They sit on the underside of the leaves, JD. You'd see them if you turned the leaf upside down. They're like tiny chartreause-colored worms or non-fuzzy caterpillars. The reason they're so hard to kill is that they're under the leaves, so even if you were to spray with chemicals, chances are you'd only hit the top of the leaves and not hurt the pests. I haven't used Sevin in a long time, but it used to come in a powdered form in a squeeze bottle that you could hold below the plant and squeeze. The Sevin dust would fly up and land on the underside of the leaves.
