Quick Facts

  • Two generations per year, sometimes a partial third generation
  • Caterpillar has a diameter of 5-6 mm
  • Caterpillar forms whitish, then brown spots, in which the frass is visible, grouped in dark concentric circles

Species Facts:

The Pear Leaf Blister Moth, Leucoptera malifoliella, overwinters as a pupa, emerging with the moths in April. Larval development is completed by June. The second generation caterpillars cause the same damage, from mid-July to early September. The most precocious larvae pupate and produce a third partial generation at the beginning of August. Pupa is formed after two days and develops in 8 days for the summer generation.

The caterpillar lives as a leaf miner. On completion of growth, the caterpillar leaves the gallery and spins a cocoon on the surface of the leaf (first generation) or in cracks in the bark on the underside of branches (second overwintering generation).

Portions of this article courtesy of: HYPP Zoology
Image of a Pear Leaf Blister Moth (Photo from: www.bugwood.org Credit to: Agriculture and Agri-Food Canada Archive)