Inspect your rose plant regularly for signs of aphids, scales and mealybugs, and spider mites. Aphids are tiny, soft-bodied insects that are commonly green or white and look like miniature moths. Scales and mealy bugs are small, flat or rounded insects that are usually immobile and look like tiny cotton balls. Spider mites are barely visible to the naked eye, but they cause tiny dots or stippling on the leaves and a fine web between the leaves or branches. A mild infestation can usually be controlled by simply spraying them off with a strong stream of water from the garden hose in the morning a few times each week. However, if the pests become a serious problem, spray the rose in the early morning with insecticidal soap, being careful to coat the tops and bottoms of the leaves as well as the stems.  This type of soap is commonly sold in ready-to-use form and comes in a spray bottle at garden or home improvement stores. Spray the entire shrub and stems until the liquid is dripping from the leaves and running down the stems. Wait about an hour, then wash it off with a stream of water.

Summary:
Check your rose plant for pests regularly. Spray an infested shrub with insecticidal soap.