I live in Mountain View, CA, and found a lot of these bugs in our back yard for the first time this year. We have a Japanese Maple that has just started sprouting leaves and we found an infestation of what we thought were aphids, but know I’m wondering if it’s the larvae of this bug.
Thank you for your help!
Your photo is of a soldier beetle.
The adults feed on aphids and other insects, while the larva feed on soft bodied insects. So this would be a beneficial insect.
The adults of some species are seen on flowers in the fall where they help with pollination.