<strong> The Eurasian species of <em> Xyela </ em> (Hymenoptera, Xyelidae): taxonomy, host plants and distribution </ strong>
Author
Blank, Stephan M.
stephan.blank@senckenberg.de.
Author
Shinohara, Akihiko
shinohar@kahaku.go.jp.
Author
Altenhofer, Ewald
stephan.blank@senckenberg.de.
text
Zootaxa
2013
2013-03-18
3629
1
1
106
http://dx.doi.org/10.11646/zootaxa.3629.1.1
journal article
53391
10.11646/zootaxa.3629.1.1
9bac424f-e31f-4780-a976-f4fe3ba62156
1175-5326
5261330
FF47F026-9CB6-4390-B900-130A3DF2B33B
Xyela obscura
(
Strobl, 1895
)
Pinicola julii
var.
obscura
Strobl, 1895: 277
,
♀
,
type
locality:
Austria
,
Styria
, environs of
Admont
,
Scheibleggerhochalpe
;
Konow 1897: 58
(junior synonym of
julii
).
Xyela obscura
:
Benson 1960: 110
(removed from synonymy, combination with
Xyela
).
Xyela julii
var.
tatrica
Gregor
in
Gregor & Baťa, 1940: 225
,
♀
,
type
locality:
Slovakia
, Vysoké Tatry Mountains, Štrbské Pleso;
Beneš 1975: 121
(junior synonym of
obscura
).
Xyela curva
:
Benson 1961: 171
(misidentification).
Xyela julii
:
Rasnitsyn 1965: 515
(partly misidentified).
Description
. Female. Color. Head dark brown to black, sometimes with indistinct brown stripes on vertex between kidney-shaped spot and eye margin (
Fig. 64
). Antennae brown, ventrally a little paler. Thorax dorsally brown, seldom with indistinct brown pattern on mesonotal lobes, tegulae pale and largely brown in middle. Thorax ventrally brown, mesepisternum pale brown. Abdomen brown, tergum 8 and 9+10 laterally pale brown. Valvifer 2 yellow or pale brown, membrane between valvifer 2 and valvula 3 white, valvula 3 pale brown, preapically infuscate and pale at tip (
Fig. 113
). Legs pale brown, coxae brown, femora more or less darkened. Wings almost clear, venation and pterostigma pale brown.
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
).
Morphology. Fore wing
3.6–4.3 mm
long, 2.00–2.15 times longer than ovipositor sheath, vein Rs+M 230–330 µm long, 2r-m meeting Rs proximal to furcation of Rs1 and Rs2. Synantennomere 3 560–730 µm long, antennomere 4 130–180 µm long and 3.5–4.5(– 5.5) times longer than wide distally. Article 3 of maxillary palp 430–530 µm long, 1.50–1.75 times longer than scape and wider than synantennomere 3. OOL: POL = 1.60–2.10: 1. Ovipositor sheath
1.75–2.10 mm
long, valvula 3 1.75–2.00 times longer than valvifer 2 and 6.5–7.5 times longer than wide at base (
Fig. 113
). 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 ca 14–15 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 sensilla campaniformia, in distal 0.1 with 4–5 annuli. Posterior tibia 0.80–1.00 mm long, claws without subapical tooth.
Male. Color. Head yellow with black and brown pattern: frontal furrows usually with wide stripes meeting ocellar and postocellar spot, medial spot of frons present and sometimes fused with frontal stripes, kidney-shaped spots on vertex separate from black postocellar area and often fused with frontal stripes anteriorly (
Fig. 65
). 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 and ventrally brown in the basal and more or less pale in distal half. Wing membrane almost hyaline, venation and pterostigma pale brown.
Morphology. Fore wing
2.9–3.9 mm
long, Rs+M 130–330 µm long, 2r-m meeting Rs proximal to furcation of Rs1 and Rs2. Synantennomere 3 (560–)630–740 µm long, antennomere 4 140–190 µm long and 4.5–6.0 times longer than wide distally. Article 3 of maxillary palp 400–470 µm long, 1.35–1.60 times longer than scape and wider than synantennomere 3. OOL: POL = (1.50–)1.75–1.90: 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 1.44–1.55(–1.60) times longer than wide on medial lobe, with distinct oblique lateral lamella, proximal lobe of penis valve 0.23–0.28 times as long as valviceps and 0.70–0.75 times as high as medial lobe, excision of lower edge 0.20–0.23 as deep as width of medial lobe, valviceps on medial lobe 1.10–1.20 times wider than on distal lobe, 2 distal flagella present, tip of longer flagellum reaching 0.60–0.70 width of distal lobe (
Fig. 146
). 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 5–13 setae. Posterior tibia 0.80–1.00 mm long, claws without subapical tooth.
Type
material
.
Pinicola julii
var.
obscura
.
Lectotype
♀
(designated by
Schedl
1978
): [label added by
G. Morge
, green handwriting:] “4”; “
Xyela obscura (Strobl)
♀
stat. nov.
Benson
1960
det.
W. Schedl
1971”; [red:] “
Lectotypus
♀
Pinicola
julii
var.
obscura
Strobl, 1895
S. M. Blank
1999
”; [hereby added copy of cabinet label:] “
X. Julii
v.
obscura
m. Scheibleggerhochalpe 26/5
94 ♀
”; “
Xyela obscura
(Str.)
♀
det.
S. M. Blank
1999”. In perfect condition.
NMBA
.
Paralectotypes
:
1♀
with Strobl’s label “
v.
obscur
[sic!] Scheiblstein [...; illegible Gabelsberg stenography] 6/6
95 ♀
. Strobl” and Morge’s label “5” and
1♀
with Strobl’s label “
Jul.
v.
obsc
.
Kalbling [...; illegible Gabelsberg stenography]
8/6 95
.
♀
.” and Morge’s label “6”,
NMBA
.
Xyela julii
var.
tatrica
Gregor, 1940
.
NMP
, not studied.
Host
plant
.
Pinus banksiana
Lamb. (
Benson 1962
)
,
Pinus cembra
L. (
Schedl 1980
),
P. densiflora
Sieb. & Zucc.
(
Kondo & Miyake 1974
,
Miyake & Kondo 1974
),
P. elliottii
Engelm. (
Smith 1978
)
,
P. heldreichii
Chr. (
Blank 2002
)
,
●
Pinus mugo
Turra
(
55♀
58♂
from 3 reared samples),
Pinus nigra
Arn. (
Beneš 1975
)
,
P. palustris
Mill. (
Benson 1962
)
,
P. ponderosa
Laws. (
Benson 1962
)
,
P. taeda
L. (
Smith 1978
),
P. virginiana
Mill. (
Benson 1962
)
,
P. uncinata
Ramond (
Blank 2002
)
.
Biology
. In samples from
Pinus mugo
, larvae of the weevil
Doydirhynchus austriacus
(Olivier, 1807)
(Cimberidae, Curculionoidea; det. L. Behne) were sometimes abundant, which are also internal feeders on the staminate cones. For additional data see
Blank (2002)
.
Geographic distribution
.
Austria
,
Bulgaria
,
Germany
,
Italy
, Slovakian Republic (
Roller et al. 2006
),
Switzerland
(
Fig. 19
). Additionally recorded from the Carpathian Basin (
Zombori 1974
) and the
Ukraine
(
Zombori & Ermolenko 1999
). The record for
France
(
Blank 2002
) refers to
X. uncinatae
.
Rasnitsyn’s (1965)
record for the Altai Mountains is a misidentification of
X. julii
. Records from
Japan
and North America (e.g.,
Benson 1962
,
Togashi 1974
) refer to other
Xyela
species.
Remarks
. See
Xyela julii
and
X. uncinatae
for diagnosis. The sexes have been associated with the help of imagines reared from
Pinus mugo
.
Beneš (1975)
studied the
type
material of
X. julii
var.
tatrica
in NMP and identified it as
X. obscura
. This material was unavailable to us, but we checked
two females
from HNHM labeled “Štrbské Pléso 21 Obenberger”, which most likely were collected at the
type
locality, and which agree well with the concept of
X. obscura
.
Benson (1961
,
1962
) considered
X. obscura
to be a Holarctic species, and he synonymized the East Palearctic
X. japonica
and the Nearctic
X. pini
Rohwer, 1913
with it. Actually
X. obscura
is restricted to Europe, and the other names actually concern
X. japonica
and species associated with the
X. minor
group.
The host records of
P. banksiana
,
P. elliottii
,
P. palustris
,
P. ponderosa
,
P. taeda
and
P. virginiana
for
X. obscura
resulted from
Benson’s (1962)
erroneous synonymy of the Nearctic
X. pini
with this species (see
Burdick 1961
and
Ebel 1966
for primary data).
Kondo & Miyake (1974)
and
Miyake & Kondo (1974)
reported
P. densiflora
for Japanese
X.
‘
obscura
’, but actually they had studied a mixture of
X. tecta
and
X. variegata
. The record of
P. cembra
is due to repeated collecting of
X. obscura
imagines from this pine (
Benson 1960
,
1961
,
Schedl 1978
), which may occur syntopically with
P. mugo
in the subalpine zone.
Beneš (1975)
listed
P. nigra
doubtfully as an additional host plant. Actually
X. obscura
has never been reared from
P. cembra
and
P. nigra
. All these pines are to be excluded as host plants for
X. obscura
.