The Earwigs of Worcestershire

(and you thought he was joking!)

By Gary Farmer

Earwigs are instantly recognisable insects - those irritating bugs that hide in your gardening gloves, eat your Chrysanthemum flowers and crawl into your ears whilst you are sleeping, not to mention those venomous pincers! Britain has recorded a massive eight breeding species of Earwigs, four of which are either extinct now in this country or so rare that there's more chance of finding a colony of Mole Crickets. 75% of the remaining species have been recorded in Worcestershire - that's three. So if you want a group of Invertebrates to "get into" but are usually put off by the sheer numbers of species involved ......... read on.

Earwigs belong to the Order Dermaptera ( part of the Orthoptera to some authors) and have the following features:

3-segmented tarsus.
Cerci modified into pincers - Those of the male being larger, more strongly curved than the females' but the latter is the more likely to deliver a "nip". In both sexes these are used defensively, and offensively to catch prey. Not poisonous.
Very short forewings (elytra) - tough, protective covers for the hind wings. Combined with their elongate bodies this feature give the earwigs their similarity to Staphylinid beetles.
Fan-folded hindwings - Reduced or absent in some species. An amazing piece of engineering. The elytra are "unzipped" using the cerci and full-size hindwings are unfolded for flight (yes! Earwigs do fly) and re-housed after use in a fraction of a second.

The Species.

The Common Earwig (Forficula auricularia).

This is the species that we are most likely to encounter. Often described as a garden pest because of their liking of flower petals, but they are omnivorous and actually consume large numbers of aphids and other small, soft-bodied insects. F. auricularia displays an amazing amount of parental care, being well documented as the species that gathers it's eggs back together if they become spread, licking them to keep them clean and free from mould. Capable of flight but their nocturnal habit means that this behaviour is very rarely observed.

Description. Dark brown species with yellowish legs. Hindwings large and slightly protruding from beneath forewings. Body length 10-15mm with forceps usually around 2.5mm, males forceps can be up to 8mm (Marshall and Haes 1988).
Distribution. Recorded just about everywhere across Britain including most off-shore islands. Very widely distributed in Worcestershire but because of its familiarity this species is often not recorded.

Lesne's Earwig (F. lesnei).

A rare species (Nationally scarce B) and almost certainly under recorded. Particularly associated with old hedgerows especially amongst wild Clematis, but this is by no means the only habitat: scrub and areas of tall herbage are worth checking. F. lesnei has much reduced hind wings and so cannot fly.

Description. Very similar to the previous species, but smaller (body length 6-7mm with male forceps not exceeding 3mm) and light brown. Hindwings never protruded from under the forewings.
Distribution. Recorded from scattered locations in the southern part of Britain but is spreading north-east. In Worcestershire it has been found near Evesham - at Twyford Country Park and at Windmill Hill NR. Hedges in other areas of the county (especially the southern half) could hold populations of this elusive species, but be aware that F. auricularia can regularly be beaten from hedges.

The Lesser Earwig (Labia minor).

This is a very small species associated with dung heaps and compost heaps and because of this it is very under recorded. It is a very active species which flies readily and is drawn to light. Too small to be confused with our other Earwigs and is most likely to be mistaken for a small Staphylinid beetle.

Description. Dull brown and pubescent with hindwings protruding from beneath forewings. Body slender and only up to about 5mm with forceps around 1mm (slender in both sexes and only slightly curved in the male).
Distribution. Very wide spread from Cornwall to Scotland but very scattered records. Very few records in Worcestershire probably due to size and habitat but this species is drawn to light and has been recorded from the library at Lower Smite Farm during a meeting when it flew in! A useful source for records could well prove to be moth-traps run on farmland or in gardens.

Pictures adapted from Lucas 1920.


HAES ECM & HARDING PT. 1997. Atlas of Grasshoppers, Crickets and Allied Insects in Britain and Ireland. London: The Stationary Office.
LUCAS WJ. 1920 A Monograph of the British Orthoptera. London: The Ray Society
MARSHALL JA & HEAS ECM. 1988. Grasshoppers and Allied Insects of Great Britain and Ireland. Harley Books.
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