The rose slug is a sawfly larva not a caterpillar and cannot be controlled with Bacillus thuringiensis (Bt). Damage to rose leaves (Rosa) caused by the feeding of sawfly larvae (Hymenoptera).
What do rose slugs look like?
The rose slugs look like caterpillars, but they are not. They are about 1/2- to 3/4-inch (12.5 to 18.8 mm) in length when fully grown. The European rose slug is smooth and greenish yellow in color with a brown head and also tends to be slimy like typical slugs. The other is the Bristly rose slug, which is covered with small hair-like bristles.
While I was writing we ran into the inquiry “What do slugs do to Roses?”.
Rose slugs chew off the leaves of the rose and cause defoliation of the rose plants and decay on the foliage of the leaves. The curled up rose slugs curl up into a coil under the leaves and chew holes into the rose leaves, removing the soft tissue of the leaves which results in the leaf looking scorched and brown.
How to get rid of Rose slugs?
While rose slugs might be particularly annoying to identify, they are exceptionally easy to combat organically. Neem oil is a great, organic solution for getting rid of rose slugs. Opt for 100% pure cold-pressed neem oil for best results. Neem oil is a natural insecticide, pesticide and fungicide.
Are rose slugs and sawflies related?
Rose slugs are the larvae (immature forms) of sawflies, non-stinging members of the wasp family. Three species of sawflies, the rose slug ( Endelomyia aethiops ), bristly rose slug ( Cladius difformis ), and curled rose sawfly ( Allantus cinctus ), are pests of roses.
The other is the Bristly rose slug, which is covered with small hair-like bristles. Both are the larvae of plant feeding wasps known as sawflies. The Bristly rose slug will typically feed on the underside of the rose leaves, leaving the translucent lacy layer of the leaf tissue that some rosarians refer to as skeletonizing of the foliage.
To the untrained eye, the insect can look like a fly from certain angles, but it is actually a wasp relative. It is not the adult rose sawfly, itself that causes damage to rose bushes but rather its larvae, which are called “rose slugs” (even though these caterpillar-like creatures are not really slugs ).
Where do slugs come from?
Slugs come from eggs in the ground or sometimes slug eggs on leaves. The average slug lays up to 40 eggs each year. These eggs are deposited by slugs to hatch in the spring and over winter in the ground. The eggs are dormant but rising temperatures above 64 degrees Fahrenheit prompt them to develop.
What is eating my rose bush leaves?
The Bristly rose slug will typically feed on the underside of the rose leaves, leaving the translucent lacy layer of the leaf tissue that some rosarians refer to as skeletonizing of the foliage. Thus, it turns brown, and later large holes may develop with all that is left being the main vein of the leaf or leaves affected.