Advice
RHS Help & Advice
Earwigs (Forficula auricularia)
Plants affected
Earwigs particularly enjoy the flowers and young leaves of dahlia, clematis and chrysanthemum, but in years when earwigs are abundant many other plants may also be damaged.
Symptoms
Flower petals and young leaves are eaten; older foliage is reduced to a tattered network of veins.
Cause
Inspect plants by torchlight on a mild night to find earwigs feeding on the flowers (other nocturnal pests that could be responsible are slugs, snails or caterpillars). Earwigs come out to feed at night during late spring to early autumn and prefer soft tissues to older foliage.
Prevention
Earwigs hide in sheltered places during the day and emerge to feed after dark. Avoid growing susceptible plants against wooden fences which provide daytime hiding places.
Control
Trap earwigs by placing upturned flower pots loosely stuffed with hay or straw on canes among plants being attacked. Every morning shake out the pots and remove the earwigs. This may not protect plants when earwigs are abundant, but it is a useful means of monitoring their numbers.
Before resorting to chemicals remember that earwigs are omnivores and can be of benefit in the garden by eating small insect pests and their eggs. If damage is extensive, you can spray with bifenthrin (Scotts Bug Clear, Bayer Sprayday Greenfly Killer Plus or Doff All-In-One Garden Pest Killer) at dusk on mild evenings when earwigs are likely to be active.
Andrew Halstead