While scouting for blast, a PCA noticed some yellow leaf tips. Close inspection revealed aphids. He got a little worried since he's never seen aphids on rice during his long career. They turned out to be yellow sugarcane aphid. These aphids are common in small grains like wheat and barley, and in corn, so it is not surprising that they can be found feeding on rice. Actually, they are considered a pest in southern rice, where they feed on rice during the seedling stage. 

Photo by Bart Drees, Texas A&M University

We went to the field to see how prevalent they were. There were some yellow leaves above the canopy level. These were mostly from bakanae infected plants. There were some yellow leaves here and there at the canopy level, on these we found aphids. 

Yellow sugarcane aphid injects a toxin into rice plants during feeding that causes the foliage to become reddish.

In California, aphids are not considered a pest of rice. Most likely, they are present in some rice fields some years at very low levels, and mostly go unnoticed. The infestation in this field was very low, and probably the aphids will disappear in a few days. Nothing to worry about - just something to be aware of.

While looking for the aphids, we noticed some feeding scars that, at first, looked like rice water weevil scars. After looking closely, we realized these were caused by something else. After some search, we found quite a few beetles feeding on the rice next to the road.

I haven't identified the beetles yet, but they look and jump like flea beetles. The field is next to some unmanaged vegetation, and most likely their food source is drying off, so they are looking for some green material. I think this is just an "incidental" infestation. Again, nothing to worry about - just something to be aware of.