It is important to clean up any infected leaves as they fall and remove them from the area and keep the soil mulched to minimize dirt splashing up onto the leaves. Aphids and rose slugs account for most of the insect damage on roses in our area. Whitefly, beetles and caterpillars can be a problem, too. Less often, you see leafhoppers, scale, spider mites and thrips. The list may sound frightening, but you rarely have more than one or two insect problems in a season.
Aphids are the most common rose pest.
They are soft-bodied pear shaped insects that line up along the most tender buds and leaves. They are sucking insects. Aphids are vulnerable to almost all insecticides. Start by washing most of them off, then treat the few that remain. Watch closely to keep them from taking over.