Worms on Live Oak Trees

Caterpillar larvae worms often feast on live oak trees.

Although they are sometimes controlled naturally by parasitic wasps and mockingbirds, the worms that feed on a live oak tree often may only be controlled or eliminated by the application of an insecticide.

Oak Leaf Roller

A number of species of caterpillar defoliate oak trees as they feed with vigor on early spring growth, sometimes destroying all of the new leaves. "Two such caterpillars are the oak leaf roller, Archips

semiferana (Walker) (Lepidoptera: Tortricidae), and an associated species, Sparganothis pettitana," reports the Texas Cooperative Extension service.

Damage

When a tree is defoliated by an oak leaf roller, it ceases production of sugar, which slows the overall growth of the tree. The live oak then becomes more susceptible to wood-boring insects like longhorn beetles, flat-headed tree borers, shot-hole borers and clear-winged tree borers. Annual defoliation could result in the death of the tree.

Time Frame

The oak leaf roller lays its eggs in May on twig tips and leaf buds where they reside for approximately 10 months. Upon hatching, larvae feed on live oak leaves until April. The larvae worms are creamy white to greenish with black or brown heads, normally growing to a size of less than 1 inch.

References

• Texas Cooperative Extension Service: Oak Leaf Roller and Springtime Defoliation of Live Oak Trees
• Texas Cooperative Extension: Bexar County: Worms in Trees Causing Homeowners Grief