The Stanislaus Sprout
Article

What’s attacking my roses, calla lilies, and other light-colored flowers?

Small brown adult hoplia beetle and chewed up rose petals. (Jack Kelly Clark)
Adult hoplia beetle and its feeding damage on petals. (Jack Kelly Clark)
Roses and many other flowers are blooming in gardens right now and several callers have asked for help with pest identification. We are happy to look at photos or samples, but home gardeners can usually easily identify this insect once they see a photo. 

To confirm your plant has hoplia beetles, inspect a flower and you may also spot this culprit (or three) hiding inside. The beetles are small, brown, and their undersides look like they've been dusted in gold. If you hold one in your hand, they will “play dead” and not move so you can examine them.

The best way to manage hoplia beetles is regularly handpicking or shaking them off the flowers into a bucket of soapy water and then disposing of it. This can help reduce beetle populations in the future. You can also fill white, 5-gallon buckets with water and a few drops of detergent. The white color may attract the beetles which will fall into the bucket and drown. Luckily, their populations begin to dwindle by June. You can read more details about these methods in the UC IPM Pest Note: Hoplia Beetles.