This could be aphids or thrips which feed on the underside of leaves and cause the leaf to be distorted. Aphids can be washed off with a mild insecticidal soap. Both aphids and thrips can be handled with a natural predatory insect like green lacewings or ladybugs.
You might even try a spray of water on the undersides of the leaves to see if that will wash off the tiny insects.
Posted by: Dennis
Posted: July 14, 2016