As a rose gardener, few things are more frustrating than walking outside to see little black bugs crawling on the leaves and petals of your prized roses. While some small black insects like ladybugs are beneficial, others can damage and disfigure roses.
In this article, we’ll cover some of the most common little black bugs found on rose bushes, how to identify them, and effective methods to get rid of them
Common Little Black Bugs on Roses
Here are some of the usual suspects when it comes to little black bugs on rose bushes
Aphids
Aphids are tiny, soft-bodied insects that come in a variety of colors, including black. They tend to feed in clusters on young rose buds and the tender new growth of leaves, damaging plants by sucking out sap. Aphid infestations can cause curled, wrinkled leaves and rose buds that fail to open.
Thrips
These tiny winged pests are attracted to light-colored rose blooms. They feed inside buds, marring petals with silvery streaks and preventing full bloom. Thrips are challenging to spot, but tapping flowers over white paper can help reveal them.
Rose Midges
Tiny rose midge flies lay eggs inside rose sepals. The emerging maggots feed on and destroy developing buds, causing curled, withered stems. Look for shriveled blooms to detect an infestation.
Rose Slugs
The larvae of rose sawflies chew holes in leaves, leaving only the veins behind. These green or yellow slug-like creatures feed at night and blend in well with foliage, making detection difficult.
Spider Mites
Too small to see without a magnifying lens, these pests colonize on the undersides of leaves. Spider mites spin fine webs and cause leaves to turn yellow or gray. Vigorous shaking of foliage over white paper will reveal them.
How to Get Rid of Little Black Bugs on Roses
If your roses are being plagued by little black bugs, here are some effective control methods:
-
Blast with Water: A strong stream of water can help dislodge many soft-bodied insects. Focus on the undersides of leaves and crevices.
-
Use Horticultural Oil: Light oils smother many small black bugs while being safe for roses. Thoroughly coat all leaf surfaces for best results.
-
Apply Insecticidal Soap: Available in concentrates, insecticidal soap kills bugs through contact. Spray buds, leaves, and stems.
-
Remove Infested Areas: Prune out badly damaged canes, leaves, and flowers. Dispose of the material immediately.
-
Introduce Beneficial Insects: Ladybugs, lacewings, and parasitic wasps prey on rose pests. Creating a diverse garden will attract them.
-
Use Neem Oil: Extracted from the neem tree, this organic oil repels and kills many insects when applied preventatively.
-
Set Out Sticky Traps: Yellow sticky cards or double-sided sticky tape can capture adult insect pests.
-
Practice Crop Rotation: Move roses to different areas of the garden each year to disrupt pest life cycles.
Preventing Little Black Bugs on Roses
An ounce of prevention is worth a pound of cure when it comes to rose pests. Here are some tips for keeping bugs at bay:
-
Select disease-resistant rose varieties, which are less stressed and vulnerable.
-
Prune roses in late winter to remove overwintering pests and infested material.
-
Clear away debris around plants that could harbor bugs.
-
Use row covers as physical barriers when bugs are active.
-
Water roses at ground level and in the morning to discourage pests.
-
Fertilize roses properly to enable them to outgrow damage.
-
Monitor plants frequently to detect infestations early when they are easiest to control.
If little black bugs have invaded your rose garden, don’t panic. Identify the pest, then take prompt targeted action to get the upper hand. Combining control methods and emphasizing prevention will help you safeguard your roses from damage while creating a welcoming habitat for beneficial insects. Paying close attention and intervening early provides the best chance of success against these common rose bush pests. With persistence, your roses can continue thriving and delighting you with their beauty.
Sign up for the Dummies Beta Program to try Dummies’ newest way to learn.
Before you wrestle with any insects on your roses, make sure you know what the problem is. For a start, consult the list of common insects in this article. Get in touch with a nearby nursery if you need more help. The staff there should know what issues roses usually have in your area. Nearby botanical gardens and your local cooperative extension office also may be able to help.
Here is a list of the most common insect pests that will likely attack your roses and the best way to get rid of them:
- Aphids are tiny bugs that look like pears and come in many colors, such as red, green, and black. (See Figure 1. They gather on new growth and flower buds and use their needle-like noses to drink plant sap. They leave behind honey dew, a sticky, sweet substance that can turn ugly black if it gets sooty mold on it. Honey dew also attracts ants.
- Aphids are easy to control. You can knock them off a plant with a strong jet of water from a hose, or you can spray them with an insecticidal soap. The soap helps wash off sooty mold, too. But usually, if you just wait a week or two, the aphid population boom is followed by a buildup in beneficial insects, especially lady beetles, and these beneficials take matters into their own hands (er, mouths) before serious damage occurs. Malathion, and acephate are traditional chemical controls for aphids. A new product packaged under the name Merit (imidacloprid), is very effective against aphids, and is fairly environmentally friendly. However, it can be hard to find.
- These bugs are easy to spot because they’re only about 1/4 inch long, yellowish green, and have black dots or stripes on their backs. Two different types exist. Mostly, they eat cucumbers and vegetable plants. But they also love rose petals and eat big chunks of them right when they open.
- Control is difficult. Try spraying spray with pyrethrum, neem, or insecticidal soap. Parasitic nematodes prey on the soil-borne larvae. Carbaryl is a traditional chemical control.
- Japanese beetles can be a big problem in the United States east of the Mississippi River. This bug is about half an inch long and has a coppery body and a metallic green head. (See Figure 2. They eat flowers and leaves, and the leaves are often stripped down to their bones.
- Control can be tough. Treating your lawn and garden soil with parasitic nematodes or milky spore may reduce the white, C-shaped larvae, but more adults will probably fly in from your neighbors yards. Milky spore takes years to spread throughout your lawn. Turning the soil in the open areas of the rest of your yard to expose the grubs to birds may also help. Floral-scented traps that attract adult beetles are available, but the traps may bring in more beetles than you had before. If you try traps, keep them at least 100 feet away from your roses.
- Neem, insecticidal soap, and pyrethrum are effective alternative sprays for controlling adult beetles. Traditional chemicals that may help include carbaryl and acephate. You can also just pick them off your roses (late evening is the best time) and or drop them into a can of soapy water.
- June bugs are about an inch long and can be black or reddish brown. They usually eat at night and like the leaves of different trees, but they will also eat roses. Japanese beetles can be controlled in the same way, but June beetle grubs can’t be killed with milky spore.
- Caterpillars are the larvae of moths or butterflies. They occasionally feed on the foliage or flowers of roses. You can get rid of them by using Bt or letting loose trichogramma wasps, which eat caterpillar eggs. Acephate and carbaryl are two common chemical controls that might work. Remember, however, that moths and butterflies are essential for pollination. Also, if you like butterflies in your garden, plant extra roses to make up for the damage done by caterpillars.
- Rose midges are tiny, nearly invisible pests that slash new growth, especially flower buds, making it slime up and turn black. Rose midge may be to blame if your rose plants look healthy but don’t flower. Insecticidal soaps sometimes work. Diazinon or chloropyrifos should be used to kill the soil-borne larvae for better control.
- As you can see in Figure 3, rose chafers are tan-colored bugs with long legs. It’s the same way to get rid of them as with Japanese beetles and June beetles, but milky spore doesn’t work on grubs.
- Rose stem borers are tiny larvae that look like worms (Figure 4). They eat inside newly cut or newly formed canes, which can kill the cane. A lot of different bugs can do this kind of damage, and it’s hard to get rid of all of them.
- Cut off the wilted stem well back into healthy tissue. (You may be able to see a small hole where the borer entered the stem. Cut back below that.) Look to see whether tissue inside the cane is damaged. If so, cut lower still until the inside of the cane is normal. If the borer has reached the base of the cane and bored into the bud union, you may lose the plant. Few sprays of any kind are effective, although you may get some of the larvae as they drop to the ground after feeding by using parasitic nematodes near the base of the plant.
- If borers are really giving you fits, put a drop of white glue (Elmers style) on the top of the cane after you cut a flower or prune. This keeps out the type of borer that enters through pruning cuts, but not the type that bores directly into new canes and causes them to wilt.
- You can hardly see spider mites without a magnifying glass because they are so small. You can see their fine webs under the leaves if there are enough of them. As the mites feed on plant juices, the leaves turn yellow and have a silvery sheen or stippling. The plant might lose its leaves if things get really bad. Mites tend to live in hot, dry places in the summer and on plants that are covered in dust.
- A daily bath with a strong spray from a hose should keep infestations down. Just make sure you work hardest on the undersides of the leaves. You can control spider mites with insecticidal soaps, which also help to clean off a plants leaves. Summer oil is also effective, as is releasing predatory mites. If the pests get completely out of control, you may have to use a miticide, such as Avid.
- Thrips are another almost-invisible troublemaker. They eat flower petals, which changes the color of the petals and makes the buds deform when they open. Thrips like all kinds of roses, but they love light-colored ones the most.
- Many beneficial insects feed on thrips, especially lacewings. Insecticidal soaps are also effective, as are several other insecticides, including acephate. Imidaclorid, mentioned previously under aphids, is also effective against thrips.
Easily Get Rid of Rose Plant Aphids or Insects
FAQ
How do you get rid of black bugs on roses?
Are rose aphids harmful?
How do you get rid of rose mites naturally?