What is eating holes in my plant leaves?
Something with jaws has been here, and the shape and position of the damage identify it more reliably than catching the culprit — most of them feed at night or drop off the plant the moment you lean in.
The one observation that decides it
Read the edge and the location. Dozens of tiny round shot-holes on the youngest leaves are flea beetle. Large ragged holes with a silvery slime trail nearby are slugs. Ragged holes plus dark green droppings are caterpillars. Neat U-shaped notches bitten out of leaf EDGES are vine weevil, and the adult damage is cosmetic while the grubs in the pot are what kills. Leaf tissue skeletonised to a lace of veins is Japanese beetle or sawfly larvae.
Start from the plant in front of you
13 things it could be
Ordered by how much they can cost you — if the first entry fits what you can see, rule it out before considering the milder ones.
Fine white webbing spun between leaves and twigs, with green caterpillars marked with black stripes and white dots feeding inside it. Leaves are eaten to a skeleton, then the bark is stripped, which kills the shoot outright.
Conditions: 12–32°CFirst move: Remove affected material nowRounded yellow-and-black striped beetles, plump orange-red humpbacked larvae, clusters of orange eggs under leaves, and rapid defoliation that can strip plants bare.
Conditions: 18–33°CFirst move: Remove affected material nowSeen on: Potatoes, Aubergines
Feeding starts low in the centre of the bush, so the outside looks fine while the middle is stripped. Pale green caterpillars with black spots eat leaves down to the midribs. Defoliated bushes still fruit but the berries stay small and the plant is weakened.
Conditions: 12–28°CFirst move: Treat, then re-check in 5–7 daysSeen on: Blackcurrants, Redcurrants, Gooseberries
Bright red beetles, 6–8 mm long, on leaves and buds from April. Ragged holes in leaves, then whole leaves eaten away. The larvae are orange grubs that cover themselves in their own black excrement as camouflage.
Conditions: 10–30°CFirst move: Treat, then re-check in 5–7 daysSeen on: Lilies
Distinctive U-shaped notches bitten out of leaf edges of heuchera, bergenia, rhododendron and strawberry. Later, a plant wilts suddenly and lifts out of its pot with no roots at all, revealing cream C-shaped grubs with brown heads in the compost.
Conditions: 5–25°CFirst move: Treat, then re-check in 5–7 daysSeen on: Strawberries, Hydrangeas
Rows of small dark eggs standing on end along the spears and fern needles. Adults and grey slug-like larvae strip the fern to bare stems, which turn brown, and spears become bent and scarred.
Conditions: 12–30°CFirst move: Treat, then re-check in 5–7 daysSeen on: Asparagus
Ragged holes and chewed leaf margins, stripped stems, dark green or black droppings (frass), and tunnelled or bored fruit; large green or striped larvae present.
Conditions: 15–33°CFirst move: Treat, then re-check in 5–7 daysSeen on: Cabbage, Kale, Broccoli, Cauliflower, Brussels sprouts, Kohlrabi and 1 more
Young plants cut clean through at soil level and left lying beside the stump. Later in the season, surface grazing on potato tubers and carrot shoulders. Scrape the soil within a few centimetres of a felled plant and a fat grey-brown caterpillar curls up in a C shape.
Conditions: 12–30°C · dry air ≤60%First move: Treat, then re-check in 5–7 daysSeen on: Sweetcorn
Dozens of small round holes peppering the leaves, heaviest on the youngest growth. Seedlings can be killed outright or checked so badly they never catch up. The beetles scatter with an audible flick when you lean over the row.
Conditions: 18–32°C · dry air ≤55%First move: Treat, then re-check in 5–7 daysLeaves skeletonised to a lacy network between the veins, chewed flowers and fruit, and clusters of feeding beetles on warm sunny days; brown patches in lawns from root-feeding grubs.
Conditions: 21–35°CFirst move: Treat, then re-check in 5–7 daysSeen on: Roses
Small purple-brown spots with a light centre appear on leaves; the dead centres drop out to leave clean round holes. Twigs develop sunken cankers that ooze gum, and fruit carries rough, scabby, raised spots.
Conditions: 8–24°C · humidity ≥85% · wet leaves / rainFirst move: Treat, then re-check in 5–7 daysIrregular ragged holes with smooth edges in leaves and fruit, seedlings eaten to the ground overnight, and tell-tale silvery slime trails on soil and foliage.
Conditions: 5–22°C · humidity ≥80% · wet leaves / rainFirst move: Treat, then re-check in 5–7 daysSeen on: Lettuce, Peas, Celeriac, Swiss chard, Rhubarb, Strawberries and 6 more
Ragged holes chewed in petals and young leaves, appearing overnight with no insect visible by day. Blooms open already tattered. Earwigs are found by day clustered in tight, dark crevices near the damage.
Conditions: 10–30°C · humidity ≥70%First move: Watch it before you actSeen on: Dahlias