Galls Normally Don’t Cause Lasting Damage to Plants

SPRINGFIELD, Mo. — A strange growth known as galls frequently appear on plants as a result of feeding activity of insects.

Even though they are unsightly, the good news is that galls normally do not cause lasting damage to plants, according to Patrick Byers, horticulture specialist with University of Missouri Extension.

“Galls, like the elm leaf gall, are just aesthetically unsightly, normally,” said Byers.

Galls form as the result of feeding activity of tiny insects, primarily wasps. The adult insect lays an egg on a plant, egg hatches and the larvae begins to feed on the plant. The plan then responds by forming a growth, which protects the larvae from predators and helps the larvae feed.

Preventing galls is difficult because once in place they do a great job of protecting the larvae.

“You really have to target the adult insects because they lay the eggs,” said Byers. “Systemic insecticides may give some control. Often, the best approach is to live and let live.”

For more information on magnolias, call University of Missouri Extension in Greene County at 417-881-8909 or visit them online at http://extension.missouri.edu/greene.

Information provided by MU Extension Southwest Region News Service.