Aphids

How to Identify and Get Rid of Aphids

Aphids
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What are those little green bugs on your plants? They’re probably aphids! Here are our best tips on how to identify and control aphids in the garden.

What Are Aphids?

Aphids seem to find their way into every garden. They are small, soft-bodied insects that feed by sucking the nutrient-rich liquids out of plants. In large numbers, they can weaken plants significantly, harming flowers and fruit. Aphids multiply quickly, so it’s important to get them under control before reproduction starts. Many generations can occur in one season.

The good news is that they tend to move rather slowly and aphid control is relatively easy.

Identification

Identifying Aphids

Aphids are tiny (adults are under ¼-inch), and often nearly invisible to the naked eye. Various species can appear white, black, brown, gray, yellow, light green, or even pink! Some may have a waxy or woolly coating. They have pear-shaped bodies with long antennae; the nymphs look similar to adults. Most species have two short tubes (called cornicles) projecting from their hind end.

Aphid
A close-up view of a rose aphid.

Adults are usually wingless, but most species can develop a winged form when populations become crowded, so that when food quality suffers, the insects can travel to other plants, reproduce, and start a new colony. Aphids usually feed in large groups, although you might occasionally see them singly or in small numbers.

While aphids in general feed on a wide variety of plants, different species of aphids can be specific to certain plants. For example, some species include bean aphids, cabbage aphids, potato aphids, green peach aphids, melon aphids, and woolly apple aphids.

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Some aphids are darker colors, like brown. The potato aphid is a common brown aphid. Photo credit: GrowVeg.com.

What Does Aphid Damage Look Like?

Nymphs and adults feed on plant juices, attacking leaves, stems, buds, flowers, fruit, and/or roots, depending on the species. Most aphids especially like succulent new growth. Some, such as the green peach aphid, feed on a variety of plants, while others, such as the rosy apple aphid, focus on one or just a few plant hosts.

  • Look for misshapen, curling, stunted, or yellowing leaves. Be sure to check the undersides of leaves; aphids love to hide there.
  • If the leaves or stems are covered with a sticky substance, that is a sign that aphids may have been sipping sap. This “honeydew,” a sugary liquid produced by the insects as waste, can attract other insects, such as ants, which gather the substance for food. When aphids feed on trees, their honeydew can drop onto cars, outdoor furniture, driveways, and so on.
  • The honeydew can sometimes encourage a fungal growth called sooty mold, causing branches and leaves to appear black.
  • Flowers or fruit can become distorted or deformed due to feeding aphids.
  • Some aphid species cause galls to form on roots or leaves.
  • Aphids may transmit viruses between plants, and also attract other insects that prey on them, such as ladybugs.

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Aphids can be various colors, including yellow, and produce a sticky honeydew substance. Photo Credit: John Obermeyer/Purdue University.

Control and Prevention

How to Get Rid of Aphids

  • Try spraying cold water on the leaves; sometimes all aphids need is a cool blast to dislodge them. Typically they are unable to find their way back to the same plant.
  • If you have a large aphid invasion, dust plants with flour. It constipates the pests. 
  • Neem oil, insecticidal soaps, and horticultural oils are effective against aphids. Be sure to follow the application instructions provided on the packaging.
  • You can often get rid of aphids by wiping or spraying the leaves of the plant with a mild solution of water and a few drops of dish soap. Soapy water should be reapplied every 2-3 days for 2 weeks.
  • One variation of this soap-water mix includes cayenne pepper: Stir together 1 quart water, 1 tsp liquid dish soap, and a pinch of cayenne pepper. Do not dilute before spraying on plants.
  • Diatomaceous earth (DE) is a non-toxic, organic material that will kill aphids. Do not apply DE when plants are in bloom; it is harmful to pollinators, too.

How to Prevent Aphids

  • For fruit or shade trees, spray dormant horticultural oil to kill overwintering aphid eggs.
  • Beneficial insects, such as ladybugs, lacewings, and parasitic wasps, will feed on aphids. Supplemental populations of these insects can be ordered online and should help keep the aphid populations controlled from the start.
  • Companion planting can be very helpful to keep aphids away from your plants in the first place. For example:
    • Aphids are repelled by catnip.
    • Aphids are especially attracted to mustard and nasturtium. Plant these near more valuable plants as traps for the aphids. (Check your trap plants regularly to keep aphid populations from jumping to your valued plants.)
    • Nasturtiums spoil the taste of fruit tree sap for aphids and will help keep aphids off of broccoli.
    • Garlic and chives repel aphids when planted near lettuce, peas, and rose bushes

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Hosing down your plants is one way to control the aphid population in your garden.

Using Alcohol to Control Aphids

Isopropyl alcohol (also called isopropanol or rubbing alcohol) works fine and is easy to find, but be sure it doesn’t have additives. Ethanol (grain alcohol) seems to work best. Alcohol usually comes in 70 percent strength in stores (or 95 percent strength purchased commercially). To make an insecticidal spray, mix equal parts 70 percent alcohol and water (or, if using 95 percent alcohol, mix 1 part alcohol to 1 ½ parts water). 

You can also add alcohol to a soapy emulsion to make it more effective. For example, in a spray bottle, combine 5 cups water, 2 cups alcohol, and 1 tablespoon liquid soap.

Caution: When applying an alcohol or soap spray, or a combination, always test a small area first, and apply in morning or evening, when the sun is not beating down. Watch the plant for a few days for any adverse reactions before applying more. Plants can be sensitive to alcohol and soap. Also, some soaps have additives that can damage plants—select the purest form.

Check out this video to learn more about how to get rid of aphids. 

Do you have more tips for controlling aphids? Let us know in the comments below!

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Reader Comments

Leave a Comment

Garlic for Garlic

The Editors's picture

Hi, Karen: Sounds like you’re giving it a good shot! Be sure to read and try everything in “Control and Prevention” above. Be very thorough in applying, and do not overlook the bases of the scapes. You could try adding alcohol, but first we would try it by itself. This goes for all solutions. If you are thinking of fixes with dish soap or Neem oil or alcohol, always try a solo one first, before combining with other agents. You might try a garlic oil spray. Start with 2 crushed garlic cloves steeped in a quart of boiling water overnight. If you think you see some results, feel free to make it stronger by adding garlic or reducing water. Feel free to add some crushed red pepper if garlic alone doesn’t work. Keep trying and keep experimenting! Good luck!

Garlic for Aphids NO NO NO

I just came from the grocery store with garlic cloves to put in my yard to shoo the mosquitos away. They were full of aphids! Know I wonder if I am going to have Aphid's over populating my yard. I saw them and dusted them off in the middle of my lawn because like I said I bought the garlic to throw around this one area that has mosquito over population. I think they like garlic.

garlic spray

The Editors's picture

Garlic oil spray has been used to battle aphids for generations. However, garlic contains sulfur, which, besides being toxic to pests, is also an antibacterial and antifungal agent. Be sure to spray the underside of the leaves where aphids gather. The one caution is that garlic spray kills beneficial insects (such as ladybugs, who are natural predators of aphids) just as easily as it kills the bad guys.

 

Aphid control

Please see my earlier post, by Vickie Morgan, on Oct.6th, 2017! It REALLY works! Good luck!

I think my plants have aphids.

I have a variety of plants on my bay window, Gobble Guts, Lilly Looks and a few others I have forgotten their names. Most have been in the bay window for four years now. Recently I had noticed a green, very small but lively bug on my plants. The stems and leaves are covered in them. Are they aphids??? If so what can I do about them. If not aphids any idea as to what they could be and how to get rid of them would be much appreciated as I really don't want to loose any of my plants on my bay window.
Thank you.

aphids on the loose?

The Editors's picture

Crowded plants can be a pest breeding ground. Add dampness and you have some happy insects. You might try separating the plants, giving them some breathing space. Let them dry between waterings. Give them sun, if they require it (some houseplants prefer indirect light).

Rather than hazard a guess on this, Wendy, we are going to suggest that you Google “household pests” and look at the images. Any look familiar?? If so, click through and see if the source page helps you clarify the matter. Come back here to see how to deal with the pests if in fact they are aphids. Don’t mean to make you work, but wouldn’t want to send you down a wrong road.

 

aphids

use merit or bayer tree & shrub. aphids gone.

aphids and milkweed plants

have several milkweed plants which are covered in yellow aphids. I have about 20 newly hatched catapillars, i have tried lady bugs and neem oil, which kills the catapillars. i have cut off all the growth with infestation. i have moved the little baby catapillars to uninfested flowers. any suggestions as to getting rid of the aphids and keeping the catapillars alive?

milkweed rescue

The Editors's picture

If you have removed the caterpillars, you can wash the aphids off with a milk soap solution or an insecticidal soap—but only if there are no caterpillars present. These solutions will kill the caterpillars. In fact, do not use insecticides on milkweed plants that you will use to fee the larvae. We hope this helps.

Aphid control

I had a lot of trouble with aphids on my chilli plants.
Washing with soap gave only temporary relief. Likewise using bug spray.
I now patrol the plants twice a day and gently pick off any aphids using a length of sticky tape.
This gently removes the insects without damaging the plants.

Yellow aphids on my hoya

I am so frustrated with these yellow aphids on my Hoya plant that I have for more then 10 years. I have tried the soapy solution and the blast of cold water and insectisidial soap and also cut some of the plant of, nothing is working. I still am getting a few on the plant and don't want to bring it inside the house. I need help. Can I soak the entire plant in a trash can filled with soapy water or what else can I do?

aphids on hoya plant

The Editors's picture

Try hitting your plant with a spray of alcohol to kill the aphids, then blast with water to knock them off. They’ll probably still return.  You can also use “Safers” soap and soak the entire plant, as the label will instruct. Yes, they will return but not right away. Finally, if you are desperate, there is a more chemical approach; you can also water with Bayer Tree & Shrub, which makes it poisonous to them and they stay away.

sticky substance

I have a sticky substance on my cherry tomatoes after i have picked them. What is this?

Honeydew

The Editors's picture

Often, stickiness on tomatoes is due to the honeydew secretions from aphids–a harmless sap substance, easily washed off.

Looked at a turned red/brown

Looked at a turned red/brown grape vine leave with a magnifier, I was shocked to see a colloney of a tiny crawling insects moving around. Some are bright red and some are blackish with many leggs on each side. what can I do to treat them.

aphids in the soil

I have a 10' X 20' garden. This year my fava beans, green beans, cucumbers and kale were completely infested with aphids. I have disposed of the plants and read comments on how to get rid of them in the soil. However, do you just spray the Neem oil or pyrethrin on top of the soil in the entire garden? Do you have to "scratch it in"? When should I spray it?
I do not want to have the same problem next year.

Applying Neem Oil

The Editors's picture

Hi Carol, Neem oil is only effective when applied directly to the aphids (not the soil). It kills them on the day they are sprayed, so applications will likely need to be repeated. You may want to consider releasing beneficial insects like ladybugs and parasitic wasps before resorting to Neem.

Aphid control

I had success with the following: In fall, mix in even proportions vinegar, baking soda and dish soap. Spread the mixture on the ground surrounding the infected tree or bushes. Around a badly infested lime tree I sprayed twice in fall and once in early spring. No aphids came back that season.

Ants, Butterflies and Bees

I'm in charge of my neighbors flowers and plants while he's away until October 1st. Something is eating his Penta's. I have found a very tiny black beetle (very shiney, round not oval) and tons and tons of what appear to be Florida Carpenter Ants - front half red, back half black. What ever it is, or they are, they are completely decimating the Penta's.

I have sprayed twice with an organic spray from Home Depot and it's done nothing. I would attack them with chemicals but I DO NOT want to hurt the bees and the butterflies. What on earth can I do to save these Penta's?

Penta Pests

The Editors's picture

Hi Michelle,

How strange! Pentas are rarely bothered by pests or disease. It’ wonderful of you to want to protect the bees! Not knowing what the pests are, I suggest two things: 1. Rub the leaves with warm soapy water to get them off of the plant. 2. If possible, take a few photos of the insects and the damage they cause and visit a local plant nursery (not Home Depot). Ask the staff if they are familiar with the pest–that is the only way to choose the right product for treatment. The spray you applied may be effective only at a certain stage of the pest’s life cycle. In order to treat, you must know thy enemy! Hope that is of some help.

 

Controlling of aphids

I want to get ride of aphids in my garden

Aphids

My kale and broccoli have aphids extremely bad I am going to pull the plants but want to know what I should do too the soil around them. It just rained and lots of them dropped off the soil is gray now. Should I treat it with soapy water? Will that help can I replant in that area right away?

Thank you for your advice.

How to Treat Soil

The Editors's picture

We would advise washing the soil with a soapy solution, avoiding overfertilization, and using insecticidal soaps or horticultural oils (neem oil) on the soil. If you’d like to plant right away, we’d also recommend perhaps planting garlic with your new plants so that the aphids will stay away. Good luck!

Leafs on green peppers are chewed on

I usually us "Seven-5" and dust it lightly on most of my plants when I see the leaves being bothered ... Will Seven-5 take care of my green pepper plants?

Pepper Plants

The Editors's picture

Given this is an edible, we don’t recommend chemical applications. See if you can identify the insect that is chomping on your leaves. It may very well be something that will be gone in a few weeks and your peppers will be none the worse for wear. Often, insect pests feed at dusk and nightfall. It’s a good time to go out there to see what you are dealing with. Sometimes a simple solution of warm water and dish soap is enough to deter pesky feeders.

Aphids

My lime leaves are curling, brown stuff at the undersides of the leaves, a lot of ants on some leaves. Are these aphids?

Distorted and Brown Leaves

The Editors's picture

It appears that you might have aphids based on the distortion and color of your lime leaves. The brown undersides could be a collection of brown aphids or sooty mold caused by the honeydew that aphids secrete. In order to be sure, use our tips to identify the small bugs. Good luck!

Tomato Problem?

My tomatoes are doing well,but am seeing the leaves curling upwards. Are these aphids?

curling tomato leaves

The Editors's picture

Curling tomato leaves can mean several things. There are some viruses that produce this effect, but it can also be signs of stress due to cold temperatures and rain, irregular watering, too much water, heat and drought, improper pruning, herbicides, transplant shock, mites … If it is aphids, they would be fairly easy to see – check under the leaves and along stems and junctions for small, pear-shape insects – usually moving very slowly or staying still. Color ranges from dark gray to green to orange, depending on species.

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