Elm Leaf Miner
Scientific Name: Scolytus multistriatus (This is a common misidentification due to visual similarity of damage; the image specifically shows leaf mining patterns, not galleries under bark from Scolytus. The pattern is characteristic of a leaf miner, likely a sawfly.) Re-evaluating based on the image's clear leaf mine pattern: Aproceros leucopoda or Fenusa ulmi are more appropriate for a sawfly leaf miner. Given the image shows leaf damage consistent with a leaf miner, and not a bark beetle, a more accurate scientific name for an elm leaf miner is Fenusa ulmi.
Order & Family: Order: Hymenoptera, Family: Tenthredinidae
Size: Adults are small, typically 4-5 mm in length. Larvae, when fully grown, are similar in size within the leaf mine.
Natural Habitat
Elm leaf miners primarily inhabit areas where elm trees are present. This includes urban landscapes, parks, residential areas, and forests where elm species (like American elm, Siberian elm, slippery elm) are common.
Diet & Feeding
The larvae feed on the mesophyll (the soft tissue) of elm leaves. Adult elm leaf miners do not feed on leaves; they may feed on nectar or pollen, but this is less documented.
Behavior Patterns
Adult female elm leaf miners lay eggs on the surface of elm leaves. Larvae, upon hatching, bore into the leaf and create winding tunnels or 'mines' between the upper and lower leaf surfaces. This larval stage is spent entirely within the leaf, feeding on the mesophyll. Pupation often occurs within the mine or sometimes in the soil at the base of the tree. There can be one to several generations per year depending on the climate. The characteristic winding lines seen in the image are the mines created by the larvae.
Risks & Benefits
Risks: Elm leaf miners can cause significant aesthetic damage to elm trees, leading to browning and premature leaf drop, which can be concerning for homeowners and arborists. While they generally do not kill mature, healthy trees, repeated heavy infestations can weaken trees and make them more susceptible to other stressors or diseases. Benefits: In certain ecological contexts, they can serve as a food source for predatory insects or birds. However, their overall ecological benefit is often outweighed by their pest status in urban and managed landscapes.
Identified on: 9/2/2025