Hi Arthur,

Thank you for reaching out to us at the UNH Extension Infoline. We have received a few inquiries over the last few weeks with Infoline client - Asiatic beetle issues. I will be including various information that we are sharing with others experiencing similar issues below:

The management of Asiatic garden beetles, particularly in their immature grub stage, may not always necessitate intervention, particularly chemical treatments. However, when faced with a severe infestation that causes significant damage, several strategies can be employed.

Culturally and mechanically, methods such as the method of collecting them at night with
soapy water is a good start for immediate control, but addressing the underlying causes will be crucial for long-term management. Adult beetles tend to drop to the ground when disturbed, making them easier to capture in a bowl of soapy water placed beneath infested foliage. You can use a flashlight at night to help them emerge.

In ornamental and vegetable garden beds, using fabric covers may deter adults unless they are already present in the soil below the plants. Additionally, cleaning up weeds and tall grasses in the fall can help discourage Asiatic garden beetle populations from thriving in subsequent seasons.

Currently, there are no recognized biological controls or natural enemies specifically targeting Asiatic garden beetles. In cases where chemical management is deemed necessary, especially in lawns and turf areas, similar strategies to those used against other white grub species can be applied.

As for chemical options, various insecticides are available for controlling Asiatic garden beetles. These include bifenthrin, clothianidin, cyantraniliprole, cyfluthrin, dinotefuran, imidacloprid, and lambda-cyhalothrin, among others. It's crucial to thoroughly read and adhere to the entire label of any pesticide product before use, ensuring it is used in strict accordance with the labeling guidelines. The label serves as a legal requirement, specifying correct application methods and safety precautions.

By integrating these strategies, you can effectively manage Asiatic garden beetle populations while minimizing environmental impact.

Asiatic Garden Beetle Fact Sheet: https://extension.unh.edu/sites/default/files/migrated_unmanaged_files/Resource000542_Rep564.pdf

I hope that this information helps, but please reach out if you have any further questions.

Thank you!

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