Some of my violets have very thick curled leaves at the base, I don't see any bugs. Is this something that can be treated?
Sometimes a photo is better than any description :-) Maybe someone having a better understanding of English will be able to answer...I really don't see what you're talking about...
Come one folks !!!!!!!
This reminds me of an infection with the Violet gall midge (Phytophaga violicola). The small fly lays eggs in the curled margins of the unfolded new leaves. When these eggs hatch the maggots causing greater curling, distortion, and twisting of leaves. Either remove the affected leaves by handpicking or try Imidacloprid (Consult the label).
I concur with Gerd.
These tend to favour V. odorata, in my experience.
The tiny larvae stay within the thickened and rolled leaves; you won't see them unless you cut or break them open.