Pest Profile: Lily Beetle

These scarlet beetles with black heads love lilies. They are such big lily fans that they consume not just the leaves of these plants but also their flowers and seedpods as well. Their appetite is not restricted to water lilies, they will also munch down on other species of lilies. These pests measure 6mm to 8mm in length. Many gardeners mistake them for ladybirds. However, they are a completely different pest.

These beetles lay their eggs from April to September on the underside of lily leaves. After one week the eggs hatch into grubs. These maggot-like reddish brown grubs consume the same plant parts as their parents. In order to either disguise or throw off predators, the larvae wrap themselves in their own black and wet feces.

How to detect Lily Beetles

Check for lily leaves that are shredded. Keep an eye out for brow-black beetle feces.

How to handle Lily Beetles

For organic pest management, manually pick the adults and grubs as soon as you spot them. The moment you touch them, adults will drop to the ground. Spread a newspaper on the ground so you can catch them. Quickly crush them with your foot or they will quickly fly off.

For chemical pest management, spray imidacloprid, sunflower oil, or thiacloprid on your plants when you detect signs of lily beetle attacks. Chemical pesticide treatment works better on beetle larvae than on adult pests.