Sumac leafroller

The Sumac leafroller (Episimus argutanus) is a moth species belonging to the family Tortricidae, order Lepidoptera. It is recognized as a specific pest that primarily targets various species of sumac (Rhus), frequently causing aesthetic and physiological damage to these popular ornamental woody plants in gardens and landscapes.

The primary hosts of this insect are Staghorn sumac (Rhus typhina) and Smooth sumac (Rhus glabra). While the moth shows a high level of host specificity, the impact of its larvae can be quite severe, especially when local populations reach high densities, leading to noticeable defoliation and stunted growth of the host shrubs.

The life cycle of Episimus argutanus consists of complete metamorphosis: egg, larva, pupa, and adult. The moths emerge in the spring, and females deposit eggs on the foliage. Upon hatching, the larvae immediately begin to construct shelters by tying leaves together with silk, which provides them with protection from predators and environmental stress while they feed.

Feeding damage is characterized by folded or tied leaves that appear distorted and skeletonized. The larvae consume the green tissue, causing the leaves to brown and eventually wither. This damage can reduce the vigor of the plant and severely mar the aesthetic appeal of the sumac, which is highly valued for its unique foliage and autumn colors.

Control strategies for the Sumac leafroller involve both cultural and chemical practices. Early detection is key; gardeners should look for webbed leaves during late spring. Mechanical control, such as picking and destroying the infested leaf rolls, is often sufficient for small gardens. In more severe infestations, the application of horticultural oils or approved insecticides during the larval hatching period is recommended to minimize damage.