Earwigs particularly enjoy the flowers and young leaves of clematis, dahlia and chrysanthemums, but in years when earwigs are abundant many other plants may also be damaged.
What are earwigs?
Earwigs are yellowish brown insects, up to 13-15 mm long (about ½in), that have a pair of distinctive pincers or forceps on their rear end.
- Flower petals and young leaves are eaten; older foliage is reduced to a tattered network of veins
- Inspect plants by torchlight on a mild night to find earwigs feeding on the flowers and foliage
- Other nocturnal pests that could be responsible are slugs, snails or caterpillars
- 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
- 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, spray at dusk on mild evenings when earwigs are likely to be active with deltamethrin (Bayer Sprayday Greenfly Killer) or lambda-cyhalothrin (Westland Plant Rescue Fruit & Vegetable Bug Killer)
Pesticides for gardeners (Adobe Acrobat pdf document outlining pesticides available to gardeners)
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 immature nymphs are smaller versions of the adult insect
- Earwigs come out to feed at night during late spring to early autumn, and prefer soft tissues to older foliage
- They can eat small insects and eggs, as well as plant material