How to stop and get rid of Scarlet Lily Beetle - treatment and control

The scarlet lily beetle (Lilioceras lilii) is as beautiful as its name suggests, however, this leaf beetle and its larvae can do a huge amount of damage to your treasured lily plants in a very short space of time.

How to identify scarlet lily beetles

The adult lily beetle  is 6-8mm long with a  bright red body and wings, and black legs and head.  From early spring until autumn, it is easy to spot these incredibly bright yet relatively slow-moving red beetles  on lilies, but once disturbed the beetle  as a cunning  defence mechanism that makes physical capture difficult, as , it drops to ground level and turns upside down,  making the black underside hard to spot.

Lily beetles only lay their eggs on lilies or frittilaries and although a bright orangey/red, they are laid in clusters on the undersides of  the leaves, making them harder to spot

Scarlet lily beetle larvae are reddish/brown, 6-8mm long with round bodies, but hard to spot as they cover themselves with their own gooey, black excrement (frass) as a defence against predators! They are mostly active from mid-summer

Scarlet lily beetles symptoms and damage

Adult scarlet lily beetles eat holes in the leaves of lily plants, often causing leaf drop which weakens the plant. Lily beetle larvae do more damage by scraping away the underside of the leaves, leaving white or brown patches. Lily beetles will also eat flower buds, lily flowers and seed pods. Over time, the lily bulbs become smaller and in subsequent years the flowers become fewer or might fail completely.

As well as attacking true lilies (Lilium species), they will also attack other members of the lily family such as snakes head fritillaries (Fritillaria meleagris), crown imperial (Fritillaria imperialis) and giant Himalayan lilies (Cardiocrinum giganteum).

Scarlet lily beetles control and treatment

How to get rid of red lily beetles?

• Remove any adult scarlet lily beetles by hand and dispose of them. They are quite dozy early in the morning, so this is the best time to catch them. Always place some light paper underneath the plant so you can spot them when they fall off the plant. , Wipe off the larvae rather than picking them off or remove a whole leaf where they are feeding and dispose of it.
• Control with an organic contact spray such as BugClear™ Ultra 2 concentrate. If there is a bad infestation. Only ever spray on a calm dry day and ideally in the early morning or evening when pollinating insects aren’t around. Never spray any type of control on to open blooms.

How to prevent scarlet lily beetles

It is difficult to prevent them completely but always:

• Check your plants. From early spring start to check lilies and fritillaries frequently for signs of scarlet lily beetles, so that you can remove them before a damaging population has developed.
• Encourage wildlife in the garden. Birds, frogs, wasps, and predatory ground beetles eat lily beetle grubs and sometimes adult beetles Learn to live with the red lily beetle but if the infestation is bad every year, then consider growing other plants that are not part of the lily family.