Pest

Elm leaf beetle

Xanthogaleruca luteola

A leaf beetle of elm. Adults chew holes in the leaves in spring, and larvae eat the leaf surface underneath, leaving a lace of veins that turns brown. Heavy feeding browns the leaves and they drop early, and adults winter in houses.

Signs

• Round holes in young leaves in spring, from the adults.
• Leaf undersides eaten to a lace of veins that browns, from the larvae.
• Yellow-green beetles with black stripes, and black-and-yellow larvae, under the leaves.
• Pupae clustered around the base of the trunk.

What favors it

Elms, especially Siberian and English elm, with two generations a year.

Prevention

• Seal cracks around windows and doors in late summer to keep wintering adults out of the house.

Crops it shows up on

Shade & ornamental trees.

Often confused with

Sources

• Elm Leaf BeetlesColorado State University Extension
• Elm Leaf BeetleUniversity of Maryland Extension

Why →