Xyela heldreichii 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 : 39-41

Xyela heldreichii Blank , sp. nov.

Type locality: Greece, Nomos Grevena, Pindos National Park E, Metsovo N 15 km, Mount Blia.

Xyela julii: Csiki 1923: 104 (misidentification).

Description. Female. Color. Head dark brown to black, usually with indistinct stripes on vertex along upper eye margin extending more or less toward facial and genal orbits, sometimes with indistinct spots lateral to postocellar area and on interantennal area. Antennae brown, ventrally a little paler ( Fig. 58 ). Thorax dorsally brown, rarely with more or less distinct pale pattern on mesonotal lobes and mesoscutellum, tegulae pale and largely brown in middle. Thorax ventrally brown, mesosternum laterally yellow. Abdomen brown, tergum 8 and 9+10 laterally and more or less preapical sterna pale brown to yellow. Valvifer 2 yellow, valvula 3 generally darker, preapically infuscate and pale at tip ( Fig. 108 ). Legs yellow, coxae brown, upper side of femora and lower side of femora 3 more or less darkened. Wings almost clear, venation and pterostigma pale brown.

Morphology. Fore wing (3.2–) 3.6–4.5 mm long, 1.60–1.80 times longer than ovipositor sheath, vein Rs+M 200–330 µm long, 2r-m meeting Rs proximal to furcation of Rs1 and Rs2. Synantennomere 3 (490–)610–860 µm long, antennomere 4 (100–)140–180 µm long and 4.0–5.5 times longer than wide distally. Article 3 of maxillary palp 470–610 µm long, 1.45–1.80 times longer than scape and wider than synantennomere 3. OOL: POL = 1.45–1.85: 1. Ovipositor sheath (2.00–)2,30–2,75 mm long, valvula 3 1.95–2.25 times longer than valvifer 2 and 7.0–8.0 times longer than wide at base ( Fig. 108 ). 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 15–16 oblique closely spaced annuli in distal quarter, without serrulae, olistether with 6–7 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 sensilla campaniformia, in distal 0.1 with 5 oblique annuli. Posterior tibia (0.80–) 0.90–1.15 mm long, claws without subapical tooth.

Male. Color. Head yellow with black pattern: narrow black stripes along frontal furrows meeting ocellar and postocellar spot, medial spot on frons, kidney-shaped spots on vertex separate from black postocellar area ( Fig. 59 ). Antennae pale brown. Thorax dorsally black, pronotum laterally sometimes with brown spot, lateral and more or less anterior mesonotal lobes with yellow, mesoscutellum with yellow spot, tegulae pale and sometimes brown in middle, mesepisternum largely yellow. Abdominal terga dark brown, hypopygium yellow to brown, usually paler than preceding sterna. Legs pale brown, posterior coxae laterally brown and ventrally brown in basal and pale in distal half. Wing membrane almost hyaline, venation and pterostigma pale brown.

Morphology. Fore wing 3.3–3.7 mm long, Rs+M 210–250 µm long, 2r-m meeting Rs proximal to furcation of Rs1 and Rs2. Synantennomere 3 640–810 µm long, antennomere 4 (130–)160–200 µm long and 4.5–5.5 times longer than wide distally. Article 3 of maxillary palp 440–530 µm long, 1.45–1.65 times longer than scape and wider than synantennomere 3. OOL: POL = 1.55–1.75: 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 1.50–1.55 times longer than wide on medial lobe, with distinct oblique lateral lamella, proximal lobe of penis valve 0.26–0.30 times as long as valviceps and 0.70–0.75 times as high as medial lobe, excision on lower edge 0.18–0.21 as deep as width of medial lobe, valviceps on medial lobe 1.15–1.25 times wider than on distal lobe, 2 distal flagella present, tip of longer flagellum reaching 0.70–0.75 width of distal lobe ( Fig. 143 ). 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 11–15 setae. Posterior tibia (0.85–)0.90–1.00 mm long, claws without subapical tooth.

Type material. Holotype ♀: “ Greece: Nom. [ Nomos ] Grevena , Pindos Natl. [National] Park E, Metsovo N 15 km, Mt. Blia , 1550 m NN, 27.– 28.5.2000, 20°54N 21°12E, swept from grass below Pinus heldreichii , leg. Blank & Kutzscher ”; [red:] “Holotype ♀ Xyela heldreichii spec. n. det. S. M. Blank 2000”. DEI . Paratypes: 63♀ 8♂, DEI, EJC, HNHM, MKC, MZLS, RSME, WSC, ZSM .

Etymology. Like its host plant, Pinus heldreichii , the new Xyela species is dedicated to Theodor von Heldreich, who was one of the first modern scientific explorers of the Olympus mountain range, where part of the material of X. heldreichii was collected. From 1851, when von Heldreich climbed the Olympus first, until his death in 1902, he contributed more to Greek botany than anybody else before ( Strid 1980).

Host plant. ● Pinus heldreichii Chr. (observation of two females ovipositing into staminate cones).

Geographic distribution. Albania, Greece ( Fig. 16 ).

Remarks. Xyela heldreichii , X. obscura and X. uncinatae differ from other Palearctic representatives of the X. julii group in their (at least predominantly) dark brown or black head. Female X. heldreichii are separated from X. obscura and X. uncinatae by the longer ovipositor and the smaller fore wing: ovipositor ratio, and the brown valvula 3. There are single specimens with a predominantly pale valvula 3, which is not darker than valvifer 2 (possibly not completely colored specimens). In males, the hypopygium is usually paler than the preceding sterna, whereas the sterna are similarly colored in X. julii , X. obscura and X. uncinatae . See also remarks under X. julii .

This species has been reported under the name Xyela julii by Csiki (1923), who studied two females collected at “Mts. Gyalicalums” at 1,650 m. This name corresponds with the Albanian mountain Gjalicë e Lumës, which lies southeast of Kukës ( Friese & Königsmann 1962).

The larval host plant is without doubt Pinus heldreichii . In Greece, imagines have been collected several times in P. heldreichii woodland either directly from the pine trees or they were swept from the grass below the trees (Mt. Olymp at 2,000 m; Pindos National Park at 1,750 m; Vasilitsa Ski Resort at 1,830 m). On collection sites at lower altitudes P. heldreichii was growing intermixed with P. nigra (Pindos National Park at 1,550 m; Mt Smolikas at 1,500 m). However, P. nigra can be excluded as the host plant for two reasons: 1, their staminate cones were too strongly developed at the time of collecting X. heldreichii , and the remaining period for a proper development of the larvae would accordingly have been too short; and 2, cones of P. nigra presented to X. heldreichii females were not accepted for oviposition, but cones of P. heldreichii were. Fully developed Xyela larvae hatched from P. heldreichii cones collected in the Pindos National Park at 1,400 m and on Mt Smolikas at 1,500 m in the year 2000. From these samples no imagines hatched in spring 2001, but living larvae were still present in the rearing jars. Possibly, larvae of P. heldreichii diapause at least two years as is known for the other European subalpine Xyela species , X. alpigena and X. obscura .

Pinus heldreichii (panzer pine, white-bark pine) occurs in the dry and usually rocky upper zone of limestone mountains in the western part of the Balkan Peninsula ( Friese & Königsmann 1962, Polunin 1988, Kindel 1995). A disjunct population is present in southeastern Italy ( Adamović 1909, Kindel 1995), but no Xyela material was available from there. In Greece, single P. heldreichii trees are found at ca 1,000 m. There and at higher altitude it grows intermixed with P. nigra , P. heldreichii becoming dominant from ca 1,700 m. Above 2,000 m it forms an open woodland. Between 2,300 and 2,500 m, the P. heldreichii is reduced to krummholz which gradually becomes lower and more scattered ( Strid 1980). Within the P. heldreichii zone, X. heldreichii has been collected from 1,400 to 2,000 m. It is possibly absent at lower altitudes as no larvae were found in 4 samples of staminate cones collected on the Mt. Olympus range between 900 and 1,300 m.

Figures

FIGURE 16. Records of Xyela heldreichii (72 specimens from 7 collection sites) and natural distribution of the host plant, Pinus heldreichii (solid line, according to Willis et al. 1998).

FIGURES 42–65. Color pattern of head of Xyela species: X. curva group, X. rasnitsyni group, X. julii group (part). Legend: HT—holotype; NT—neotype; PT—paratype.

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

FIGURES 136–145. Penis valves of Xyela species: X. curva group, X. julii group (part). Figs 138–139 and 141 reproduced from Blank et al. (2005).