The larva and prepupa of Eupareophoraexarmata (Thomson, 1871) (Hymenoptera, Tenthredinidae)
Author
Liston, Andrew David
Author
Prous, Marko
Author
Buecker, Josef
text
Biodiversity Data Journal
2015
3
7147
7147
http://dx.doi.org/10.3897/BDJ.3.e7147
journal article
http://dx.doi.org/10.3897/BDJ.3.e7147
1314-2828-3-7147
Eupareophora exarmata (Thomson, 1871)
Materials
Type status:
Other material
. Occurrence: catalogNumber:
DEI-GISHym19361
; individualCount:
1
; lifeStage:
prepupa
; occurrenceStatus: present; preparations: whole animal (ethanol) and larval exuvia; disposition: in collection; Taxon: scientificName: Eupareophoraexarmata (Thomson, 1871); kingdom: Animalia; phylum: Arthropoda; class: Insecta; order: Hymenoptera; family: Tenthredinidae; genus: Eupareophora; specificEpithet: exarmata; scientificNameAuthorship: Thomson, 1871; nomenclaturalCode: ICZN; taxonomicStatus: accepted; Location: continent: Eurasia; country:
Germany
; countryCode: DE; stateProvince: Nordrhein-Westfalen; locality:
Hagen-Hohenlimburg
; decimalLatitude:
51.32099
; decimalLongitude:
7.57673
; Identification: identifiedBy: Andrew Liston; Event: year: 2012; month: 6; day: 2; Record Level: type: PhysicalObject; language: en; institutionCode:
SDEI
; basisOfRecord: PreservedSpecimen
Description
Sequencing results
Phylogenetic analyses of 1078 bp of COI sequences showed with strong statistical support (bootstrap proportion 92%) that the closest relative of the putative
Eupareophora exarmata
prepupa is the Nearctic
E. parca
(Fig. 1), from which it nevertheless differs significantly at the sequence level, by 10.8%. The tree is otherwise poorly resolved, because of the limited amount of sequence data used. Closest relatives of the genus
Eupareophora
on the tree are
Cladardis
,
Monardis
, and
Periclista
, although without statistical support (Fig. 1). A strongly supported clade of the latter three genera was found by
Malm and Nyman 2014
using 8 nuclear and one mitochondrial (COI) protein coding genes, suggesting that
Eupareophora
(which Malm & Nyman 2015 did not sample) might also belong there.
Hosts
Liston 1995
stated that the hosts of
Eupareophora exarmata
are
Rosa
species (
Rosaceae
) and that the larvae bore in shoots. Although not cited by Liston, this statement was based on a record by
Reichert 1933
: "mit Larven von
Ardis brunniventris
eingetragene Rosenzweige ergaben 13.2.18. im geheizten Zimmer 1 #w, det Enslin". In view of the morphological similarity of adult
M. plana
(whose hosts are
Rosa
spp.:
Scheibelreiter 1973
) and
E. exarmata
, it seems likely that Enslin misidentified the specimen.
Zhelochovtsev [Zhelohovcev] 1988
) mentioned under
E. exarmata
simply "on ash" [translated] (
Fraxinus
sp.,
Oleaceae
). Probably this information is based on original observations made by
Supatashvili et al. 1972
al. (1972) in Georgia, who reared adults from larvae. Adults were examined by Zhelochovtsev and determined as
E. exarmata
. The larva is very briefly described by
Supatashvili et al. 1972
[translated]: "Larva grey coloured, body covered with awl-shaped processes". These authors also record
"ash"
as the host, but do not mention which
Fraxinus
species was involved. Apart from
Fraxinus excelsior
L., some other ash species occur in Georgia, such as
F. angustifolia
Vahl subsp. oxycarpa (M. Bieb. ex Willd.) Franco & Rocha Afonso (
USDA 2012
). The recent German records indicate that
F. excelsior
L. is a host. As far as we are aware, the publication by
Supatashvili et al. 1972
is unique in referring to
E. exarmata
as a pest. Their observations were made in stands of planted ash. It is noteworthy that the occasional reports of defoliation caused by
E. parca
in North America involve "planted ash species [..] in urban settings" (
Williams 2007
), although D. R. Smith (personal communication) states that it is also fairly common throughout the eastern deciduous forests.
Description of mature larva (Figs 2, 3, 4).
Terminology follows
Viitasaari 2002
, with notation of annulets of abdominal segments according to
Vikberg and Nuorteva 1997
, i.e. annulet 3 bears the spiracle.
Length: approximately 15 mm.
Head completely black except for pale mouthparts. Ground colour of trunk above spiracular line grey; whitish below this, with yellow tinge on abdominal segments 1-8. Cuticular processes (hereafter: spines) above spiracles located on more or less black glandubae. Above spiracles, on thorax, most spines entirely black; on abdomen all supraspiracular spines blackish above fork, whitish below this; the outermost of each dorsal pair of spines darker. All subspiracular spines paler than more dorsal ones; apically at most pale brown, and if located on glandubae, then these also completely pale.
Antenna with 5 articles. Clypeus with 2 setae. Thoracic leg with 5 articles. The 4 most dorsal and anterior spines on thorax are trifid. Prolegs on abdominal segments 2-8 and 10. Abdominal segments 1-9 with 5 dorsal annulets. Annulet 3 with 2 supraspiracular bifid spines. Annulet 5 with 3 bifid spines: 2 supraspiracular and 1 on spiracular line. Abdominal segment 10 without spine on midline. Subspiracular lobe with two spines; anterior one bifid, other simple. Suprapedal lobe with two simple spines.
Description of prepupa (Fig. 5).
Length: approximately 13 mm.
Head grey above; yellowish on and around mouthparts. Thorax yellow-white. Abdomen largely grey, with yellow patches on and below spiracular line, and yellowish prolegs.
Spines absent, except on abdominal segments 9 and 10, where they are replaced by unbranched, peg-shaped structures. Prothorax dorsally and anteriorly more strongly produced than in the feeding larva, giving it a hooded appearance.
Identification
Other spiny West Palaearctic
Blennocampinae
larvae belong to the genera
Monardis
,
Periclista
,
Pareophora
,
Monophadnoides
and
Claremontia
. Larvae of all of these, none of which feeds on
Fraxinus
, have a mainly pale green or yellowish body and are thus easily distinguished from the predominantly grey larva of
E. exarmata
.
Smith 1969
stated that the larva of
Eupareophora parca
has two bifurcate spines on the subspiracular lobe, and can therefore be distinguished from those of
Periclista
species in which the anterior of these two spines is bifurcate and the posterior one simple. The larva of
E. exarmata
in this respect (Fig. 4) is however like
Periclista
, not
E. parca
. The coloration of the mature larva of
E. parca
(illustrated by
Williams 2007
) and
E. exarmata
(Figs 2, 3, 4) is similar, although the latter is apparently darker. According to
Williams 2007
(fig. 10B), the caudal abdominal terga of the
E. parca
prepupa entirely lack large cuticular processes, whereas the prepupa of
E. exarmata
clearly possesses some (Fig. 5).
Behaviour
All adult collection records and observations on larvae (here, and by
Supatashvili et al. 1972
, suggest that
E. exarmata
is univoltine, flying soon after bud-break in spring, with larvae developing, according to local climate, between the end of April and start of June. The behaviour of the feeding larvae, although only briefly described by
Supatashvili et al. 1972
seems to resemble quite closely that of the Nearctic
E. parca
as described by
Williams 2007
.
At Hagen-Hohenlimburg only mature larvae of
E. exarmata
were found, apparently when they crawled down the trunk of the host in order to reach a spot in which to complete their development.
Williams 2007
recovered eight prepupae of
E. parca
from the soil litter layer, and 2 from branches of the host. Further observations are therefore needed to establish whether
E. exarmata
always leaves its host before moulting to a prepupa. According to
Supatashvili et al. 1972
, the mature larvae form cells in the bark of
Fraxinus
, in which they overwinter. A further apparent peculiarity noted by these authors, is that the freshly moulted larvae lack spines, but that these re-appear within a day. Neither of these phenomena was observed by
Williams 2007
in the Nearctic
E. parca
, who found that the rather flimsy cocoon was usually constructed in the upper layers of the soil.