Salix repens, Denmark © Simon Haarder
the larvae of the genus Egle feed on the catkins. Evidently some species start their development already in the closed, swollen, flower buds.
larva and puparium of Egle parva Robineau-Desvoidy, 1830 are described and illustrated by Dušek.
Dušek (1970a), van Erkelens (2013a), Martens & Mortelmans