Knowledgebase
Strange ladybugs #322933
Asked May 18, 2016, 11:02 PM EDT
Washington County Oregon
Expert Response
Thank you for including the high quality images with your inquiry. The insects are not lady beetles. They are coreopsis beetles, Calligrapha californica and they definitely are not beneficial. In fact. If you have coreopsis (tickseed) in in your garden, those plants may now be severely damaged.
Coreopsis beetles have been periodic pests in local gardens here in the northwest, with 5 or so years between successive events.
In any case, you would be wise to get rid of these beetles as soon as possible. The least toxic method for a wildflower garden is to flick the beetles, both adults and larvae, into soapy water. Other than that, some gardeners have enclosed a heavily infested plant in a plastic bag, cut off the plant at the ground, tightly secured the bag and, then, disposed of the mess in the trash.
This site for commercial growers has some basic facts and several links: http://oregonstate.edu/dept/nurspest/Calligrapha%20californica.html.
For images of the black larvae of coreopsis beetles and damaged coreopsis plants, see http://growingthehomegarden.com/2009/05/leaf-beetle-larvae-calligrapha.html.My research about their life cycle has revealed very little. Unfortunately, we've not received any follow-up reports from gardeners who have had these beetles. Even so, it does seem that gardeners complain about them every 5 years or so. No one has yet reported damage to vegetables.
