Webbing and distorted leaf growth (especially new leaves) are a sign of a spider mite infestation. They suck the content of the cells, making the leaves turn yellow and then brown. To check for mites, place a 8.5x11" piece of paper under the affected area and shake the shrub. Any mites that fall down onto the paper will appear as tiny moving specks. Mites usually become a problem as temperatures warm up (I have seen indications of them already in my garden). To control an infestation, you can release ladybugs or lacewing larvae or parasitic wasps; or you can apply insecticidal soaps/oils (Sunspray Ultrafine Spray Oil, Safer Insecticidal Soap, etc); or you can apply miticides (like Spectracide Permethrin Insect Control, Bonide Kelthane, Schultz Houseplants and Gardens Insect Spray, etc) per label directions. If you decide to use mitices, try using two miticides with different active ingredients (apply miticide "A" first, then "B", "A", "B", etc per each one's label directions). This helps prevent mites from becoming resistant to any one miticide. Does that help you? Luis