Trachys subglaber Rey, 1891 (Buprestidae) an unrecognised British species

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67
Trachys subglaber an unrecognised British species
[The Coleopterist 21(2): 67-72, September 2012]
Trachys subglaber Rey, 1891 (Buprestidae)
an unrecognised British species
Brian Levey
Dept. of Biodiversity & Systematic Biology, National Museum Wales, Cathays Park, Cardiff CF10 3NP
e-mail brian.levey@museumwales.ac.uk
Introduction
Over 35 years ago, when looking at material for my handbook to Buprestidae
(Levey, 1977), I realised that some British specimens of Trachys troglodytes
Gyllenhal in Schönherr I had dissected had aedeagi that looked like those of T.
troglodytes ssp. subglaber (called subglabra then) as figured in Schaefer (1949).
Some of the other differences between the two subspecies listed by Schaefer were
difficult to reconcile in the British material I had examined. At that time, because T.
subglaber was considered to be a southern European subspecies of T. troglodytes,
and since the distributions of the two aedeagal types in Britain were not allopatric, I
thought that the aedeagal differences I had observed were probably intraspecific
variation. T. subglaber is now recognised more widely in Europe and is no longer
considered to be a southern European subspecies of T. troglodytes. I am currently
revising the handbook and having looked at additional specimens I have come to
the conclusion that we have both species in Britain.
There is a problem with the usage of both the names T. subglaber and T.
troglodytes. Apparently the current usage of the name T. subglaber is a
misidentification and the true identity of T. troglodytes (s. lat.) has not been
established (Kubán, 2006 p. 52). It is therefore quite possible that one or other of
the species will have a new name in the future. It needs to be noted that the genus
Trachys is now to be treated as masculine (Opinion 2222) and T. subglabra
therefore becomes T. subglaber, not T. subglabrus as listed in Bellamy (2008).
In this paper I am following Schaefer (1949) concept of these species. It should
be noted that Cobos (1986, figure 358) of the aedeagus of T. troglodytes ssp.
compressa Abeille appears to be that of T. subglaber, but the habitus outline (figure
355) appears to be that of T. troglodytes.
Distribution & material examined
P. Harwood drew A.A. Allen’s attention to a small Breckland race of T. troglodytes
which he thought must be a different species (Allen, 1968). Allen lists some
external characters of the specimens from Mildenhall, W. Suffolk he examined
which suggest they are in fact specimens of T. troglodytes. The specimens Allen
dissected were all females. I have however dissected a male in A.A. Allen’s
collection (now in BMNH) labelled P.H. v.21 which is almost certainly one of P.
Harwood’s specimens from Mildenhall. I have also dissected a male from
Freckenham, W. Suffolk, which corresponds well, externally, with two females

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[The Coleopterist 21(2): 67-72, September 2012]
from Mildenhall, v.21, the same date as the material examined by Allen. These
specimens now in NMW (ex. Tomlin Coll.) are presumably specimens collected by
Harwood. The aedeagi of the male from Freckenham and that in Allen’s collection
agrees with that of T. troglodytes s. str. figure 489 in Schaefer (1949). It is
premature to say what the distribution of the two species in Britain may be but the
different habitat preferences recorded in continental Europe and the records below
suggest that T. troglodytes might be found in the drier areas of southern and eastern
England, and T. subglaber may be more widespread.
Because I did not know that we had both species in Britain when I looked at
material for the original handbook, only dissected male specimens, where I made a
note of the form of the aedeagus, can be assigned to one or other species and are
listed below, along with recently examined material.
T. troglodytes: recently examined: E. Kent: 1♂, 1♀, Charing, iv. 1905, ex. J.R. le. B. Tomlin
coll. (NMW); W. Kent: 1♂, Cuxton, 24.73 G.C. Champion (BMNH); W. Suffolk: 1♀
Mildenhall, ex. J.R. le. B. Tomlin coll. (NMW). 1♀, Mildenhall, 5. 21., ex. J.R. le. B. Tomlin
coll. (NMW); 2 unsexed, Mildenhall, v. 1921, P.Harwood, ex A.A. Allen coll. (BMNH); 1
unsexed, Mildenhall, P. Harwood, ex A.A. Allen coll. (BMNH); 2 unsexed, Milden.[hall], ex
A.A. Allen coll. (BMNH). 1 unsexed, Mildenhall, Harwood, ex G.C. Champion coll.
(BMNH); 1♂ Freckenham, ex. J.R. le. B. Tomlin Coll. (NMW); 1♂, 1♀, P.H. v.21, ex A.A.
Allen coll. (BMNH);
T. subglaber: recently examined: W. Cornwall: 1♀, Kynance Cliff, 29.v.1989 (KNAA); E.
Cornwall: 1♀, Blisland, S. Penquite Farm, 23.viii.2005, K.N.A. Alexander (KNAA); S.
Devon: 1 unsexed, Colyton, R. Coly 1.ii.1943 ex. A.A. Allen (BMNH); 1 unsexed, Colyton,
Scabiosa succisa 27.ix.1945 G.H.A. ex. A.A. Allen (BMNH);1♀, Bovey Tracey, 18.vi.1926
H. Donisthorpe (BMNH); S. Wiltshire: 1♂, Cherhill Down, SU0569, 30.v.2004, P.M. Pavett
(NMW); Dorset: 1♂, Corfe Common, 3.vi.1989, K.N.A. Alexander (KNAA); Isle of Wight:
I unsexed, Parkhurst, 25.vii.1926, F.D. Buck, ex West Weal coll. (CM);1♂, 1♀ S. Hants.:
1♂, 1♀, Winchester, St. Catherine’s Hill Nature Reserve, SU484275, 30.vii.2008, B. Levey,
suction sampling chalk grassland (NMW); 1♂, Botley Wood near Fareham, 29.iii.1969, in
moss amongst Devils bit Scabious, ex A.E. Gardner coll. (NMW); 1 unsexed, Botley Wood,
Fareham, 29.i.1972, D. Appleton (BMNH); 1 unsexed, New Forest, 19.vii.1904, H.
Donisthorpe (BMNH); 1 unsexed, New Forest, New Cops, v.1906, ex West Weal coll. (CM);
1 unsexed, New Forest, v-vi,1915; 1♀, New Forest, Emery,11.iv.37, T. Hudson Beare coll.
(NMS); W. Sussex: 2♀, Holm Bush (near Brighton), 56.35; J.A. Power (BMNH); 1♂, near
Hurstpierpoint, in moss, Hemmings, ex.G.R. Waterhouse Coll. (NMS); E. Sussex: 1
unsexed, Ditchling, viii.1910, H.C. Dollman (BMNH); 2 unsexed, Barcombe, 21.ii.1927 &
25.xi.1931, C.J. Saunders (BMNH); E. Kent: 2♂, 1♀, Detling, 24.iv. 97, J.A. Owen (NMS);
S. Essex: Loughton, ex West Weal coll. (CM); Hertfordshire: 1♀, Bricket Wood,
7.ix.1927, H. Donisthorpe (BMNH); E. Suffolk: 2♂, Ipswich,22.iii.1897, C. Morley, ex G.C.
Champion coll. (BMNH); E. Norfolk: 1♂, Norwich, St. Faiths, 4.vi.1870, ex Power coll.
(BMNH); Cambridgeshire: 1♂, Cambridge, 2108A, C.E. Tottenham coll. (BMNH); E.
Gloucestershire: 1♂, Overley Wood, vii.84, J.A. Owen (NMS); Glamorgan: 1♀, Gower,
24.vii.1994, K.N.A. Alexander (KNAA); Merionethshire: 1♀, Barmouth, Chappell Coll.
(NMS); 1♀ ? S.E. Yorkshire: 1♀? Hornsea, 6.vi.1836, J.A. Power (BMNH). Previously
examined and identification based on aedeagus: S. Devon: 1♂, Colyton, R. Coly, 20.ii.1944,

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[The Coleopterist 21(2): 67-72, September 2012]
G.H.A., in A.M. Massee coll. (BENHS ); Dorset: 1♂, Bere Regis Dist., 22.ix.1938,
(BENHS); Sussex: 1 ♂, Brighton, E.W.S. ex, G.R.C. coll. (CUMZ); N.E. Yorkshire: 1♂,
Scarborough, R. Lawson, (CUMZ).
Biology
Bílý (2002) says that T. subglaber is probably monophagous and the larvae mine
the leaves of devil’s-bit scabious Succisa pratensis, and that T. troglodytes larvae
mine the leaves of Knautia spp. including field scabious K. arvensis and Scabiosa
spp. including small scabious Scabiosa columbaria. Bílý says that T. subglaber
prefers wet meadows or marshes in lowland and warm escarpments, whilst T.
troglodytes prefers steppes, rocky slopes and uncultivated meadows. This habitat
difference presumably partly reflects the preferred habitat of the host plants and
would suggest that in Britain T. troglodytes is likely to be found in drier habitats
than T. subglaber. However, since the habitats of the putative hosts in Britain are
not entirely exclusive, both species might occur together.
In Britain most reported host records of T. troglodytes s. lat. are from devil’s-bit
scabious. Specimens I have examined found in association with this plant are in fact
T. subglaber. The larval hosts of T. troglodytes are not known with certainty in
Britain but Knautia arvensis which is common in the Breckland of E. Anglia and on
the chalk grassland of Kent is the most likely host.
Identification
Some of the external differences between the two species as mentioned in Schaefer
(1949) do not work well for British specimens. The key below lists the external
differences which appear to be useful in distinguishing both British material and
specimens from mainland Europe I have examined, and are in agreement with the
differences seen in the male genitalia. The degree of widening of the apex of the
parameres in T. subglaber shows some variability, sometimes due to the more
lightly chitinised external apical area becoming collapsed in some specimens, but
the other aedeagal differences appear constant.
The elytral colour of all the T. subglaber I have examined is blue-green or
violet-blue. The elytral colour in T. troglodytes is more variable, being greenish
bronze, dull green blue-green or deep blackish violet. T. subglaber (Fig.1) is also
slightly proportionally broader than most T. troglodytes (Fig. 2), but this difference
is only obvious when the species are compared side by side.
1 Humeral callosities of elytra more pronounced, the elytra slightly but noticeably
wider than pronotum at base (Fig. 3); tiny pin-prick punctures of elytra absent or
scarcely visible between the larger punctures; depression at inner anterior angle of
proepisternum relatively smaller and deeper, less than half the width of the
proepisternum at the anterior margin; parameres of aedeagus strongly widened at
the apex, spoon shaped basal piece of aedeagus scarcely constricted near the
middle, median lobe widest near mid length (Fig.5) ...................... T. subglaber Rey

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[The Coleopterist 21(2): 67-72, September 2012]
- Humeral callosities of elytra less pronounced, the elytra scarcely wider than the
pronotum at the base (Fig. 4); tiny pin-prick punctures of elytra usually more
obvious between the larger punctures; depression at inner anterior angle of
proepisternum relatively large and shallow, about half the width of the
proepisternum at the anterior margin; parameres of aedeagus less widened near
apex, spoon shaped basal piece of aedeagus strongly constricted near the middle,
median lobe strongly widening towards the base (Fig. 6) ...........................................
.........................................................................T. troglodytes Gyllenhal in Schönherr
Depositories
The following codons are used for collections in which specimens examined are
lodged.
BENHS – The Massee collection of the British Entomological & Natural History Society
BMNH – The Natural History Museum, London
CM – Colchester Museum, Colchester.
CUMZ – University Museum of Zoology, Cambridge
KNAA – Keith Alexander’s private collection
NMS – National Museums Scotland, Edinburgh
NMW – The National Museum Wales, Cardiff
Acknowledgements
I thank Keith Alexander for sending me his specimens for examination, and Jerry
Bowdrey (CM), Malcolm Kerley (BMNH), and Richard Lyszkowski (NMS) for
allowing me to examine specimens in their care. I thank Vit Kubáň (Prague) for
commenting on the manuscript and alerting me to the correct usage of the name
subglaber.
References
ALLEN, A.A. 1968. Notes on some British Serricorn Coleoptera, with adjustments to the
list. I Sternoxia. Entomologist’s Monthly Magazine 104: 214.
BELLAMY, C.L. 2008. A world catalogue and bibliography of the Jewel Beetles
(Coleoptera: Buprestoidea) Vol. 4 Agrilinae: Agrilina through Trachyini. Sofia: Pensoft.
BÍLÝ, S. 2002. Summary of the bionomy of the buprestid beetles of Central Europe
(Coleoptera; Buprestidae). Acta Entomologica Musei Nationalis Pragae, Suppl. 10, 104
pp.
COBOS, A. 1986. Fauna iberica de coleopteros Buprestidae. 364 pp. Madrid: CSIC.
KUBÁN, V. 2006. Buprestidae, Agrilinae excluding Agrilus, pp. 403-421. In Löbl, I. &
Smetana, A. (eds.) Catalogue of Palaearctic Coleoptera, Vol. 3. 690pp. Stenstrup:
Apollo BooksLEVEY, B. 1977. Coleoptera Buprestidae. Handbooks for the
Identification of British Insects Vol. V part 1(b). Royal Entomological Society of
London.
OPINION 2222 (Case 3335) March 2009. Trachys Fabricius 1801 (Insecta, Coleoptera):
masculine gender of the genus fixed. Bulletin of Zoological Nomenclature 66(1): 100–
102.

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SCHAEFER, L. 1949. Les Buprestides de France. Miscellanea Entomologica. Supplement.
511 pp., 25 plates. Paris.
Fig. 1 Habitus of T. subglaber (Botley Wood, S. Hampshire); Fig. 2 habitus T.
troglodytes (Mildenhall, W. Suffolk)

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Fig. 3 Shoulder of T. subglaber (Botley Wood, S. Hampshire); Fig. 4 Shoulder of
T. troglodytes (Mildenhall, W. Suffolk); Fig. 5 Aedeagus of T. subglaber (St.
Catherine’s Hill, S. Hampshire); Fig. 6 Aedeagus of T. troglodytes (Charing, E.
Kent)