Help for the Home Gardener from the Help Desk of the UC Master Gardener Program of Contra Costa County
Help Desk Response: Thank you for contacting the UC Master Gardener Help Desk with your question about the large bugs on your pomegranate tree. You're right, they are leaf-footed bugs. Your photos are helpful and show adults on your pomegranate fruit.
The following website has useful information about these bugs and how to manage them:
The adults can cause small blemishes on the surface of the pomegranates, with brown spots inside the fruit. The adults are common now because the fruits are getting close to harvest time. As noted in the website, insecticides are usually not warranted but they can be used if an infestation is particularly severe. If your infestation reaches a level at which you conclude you need to apply an insecticide, you'll find recommendations about the type of insecticide to use and when to apply it in the attached document. You will want to be cautious about the use of insecticides if you want to consume the fruit. If you do apply a pesticide, make sure that you follow the instructions on the label regarding the time period to wait between applying the pesticide and harvesting the fruit. Also, wash the fruit before eating it. Additionally, keep in mind that spraying with insecticides may be harmful to bees and other beneficial insects.
Control of the bugs using more physical measures may be helpful. You can get the nymphs and adults out of the tree by shaking the branches or by using a stream of water from the nozzle on the hose. You can squash the bugs once they are on the ground. Because some adults may fly away, you'll want to repeat this process every week or so. You may also be able to pick the bugs off the plants by hand and crush them, wearing gloves to avoid the odor of the bugs.
As you'll see on the website, the adult leaf-footed bugs can overwinter and then re-emerge in the spring to lay eggs. Each adult female can lay up to 200 eggs over a two-month period in the spring. Given this life cycle trait, a good management approach is to try to eliminate places where the insects can overwinter. In your fall cleanup, you will want to remove all the fruit from the tree and clean up debris below the tree to help remove overwintering populations. The adults also overwinter under woodpiles so if you maintain a woodpile you might want to inspect it carefully to remove any of the insects you can locate. In the springtime, the adults feed on weedy plants, so eliminating or mowing woody plants in the vicinity of your pomegranates can also be a good strategy for reducing populations.
Good luck with you pomegranate tree.
Help Desk of the UC Master Gardener Program of Contra Costa County (SMT)
Note:s Contra Costa MG's Help Desk is available almost year-round to answer your gardening questions. Except for a few holidays (e.g., last 2 weeks December), we're open every week, Monday through Thursday for walk-ins from 9:00 am to Noon at 2380 Bisso Lane, Concord, CA 94520. We can also be reached via telephone: (925) 608-6683, email: firstname.lastname@example.org, or on the web at http://ccmg.ucanr.edu/Ask_Us/. MGCC Blogs can be found at http://ccmg.ignore.edu/HortCoCo/ You can also subscribe to the Biog.