Xyela alpigena: Taeger 1987: 1 (misidentification); Blank 2002: 214 (partly misidentified).

Description. Female. Color. Head yellow with black pattern: two black stripes along supraantennal furrows 2–4 times wider than ocellar diameter, meeting black ocellar and postocellar area and black longitudinal spot in middle of frons always present; kidney-shaped spots on vertex often separated by small yellow gap from stripes along supraantennal furrows ( Fig. 34 ), sometimes fusing with stripes. Antennae black, brown below. Thorax dorsally black, usually more or less brown or yellow on pronotum, mesonotal lobes and mesoscutellum, tegulae pale and infuscate in middle, mesepisternum largely pale brown to yellow. Abdominal terga dark brown, lateral parts of terga 8 and 9+10 paler and 2 preapical sterna more or less pale brown, valvifer 2 pale brown basally and dark distally, membrane between valvifer 2 and valvula 3 white, valvula 3 black with small white ventral margin extending up to preapical region ( Fig. 100 ). Legs pale brown, femora usually with infuscate longitudinal stripes, posterior coxae dark brown (sometimes pale brown) with distal 0.3–0.5 pale ventrally. Wing membrane slightly infuscate, venation and pterostigma pale brown.

Morphology. Fore wing 3.9–4.8 mm long, 1.85–2.00 times longer than ovipositor sheath, vein Rs+M 0–100 µm long, 2r-m meeting Rs proximal to furcation of Rs1 and Rs2, seldom fusing with Rs2 0–50 µm distal of furcation. Synantennomere 3 600–860 µm long, antennomere 4 200–250 µm long and 5.5–7.0 times longer than wide distally. Article 3 of maxillary palp 490–600 µm long, 1.55–1.80 times longer than scape and distinctly wider than synantennomere 3. OOL: POL = 1.75–2.10: 1. Ovipositor sheath 2.15–2.50 mm long, valvula 3 (1.90–)1.95–2.20 times longer than valvifer 2 and 7.5–8.5 times longer than wide at base ( Fig. 100 ). Valvula 3 of ovipositor sheath wedge-shaped, in distal third diamond-shaped in cross section, pale membranous area distally extending up to preapical region as small ventral pale margin, valvula 3 distally narrowing to small round tip, distally with sensilla field directed caudally, bearing about 8 setae. Ovipositor indistinctly bent downwards. Valvula 1 of ovipositor compressed, aulax terminating preapically, ventral edge sloping up to tip, with 4 vertical and 2–3 oblique annuli in distal 0.05 of ovipositor length, 4 serrulae, olistether with about 4 setae. Valvula 2 evenly tapering toward tip, distally with about 5 teeth, in preapical 0.6 with irregularly spaced groups of sensilla campaniformia surrounded by dense sclerotization protruding roundly from dorsal edge of valvula 2. Posterior tibia 0.90–1.10 mm long, all claws with delicate subapical tooth.

Male. Color. Dark pattern less extensive, e.g., stripes along frontal furrows only little wider than diameter of ocellus ( Fig. 35 ), scape, pedicel and synantennomere 3 pale brown, posterior coxae predominantly pale, hypopygium completely and preceding sterna more or less pale.

Morphology. Fore wing 3.9–4.0 mm long, Rs+M 60–100 µm long, 2r-m meeting Rs proximal to furcation of Rs1 and Rs2. Synantennomere 3 740–810 µm long, antennomere 4 250–300 µm long and 6.5–8.5 times longer than wide distally. Article 3 of maxillary palp 480–490 µm long, 1.50–1.65 times longer than scape and distinctly wider than synantennomere 3. OOL: POL = 1.70–1.80: 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 present. Valviceps 1.55–1.60 times longer than wide on medial lobe, lateral lamella vertical with proximal and distal edge s-shaped, proximal lobe of penis valve 0.20–0.21 times as long as valviceps and 0.90–1.00 times as high as medial lobe, excision on lower edge 0.11–0.12 as deep as width of medial lobe, valviceps on medial lobe 1.65–1.75 times wider than on distal lobe, 2 distal flagella present, tip of longer flagellum reaching 0.75–0.85 width of distal lobe ( Fig. 132 ). Valviceps without median longitudinal sclerotization, medial lobe broad and slightly truncate on upper edge and evenly sloping down to distal lobe, with dense group of 14–15 cone-like sensilla along upper edge and on lateral surface, upper edge between medial and distal lobe with dense pattern of setae. Posterior tibia 0.95–1.00 mm long, claws with delicate subapical tooth.

Type material: Holotype ♂: “BG: Pirin-Geb. Nähe Begovica [= Bulgaria: Pirin Mountains , environs of Begovica mountain refuge] 1800 m, 10.6.1990, [leg.] Taeger & Menzel”; [red:] “ Holotype Xyela peuce spec. nov. det. S. M. Blank 2001”. Genitalia stored in small vial on pin of holotype. DEI . Paratypes: 19♀ 1♂, DEI, USNM .

Etymology. The species is named in accordance with the strongly suspected host plant, Pinus peuce . The Latin noun peuce is derived from the Ancient Greek noun η πƐύκη meaning spruce or pine, and mainly referring to mountain pines ( Le Maitre 1998).

Host plant. Ο Pinus peuce Grisebach.

Geographic distribution. Bulgaria ( Fig. 8 ).

Remarks. Xyela peuce is most similar to the allopatric X. alpigena . Males of X. peuce have a comparatively longer valviceps than males of X. alpigena (relative length: width of valviceps 1.54–1.61 in X. peuce / 1.42–1.52 in X. alpigena ), and the medial lobe bears fewer cone-like sensilla (14–15 / 22–30). Most females can be identified by the relative length of valvifer 2: valvula 3 ([1.90–]1.95–2.20 / 1.75–1.95). Females of X. peuce are on average paler: only ca 75 % have the kidney-shaped spots separated in front from the black stripe of the frontal furrow by yellow, whereas only ca 25 % of such pale specimens occur among females of X. alpigena . Other Palearctic species of the alpigena group have either the wings clear ( X. koraiensis , X. ussuriensis ), an evidently longer ovipositor sheath ( X. sibiricae ), or a different relative length of valvifer 2: valvula 2 ( X. kamtshatica ).

Taeger (1987) first recorded this species from Bulgaria under the name X. alpigena . A female was collected at the edge of snow patches at 2,050 m altitude. At the collection sites in the Pirin and Rila Mountains in southern Bulgaria, Pinus peuce is the only representative of the Pinus (‘ Strobus ’) group. This presumed Tertiary relic is endemic to the southern Balkans, where it grows in a few places in Macedonia, Albania, Bulgaria and Greece between 800–2,100 m and forms pure stands above 1,700 m ( Mirov 1967, Richardson & Rundel 1998; 17 specimens of X. peuce were collected between 1,865 –2,185 m, 1 specimen at 1,000 m altitude). Although it has never been reared from P. peuce , this pine species is strongly indicated as the host plant of X. peuce due to (1) evidence of the records for X. peuce covering the geographical and altitudinal distribution of P. peuce and (2) the occurrence of other representatives of the alpigena group on Pinus (‘ Strobus ’). Pinus mugo also occurs in the subalpine zone of the Rila and Pirin Mountains, but the restricted distribution of X. peuce cannot be explained by the far wider range of P. mugo , which is a member of Pinus (Pinus) .

Figures

FIGURE 8. Records of Xyela alpigena (51 specimens from 22 collection sites) and X. peuce (21 specimens from 5 collection sites) and natural distribution of the (supposed) host plants, Pinus cembra (solid line) and P.peuce (dashed line, both according to Willis 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 95–104. Ovipositor sheaths of Xyela species. All figures at same scale. Legend: HT—holotype; PT—paratype.

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.