Caterpillar eating rose foliage leaves clues behind
Q: I have a young rose bush but I have been fighting something that is eating the leaves. Do you have any suggestions?
A: Sometimes the best way to identify a pest is by its droppings or perhaps by its chewing pattern. I can see both on your rose.
The black dots on the leaves are caterpillar droppings. The extremely ragged leaf edges are the mark of caterpillars as well.
If you saw these clues in early summer, you could apply an organic product that contains Bacillus thuringiensis. This would kill the caterpillars almost immediately. But at this point in the year, October, there is not much I would recommend except wait for cold weather to kill the critters.