Earwigs
Forficula auricularia
Nibble ragged holes in petals and soft leaves overnight — dahlias and clematis suffer most. Trap in upturned straw-filled pots on canes and empty each morning.
How to know it
A shiny reddish-brown insect 12–15 mm long with the familiar pair of pincers at the tail — curved on males, straight on females. Strictly nocturnal, so by day it is packed into a flower, a fold of leaf or a crevice, and only the damage shows.
What you'll see
- Ragged holes and notches eaten out of petals overnight, on dahlias and chrysanthemums above all.
- Soft young leaves grazed into a lace, with no slime trail to blame it on.
- Earwigs falling out when a bloom is cut and shaken.
- Damage that appears in the night and no culprit visible by day.
- Shallow holes grazed in soft fruit and in ripe apricots and peaches.
Where it comes from
A remarkable insect for a garden pest: the female lays in an underground chamber in winter and guards and cleans her eggs and young — rare devotion among insects. One generation a year, with young emerging in spring and adults feeding from midsummer into autumn. It is also a serious predator of aphids and codling moth eggs, which complicates the verdict considerably.
Warm dry summers and gardens with plenty of daytime shelter. Damage is heaviest on show blooms and late-summer flowers; on fruit trees, the same insect is doing you a considerable favor.
Dealing with it
- Set upturned pots stuffed with straw or newspaper on canes among dahlias; empty them each morning well away from the border.
- Move the trapped earwigs to the fruit trees rather than killing them — they eat aphids and codling moth eggs there.
- Check blooms after dark with a torch and pick off what you find on show plants.
- Grease-band or barrier the stems of a few prize plants rather than treating the whole border.
- Accept the damage anywhere it is not a show flower; the trade is well in your favor.
Keeping it out
- Clear the debris, boards and old pots that give them daytime shelter near dahlia beds.
- Disbud and stake show blooms so they are easy to inspect.
- Keep the traps running from midsummer, before the damage starts, not after.
- Do not spray: an earwig killed on a dahlia is an earwig not eating aphids on the apple.
- Grow the plants they favor away from walls, sheds and log stacks.
What it goes for
Dahlias, chrysanthemums, clematis, delphiniums and other soft-petalled flowers; occasionally soft fruit and stone fruit.
Who hunts it for you
- Frogs & toadsAnura A resident toad works the beds every night for slugs, cutworms, and weevils. Recruit them with water — even a sunken basin pond — plus damp shade and an upturned-pot toad house; skip the slug pellets that poison their prey.
- HedgehogErinaceus europaeus A European animal, and worth saying so plainly: there are no hedgehogs in North America, and the ally that does the same night shift here is the toad, the opossum or the ground beetle. Where they do occur, cut a gap in the fence and skip the pellets.
- Praying mantisMantidae A sit-and-wait ambusher that snatches caterpillars, beetles, and anything else that wanders close — friend and foe alike, so count it a mixed blessing. Tall, structured plantings give it perches and egg-case anchors. Grow to recruit it: Cosmos,Fennel,Sunflower
- Salamanders & newtsCaudata Damp-loving hunters of slugs, worms, woodlice and beetle larvae that spend the day under a log or a stone and work the beds at night. Companions to the toads: they want the same damp shade, the same log pile, and the same absence of slug pellets.
- Snakes & lizardsColubridae & Phrynosomatidae A garter snake works the beds for slugs and voles and a fence lizard clears grasshoppers off a sunny wall. Almost every snake a gardener meets is harmless and useful; give them a log pile, a warm flat stone and a bit of cover and they stay.
- SpidersAraneae Webs, ambushes, and night patrols make spiders the garden’s steadiest generalist predators, taking whatever flies or crawls past. Mulch, ground cover, and undisturbed corners keep the population dense. Grow to recruit it: Lavender,Thyme
- Tachinid flyTachinidae Bristly, house-fly-lookalike parasitoids that lay eggs on caterpillars, beetle grubs, and earwigs — the maggot consumes the host from within. Adults sip nectar from shallow umbels and daisies. Grow to recruit it: Cilantro,Dill,Feverfew,Parsley,Sweet alyssum
See also
The Cottage Garden Companion — the gardener's bestiary at cottagegardencompanion.com