Elm Zigzag Sawfly

Natural Habitat

Deciduous forests, urban landscapes, and gardens where elm trees (Ulmus species) are present.

Diet & Feeding

Larvae feed exclusively on the leaves of elm trees; adults are not known to feed significantly.

Behavior Patterns

Notable for the distinct zigzag feeding pattern left by young larvae on elm leaves. They are parthenogenic, meaning females can reproduce without mating, and they can produce multiple generations per year.

Risks & Benefits

Considered an invasive pest in North America and Europe. They can cause significant defoliation of elm trees, which may weaken the trees and make them susceptible to other stressors, though they do not bite or sting humans.

Identified on: 4/12/2026