Elm Zigzag Sawfly (Adult)

Natural Habitat

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

Diet & Feeding

Adults take nectar or pollen, but the larvae are specialist herbivores that feed exclusively on elm leaves.

Behavior Patterns

Reproduction is primarily through parthenogenesis (females clones themselves without mating). Larvae create a distinctive 'zigzag' feeding pattern on the edges of leaves as they grow. They can produce up to four generations per summer.

Risks & Benefits

Regarded as an invasive pest in North America and Europe. While they do not bite or harm humans, heavy infestations can cause significant defoliation of elm trees, weakening the trees and reducing their aesthetic value. There are no significant benefits to the ecosystem in their invasive range.

Identified on: 4/12/2026