Roseslug

Yellow-green sawfly larvae with orange heads feed on the undersides of rose leaves in Western Washington, grazing away tissue and leaving only the leaf epidermis; this window-pane damage dries and becomes white or pale brown. Roselugs reach about 3/4 inch length and often feed in groups, creating a distinctive ragged and skeletonized appearance.

Inspect leaf undersides in late spring for damage and larvae. Hand-pick roselugs or spray leaf undersides to dislodge them. Apply horticultural oil or soap targeting new growth. Roses recover well from damage and often require no chemical intervention.