Maple leafcutter

Maple leafcutter - Green foliage inside the defoliated ring, seen after removing the habitaculum, and series of disks forming the habitaculum
  • Latin name: Paraclemensia acerifoliella (Fitch)
  • French name: Coupe-feuille de l'érable
  • Order: Lepidoptera
  • Family: Incurvariidae
Description

Distribution

Eastern Canada

Micro-habitat(s)

Leaf

Damage, symptoms and biology

In summer, oval holes of variable size and small defoliated rings on the upper surface of leaves (which have an intact green centre) are signs of maple leaf cutter attacks.

On leaf surfaces, small oval disks can also be observed; these disks have been cut by larvae that are mining into the foliage. The cases consist of two superimposed disks attached to the leaf surface. Destruction of the upper epidermis by larval feeding and the many cases cut by larvae at each moult lead to foliage desiccation.

In spring, when the leaves are unfolding, the female deposits her eggs in a tiny pocket just under the lower epidermis of the leaf. After hatching, the larvae begin to mine into and feed on the parenchymal tissues between the upper and lower epidermis. They later cut cases out of the leaf and live as case-bearers. The older larvae feed on the leaf's surface, eating the foliar tissues in a circle around the case as far as they can reach. When full grown, the larvae fall to the ground within their cases; they subsequently spin a silk cocoon and change into a chrysalid. The insect overwinters in this stage.

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

There have been numerous maple leaf cutter outbreaks in Eastern Canada over the past two centuries. This species is native to North America. The two largest and best known infestations were reported in Ontario and Quebec during the period 1939 to 1965. Since then, there have been periodic outbreaks, with the level of damage varying from year to year.

To protect ornamental trees from a maple leaf cutter infestation two years in a row, it is important to collect and burn all the dead leaves in the fall. This will destroy the overwintering populations of chrysalids.

Canadian Forest Service Publications

Maple leafcutter

Diet and feeding behaviour

  • Phyllophagous : Feeds on the leaves of plants.
    • Leaftier: Ties two or more leaves together with silk threads, forming a tube in which to hide and feed.
Information on host(s)

Main host(s)

Black oak, hawthorns, red maple, red oak, sugar maple, white oak

Photos
  • Maple leafcutter Damage by larva
  • Maple leafcutter Green foliage inside the defoliated ring, seen after removing the habitaculum, and series of disks forming the habitaculum
  • Maple leafcutter Larva inside the ring cut from a leaf
  • Maple leafcutter Pinned adult (wingspan: 8.5-13 mm)
  • Maple leafcutter Hole cut in a maple leaf blade by the larva to get a disk that will be used to cover the habitaculum
  • Maple leafcutter Series of holes and defoliated rings made by the larva
  • Maple leafcutter Pupal case
  • Maple leafcutter Adult at rest
  • Maple leafcutter Typical MLC leaf damage.
  • Maple leafcutter Feeding damage by MLC larvae in their cases.
  • Maple leafcutter Adult Maple Leafcutter moth.
  • Maple leafcutter Typical MLC leaf damage.
  • Maple leafcutter Typical MLC leaf damage.
  • Maple leafcutter Pinned adult MLC
  • Maple leafcutter Copulating MLC at Lac La Biche.
  • Maple leafcutter Adult female MLC ovipositing on a saskatoon leaf.
  • Maple leafcutter MLC egg in an oviposition hole on a saskatoon leaf.
  • Maple leafcutter Leaf mines of first-instar MLC larvae on saskatoon.
  • Maple leafcutter Holes cut in leaf epidermis to construct the first larval case.
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