Aphids damage a huge variety of host plants by sucking the juices from leaves and stems, causing discoloration, leaf curling, yellowing, and stunted growth. Large infestations can produce a sticky, sugary waste product known as honeydew. Honeydew can attract ants, and fuel the growth of fungus on plant surfaces. Aphids can also transmit plant viruses, injecting them into the plant as they feed. These viruses can cause molting, yellowing, or poor yields in various garden vegetables and ornamentals. In an aphid's average lifetime of one month, they can produce 40-85 offspring. Some aphids have wings; some do not.

Control tips:

• An Integrated Pest Management (IPM) approach for aphids may involve biological, physical, and chemical controls.
• Consider contacting your Cooperative Extension Service for assistance in identifying aphids. You might learn about simple control techniques and/or plant diseases that could have been transmitted.
• Frequent monitoring helps in identifying early infestations. Regularly inspect new growth, flower buds, stems, and tender shoots.
• Be sure to check the underside of leaves. Monitor when temperatures make aphids more active, between 65° to 80°F.
• Avoid overusing nitrogen fertilizer, which aphids love. Use only the amount recommended on the fertilizer label.
• Consider growing vegetable seedlings under protective covers in the garden or inside a greenhouse.
• On sturdy plants, aphids can be blasted away with a strong spray of water, breaking their sucking mouthparts and preventing them from feeding.
• Consider pruning dense tree canopies to minimize aphid habitat.
• Consider providing a habitat for other insects that that feed or prey on aphids, such as lady beetles, parasitic wasps, and lacewings. To do that, avoid using broad-spectrum insecticides, and try to make nectar available throughout the season.
• If you decide to use a pesticide, always read and follow label directions. Make sure the pesticide is intended for aphids.

If you have questions about this, or any pesticide-related topic, please call NPIC at 800-858-7378 (8:00am - 12:00pm PST), or email us at npic@ace.orst.edu.

Aphids

• Identify your pest first, and make sure you have aphids.
• If a few shoots are heavy with aphids, prune them out and remove from the area.
• On sturdy plants, knock aphids away with a strong spray of water.
• On houseplants, you can wipe aphids away from leaves with a damp cloth.
• Aphids like excess nitrogen. Use only as much fertilizer as plants need.
• You can repel aphids by using aluminum foil as mulch.
• Ant colonies help aphids thrive. Eliminate aphid-tending ant colonies.
• Insects that attack aphids need nectar. Plant some nectar-producing plants nearby.
• Consider releasing natural enemies. Ladybugs, lacewings, and parasitic wasps are widely available.
• Thinning shrubs and tree canopies can reduce aphid habitat.
• If you choose to use a pesticide, read the label before you buy. Try a lower toxicity product first.

If you have a pesticide product in mind, have your label handy and click here for information about that product.

County Extension Offices

Through its county agents, the Cooperative Extension Service gives individuals access to the resources at land-grant universities across the nation. These universities are centers for research in many subjects, including entomology (the study of insects) and agriculture. Each county within the United States has an Extension office, which is staffed with agents who work closely with university-based Extension specialists to deliver answers to your questions about gardening, agriculture, and pest control. You can find the phone number for your local county extension office in the local government section (often marked with blue pages) of your telephone directory or by clicking on the map below.

U.S. States:

AK | AL | AR | AZ | CA | CO | CT | DE | FL | GA | HI | IA | ID | IL | IN | KS | KY | LA | MA | MD | ME | MI | MN | MO | MS | MT | NC | ND | NE | NH | NJ | NM | NV | NY | OH | OK | OR | PA | RI | SC | SD | TN | TX | UT | VA | VT | WA | WI | WV | WY | Washington D.C. |

U.S. Territories:

Puerto Rico | American Samoa | Guam | Northern Mariana Islands | Virgin Islands

Additional Resources:

• Aphids - University of California
• Aphid Management - Texas A&M University
• Aphids, Scales and Mites on Home Garden and Landscape Plants - University of Missouri
• Aphids - University of Kentucky
• Aphids - Maine Forest Service
• Aphids on Shade Trees and Ornamentals - Colorado State University
• Aphids - Cornell University
• Aphids on Ornamentals - Penn State University
• Aphids - University of Connecticut, Home and Garden Education Center