Hello,

To prevent another year of infestation by scarlet lily beetles, it’s important to combine various strategies for effective control. Here are some recommendations based on educational resources:

Hand-picking: Regularly inspect your lilies and manually remove any adults, eggs, or larvae you find. Crushing the insects or dropping them into soapy water can be an effective way to kill them. More information at this link:

What can I do to protect my lilies from lily leaf beetles? | Extension (unh.edu)

Chemical Control: Azadirachtin (neem oil) and insecticidal soaps have shown some control of LLB when applied every 5 to 7 days after the egg hatches. Systemic insecticides, such as imidacloprid, may provide effective control as a foliage spray or soil drench, depending on the label instructions, but note that imidacloprid and other insecticides must not be applied to plants in bloom or when bees are active. Contact insecticides that are effective against larvae contain permethrin, cyhalothrin, deltamethrin, or pyrethrin (Saeed, 2017; Smith, 2013). In general, insecticides with shorter persistence are less damaging to nontarget species than those with longer persistence and/or systemic action. If chemical control is warranted, less toxic chemicals such as insecticidal soaps and azadirachtin should be applied late in the day or early in the morning when bees are not active. More information at these links:

Lily-Leaf-Beetle-Pest-Alert.pdf (wisc.edu)

Lily Leaf Beetle | Home and Garden Education Center (uconn.edu)

lily-leaf-beetle.pdf (usu.edu)

Biological Control: In some areas, researchers have developed biological control programs using parasitoids that target the larvae of the lily leaf beetle. This method has been successful in reducing populations. More information at this link:

Lily leaf beetles continue to spread in Michigan - Gardening in Michigan (msu.edu)

Cultural Practices: Clean up plant debris in the fall to reduce overwintering sites for adults. Also, consider rotating where you plant lilies in your garden to disrupt the life cycle of the beetles. More information at this link:

Lily Leaf Beetle – Wisconsin Horticulture

Combining these methods should help you manage the scarlet lily beetle population and protect your lilies. Always follow the label instructions when using pesticides and consider the impact on beneficial insects and the environment.

I hope this helps!