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A Guide to the Insects That Feed on Roses
This easy, accurate guide will help you identify the insects that are eating your roses. It will help you decide if the insects on your roses are a true threat, and what to do about them if they are.
Identification Chart for Insects on Roses
Stinging rose caterpillar
Colorful; tentacles with spines
Slug-like; can fall from plants
Very furry; light to dark brown
Same as stinging rose
Look like honeybees but smaller and darker
Cut perfect round holes out of leaf margins
Long legs; can jump and fly
Jumps and flies when disturbed
Small green bugs
Jumps and flies when disturbed
Rose slugs (sawfly larvae)
Translucent green worms, often with markings on head
Occur in groups; several kinds
Bumps or lumps covered with waxy "scale"
Tough outer covering resistant to pesticades
Tiny insects; feed on plant juice
Very hard to see
Similar to thrips
Similar to thrips
Shiny copper-green; can fly
Resemble bees; can be picked off by hand
small, green, soft-bodied
Occur in colonies; may be attended by ants
Stinging Rose Caterpillar
It's not very common for caterpillars to become a serious pest on your rose plants, but it happens. One of the most common is the stinging rose caterpillar, which is a member of the Limacodidae family. These caterpillars are brightly colored and move like slugs; they also, as the name suggests, have stinging spines. If one of these slow-moving critters happens to wind up on your gardening glove, you might wind up with a sting. It's not usually severe, much like a stinging nettle. Wash the area with soap and water and apply a little calamine lotion and you'll be fine.
This is another stinging caterpillar that sometimes feeds on roses. It is instantly identifiable, with its luxurious "pompadour" of brown fur; one nickname for this species is the "Elvis Caterpillar." Like the stinging rose caterpillar, it moves slowly, like a slug. Unlike the stinging rose caterpillar, the puss moth packs a ferocious sting, by far the most severe of any North American stinging caterpillar. Especially if you're allergic to stings, you should contact health care if you get a particularly severe envenomation.
It's very unusual for there to be enough of these caterpillar to cause much damage – they're small, and they don't eat much. But if they're an issue, then dusting with diatomaceous earth, or spraying with neem oil should help.
Mineral Oil-Based Insecticides for Roses
I avoid using chemical insecticides whenever possible, and I have found that many of the rose pests that are described in this guide can be successfully controlled with oil-based treatments. I recommend trying Bonide All Seasons Horticultural Oil. This product, and others like it, smother insects and prevent them from respirating and reproducing. I have found it to be an ideal substitute for man-made chemical toxins that remain in the environment and can damage other insects and animals. Bonide's version is affordable and has great reviews on Amazon.
Leafcutting bees may sometimes go after the leaves of a rose bush, but the damage is usually minimal. These fascinating insects cut perfect circles out of the edge of leaves of many different plants (in my garden, they appear to be fond of dogwood and redbud). They use these circular pieces to line the inside of their nest; most species have a very orderly sense of construction, using the circles as overlapping sheets to insulate and fortify the tunnel walls.
If the perfect little circles being nipped out of your rose leaves troubles you, you may want to place a net over them for a few days until the bees find another source of material for their construction project.
The bees themselves, in the genus Megachile, look like little honey bees but are darker in color. You will seldom see them in action, since they get their leaf-cutting done very efficiently and quickly
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Grasshoppers can sometimes be a problem on roses. They will eat leaves and sometimes flowers, chewing characteristic ragged holes. Since grasshoppers are rather large and identifiable, the culprit should not be much of a mystery.
Control grasshoppers with diatomaceous earth. You may also pay local kids a dollar or two to pick them off by hand and drop them in soapy water.
Leafhoppers are small, inconspicuous little bugs that live and feed in colonies on the undersides of leaves. Rose leafhoppers are about an 1/8th of an inch long when full-grown; immature forms look like a smaller version of the adult. Unless you are checking the undersides of leaves, you might not be aware of a leafhopper issue until small white spots begin appearing on the upperside; this signals an infestation. Another sign is a swarm of hopping, flying little bugs when you shake the plant.
Leafhoppers use their sharp proboscis to pierce the underside of the leaf and drink the sap. If there are enough of them, they can kill an otherwise healthy plant.
Usually, natural enemies arrive to feast on leafhopper colonies. If they don't and your roses are in trouble, there are chemical insecticides that can be used as a last resort, including permethrin. Just make sure you apply it to the underside of the leaves.
Rose Slugs (Sawfly Larvae)
Rose slugs are not true slugs, but instead are the slug-like larvae of a small, stingless wasp called a sawfly. Most gardeners are familiar with sawflies, since they come in many varieties and attack many plants, especially willow and dogwood. They are often mistaken for caterpillars, and in most ways they are very similar.
The three species most likely to attack rose plants are small, translucent green "caterpillars" that feed in groups. There are no true caterpillars that feed on roses and have this same appearance and habit.
You can deal with rose slugs pretty easily by spraying the plant with a hose; the water pressure will knock the sawfly larvae off the plant, and they're not mobile enough to get all the way back up to where they were. Adding a little non-toxic insecticidal soap to the mix may not be a bad idea, either.
Rose Scale Insects
While they may not look like your typical insect, rose scale is technically in the same class as butterflies, beetles, and bees. They resemble barnacles or bumps, and adults do not move (immature forms are called "crawlers" and do move, a little). Scale insects secrete a protective coating that fends off many kind of pesticides and other control strategies. These insects pierce the twigs and suck sap for food; a serious infestation can damage or kill a rose bush.
The best approach to scale insects is the natural one: ladybugs and other natural controls. If these are not keeping the population in check, scale insects can be scraped off by hand (the adults can't climb back onto the plant). Summer oils and other horticultural pest control oils can also be used.
Thrips and Mites
Thrips and mites are so tiny that you may need a magnifying glass to see them. You will know you have a problem, though, if your roses are clearly under attack, with wilting, curling leaves and flower petals streaked with brown.
Thrips are insects, while mites are a kind of arachnid. Shaking a plant will cause thrips to jump and move, and you may see them as a small cloud. If you hold your hand under a leaf infested by mites and give it a shake, and then wipe your hand on a piece of white paper, you will see red marks and streaks from crushed mites.
Controlling either of these tiny pests is difficult. It's best to consult with a garden center or rose specialist to go over the options available to you.
Although there are several species of beetles that might chew on your rose leaves and flowers, the Japanese beetle is by far the most common, widespread, and destructive. Adult Japanese beetles are about a half-inch long, with a shiny metallic green body and legs. The wing covers, or elytra, are coppery-brown wing covers, and there are tufts of white hair visible from the strips across the end of the abdomen. They are actually very attractive little insects, and it's too bad they do so much damage.
The beetles cling to flowers and leaves and chew holes in both. When disturbed, they either bly or drop to the ground, where it is very hard to find them. They fly often, and resemble bees, which likely protects them from some predators.
Controlling Japanese beetles on roses involves either labor intensive hand-picking, which is a good method since they are harmless and don't bite; you can take care of a bunch at once by putting a bucket of soapy water under the plant and giving it a shake. Other insects like sawfly grubs can also be dealt with this way. You may also try netting your roses, but Japanese beetles are quick and persistent, and will eventually find a way in under or through the netting.
Other methods, like traps and biologics, might be called for in an intense infestation. It's best to consult with an expert before taking this step.
Aphids are small, soft-bodied insects that occur in colonies of up to hundreds of individuals. They feed on plant sap, and are frequently protected by ants, whom they "pay" with drops of a sweet fluid called honeydew extruded from the tip of the abdomen.
Rose aphids are hard to miss, even though they're small; their body shape, wings, and presence of insects in many developmental stages, and the presence of ants, is diagnostic. There are several commercial aphid control measures, but a good strong wash with soap and water is a good place to start; they are very fragile and will have trouble returning to the plant.
- Rose and Pear Slugs (Sawflies) l Missouri Botanical Garden
- How to Kill Thrips in Your Rose Garden l Gardening Know How
- Controlling Aphids on Roses l Gardening Know How
- Rose Insects & Related Pests | Home & Garden Information Center
This content is accurate and true to the best of the author’s knowledge and is not meant to substitute for formal and individualized advice from a qualified professional.