The larvae pupate in the mined leaves in mid-summer and the adult weevils emerge in August. In heavier infestations, by early August the trees appear as though scorched by fire. Normally the willow flea weevil is not a problem on weeping willow, except where grown in close proximity to bayleaf willow. Salix alba is often heavily infested in the countryside. In late summer, trees appear scorched in heavy infestations.
Adults chew small pits in leaves, which later become small holes in the leaves.
Larvae mine in leaf tissues producing dark brown blotches in infested leaves. Overwintering adults will also feed on opening buds as well as new foliage. The willow flea weevil can be difficult to control even with thorough and timely spraying. Treatments should be directed at the adult weevils as they emerge from hibernation in the spring. Because the emergence of these weevils may be extended over a considerable period, several applications are recommended.