Common insect pests of viburnums include the black bean aphid (Aphis fabae) and the snowball aphid (Neoceruraphis viburnicola), Viburnum Leaf Beetle (Pyrrhalta viburni), the viburnum clearwing borer (Synanthedon viburni) and the lesser viburnum borer (S. fatifera). Common diseases of viburnums include Bacterial Leaf Spot (caused by the bacterium Pseudomonas syringae pv. viburni), Downy Mildew on Viburnum (caused by the water-mold Plasmopara viburni) and Powdery Mildew (caused by Erysiphe viburni).