Xyela menelaus Benson, 1960

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 : 45-46

Xyela menelaus Benson, 1960

Xyela menelaus Benson, 1960: 111 , ♀, type locality: Greece, Peloponnesus, Taïygetos Mountains .

Xyela graeca: Pschorn-Walcher & Altenhofer 2000: 276 (partly misidentified); Blank 2002: 218 (partly misidentified).

Description. Female. Color. Head yellow with brown and black pattern: black stripes along frontal furrows often fading and at most 2 times wider than ocellar diameter, meeting black ocellar and postocellar area, black longitudinal medial spot of frons always present, weak in pale specimens, kidney-shaped spots on vertex separate from black postocellar area ( Fig. 62 ). Antennae brown or pale brown. Thorax dorsally brown with rich yellow pattern on pronotum, mesonotal lobes and mesoscutellum, tegulae yellow and sometimes brown in middle, mesepisternum largely pale yellow. Abdominal terga brown, lateral parts of terga 7, 8 and 9+10 yellow or pale brown, valvifer 2 completely yellow or pale brown, membrane between valvifer 2 and valvula 3 white, valvula 3 varying from yellow to pale brown ( Fig. 110 ). Legs pale brown, posterior coxae pale brown or yellow and more or less infuscate from base. Wing membrane clear, venation and pterostigma pale.

Morphology. Fore wing 3.2–4.2 mm long, (?2.25–)2.40–2.80 times longer than ovipositor sheath, vein Rs+M 200–310 µm long, 2r-m meeting Rs 230–300 µm proximal to furcation of Rs1 and Rs2. Synantennomere 3 530–690 µm long, antennomere 4 140–170 µm long and 4.5–6.0 times longer than wide distally. Article 3 of maxillary palp 400–500 µm long, 1.45–1.75 times longer than scape and wider than synantennomere 3. OOL: POL = 1.45–1.90: 1. Ovipositor sheath 1.30–1.65(–1.70) µm long, valvula 3 1.35–1.70(–?1.80) times longer than valvifer 2 and 4.0–4.5(–4.8) times longer than wide at base ( Fig. 110 ). 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. Left and right valvulae 2 fused along dorsal edge in basal half. Valvula 1 with aulax terminating distally, ventral edge sloping up to tip, with 14–15 oblique closely spaced annuli in distal quarter, without serrulae, olistether with 5 setae. Valvula 2 with smooth dorsal margin, tapering in distal half, pale and evenly sclerotized, with 4(–5) annuli and in distal 0.4 with single sensilla campaniformia. Posterior tibia 0.80–1.10 mm long, claws without subapical tooth.

Male. Color. Similar to female, but often generally paler (see Fig. 63 for color pattern of head). Hypopygium yellow, often also preapical sterna largely yellow.

Morphology. Fore wing 3.0– 3.6 mm long, Rs+M 160–290 µm long, 2r-m meeting Rs 170–290 µm proximal to furcation of Rs1 and Rs2. Synantennomere 3 560–750 µm long, antennomere 4 160–220 µm long and 5.5–7.0 times longer than wide distally. Article 3 of maxillary palp 360–450 µm long, 1.30–1.50 times longer than scape and wider than synantennomere 3. OOL: POL = 1.55–1.95: 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 1.60–1.85 times longer than wide on medial lobe, lateral lamella distinct and oblique, proximal lobe of penis valve at proximal vertical edge truncate, 0.18–0.27 times as long as valviceps and 0.75–0.80 times as high as medial lobe, excision on lower edge 0.23–0.27 as deep as width of medial lobe, valviceps on medial lobe 1.15–1.30(–1.35) times wider than on distal lobe, 2 distal flagella present, tip of longer flagellum reaching 0.85–0.90(–0.95) width of distal lobe ( Fig. 145 ). Valviceps with median longitudinal sclerotization present, medial lobe almost symmetrical 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 0.75–0.95 mm long, claws without subapical tooth.

Barcodes. GUID ABU9016 , ABU9017 (2♀ 3♂).

Type material. Holotype ♀: [round label with red margin:] “Type”; “ Gréce — Péloponése Taygéte 21 V 1955 J. Aubert ” [back side:] “ 2400 m ”; “ Xyela menalaus [sic!] sp. n. ♀ det. R. B. Benson 1959”; “ Xyela menelaus Benson det. S. M. Blank 2000”. Abdomen partly covered by mould, right anterior wing missing. MZLS.

Host plant. ● Pinus nigra ssp. nigra Arn. (3♀ 7♂ from 2 reared samples), ● Pinus nigra ssp. pallasiana Lamb. (69♀ 90♂ from 7 reared samples).

Geographic distribution. Austria, Croatia, France ( Corsica), Greece, Hungary, Italy (Sicily), Turkey ( Fig. 18 ).

Remarks. See Xyela graeca for species differentiation. According to Benson (1960) the relative length of valvifer 2: valvula 3 should be 1: 1.1, but actually the holotype measures 1: 1.48. Possibly due to these wrong data and the high similarity with X. graeca , X. menelaus has never been reported since Benson’s original description until Blank (2002).

The five specimens of X. menelaus included in the barcoding analysis display an intraspecific variation of 6.44 % ( Fig. 23 ). They form two clusters at a distance of 5.85 %; specimens from Greece with ABU9017 and specimens from Sicily with ABU9016. No evident morphological differences could be found between these clusters so far. The next neighbor of X. menelaus , X. obscura , is placed at an interspecific distance of 5.55 %.

Blank (2002) did not recognize the presence of X. menelaus among X. graeca in the Vienna Basin. Ecological characters reported for X. graeca like parasitism by Xyeloblacus leucobasis and up to 3 years’ duration of the diapause may apply to both taxa, which were reared from the same samples ( Pschorn-Walcher & Altenhofer 2000, Blank 2002). Actually these two species display different imaginal emergence phenologies ( Fig. 14 ; see X. graeca ), which possibly may also be reflected in larval feeding strategies and parasitism.

Figures

FIGURE 14. Emergence phenology of imagines of Xyela curva, X. graeca and X. menelaus under laboratory conditions between 24.3. (= day 1) and 19.4.1999 (= day 25). Rearing data from two almost syntopic samples (Z42A/98, Z42B/98) taken from Pinus nigra pallasiana in southern Turkey in 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 23. Barcoding analysis of Xyela species. The tree is primarily based on specimens for which COI sequences longer than 600 bp and including less than three ambigous nucleotides could be obtained. Some shorter sequences have been added to associate sexes or larvae with imagines. Each specimen is labelled as follows: “Xyela ...”—species name; “DEIGISHym ...”—unique identification number of specimen in DEI collection; “Male / Female”—sex, larva if no sex is indicated; e.g., “661” / “603” / “658” ...—base pairs [bp] sequence length; “[0n] / [1n] / [2n]”—0–2 ambiguous nucleotides included in sequence; e.g., “Austria, Karnten [= Kärnten, Carinthia]”—country and province of origin of specimen; “BOLD: ...”—globally unique identifier (GUID). The label “Xyela 005 P. sabiniana sp.” refers to larvae obtained from Pinus sabiniana which here are identified as X. bakeri.

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).