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Pest SolutionsPESTS + WEEDSUSING PESTICIDES OR HERBICIDES?
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Rose Aphids
Macrosiphum rosae and other species
Updated Oct 10, 2024
Make a Positive Identification
- Aphids are soft-bodied insects that feed on new plant growth. They have piercing/sucking mouth parts that distort leaves, stems, and flowers.
- Aphids produce honeydew: a sweet, sticky substance that promotes sooty mold growth.
Species: Aphids
© Ken Gray Insect Image Collection
Rose aphids range in color from green (shown in photo) to deep pink or red-brown.
Species: Aphids
"aphids on rose leaf" by minicooper93402 is licensed under CC BY 2.0.
Aphids congregate on the underside of leaves as shown in the photo.
Species: Aphids
Signe Danler, Oregon State University
Severe aphid infestations damage leaves and flowers.
Species: Sooty Mold
Rebecca A. Melanson, Mississippi State University Extension, Bugwood.org
Aphids secrete a sweet, sticky substance called honeydew. Honeydew promotes sooty mold growth. The fungus places a black residue on plant leaves as shown in the photo (not a rose leaf).
LOOK-ALIKE: ROSE LEAFHOPPER
Species: Leafhopper
Whitney Cranshaw, Colorado State University, Bugwood.org
Leafhoppers (Edwardsiana rosae) cause feeding damage (stippling) on rose leaves as shown in the photo.
Species: Leafhopper
Whitney Cranshaw, Colorado State University, Bugwood.org
The photo shows a leafhopper nymph (life stage). Leafhoppers have a pointed body shape. They hop quickly when disturbed.
Rose Aphids Benefits
- Many helpful insects and birds eat aphids.
Rose Aphids Risks
- Aphids suck sap out of leaves, buds, and stems.
- Severe infestations distort or kill leaves and flower buds.
- Aphids secrete a sweet, sticky substance called honeydew. Honeydew promotes sooty mold (fungus) growth. This fungus leaves black residue on rose bushes.
- Rose aphids spread plant viruses from one plant to another.
Risk Card
Does it cause harm?
Adults & Children
None
Property
Low
Damage rose plants
Pets
None
Annoyance
Some
Depends on your tolerence for insect damage
Environment
None
Food source for insect predators and birds
Action Optional
TAKE ACTION?
Aphids affect the way rose plants look. Take action if you can’t tolerate the damage.
Do I need to take action?
Take action if you desire manicured roses. You can leave aphid infestations alone if you can tolerate the damage.
What if I do nothing?
Aphid damage may get worse as the population grows.
Prevent Aphids
Signe Danler, Oregon State University
Grow Healthy Roses
- Stressed plants are more susceptible to insect damage.
- Grow roses in full sun.
- Provide water as needed.
- Don’t overfertilize.
Signe Danler, Oregon State University
Watch for Aphids
- Begin looking for aphids prior to bud break and during new growth flushes.
- The best time to manage is early in the season before aphids become more abundant.
- Check the upper surfaces of the lower leaves for honeydew and black sooty mold.
Winston Beck, Iowa State University, Bugwood.org
Encourage Aphid Predators
- Aphids have many natural enemies that reduce their numbers. Avoid using broad-spectrum pesticides that kill those enemies too.
- Ants protect aphids from natural enemies. Keep them out of bushes with sticky barriers, baits, or traps.
David Cappaert, Bugwood.org
Look for Signs of Natural Enemies at Work
- Aphid mummies are the empty shells of dead aphids as shown in the photo.
- If you see aphid mummies, then you know that natural enemies are at work, helping you to control aphids.
- A parasitic wasp laid its eggs on these aphids. The eggs hatched into larvae that fed on the tissue in the aphids’ bodies. Adult wasps then exited and continued their life cycle.
SOLUTIONS FOR ROSE APHIDS
Monitoring & Timing
- Look for aphids every week starting in early spring.
- Aphid control efforts early in the growing season will lower their numbers throughout the season.
Non-chemical Methods
- Encourage aphid predators such as ladybugs and green lacewings. Planting flowers to attract aphid predators is a preventive strategy. See Biological Pest Control Methods.
- Spray aphids on rose plants with a strong stream of water.
- Squash aphids living on the plant's leaves and stems, including the underside of leaves.
Insecticides (Insect Killers)
- Insecticides effectively control aphids when used according to the label instructions.
NEED HELP?
Consider a licensed pest control company. Learn How to Hire a Pest Control Company.
Your local Extension Specialist in Oregon and other states can suggest other methods.
Jump to
| Method | Does it work? | Is it safe? | Recommendation |
|---|---|---|---|
A Attract Aphid Predators |
Effective |
Low risk |
Recommended |
B Spray Plants with a Strong Stream of Water |
Effective |
Low risk |
Recommended |
C Control with Insecticides |
Effective |
Moderate risk |
Use if Necessary |
D Homemade Insect Killers |
Somewhat effective |
Moderate risk |
Not Recommended |
|
E If Using Insecticides, Protect Yourself & Minimize Risks
|
A
Attract Aphid Predators
Non-Chemical Method
Cheryl Moorehead, Bugwood.org (cropped)
Attract Aphid Predators
Recommended
Birds, spiders, and insect predators are natural enemies that feed on aphids and other insects.
| Does it work? | Effective
|
| How much effort? | Low effort Include trees, shrubs, and flowers that attract wildlife and natural enemies in your landscape. |
| What's the risk? | Low risk |
| Possible risk of exposure or harm from chemicals | NONE |
"Hutton’s Vireo (Vireo huttoni)" by Jamie Chavez is licensed under CC BY-NC 2.0.
Purchase & Release Aphid Predators
- Some aphid predators such as ladybugs can be purchased and released on infested plants.
- Released predators may leave the garden before controlling aphids.
Ants & Aphids
- Ants protect aphids from natural enemies.
- Keep them out of rose bushes with sticky barriers or ant baits intended for outdoor use.
Natural Enemies Reference
For more information, see A Pocket Guide to Common Natural Enemies of Nursery Crops and Garden Pests in the Pacific Northwest (OSU Extension Service).
B
Spray Plants with a Strong Stream of Water
Non-Chemical Method
"Water, Garden, Beam" by stux is licensed under Creative Commons Zero (CC0)
Spray Plants with a Strong Stream of Water
Recommended
Spray a strong stream of water at leaves, stems, and flowers of infected plants to remove feeding insects.
| Does it work? | Effective Use preventive measures for best results. |
| How much effort? | Moderate effort |
| What's the risk? | Low risk |
| Possible risk of exposure or harm from chemicals | NONE |
C
Control with Insecticides
Chemical Method: Use with caution
iStock
Control with Insecticides
Use if Necessary
- Insecticides effectively control aphids when used according to label instructions.
- If you choose to use insecticides, also use monitoring and prevention.
- Insecticides can also have an impact on beneficial insects such as bees and aphid predators.
| Does it work? | Effective
|
| How much effort? | Moderate effort |
| What's the risk? | Moderate risk Insecticides come with real risks. ALWAYS read the entire label front to back. Use a magnifying glass for small print. |
| Possible risk of exposure or harm from chemicals | El uso de insecticidas conlleva cierto grado de riesgo. El riesgo más bajo se presenta con el uso de métodos alternativos. You may be exposed to an insecticide if you:
Follow directions closely to reduce risk. |
Some insecticides are available for home use. A few are listed below. These active ingredients are suggested chemical treatments to control aphids on roses. Look for these chemical names in the “Active Ingredients” section of product labels.
- Mineral oil (Note the time of application for effective control.)
- Neem extract (Azadirachtin) Some formulations are OMRI-listed for organic use.
- Potassium Salts of Fatty Acids (Potassium laurate)
- Pyrethrins
- Imadicloprid
Suggested active ingredients are from the Pesticide Information Center Online (PICOL) Database. They are permitted for HOME use in Oregon. Read the label for application directions and effectiveness information.
ONLY professional pesticide applicators can use Restricted-Use Pesticides (RUP) that may be more effective. If you need further support, contact a licensed pesticide applicator.
Insecticide Application Tips
- Insecticides must contact aphids to be effective. Thorough coverage of leaves and stems is required.
- Lift leaves and spray undersides of leaves.
- Apply at the first sign of aphid activity. Repeat as needed.
- Read the label carefully for application and frequency details.
- Some insecticides are highly toxic to bees. Do not spray onto blooming crops. Do not allow to drift onto blooming crops or weeds when bees are active.
- Using insecticides comes with real risks. ALWAYS read the entire label front to back. Review instructions even for brands you know.
Dormant Season Applications with Horticultural Oils
- Another effective method for controlling aphids is to spray rose bushes with horticultural oil during the dormant season (early spring before buds break).
- The oil smothers soft-bodied insects such as aphids and their eggs overwintering on rose stems.
D
Homemade Insect Killers
Not Recommended
iStock
Homemade Insect Killers
Not Recommended
Homemade mixtures with oil, soap, or other ingredients are not recommended for use as an insect killer (insecticide).
| Does it work? | Somewhat effective Homemade mixtures have not been tested in terms of effectiveness. How will you know if it works? |
| How much effort? | Moderate effort |
| What's the risk? | Moderate risk
|
| Possible risk of exposure or harm from chemicals | Using homemade insect killer includes some amount of risk. The lowest risk comes with using alternative methods. You may be exposed to homemade insect killer if you:
Homemade insect killers don't have safety instructions. How will you know how to keep yourself, desired plants, and the environment from harm? |
If Using Insecticides, Protect Yourself & Minimize Risks
Chemical Method: Use with Caution
Brandon (@greener_30) on Unsplash
Why Is It important to Read Insecticide Labels?
- They have detailed information on how to use the product correctly and legally.
- They contain information on potential hazards of the product.
- They provide instructions you should follow for poisonings and spills.
- Following label instructions helps you to minimize the risks and maximize the benefits.
Key Safety Tips
- Read the entire label front to back.
- Follow the instructions.
- Review the instructions even for brands you know.
- Only apply the product where the label says it can be applied.
- Keep all insecticides in their original container.
The Label is the Law
ALWAYS read the label before using insecticide products. The label is a legal document that provides information on how to safely use the insecticide. This helps avoid harm to human health and the environment. Using an insecticide in off-label ways is illegal. It can result in legal enforcement actions.
READ THE LABEL & Follow Instructions
It has instructions to protect you and the environment.
- Labels are different for every product and they often change over time.
- Use a magnifying glass for small print.
- Pay attention to CAUTION, WARNING, and DANGER statements.
- Pay attention to the PRECAUTIONARY STATEMENTS.
- The law states you must read and follow insecticide instructions.
Protect Yourself
Eye, skin, & lung irritants
- Wear gloves, safety glasses, a long-sleeve shirt, pants, socks, and shoes.
- Avoid contact with eyes, skin, or clothing.
- Wash hands after mixing or applying, and before eating or smoking.
- Never spray directly overhead. Pay attention to wind conditions.
Protect Children & Pets
Keep out of the reach of children.
- Keep children and pets away from the application area.
- Remove toys and pet dishes from the area before applying insecticides. Wait until spray has dried or dust has settled.
Protect Pollinators
Many insecticides are extremely toxic to bees.
- Honey bees and other pollinators are harmed by most insecticides.
- Don’t spray on bees or other flying insects.
- Don’t allow spray to contact blooming plants.
Avoid Wet Weather & Keep Insecticides Out of Waterways
Some insecticides are toxic to fish and aquatic invertebrates.
- Don’t spray insecticides in water.
- Insecticides sprayed on plants can wash off with rain and enter waterways.
Storage & Disposal
- Store out of the reach of children and pets.
- Store in a cool and dry place.
- Never pour down any drain.
- If you mix too much, apply it rather than storing it.
- Don’t put pesticide containers in the trash unless instructed by the label.
- Take unused insecticides to a hazardous waste facility.
Call 1-800-CLEANUP (1-800-253-2687) to find out where to dispose of pesticides.
For the Portland metro region in Oregon, contact Metro’s Recycling Information. Call 503-234-3000, email or visit Metro’s website
More about:
About Using Pesticides on School Grounds in Oregon
If using pesticides on school grounds, there are special rules in Oregon. See School Integrated Pest Management (Oregon Department of Agriculture).
NEED HELP?
The National Pesticide Information Center (NPIC) can answer questions about pest control chemicals.
1-800-858-7378 or npic@ace.orst.edu
Consider using a licensed pest or weed control company. Learn How to Hire a Pest Control Company.
Your local Extension Specialist in Oregon and other states can suggest other methods.
Content provided by writer Signe Danler by editor Weston Miller. Pesticide safety information edited by Kaci Buhl.
Peer review facilitated by OSU Department of Horticulture.
ROSE APHID REFERENCES
Controlling Diseases and Aphids on Your Roses
Oregon State University
Pest in Gardens and Landscapes: Aphids
University of California IPM
Roses: Insects and Mites
University of California IPM