Wingspan: 14–20 mm. The moth is a larger Gelechiid species that holds its wings flat at rest. Usually a dull greyish fuscous moth with a transverse pale fascia at three-quarters (if visible) often more curved in the costal half.
The moths of these two species (A. populella and Anacampsis blattariella) are so variable that it is not possible to determine each moth with certainty based on its external appearance.
Species can only be determined through genital examination or breeding!

Male: The gnathos of A.populella is noticeably more robust than that of Anacampsis blattariella, the uncus lacks obvious lateral lobes and the studded section is paramedian, in the long axis of the abdomen.
The valvae of A.populella appear smaller than those of Anacampsis blattariella.

Female: The crucial feature is in the shape of the posterior margin of the dorsal plate of S8 which is broadly rounded with a small apical pimple.

Females lay eggs about two weeks after hatching. Eggs are laid individually or group-wise at the base of buds or at the end part of branches.

The larva only needs three stages to develop.

Hibernation as an egg. The larva lives in a rolled leaf on his food plants. Pupation takes place in the larval feeding place.
The adults rest on tree trunks and leaves of the food plant during daytime and later come to light.

The larva lives mainly on Populus tremula, less on Salix caprea, Salix cinerea, Salix repens, Salix fragilis, Salix viminalis, Populus alba, Populus nigra and Populus alba x tremula.

It occurs in woodland, parkland, gardens, marshy habitats, banks of streams etc...