Check with your local nursery. WE had aphids attacking a lot of our trees and plants. We used a systemic solution sprayed on.
This might help you out: https://homeguides.sfgate.com/bugs-clematis-plants-78185.html
A number of insect pests will feed on clematis leaves and damage them, including earwigs and the caterpillars of various moths. If the young leaves appear distorted or torn and are full of small, brown-edged holes then the likely culprits may be capsid bugs. Slugs and snails are also common pests of clematis leaves.
see if this helps you out
I included pictures. I guess they didn’t go through.....