Hoplia Beetles

The hoplia beetles can be seen damaging light colored flowers (specifically here-- my apricot-colored roses and light-colored irises) in gardens throughout the valley. They show up each year, when we have the first flush of roses, irises and other flowers blooming, but the beetles don't last long--usually a few weeks from April into May.
You can see that they do a lot of damage. The best way to get their populations down is to shake the beetles into a container of soapy water, where they will drown. If you continue to do this, then there will be fewer females that will lay eggs, which means less beetles to contend with next year.
The adults chew the light-colored flowers (but, not the leaves) of several different kinds of flowers. The females will lay their eggs in the soil around where they have been feeding. Only one hatching per year takes place, so if you can clip off the effected flowers, shake the beetles into soapy water, or tolerate some flower damage, then they will soon be gone. Insecticides are not very effective and will usually kill off the honey bees and other beneficial insects. For more information, see the University of California Integrated Pest Management website here.--Gard'n Judy