Lombardy leafminer

Lombardy leafminer - Track followed by the larva inside the poplar leaf (gallery)
  • Latin name: Paraphytomyza populicola (Walker)
  • French name: Agromyze pâle du peuplier
  • Order: Diptera
  • Family: Agromyzidae
  • Synonym(s): Phytagromyza populicola (Hal.)
Description

Distribution

New Brunswick, Nova Scotia, Quebec, Ontario

Micro-habitat(s)

Leaf

Damage, symptoms and biology

Small mines on the upper surface of the leaves are evidence of the presence of Lombardy leafminer. The larvae produce mines by feeding on the parenchymal cells of the leaves. As the larvae mature, the mines expand and the affected leaves turns light green. The damage caused by this insect does not affect tree survival.

The larvae are active from June to October. When fully grown, they vacate the mine by cutting a semi-circular slit in the mined leaf. They transform into a small oval pupae either in the opening made at the end of the larval gallery or at the surface of the leaf. The pupae, which often remain suspended to the leaf until fall, drop to the ground, where they generally overwinter. They transform into adults the following spring.

Life cycle (East of the Rockies)

Life cycle (East of the Rockies)
Stage/Month J F M A M J J A S O N D
Egg
 
Larva
 
Pupa
 
 
Adult
 

Other information

Native to Europe, the Lombardy leafminer was first reported in Canada in 1956 on Lombardy poplars in Quebec City. It has subsequently been reported in southern Ontario and several parts of Quebec. The insect appears to be well established in eastern Canada.

No control measures are warranted since the damage generally occurs near the end of the growing season.

Canadian Forest Service Publications

Lombardy leafminer

Diet and feeding behaviour

  • Phyllophagous : Feeds on the leaves of plants.
    • Miner: Feeds inside the blade of a leaf, between the epidermal layers, or beneath the bark of plants, by first excavating a mine into these tissues.
Information on host(s)

Main host(s)

Eastern cottonwood, Lombardy poplar, trembling aspen

Photos
  • Lombardy leafminer Eggs spread out on a poplar leaf
  • Lombardy leafminer Tunnel opened to show larva
  • Lombardy leafminer Adult near the pupa
  • Lombardy leafminer Pupa in opening bored at the end of the larval mine
  • Lombardy leafminer Track followed by the larva inside the poplar leaf (gallery)
  • Lombardy leafminer Leaf attacked by several larvae (several galleries)
Date modified: