Oak Leaf Roller (Archips semiferanus)

The oak leaf roller is one of the more common reasons for oaks to defoliate. They’re found mostly in the Rocky Mountains, and favor the gambel oak. Here’s all you need to know about the pests and how to manage them.

Life Cycle of the Oak Leaf Roller

You’ll know one of these moths from the color of its back. They’re an olive brown with a band that looks almost like rust. The moths lay their eggs into the tree canopies around July and August, with many of them in the canopy branches. You will mostly find them on the south side of the tree, where they can get more heat from the sun. In the spring, the larvae emerge and feed on the clusters of leaves. They then use leaf rolls for protection during pupation, until they turn into moths.

Oak Leaf Roller Damage

Gambel oaks are the most common hosts for these pests, but they can also be found on maples. The leaf rollers cause many oaks to defoliate. Sometimes, the defoliation can cause the trees to weaken. While direct damage is unlikely, the weakened trees are often more susceptible to wood borers and late frosts.  Leaves are directly damaged. The pests will roll the leaves for shelter, causing them to break and lose access to nutrients. Most outbreaks will last 3-5 years and they will move on. In the central Rockies, the outbreaks are sporadic.
What to Do
Horticultural oil is the most popular treatment to help control and manage the population of the pest. The moths will quickly retreat from their home and the treatment can control the development of the eggs throughout the winter. It’s best to focus directly on the twigs and branches that the egg masses have been placed.

If you have any question about oak leaf roller on your scrub oak or any other tree insects, call SprayTech, tree health experts, at (720)248-0000 for treatment recommendations.