The Birch Leaffolder or Yellow Birch Leaffolder Moth (Ancylis discigerana) is a moth

Moth

A moth is an insect closely related to the butterfly, both being of the order Lepidoptera. Moths form the majority of this order; there are thought to be 150,000 to 250,000 different species of moth , with thousands of species yet to be described...

 of the Tortricidae

Tortricidae

Tortricidae is a family of moths, commonly known as tortrix moths, in the order Lepidoptera. Tortricidae is a large family with over 9,400 species described, and is the sole member of the superfamily Tortricoidea. Many of these are economically important pests. Olethreutidae is a junior synonym...

 family. It is found in north-eastern North America

North America

North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...

.

The wingspan

Wingspan

The wingspan of an airplane or a bird, is the distance from one wingtip to the other wingtip. For example, the Boeing 777 has a wingspan of about ; and a Wandering Albatross caught in 1965 had a wingspan of , the official record for a living bird.The term wingspan, more technically extent, is...

 is 13-14 mm. There is one generation per year.

The larvae feed on Betula alleghaniensis. The first two instars skeletonise the lower surface of a leaf of their host plant. They feed from beneath a sheet of silk that is constructed between two lateral veins. Third instar larvae move to the upper surface of a different leaf and fold it lengthwise. They then feed on the upper epidermis within the fold until the leaf falls down.