I have seen reference to abundant white deposits on plants in a couple Texas blogs I follow. They seem to be appearing in greater number this summer. One said it was mealy bugs. Another delved a little deeper and with the help of iNaturalist identified them as Citrus Flatid Planthopper larva. (Her blog is here). She had a video of the planthopper moving away from its wooly nest, then going back. So I had to go prod and the ones in our yard to see if there were critters. Yup! Same behavior too, moves away from contact, but then eases back into the cottony camouflage.