The hydrangea is affected by several types of bugs. This includes the black vine weevil. This bug feeds on the small roots of the hydrangea, then progresses to chewing the bark.
The rose chafer beetle sometimes feeds on hydrangeas by skeletonizing the leaves. Additionally, they feed on the flowers and leave excrement.
Two types of plant bugs affect the hydrangea. The tarnished plant bug and the four-lined plant bug lay eggs in the soft stem of the hydrangea. They also suck sap from tender leaves and leave sunken areas where the leaves were punctured.
Several other bugs affect hydrangeas, according to the University of California website. This includes aphids, spider mites, scale insects, nematodes, foliage-feeding caterpillars and whiteflies.