Woolly Aphids: What's that Fluffy White Stuff on my Tree?

White, Fluffy, Cottony Covering on Tree

A woolly aphid colony
A woolly aphid colony

If you have discovered a tree with a fluffy, white, cottony looking growth on it it's probably a colony of Woolly Aphids.

Woolly Aphids get their name from the fluffy, wax like substance which covers their bodies and serves as a deterrent to other predators.

At first glance you may mistake them for a fuzzy mold.

What is a Woolly Aphid?

A Woolly Aphid or Erisoma lanigerum is a type of sucking insect that lives on the fluid of plants and trees. Adults are approximately 2 mm in length and are a pinkish brown color. Each adult can produce up to five live young per day. The young Woolly Aphids are green or blue in color. After a few generations winged adults develop to spread to new branches and nearby trees.

A Woolly Aphid Colony up close.

A close up look at a Woolly Aphid Colony.
A close up look at a Woolly Aphid Colony.

Black Sooty Mold

Black Sooty Mold growing on honeydew.
Black Sooty Mold growing on honeydew.

Close-Up of a Woolly Aphid Colony

From a distance a Woolly Aphid Colony can appear to be a fuzz or moldy growth on the tree branch. The close up picture of the Woolly Aphid colony on the right shows tiny black 'dots' amongst the fuzzy, white, cottony substance. Those dots are the bodies of the Woolly Aphids.

The fluffy looking stuff is the waxy secretions that cling to their bodies. The wax secretions blow in the breeze adding to the appearance of cotton or wool growing on the branch.

Honeydew & Black Sooty Mold

Woolly Aphids secrete a sweet, sticky liquid called honeydew. The honeydew can drip to lower branches, leaves and even the ground.

Honeydew is difficult to remove but otherwise it doesn't cause any real problems. It does however, attract Black Sooty Mold. Sooty molds are a type of fungi that grow on the sugary honeydew secreted by sap sucking insects like aphids. Where there is black sooty mold there is always honeydew.

The picture on the right shows a black, sooty covering on the leaves in the center. The branch directly above the sooty covering was covered with the Woolly Aphids shown in the other two pictures.

How to Get Rid of Woolly Aphids

Having Woolly Aphids is not a major cause for concern. Severe cases are extremely rare and getting rid of a colony of them is fairly simple. The biggest hindrance is to the host plant or tree which may show signs of stunted growth, curling of the leaves, browning or wilting.

The best solution is also the quickest and most inexpensive. It's a garden hose with the nozzle set on full blast. Spraying them will knock them to the ground and they will be unable to return to the host. Do this every few days until you no longer see any signs of them.

Another simple method is spraying them with soapy water and rubbing them off with a brush, rag or sponge.

It is not recommended that you use any type of pesticide on them. Pesticides will do more damage to beneficial insects in your yard or garden than they will to the Woolly Aphids.

Comments 25 comments

Peggy W profile image

Peggy W 4 years ago from Houston, Texas

This was interesting. I don't know if it was the same thing or not...but at one point there was a white web like film over some of my mother's oak trees and a tree expert said that she was not to worry. It was actually beneficial to the tree. It disappeared by itself. Your photos do make it look more fluffy and cotton like, so it was probably something else. Voted up, useful and interesting.

TeachableMoments profile image

TeachableMoments 4 years ago from California

Whooly Aphids?! The title alone caught my attention. Never heard of whooly aphids. Interesting. My daughter would have a blast investigating these things. Informative hub and I love the pics. Great job.

Christine Miranda profile image

Christine Miranda 4 years ago from My office. Author

@ Peggy. Thank you for stopping by and leaving a comment. The stark white of the aphids against the green leaves was quite unusual.

@ Teachable. It has been interesting to see the trail change from day to day over the summer. The Woolly Aphids have definitely been the most interesting so far. When the kids got off the bus I brought them into the woods and told them everything I discovered.

Mama Kim 8 profile image

Mama Kim 8 4 years ago

Eww.... ^_^ I don't like green aphids... I would hate to find woolly aphids in my garden ^_^ Glad to know they're easy to get rid of. Voted up and interesting!

Christine Miranda profile image

Christine Miranda 4 years ago from My office. Author

Thank you for reading and taking the time to leave a comment. If I had a choice I would take Woolly Aphids as they are white and fluffy looking, they hardly look like a bug at all. In all honesty though, I had the creepy crawlies while writing this hub. :)

Bob Bamberg profile image

Bob Bamberg 4 years ago from Southeastern Massachusetts

Great hub, Christine. I'm familiar with the wooly adelgid (looks similar and attacks hemlocks) but hadn't heard of the name wooly aphid. Around here it's known as a mealy bug and seems to be a particular problem of house plants. Thanks for the enlightenment. Voted up, useful and interesting. Regards, Bob

Christine Miranda profile image

Christine Miranda 4 years ago from My office. Author

Thank you Bob. I have never seen anything like it. It covers the whole branch. Thanks for reading and taking the time to comment.

Annnie profile image

Annnie 4 years ago

Hi Christine.. this is an interesting hub. I took Agriculture in high school and one of the greatest challenges to farmers is Aphids. This is especially so in Africa where even the simplest of challenges can reduce a farmer's efforts to zero. I have seen the wooly aphids but the black common ones here are the worst. They lower farm yields considerably especially beans, maize (which you call corn), horticultural products especially french beans, kale and cabbage.

Christine Miranda profile image

Christine Miranda 4 years ago from My office. Author

Annie, I had heard of and seen green ones in vegetable gardens before but these Woolly one actually look so pretty. Until you realize its millions of little insects crawling around. Thank you for reading and leaving a comment.

Annnie profile image

Annnie 4 years ago


Christine Miranda profile image

Christine Miranda 4 years ago from My office. Author

Yep, that's what I meant...pretty creeepy! :)

faisalb87 profile image

faisalb87 3 years ago from Pakistan

Nice Information

Christine Miranda profile image

Christine Miranda 3 years ago from My office. Author

Thank you for taking the time to read this Faisalb87. I appreciate your commenting.

Brittany 2 years ago

Thank you! Very informative. I found these buggers on my trees that we brought inside for the winter (they're saplings, and we're in an apt.). Good to know they're not harmful, and thank you for posting how to get rid of them.

Nancy 14 months ago

We just found this in our yard. We initially thought the black mold on the ground appeared to be a lightening strike. When we saw the fuzz covered branches above it we were quite concerned for our beautiful Maple Tree! What a relief to know our tree isn't dying. Thanks so much!

Juniper 4 months ago

Thank you, found them on a potted Olive Tree I bought in Tesco, have taken out of my greenhouse (it wouldn't survive outside up here in Shetland !) and put it in isolation in porch will try blasting with water hose

Whyney1 4 months ago

I looked these suckers up last year ... in our house we've been referring to them as "sweater bugs," they look like they're wearing angora sweaters. I've been spraying with soapy water and will now try the hose method too.

weaver 6 weeks ago

The white woolly aphids seem to be only on new branches. I removed the small new branches from the tree and now I'm worried that those new small branches are where we would have had fruit next year. Am I right and should I stop removing the small new branches from the tree even though they are covered with the white woolly aphids? thanks.

Jay 6 weeks ago

Just seen these today,cool to watch,thanks for the info on them

Manish 5 weeks ago

Thanks for the information posted, i noticed them in my yard in Houston a few weeks back and took the action of blasting them with the garden hose. Did not get all of them out in the first session, but will follow up with another in the coming days. Will post back with success :) hopefully.

Cristina 4 weeks ago

How are you supposed to spray them off of 70ft tree?

Pinky 3 weeks ago

I always treated my birch trees in early spring as the leaves appeared to get rid of aphids. Although the extension service will no longer recommend it (back in 1977; they did) I purchased Cygon 2E from the feed store and poured several ounces in a five gallon bucket, stir. Then following the perimeter of the upper tree line which is where your roots are int he ground, pour the watered solution. Results is No aphids for the year. When talking of a 60 ft. tree and aphid sap on vehicles, this was the only solution I found to work. I would not apply near run off to water sources or near edible gardens. Used this for over 23 years with great success. BTW, it also meant I never got aphids on my flowers as well.

Ticia capps 3 weeks ago

Mine are in a tree over the swimming pool, and cover it. How healthy are they for swimming?

country marian 2 weeks ago

I have a yard full of trees that are covered with these pests. I certainly cannot wash them off with a water hose. For the past two years, I have had this problem but I am afraid to use insecticide for fear of killing birds and bees. The infestation is worse this year and I am afraid it will continue to get worse each year. This is a real problem because this black and sticky residue gets all over our cars, carport, and patio. The sticky leaves and residue gets tracked into the house. Should I break down and use Bayer Advanced Protect and Feed?

Thurman Moore 33 hours ago

Thanks. I did spray them with soapy water but did not knock them off the tree. Will do that tomorrow. Too fr to use a hose so will put clear water in my fruit tree spray unit and use it. Very helpful.

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