They belong to the lower part of the lepidopteran clade "Apoditrysia" (Dugdale et al., 1999) (i.e. not "Obtectomera"[1]), but their closest relatives are as yet unknown and it is hoped that DNA sequencing can help resolve this question.

These small to medium-sized moths measure 11 to 37 mm in wingspan and often have a greyish or mottled forewing background colour.

The "bumelia webworm moth" (Urodus parvula) is recorded on Lauraceae: (avocado=Persea), Fagaceae (Quercus), Sapotaceae (Sideroxylon) and Erythroxylaceae: Erythroxylum.

W. asperipunctella has in North America been reared from quaking aspen (Populus tremuloides) (Landry, 1998) and also Salix in Europe.

The pupa is contained in an open-mesh cocoon, which can be bright orange in colour, and is sometimes suspended on a very long thread below a leaf.