The leaf and stem mines of British flies and other insects

(Coleoptera, Diptera, Hymenoptera and Lepidoptera)

by Brian Pitkin, Willem Ellis, Colin Plant and Rob Edmunds


Trachys troglodytes Gyllenhal, 1817
[Coleoptera : Buprestidae]

Trachys troglodytes Gyllenhal, 1817
Trachys carinthiaca
Obenberger, 1918
Trachys laevicollis
Kiesenwetter, 1857
Trachys puncticeps
Abeille de Perrin, 1900.
Trachys troglodytes Gyllenhall, 1817; Alexander, 1989

Comment: Since compiling this page, Trachys troglodytes has been recognised as comprising two species - Trachys troglodytes, from E. Kent, W. Kent, W. Suffolk and Trachys subglaber (Rey, 1891) from W. Cornwall, E. Cornwall, S. Devon, S. Wiltshire, Dorset, Isle of Wight, S. Hants, W. Sussex, E. Sussex, E. Kent, S. Essex, Hertfordshire, E. Suffolk, E. Norfolk, Cambridgeshire, E. Gloucestershire, Glamorgan, Merionethshire, S.E. Yorkshire, N.E. Yorkshire. The two species are distinguished by the male aedeagus.

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 (Levey, B. 2012. The Coleopterist 21(2): 67-72).

Leaf-miner: Full depth, transparent blotch. Oviposition site, at the leaf upper surface, covered by a brownish black drop of hardened secretion. Frass in granules or thread fragments (Bladmineerders van Europa).

Larva: The larvae of beetles have a head capsule and chewing mouthparts with opposable mandibles and lack abdominal legs (see examples).

The larva is illustrated in Bladmineerders van Europa.

Trachys troglodytes larva,  dorsal
Trachys troglodytes larva, dorsal
Image: © Steve Wullaert (Bladmineerders van Europa)

Pupa: The pupae of beetles have visible head appendages, wings and legs which lie in sheaths (see examples).

Pupation in the mine, not in a cocoon (Bladmineerders van Europa).

Hosts in Great Britain and Ireland: Unknown

Hosts elsewhere:



Knautia arvensis Field Scabious British Wild Flowers by John Somerville et al. Bladmineerders van Europa
Knautia dipsacifolia     Bladmineerders van Europa
Scabiosa canescens     Bladmineerders van Europa
Scabiosa columbaria Small Scabious British Wild Flowers by John Somerville et al. Bladmineerders van Europa
Succisa pratensis Devil's-bit Scabious British Wild Flowers by John Somerville et al. Bladmineerders van Europa

Time of year - larvae: Currently unknown.

Time of year - adults: Currently unknown.

Distribution in Great Britain and Ireland: Recorded in East Kentand West Kent, West Suffolk (Levey, B. 2012. The Coleopterist 21(2): 67-72).

Distribution elsewhere: Widespread in continental Europe including Albania, Austria, Belgium, Bosnia and Herzegovina, Bulgaria, Crete, Croatia, Czech Republic, Danish mainland, Estonia, European Turkey, French mainland, Germany, Greek mainland, Hungary, Italian mainland, Kaliningrad Region, Latvia, Lithuania, Luxembourg, Poland, Romania, Russia - Central, Northwest and South, Sicily, Slovakia, Slovenia, Spanish mainland, Sweden, Switzerland, The Netherlands, Ukraine. Also recorded in the East Palaearctic (Fauna Europaea).

NBN Atlas links to known host species:

Knautia arvensis, Scabiosa columbaria, Succisa pratensis

British and Irish Parasitoids in Britain and elsewhere:

Ichneumonoidea - Links to species no longer available  
Bracon obscurator Nees, 1811 Braconidae: Braconinae

External links: Search the internet:

Biodiversity Heritage Library
Bladmineerders van Europa
British leafminers
Encyclopedia of Life
Fauna Europaea
NBN Atlas
NHM UK Checklist

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