In summer the adults are a fairly pale colour but in winter they are reddish-brown to black, the transparent wings being dusky.

[3] Along with the codling moth (Cydia pomonella), it is considered one of the most important pest of pears in the United States.

In the spring, the female lays eggs on twigs and expanding shoots of host trees, attaching them by means of short stalks on their ventral surfaces.

On hatching, the nymphs feed on the buds and flowers of the host tree, inserting their mouthparts and sucking out the sap.

The nymphs produce copious honeydew which attracts ants, flies, bees and other insects.