Its always hard when your an avid gardener with prize winning roses to go out one day and see holes in your leaves. A lot of rose bushes around town usually get hit about this time with pesky vermin having your roses as its main course. There are a number of insects that can be the culprit of the crime.
The most common are aphids, the are small to the naked eye and can be green, red, or brown. The feed on the new buds that are forming. They can usually be controlled by a strong blast of water from your garden hose, begins spraying from the bottom and working your way up making sure to get the underside of the leaves. If the aphids fall from the plant and into the soil, they for the most part don`t crawl back up. There are also good insecticides on the market to control them.
Rose slugs and thrips are the most common leaf eater found in the St. Louis area. They eat the rose leaves leaving small holes and small gray spots that look like scales. Most of this damage isn`t severe enough to hurt the plant. A good watering daily will help the plant survive while the leaves are eaten. Try to treat early, if so desired, once the leaf damage becomes apparent.
Most pests on any plant can be dislodged from the plant from a good hose blast, as stated earlier, and daily monitoring of the plant.
