Host plants:
The caterpillar lives on willow (Salix caprea, probably also S. viminalis, S. appendiculata, S. cinerea, S. aurita) and also according to literature on Vaccinium.
Habitat:
Rheumaptera undulata colonizes often cool and wet forests, clearcuts and other forest-like biotopes.
Life cycle:
The moths fly in a single generation from late May to early August. The caterpillars live from July to September in a housing made of leaves which are spun together. The pupa overwinters.
Remarks:
Rheumaptera undulata is widespread in the Holarctic region. In Europe it is missing in the Mediterranean.