Appearance and Life Cycle
The life cycle of these insects is very simple and consists of four stages: egg, larva, pupa and adult. The adult stage are moths, usually grey, tan or brown with spots or mottled colouration. The larvae are usually present in the early part of the growing season, building their protective shelters by rolling, folding or tying developing leaves together. The larvae feed within the damaged leaves, passing through a series of molts until full grown. Most leafrollers and leaftiers are solitary feeders. The larvae vary in colour from light green to dark greyish-green and range in size from 12-20 millimetres (mm) in length when full grown. Once the larvae are full grown, they pupate either in damaged leaves, top soil, or litter on the ground. In the prairies, most leafrollers and leaftiers complete one generation in a growing season.
Larvae feed on leaves within the nests they construct. Some newly emerged species attack the buds causing holes in the unfolding foliage. Damage is temporary and will not kill the trees.
Leafrollers and leaftiers of poplar are attacked by parasites, predators and diseases. Chemical control is required only when the damage done on the trees is significant. When only a few trees are affected, populations can be reduced by hand picking larvae-infested leaves and destroying them.