We have a yellow trumpet bush. It is plagued by tiny white worms or maybe caterpillars. The leaves end up skeletonized and stuck together with some sort of silk like substance. Besides the leaves there are profuse amounts of black things that look like droppings. My wife says she has see the worms, 1/8 to 1/4 inch long and white. Very tiny she says. We have tried Captain Jack's, Bayer spray, Ortho and homemade soap spray.