Good Bug for Milkweed

Advice for the Home Gardener from the Help Desk of the 
UC Master Gardener Program of Contra Costa County

Good Bug for Milkwood
Client Gardener from Mid-County:  Hello Master Gardeners, can you tell me who this guy is, and whether he's a friend or foe?  Thanks,
Client Gardener from Mid-County (Again):  Actually, never mind, it's the nymph of a small milkweed bug, isn't it?  Finally found it online - wasn't seeing at first because they mostly have pictures of adults. Will continue to ignore them since they are harmless.

Milkweed Bug
Milkweed Bug
Response from the MGCC Help Desk:  Thank you for contacting our UC Master Gardener Program Help Desk about identifying your insect. You are correct - this is an immature Milkweed Bug (Lygaeus kalmii). They are primarily seed eaters, but they are also opportunistic and generalists. They will get protein wherever they can find it. Milkweed Bugs will also eat monarch butterfly eggs, larvae and the immature stages of other butterflies. They also feed on nectar and if the opportunity arises, they'll eat other small bugs as well.
These bugs have few predators as they feed on toxic milkweed that makes them distasteful. Their red and black coloring also sends this same warning signal to predators.
Below are two links with additional information.
Please let us know if you have any questions.

Thank you again for contacting our office!

Help Desk of the UC Master Gardener Program of Contra Costa County (JMA)

Note:  UC Master Gardeners Program of Contra Costa'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:, or on the web at MGCC Blogs can be found at You can also subscribe to the Blog.

By Steve I Morse
Author - Contra Costa County Master Gardener