These shiny green or coppery beetles are particularly fond of rose blooms, leaving small round holes in the petals and occasionally in adjoining leaves. Otherwise, you can try a variety of commercially-available insecticides. For those who prefer organic solutions, the application of milky spore disease to the soil around the bushes will eradicate the larvae. If you find large holes in your rose leaves, they're probably the work of caterpillars or leafcutter bees. If the holes are irregular and occur within the central portions of the leaves, or if entire leaves have been eaten, then your plants are plagued by caterpillars.
Caterpillars are the larvae of various insect species, and as such they eat leaves for food.
They can cause a great deal of damage to a growing plant. On the other hand, semicircular sections taken out of the edges of rose leaves are a sure sign of leafcutter bees. Like beetles, caterpillars can be picked off by hand and destroyed. They can also be controlled using various chemical sprays. The organic alternative is the use of sprays containing Bacillus thuringiensis, an organism fatal to caterpillars but perfectly safe for plants and other animals.