Search

Hi Laura, Great job with our Tree! Many thanks to you and the crew. ”- Bob G.

Search

Mr. Andrade said yes to every request with patience and understanding on a very cold day. Superb representative of PTS. ”- Rob P.

Tree Pest Alert: Oak Sawfly

Are some of the leaves on your oak trees turning brown or look skeletonized? If so, the larvae of oak sawfly could be making a meal of your tree!

ID Oak Sawfly

Oak sawfly is really not a fly at all. If fact, it is a small black wasp that closely resembles a fly. They use a saw-like structure at the tip of their abdomen to “saw” into leaves when depositing eggs. Once the eggs hatch, the larvae quickly and aggressively chew up your tree’s leaves.

Oak sawfly larvae are leaf skeletonizers. Meaning they feed on the lower surface of leaves, mowing down everything except the leaf veins. This leaves a transparent look to the leaves that can be quite startling. As the leaf dries, it quickly turns brown. If you suspect sawflies, simply flip over a few leaves & look for the larvae.

1518008-SMPT

William A. Carothers, USDA Forest Service, Bugwood.org

Oak sawfly larvae are quite interesting, to say the least. They are commonly referred to as ‘slugs’ because of their slimy appearance and similar body shape. The larvae are yellow & bowling pin shaped, and as they grow and get larger – up to a ½” – two black dots that look like eyes form on their heads.

It most parts of the country, there is only one generation of oak sawfly per year. But in warm southern climates, we may see a 2nd or 3rd generation that re-emerge to do their feeding in late summer. The insect overwinters as pupae in the soil.

5370019-SMPT

Steven Katovich, Bugwood.org

Different trees; same damage

There are many different types of sawfly and each type prefers to feed on a specific type of tree or ornamental plant. Oak sawfly feeds on red, white and pin oak. Other types of sawflies feed on ash, elm, pine, and azalea, to name a few.

Should you treat?

Oak sawfly is mainly a nuisance pest – most healthy trees can tolerate some defoliation damage from sawflies. Established trees will typically rebound & leaf out just fine in the spring. Pesticides are not typically necessary, unless your arborist feels your tree is already unduly stressed by other factors.

Trees that are suffering from other pest or diseases issues, decay, or severe storm damage might not be able to handle additional sawfly defoliation. Your arborist can determine if treatment is necessary on a case by case basis.

If you notice leaf skeletonization on the leaves of your tree give us a call. Our experienced arborists will diagnose your tree issue & offer the best solution.

Entry Info

Leave a Comment