Advice for the Home Gardener from the Help Desk of the
UC Master Gardener Program of Contra Costa County
MGCC Help Desk Response: Thank you for contacting the UC Master Gardener Program Help Desk with the photo of your bugs. These are leaffooted bugs in the nymph stage.
Leaffooted bugs seem to be an increasing problem in our gardens. They are not new to California, but they seem to be occurring more commonly in the past several years. Adults overwinter, often in large groups, in protected spots such as woodpiles, palm fronds, under peeling bark, or in tree cracks. In the spring or summer, they move into gardens looking for fruit that's ripening so they can lay their eggs. Tomatoes seem to be one of their preferred crops.
Leaffooted bugs have piercing-sucking mouths they use to suck plant juice. When they feed on small tomatoes, the fruit will sometimes fall off prematurely. Feeding on mature tomatoes can cause a slight discoloration that doesn't really harm the tomato--they are still edible.
For control of leaffooted bugs right now (July), hand pick them when you see them (wear gloves because they don't smell very good), and look for and remove eggs which are usually laid in a chain on the underside of leaves. If you experience a heavy infestation this year, remove overwintering sites, clear weedy areas around your garden site where the adults feed before the fruit ripens, and next year, you can try using row covers to protect crops if you see the problem again. Use of an insecticide for control is rarely warranted.
This link will take you to more information about leaffooted bugs from the University of California: http://ipm.ucanr.edu/PMG/PESTNOTES/pn74168.html.
Please do not hesitate to contact us if you have more questions.
Help Desk of the UC Master Gardener Program of Contra Costa County (SEH)
Note: The UC Master Gardeners Program of Contra Costa's Help Desk is available year-round to answer your gardening questions. Except for a few holidays, we're open every week, Monday through Thursday for walk-ins from 9:00 am to Noon at 75 Santa Barbara Road, 2d Floor, Pleasant Hill, CA 94523. We can also be reached via telephone: (925)646-6586, email: firstname.lastname@example.org, or on the web at http://ccmg.ucanr.edu/Ask_Us/ MGCC Blogs can be found at http://ccmg.ucanr.edu/HortCoCo/ You can also subscribe to the Blog (http://ucanr.edu/blogs/CCMGBlog/).