Aphids

How to Identify and Get Rid of Aphids

Aphids
Pixabay

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.

how-to-identify-aphids.jpeg
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!

Reader Comments

Leave a Comment

Aphids on peas

My peas started showing aphids, so I tried the soapy water. It seemed to work, but then the lady bugs showed up and I didn't know if that would hurt the lady bugs. Does it?
I have a losing battle now with the little suckers (literally). Can I still use the peas for compost or do I need to dispose of them?
Thanks for any help.

aphid-infected plants

The Editors's picture

Discard, do not compost, aphid infected plants. Soapy water does not usually affect/harm lady bugs. (Sad to hear this story. Fresh peas are glorious.)

Tiny unknown bugs eating my flowers

These tiny tiny little bugs are a little brownish to ..golden? Color. They jump when I open up my flower to my pumpkins their eating away at my pollen and the flower wilts and eventually falls off?? I've used neem oil and also Sevin but still there coming into my flowers then the flowers shuts and wilts then falls off?

aphids, rust, black spot...

I've been trying to control all these pests with neem (+ bicarbonate + a solvent) and it seems to do absolutely NOTHING. Today a rose bush was literally covered with aphids and I had sprayed it a few days ago. I gave up and sprayed insecticide on it (after removing the aphids manually). I don't know, neem just doesn't seem to work for me. One day the plants have rust and the next day they also have black spot....

aphids on milkweed

this particular comment is for Cass who crushes the orange aphids on milkweeds. Butterflies are attracted to those aphids and lay there eggs there on purpose, Please do not crush them. They are harmless to the milkweed

Alphids

Last year was the first year we grew plants to attract butterflies. When we returned from a long weekend, we came home to an aphids invasion. I about cried! I quickly read everything I could on the internet about it and ordered some ladybug online. A few days later, they arrived and went to work eating the alphids. Yes, I would buy them again. I. The meantime, I washed the leaves a couple times a day, used cayenne pepper, and tried to pick a thousand of them off. This year, we planted onions, garlic, rosemary, basil, and a few other plants around my butterfly plants to hopefully, keep the alphids away. We shall see!!!

aphid experience

The Editors's picture

Thans for sharing–good info here.

aphid

Hi,
I've heard that yellow ribbon hung on the tree attracts ladybugs. They can help us with aphid.
Is anyone use it?

Ribbons

The Editors's picture

This is unlikely to have any noticeable effect, unfortunately. The best way to attract ladybugs is to create an environment that they’ll thrive in: lots of wildflowers or tall grass (hiding places and things that will attract their prey.

Aphids

I had aphids on my lettuce and kale, so treated it with soapy water spray. Since doing this my lettuce and kale have become bitter. Any relationship between that and the soapy water?

Aphids on plants

How much LIME do you put in the quart of water ??

aphids

I have sprinkled flour on my plants because I read that it constipated the aphids. It kept them away for a while. I live in Texas and we have bugs so it's a constant battle but I rotate between soapy water, flour, and neem oil. It seems like it takes a full arsenal to keep them at bay.

Aphids on milkweed

I raise monarchs butterflies that need milkweed for their larva. The yellow aphids cover the milkweed so badly that the stems look like tiny ears of corn! I smash them with my hands but would love to know a way to discourage or kill them that will not hurt my butterflies. Please help!

Aphids on Milkweed

The Editors's picture

This is tricky, as you should not use any substances that could harm other soft-bodied insect, like the caterpillars. Normally we could recommend using a sprayer or hose to spray down the plants and blast some of the aphids off, but in this case, you may inadvertently get rid of eggs or caterpillars, too. Perhaps you can do this before the monarchs arrive?

Destroying the aphids by hand is likely the best way to ensure that butterfly eggs and caterpillars are not damaged in the crossfire. You could also look into purchasing ladybugs online and setting them loose in your garden. If there are plenty of aphids, the ladybugs should stick around, though there’s no guarantee they won’t venture elsewhere.

Aphids

I recently read that crushed eggshells at the base of rose bushes will keep aphids away. Any truth in this?

Crushed Eggshells as Pest Control

The Editors's picture

No, this will not stop aphids. Aphids tend to spread from plant to plant either by flying or crawling from leaf to leaf. A ring of eggshells at the base of a plant is traditionally thought to keep  slugs away, but this is also untrue—eggshells just aren’t sharp or gritty enough to damage slugs’ bodies. 

APHIDS

To MELBA STREIFF, how much lime do you put in the quart of water ??

Aphids on plants

My husband, being a biodynamic ag consultant, uses calcium spray. A little lime or coral calcium in a quart of water, settle out and then use the clear water part to spray on. Works within seconds. Bugs leave, plant is healthier.

Aphids-

I had never had aphids before now on a Spirea ornamental plant. Very small and green. I tried blasting, picking, shaking and ultimately spraying with a neem oil spray. They just kept coming back doubled and tripled. I had just purchased this plant so I took it back to the store. My ? Is should I treat the soil somehow before planting a Barberry-Orange Rocket plant? Or is it okay to go ahead and plant? It’s also suppose to frost tonight which is crazy for my zone-SW Missouri.

APHIDS

I used water with white Vinegar and wipe down the leaves. Solve my problem

Aphid spray

I use a mix of Peppermint Castille soap and water. The soap is oily and suffocates the aphids

Aphid control

Using a strip of sellotape you can quite easily catch these pests by touching them with the sticky side of the tape. Easy for the tops and underside of leafs. Has worked well on my indoor lemon tree. You’ll be surprised how easy it is to remove them.

Aphids

I used Dawn dish soap and icy cold water
They died within seconds

Aphids

I have hops growing in my yard that are destroyed by aphids every year. I've tried the insecticidal soaps nothing seems to work. Is there something I can do in the spring before the plants starts to grow. My black and red currants bushes next to the hops are also affected. Help

Aphid remedy

Brake-Cleaner from Autozone gets rid of them the fastest. But keep in mind, you must consider how important you consider the plant that you find them on. Your welcome!

Aphid control

You can also use local cow urine which is again benificial in controling aphid attack. For this purpose add 1:6 ratio of cow urine to water. Tested and easiest methord in controling aphids.

aphids

I tried to discover why aphids when I washed them off of my plants inside or outside I continued to get a worse infestation quite quickly, so I used a piece of scotch tape and picked some aphids of my plant where they were firmly stuck , I put them where I could keep an eye on them over a black background and with a magnifier was astounded to see they lived for up to 3 or 4 days, and worse than that several of the more mature ones spit out more aphids , shocked I was so I no longer blast them of , I prefer just to remove them physically if i can and squish them eliminating the possibility of recreation , I would sure like to know if any one else has discovered this, try it your self, you may be very surprised at the results.

Aphid control

for the soap mixture, what exactly do you mean by "do not dilute before spraying on plants"?

Soap Spray

The Editors's picture

By this, we just mean that it’s not necessary to dilute the solution before using it on your plants! Though it’s always wise to test it on a leaf first and dilute it if any adverse reaction occurs.

Aphid control

I use banana peels. Cut them into long strips and drape them over the center of collards, cabbage etc. Also tie them around the base of plants. My sister ties them below favorite rose blooms to keep them off. IT DOESN'T WORK to blend up the peel (tried it) eat your 'nana's and use the peels in the garden. (Oregon)

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