This Bug is eating my plants!

Damaged Hibiscus 

I have searched all my books, the web and asked everyone I know and I have no idea what this pest is but I can tell you what it's doing. It's eating it's way through my garden as well as the garden's of many of my friends and customers! It acts like the rose slug but is eating everything EXCEPT my roses! It's a tiny (almost invisible) Caterpillar on the underside of the leaves and as you can see if left untreated, the leaves become skeletons.

Neem oil and Insecticidal Soap did not work. Neem is what I always try first because it is recommended for organic control. I don't like using chemicals but I also can't afford to lose all my stock plants either. Mimi's Greenhouse Nursery would be out of business without my stock plants for making cuttings and new plants to sell.

After about six weeks I resorted to Malathion spray on underside of leaves. I was careful not to use this around where the butterflies and Humming Birds were feeding.  The before and after can be seen on the two plants below. The top growth is healthy - Finally! If this had only been on a few plants I would have let them be and hoped for regrowth in the late fall but it was all over my plants both in the ground and potted plants - spreading since May!

If any of you have any idea what this pest is, I'd appreciate a comment.

new growth on Hibiscus

Angel Trumpet getting new healthy leaves