Mealybugs, like many houseplant pests, seem to pop up out of nowhere. One day your plant is healthy and pest-free and the next day small, white insects have appeared.
While finding these unwelcome guests can be unsettling, mealybugs are one of the houseplant pests that are more easily controlled in my experience (except in large numbers).
We will go through what mealybugs are, what they look like, where to find them, and how to get rid of them!
Table of Contents
- What are mealybugs?
- What do mealybugs look like?
- Where do you often find mealybugs on your plant?
- Where do mealybugs come from?
- How do you control mealybugs?
- Do you need to worry about the plants near your affected plant?
- What about root mealybugs?
- Related Posts
What are mealybugs?
Mealybugs are soft-bodied insects that suck the sap out of the leaves and stems of plants, often leaving behind a sticky residue. This residue, called honeydew, may look like white cotton-like fuzz.
As more honeydew collects on the plant, it creates the perfect environment for black sooty mold to grow. The mold doesn’t harm your plant, but its black patches are unsightly.
Photo of mealybug by: tiwane, https://www.inaturalist.org/observations/7443700
Photo of mealybugs and honeydew by: aubreymoore, https://www.inaturalist.org/observations/8528665
Photo of black sooty mold by: Joseph OBrien, USDA Forest Service, https://www.forestryimages.org/browse/detail.cfm?imgnum=1427012
Mealybugs are prolific at reproducing, laying hundreds of eggs at a time that hatch in just a couple of weeks. No wonder why small populations can become huge infestations so quickly!
They are part of the scale family, but unlike other scale insects that are immobile in their adult stage, mealybugs can move at all stages. However, they do not move quickly and often move very little.
Similarly to scale, mealybugs at juvenile stages are also called crawlers. To read more about scale, click here to see my post.
What do mealybugs look like?
Mealybug adults are most often white and cottony in appearance, though they can also appear in shades of cream or tan.
In juvenile form, they are smaller and can be varying shades of pink, cream, tan, yellow, or orange.
Some species have one or more long tails.
They are often surrounded by a white fuzz, which is the honeydew left behind from their feeding.
The bugs we generally see on our plants are females, which are wingless and roam the plant for both feeding and egg-laying spots.
Males take on a more gnat-like appearance and are rarely seen. They only feed when they are very young and spend the majority of their short lives flying around in search of females to procreate with.
There are also asexual mealybug species that reproduce on their own – yikes!
Photo of mealybug with tails by: cedric_lee, https://www.inaturalist.org/observations/12056820
Photo of male mealybug by: magazhu, https://www.inaturalist.org/observations/3079264
Photo of pink mealybug by: nthenature, https://www.inaturalist.org/observations/3079264
Photo of mealybugs at multiple lifestages by: Peggy Greb, USDA Agricultural Research Service, https://www.forestryimages.org/browse/detail.cfm?imgnum=1317079
Where do you often find mealybugs on your plant?
Mealybugs are attracted to new growth, so they are often found on new or young leaves.
They also like to hide where stems join together, leaves meet stems, or under and in-between foliage.
While the previous locations are the most common, mealybugs can be found anywhere on a plant including in the top layer of soil.
Where do mealybugs come from?
Mealybugs come from many locations. Mealybugs might sneak into our homes with:
- new plant purchases,
- new bags of potting mix
- fresh produce purchased from the grocery store
- plants that were previously kept outdoors for certain periods or seasons
How do you control mealybugs?
1st – Use Rubbing Alcohol on a Q-Tip to Remove Visible Mealybugs
Adult mealybugs are quickly controlled by swabbing them with a q-tip dipped in rubbing alcohol. The rubbing alcohol controls them on contact and you will see the mealybug go from white to brown/black instantly.
You can also check the bottom of the pot, the saucer and the bottom of the saucer, in case mealybugs are hiding there. You can remove any you see using rubbing alcohol here as well.
2nd – Spray the Plant with a Homemade Insecticide to Help Control Mealybugs You Can’t See
There are 2 different homemade insecticides that I like to use regularly:
Neem Oil and Soap Spray
To make this one, mix 17 ounces water, .5 tsp neem oil, and .75 tsp mild dish soap in a spray bottle.
Many sources recommend testing this mixture on a small portion of your plant first to ensure it will not damage the plant because some species do not tolerate neem oil well. I’ll admit here that I don’t generally do that, but I probably should.
Pro: I prefer this spray over the rubbing alcohol spray because it seems to be a little more effective at pest control.
Con: Neem oil has a strange smell that really turns some people off. I don’t hate it usually, but when I’ve sprayed a large plant with it I do get tired of the smell because it takes longer to wear off.
I currently use Plantonix brand of neem oil. I purchased this bottle a year ago and I think I will still have it for years to come since I use so little in each spray. Here is a link to Amazon, where I purchased mine.
I use 2 different types of dish soap (both purchased on Amazon):
I have been currently using Dr. Bronner’s Peppermint Pure-Castille Soap which is known for being gentle on plants and the peppermint oil also helps to repel pests. Link to Amazon for Dr. Bronner’s. (there is also a Dr. Bronner’s without peppermint, if you would prefer not to use it)
I also use Dawn Ultra Gentle Dishwashing Liquid and have had success with it.
If you are interested in the glass spray bottles I use, here is a link to Amazon for those as well.
Note: The Amazon links in this post are affiliate links, which means that if you purchase using this link I might get a small percentage of the purchase. It is no additional cost to you to do this. I only link to products that I use and love.
Rubbing Alcohol and Soap Spray
To make this one, mix 4 ounces rubbing alcohol, 1.5 tsp mild dish soap, and 16 ounces water in a spray bottle.
Pro: This spray is not very smelly, unlike the neem oil spray, while still being effective at pest control.
Con: I do feel like I’ve had to apply this spray more often to control a pest outbreak than the neem oil spray (though I have no formal documentation to back this up – so maybe I’ll do a more formal study and let you all know what the results are!)
3rd – Once you’ve chosen which spray to use:
Spray your plant thoroughly, making sure to cover the tops and bottoms of leaves and any hidden surfaces.
Let the plant dry and then either return the plant to its normal area or place the plant in a quarantined area where it will not infest other plants.
4th – Check the plant regularly for mealybugs and remove them manually with a q-tip dipped in rubbing alcohol.
I check mine daily or, if I’m really worried, I’ll check in the morning and the evening. However, I know there are other people who do not check quite as often and do just fine with their plants. I admit I’m paranoid. 🙂
5th – If you are finding mealybugs regularly or are worried about the plant, you could spray again after a week or two.
Continue to check the plant regularly for more mealybugs and spot treat as necessary.
You can also spray the entire plant with a homemade spray after a couple of weeks to ensure any nymphs are controlled.
For bad infestations, stronger options could be considered:
Store-bought insecticidal soaps are a stronger option.
I keep Garden Safe Brand Insecticidal Soap on hand for pest management, which is often available in greenhouses and online. I use it rarely.
Since these are stronger sprays, I have had plants be a little burned by them. I would recommend testing the spray on a portion of your plant or making sure that the spray doesn’t collect in a pool on any leaves. I think that was the mistake I made.
Systemic pesticides are also an option, but 2 important notes here:
1) Systemic pesticides are harmful to everything it comes into contact with, including you.
2) Systemic Pesticides work for long periods of time, coursing through the veins of the plant for a couple of months. As a result, a plant that is normally pet and child safe is now toxic to be around for at least 2 months after application.
Because systemic pesticides are so powerful, they are very effective. The instructions with a systemic pesticide will show you the right amount of granules to use for your specific pot size. I usually mix those granules into the top inch of potting mix and then water them in.
The plant then absorbs the chemicals while absorbing the water, becoming a toxic plant. So if any pest takes a bite out of the plant, it dies quickly. System pesticides are useful in helping to control future generations which might have survived one of the sprays we discussed previously due to how long they remain effective.
I do keep a systemic pesticide on hand, but have only used it once (even with a house full of plants).
I use Bonide Systemic Houseplant Insect Control. Here is a link to Amazon to see more details.
Do you need to worry about the plants near your affected plant?
Unfortunately, yes! Mealybugs are able to crawl to nearby plants, even if your plants are not touching.
If your plants are touching one another, the likelihood of mealybugs spreading to other plants is much higher.
Conversely, the more distance there is between your plants, the less likely it is that mealybugs will show up on other plants in your home.
What about root mealybugs?
There is another type of mealybug that lives underground and feeds on the roots of a plant called root mealybug. These pests are dealt with differently than the mealybugs we have discussed in this post so we will cover them in a separate post!
Resources used for this article:
Thank you for all the information. I spray only alcohol on my plants when infected by mealybugs, I let the plant dry and then wash the alcohol off, I also remove the soil wash of the roots and add new soil. It helps for me.
I did this very recently with a cactus that was hiding a good deal of mealybugs beneath its spines and it worked beautifully. I was worried maybe too much full-strength alcohol would harm the plant, but so far so good. Do you use full-strength on your foliage plants without damage as well?