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Notebook · Guide 8 October 2026 · seasonal

Lily beetle: the bright red beetle eating your lilies

Lily beetle adults, eggs and dung-covered larvae strip lilies and fritillaries from late March. Check every few days and pick them off by hand: it's the method that works.

seasonal

If there are ragged holes in your lily leaves and a glossy scarlet beetle sitting on top, you've met the lily beetle. It's been widespread across Britain and Ireland since the early 1990s, and it goes for true lilies and fritillaries. The honest answer is that there's no clever trick. You find them and you remove them, little and often, from late March. Do that and your lilies will still flower well.

01At a glance

  • What it is: Lilioceris lilii, a leaf beetle about 8mm long with bright red wing cases and thorax, and a black head and legs.
  • What it eats: true lilies (Lilium), fritillaries (Fritillaria) and giant lilies (Cardiocrinum). Adults rarely turn up on anything else.
  • When: active from late March to October. Eggs go on from April to midsummer.
  • The fix: check plants every few days and pick off adults, eggs and larvae by hand.
  • Don't bother: treating the soil. The beetles find lilies by scent from the leaves, not from the ground.

02Know all three stages

Most people spot the adults and miss the rest. The larvae do more of the damage, so learn what they look like.

  • Adults: shiny, pillar-box red, about 8mm long. They chew rounded holes in the leaves.
  • Eggs: small, orange-red and sausage-shaped, laid in neat rows on the undersides of the leaves.
  • Larvae: squat, reddish-brown grubs with black heads, 6–8mm long. They hide under a coat of their own wet, black droppings, so they look like blobs of dirt. Young ones graze the undersides of leaves, leaving dried white or brown patches. Older ones eat whole leaves, and can strip petals, stems and seed pods.

There is one generation a year. New adults appear from midsummer, but they don't mate until the following spring. They spend the winter in soil, leaf litter or any sheltered nook, and it doesn't have to be anywhere near your lilies.

03How to pick them off

Adults have one trick. When disturbed, they drop off the plant and land on their backs. Their undersides are dark, so on soil they all but vanish. Work with it, not against it.

  1. Start early. Adults are active from late March, so begin checking as soon as the shoots are up.
  2. Cup a hand or hold a tray under the leaf before you reach for the beetle. If it drops, it lands in your hand rather than in the soil.
  3. Squash the adult, or knock it into a jar of soapy water. Don't be surprised if it squeaks when squeezed. That's normal.
  4. Turn the leaves over. Rub off rows of orange eggs with your thumb.
  5. Wipe off the larvae. They're messy, so wear gloves and wipe them off with a damp cloth or a leaf, then squash them.
  6. Repeat every few days through spring and early summer, which is when the eggs and larvae are about.

Pot-grown lilies are the easiest to protect. You can stand the pot at waist height on a table and check every leaf in a minute.

04Is it worth the effort?

Yes, but you don't need to be perfect. The RHS suggests tolerating a few beetles where you can, because lilies and fritillaries can take some damage. What hurts is heavy leaf loss in early summer. The leaves feed next year's bulb, so a plant stripped in June tends to come back with a smaller bulb and fewer flowers.

Help is on the way, too. Three parasitic wasps that develop only inside lily beetle larvae now live in Britain, and ground beetles eat the larvae. Birds and frogs are worth encouraging as well. These won't clear an outbreak for you, but they're good reasons not to reach for anything that kills every insect in the border.

05Mistakes that cost you flowers

  • Only checking the tops of the leaves. Eggs and young larvae are underneath.
  • Mistaking larvae for bird droppings or soil. If a "blob" sits on a chewed leaf, it's probably a larva.
  • Starting in June. By then the first eggs have hatched. Start when the shoots come up.
  • Grabbing from above. The beetle drops and disappears. Hand underneath first.
Save your money
Don't buy soil treatments for lily beetle. The RHS says treating the soil under lilies doesn't help, because the beetles find plants through scent from the leaves.
Your fingers and a jar of soapy water are the most reliable tools there are, and they cost nothing.
Grow a few lilies in pots rather than a big drift you can't keep an eye on. Fewer, well-watched plants beat many chewed ones.

Lilies carry our most serious pet warning. If you have a cat, read the safety flags on our lily profile before you grow them or bring cut stems indoors.

How we checked this

Every care and safety claim on this page is verified against horticultural and veterinary sources.

Sources: RHS — Lily beetle · University of Wisconsin–Madison Extension — Lily leaf beetle

Checked 8 October 2026. If our advice ever conflicts with the RHS, believe them and tell us.