Some rhubarb leaves have red spots
My rhubarb plants have red spots, about 1/4 inch in size on the leaves. It is a green leaf plant. Is this a problem?
Certified GKH Gardening Expert
Many spring caterpillars will feed on rhubarb leaves as well as slugs and ants.
You can try treating them but if it's just the leaves I would not worry.
Here is a link to care of rhubarb.