What are earwigs?

The common European earwig is a brown insect, it is up to 13-15 mm long (about ½in), and has a pair of distinctive pincers or forceps on their rear end.

Symptoms

• Earwigs can be beneficial on fruit trees where they eat aphids
• Flower petals and young leaves can be eaten; older foliage is sometimes reduced to a tattered network of veins
• Inspect plants by torchlight on a mild night to find earwigs feeding on the flowers and foliage 
• Earwigs hide in sheltered places during the day and emerge after dark to feed
• Other nocturnal animals that might be responsible for similar damage are slugs, snails or caterpillars

Control of fruit aphids

On fruit trees earwigs can give good control of fruit aphids and do not cause damage to the trees or fruit. Providing shelters such as flower pots loosely stuffed with hay in trees can help increase numbers.

Control

On fruit trees earwigs should be encouraged as they are useful predators of fruit aphids.

Non-pesticide control

• Trap earwigs by placing upturned flower pots loosely stuffed with hay or straw on canes among plants being attacked (This can also provide useful shelter when encouraging earwigs in fruit trees).
• Every morning shake out the pots and remove the earwigs (Do not do this if encouraging earwigs in fruit trees)
• This may not protect plants when earwigs are abundant, but it is a useful means of monitoring their numbers

Pesticide control

• Before resorting to chemicals remember that earwigs are omnivores and can be of benefit in the garden by eating small insect pests
• If damage is extensive, spraying at dusk on mild evenings when earwigs are likely to be active with products such as the synthetic pyrethroids lambda-cyhalothrin (e.g. Westland Resolva Pest Killer), deltamethrin (e.g. Provanto Ultimate Fruit & Vegetable Bug Killer) and cypermethrin (e.g. Py Bug Killer) may give some control
• Do not spray plants in flower due to the danger to pollinating insects
• Inclusion of a pesticide product does not indicate a recommendation or endorsement by the RHS Garden Advice. It is a list of products currently available to the home gardener

Download

Pesticides for gardeners (Adobe Acrobat pdf document outlining pesticides available to gardeners)

Biology

Earwigs overwinter as adult insects in the soil and other sheltered places.

• Batches of eggs are laid in the soil in midwinter and again in early summer
• Female earwigs remain with their eggs until they have hatched 
• The nymphs look like smaller versions of the adult insect 
• Earwigs are one of the few insects where the adults show some parental care, protecting the eggs and nymphs from predators and fungal infections
• Earwigs are largely nocturnal, coming out to feed at night during late spring to early autumn and prefer soft tissues to older foliage
• Earwigs also feed on aphids and some other invertebrates and can help reduce infestations particularly in fruit trees