These small insects feed upon the rose leaves. Identify them early and get rid of them appropriately.
If you’re seeing small green worms on the underside of your rose leaves, it’s time to act. Often called rose slugs, these soft-bodied pests are actually the larvae of sawflies—a type of harmless, non-stinging wasp. While rose slugs won’t harm people or kill your plants outright, they can quickly leave your roses looking tattered by chewing through the foliage. The good news? It’s easy to take control. Here’s how to identify and eliminate rose slugs.
What Are Rose Slugs?
As the name and color would imply, rose slugs aren’t slugs or caterpillars (caterpillars of butterflies or moths). Rose slugs are green, soft insects that are larvae of the rose sawfly and are half an inch long. They are confused for slugs and caterpillars because they resemble them.
Identifying Rose Sawfly Damage
These larvae start to feed in late spring on roses, eating through soft green leaf tissue. The only thing that is left is papery brown skeletons—leaf veins without the leafy tissue in between them. The damage is similar to lace or « windowpane » patterns. While the damage is mostly cosmetic, heavy infestations can stress the plant and make it vulnerable to other problems.
Inspect Plants for Early Signs
To get ahead of a rose slug infestation, inspect your rose leaves frequently—especially in spring. Examine the underside of the leaves, where the larvae will be camping out. The earlier you catch them, the less damage will result. Once the larvae have migrated off, you don’t have to treat the plant—they only remain active for several weeks before they pupate.
How to Remove Rose Sawfly Larvae
For small infestations, hand-pick larvae and deposit them in soapy water. A forceful blast from a garden hose also dislodges the majority of them—be sure to spray upper and lower leaf sides. For broader control, spray neem oil or insecticidal soap on leaf undersides where larvae tend to accumulate.
