I would try a soap bath...sounds like bugs are trying to make a nest...................after the sun goes down mix 1 teasp liquid hand soap & 1 qt of water mix & spray........repeat as necessary.......get under and in each leaf...........repeat....................and also spray the other bushes so whatever it is has no place to hide...........also the dirt underneath....................try that..................do it again if it rains...this is a safe one.
next week see if that has helped...........if not they sevin...follow the directions on the container, see what mix and if your plant is on the list...................wear old clothes, goggles, gloves, mask & a hat.............mix with water and spray...........keep children & pets away until it dries.