Leafroller tree infestations are a serious problem facing trees in North America. These small, caterpillar-like insects can cause extensive damage to trees, shrubs, and other plants by skeletonizing leaves, boring into stems and branches, and webbing leaves together. Leafrollers can also transmit diseases from one plant to another.
Leafrollers have been known to affect maples, cherries, plums, apples, pears, roses, and various other ornamentals. In some cases, entire crops have been destroyed by these pests.
In order to prevent leafroller infestations, it is important to understand the biology and behavior of these insects. Leafrollers belong to the family Tortricidae, which includes more than 10,000 species of moths and butterflies worldwide. There are approximately 700 species of leafrollers in North America, including the obliquebanded leafroller, the apple leafroller, and the cherry leafroller.
Leafrollers overwinter as eggs, which are laid on the leaves or stems of host plants. In the spring, the eggs hatch and the young larvae begin to feed. They continue to feed for several weeks before pupating into adults. The adult moths emerge from the pupae in late spring or early summer.
The moths mate and the females lay eggs on the leaves of host plants. This process is repeated several times throughout the summer, resulting in multiple generations of leafrollers.
Leafroller damage is most often seen in late summer or early fall, when the larvae are mature and feeding heavily. The larvae skeletonize leaves by eating the tissue between the veins, causing the leaves to appear ragged or “laced.” They also bore into stems and branches, causing twigs and small branches to break.
Webbing leafrollers build webs in which they live and feed. These webs can completely encircle branches, causing the leaves to turn brown and drop off.
Heavy infestations of leafrollers can weaken or even kill trees and shrubs. In addition, the presence of leafroller larvae can make fruit and vegetable crops unmarketable.
To prevent leafroller infestations, it is important to remove potential hosts, such as wild berries and other weeds, from the area around your home. Keep trees and shrubs well-trimmed and free of dead leaves and branches, which can provide shelter for the insects.
If you do find leafrollers on your plants, you can remove them by hand or with a strong stream of water from a hose. A Licensed Tree Expert can also treat your trees with the appropriate insecticide and fertilize the tree to reinvigorate it as it battles the insects.
Leafroller tree infestations are a serious problem, but with proper prevention and treatment, they can be controlled.