Leslie's Earwig Forficula lesnei Finot (Dermaptera: Forficulidae) at Thorpe-le-Soken
JERRY BOWDREY
Colchester Museums, 14 Ryegate Road, Colchester, Essex COl 1YG
On 26th February 2003 at 23.00 hrs an earwig was noticed on the house wall beneath an outside
lamp fitted with a 60 watt tungsten bulb. The evening was mild and cloudy following a cold spell
the previous week. On examination the insect proved to be a male Forficula lesnei Finot,
characterised by the shape of the base of the forceps and the apparent lack of hind wings. There are
few records for the species from Essex (Haes & Harding 1997) and its life history is poorly known
(Marshall & Haes 1988). The following data are held by the Biological Records Centre at Monks
Wood: Alresford (1911); Colchester (1911 and 1952); nr. Tollesbury (1983); Frinton area (two
records 1984); Grays Chalk Pit (1986) and Rowhedge Pits (1992). The Thorpe record is from
TM 173229. Where sufficient detail is given, the sightings were mostly between May and September.
On the Continent the species has been observed into November (Marshall & Haes, 1988) The
Rowhedge record (14 March) and the most recent Essex record would suggest that the species
passes the winter in hibernation, as does the Common Earwig Forficula auricularia, although in
the latter species the male dies during the winter, only the female surviving to lay her eggs and
remaining with the young until early summer (Marshall & Haes, 1988).
It is very easy to pass F. lesnei over as its commoner relative, but differences in the male forceps are
well illustrated in Hincks (1956). The Thorpe specimen was slightly longer in the body than the 6-
7mm given in Marshall & Haes (1988) although within the range 6-10mm given in Hincks (1956).
The hind wings in F lesnei are vestigial while those of F. auricularia are fully formed and project
beyond the elytra, but as pointed out by Burr (1936) the apices can be nibbled off by other earwigs.
Acknowledgements
The author would like to thank Henry Arnold of the Biological Records Centre for supplying
details of the records obtained by the Orthoptera Recording Scheme mapped in Haes & Harding
(1997) and Tim Gardiner (Essex Field Club Orthoptera Recorder) for checking his Essex database
for F. lesnei records.
References
BURR. M. (1936) British Grasshoppers and their Allies. Allan.
HAES, E.C.M. & HARDING, RT. (1997) Atlas of Grasshoppers, Crickets and Allied Insects in Britain and
Ireland. Institute of Terrestrial Ecology.
HINCKS, W.D. (1956) Dermaptera and Orthoptera. Handbooks for the Identification of British Insects 1(5).
Royal Entomological Society.
MARSHALL, J.A. & HAES, E.C.M. (1988) Grasshoppers and Allied Insects of Great Britain and Ireland.
Harley.
Essex Naturalist (New Series) 20 (2003)
49