Fragrant viburnum, known botanically as Viburnum farreri, is a flowering deciduous shrub that produces billowy white blooms in spring and deep red or black fruits in the fall and winter. The foliage is green in spring and summer and evolves to a deep bronze purple. It has a sprawling growth shrub growth habit and can be trained to climb vertical surfaces. Fragrant viburnum does not generally encounter life-threatening pest problems, but a few pest issues can arise that threaten the appearance or performance of the shrub.
Small hard shell scales such as oystershell scale, known as Lepidosaphes ulmi, colonize on viburnum branches causing tissue and then branch death. In extreme infestations the life of the viburnum can be threatened. Adult oystershell scale beetles survive the winter nestled against the bark and can protect their eggs. The eggs hatch in spring and the young crawlers attack tender new plant tissues before beginning their adult life cycle.
Flower thrips, known as Frankliniella tritici and other species of thrips can infest fragrant viburnums. The tiny winged insects are less than 1/16-inch long but can cause significant damage by perforating the plants surface tissues and sucking out the phloem. They congregate on tender young leaves and leave reddish purple specks on the lower leaf followed by curled shriveled foliage and premature shedding of leaves.
Southern red mites, known as Oligonychus illicis, are actually deep reddish brown in color and can be active on viburnums in spring and fall. They penetrate the tissue of the lower leaf surface with a thin needle-like sucker and feast on the sap and phloem. The leaves will wilt or become skeletonized, turn brown and drop from the tree. When infestations are significant the mites will begin to colonize on the tops of leaves and other tender green tissues.