Roses are very popular landscape plants grown for their beauty. Roses are susceptible to several insects and diseases which reduce flower growth and quality as well as frustrate rose gardeners. In general, these insects do not kill the plant, but may stunt or kill parts, affect flowering, or cause aesthetic damage. Learning the proper care of roses and management of pest problems increases your success in growing a beautiful rose bush.
Chemical insecticides are only effective until the target pest develops a resistance to that chemical. Then it becomes necessary to alternate harmful substances to control an insect population that continually gets worse because of lack of competition and natural predators due to high concentrations of chemicals. The major rose pests that we encounter here in your rose garden can be controlled by establishing populations of two beneficial insects and periodic treatments with a bacterium and a tree sap extract. The two beneficial insects are the Green Lacewing and Trichogramma Wasps. These two insects will guard your roses against everything from Aphids to some Scales and Spider Mites. Lacewings are very active and voracious feeders whose host or target prey are aphids, mealybugs, whiteflies of some species, juvenile scale insects, and some spider mites. The tiny Trichogramma wasp is a parasite of caterpillars some species of budworm and will antagonize a number of other butterfly and moth species. These parasites do not have a stinger (no need to fear them), they have an ovipositor that lays her eggs inside the host. As the wasp larvae develop they use the host as a food supply.