Mealybugs on Orchids:
7 Remedies to Eliminate Them For Good
What’s the white stuff on my orchid leaves? Mealybugs look like white fuzz, elaborate cotton candy, or the result of a drunk spider trying to make its web.
Mealybugs are white insects 1/16 to 1/10 of an inch big (0.2 cm) that chew away at orchid tenders, concentrating on younger growths: any new roots, leaves, sheaths, and new buds. The younger the sprout on your orchid, the more hydrated the cells are, rich with minerals and nutrients. This is extremely attractive to mealybugs, and other insects and pests as well.
"Mealybugs on a flower stem, Yogyakarta, 2014-10-31"
by Crisco 1492 is licensed under CC BY-SA 2.0
Even though there are several different sub-species of mealybugs, they all infest orchids and chew on household plants.
So, there’s no need to identify which mealybug is on your orchid, because our goal is to kill them all.
What is a mealybug? A mealybug is an orchid hazard. There's no other way to put it. Its body is actually pink, not white. The impression that it’s white is because it’s coated in white, fuzz-like cotton all over its body. Wherever it goes, it leaves a sappy wax, which attracts ants.
The male mealybug will have wings and be a bit bigger. The purpose of the male is only for reproduction. For this reason, their lives are shorter than the females. I heard once that males don’t have mouths, since they have no use for them, but I find this hard to believe.
Females, on the other hand, are the ones that will destroy your orchid. They look like smaller, albino versions of a roly-poly with fuzz and two long antennas. Each female can lay over 600 eggs. (Actually, they aren’t eggs. A female births live young and doesn’t lay eggs.)
This is why a mealybug infestation is so hard to treat. If not observed and treated, within a week the orchid could be covered in mealy bugs.
"Aphids and mealybug destroyers"
by Plant pests and diseases is licensed under CC PDM 1.0
Once an orchid is infested, even in the tinniest bit, it needs to be removed from the orchid collection as soon as possible.
Mealybugs transfer form one plant to another, not because they fly (the females don’t) but because the young mealybugs are windborne.
Since having a fan and circulating air is so important to orchid growth, mealybugs become a major problem—rapidly.
Mealybugs also wander. The leave the orchid pot and crawl all over the shelves, humidity trays, and onto other orchids. They aren’t happy just eating at one place for the rest of their lives. (I can relate.) They add other orchids to their menu, too. Mealybugs also walk, crawl, run, scatter…or whatever they do… really fast.
Phalaenopsis are one of the orchids mealybugs prefer the most. Even though other orchids will also be infected, since their appetites are very vast, the Phals will be more infested then your other orchids.
You can find mealybugs in the crevices of the pedicles and peduncles. (Check out orchid anatomy in this article.)
They love to be hidden and in hard to get locations for their own protection.
If the small crevices were the only problem, that could be easily fixed. Think a bit about your potting medium. Roots are just as tasty as new leaves,
and being protected with bark, having water supply, and plenty of oxygen, the potting medium is the perfect place for mealybugs to live and reproduce. Mealybugs also thrive on nitrogen, which is present in all fertilizers.
Once the mealy bug digs in the potting medium, it’s best to throw away the entire potting medium and repot immediately. Don’t try to salvage it.
"Mealybug" by incidencematrix is licensed under CC BY 2.0
When you're orchid shopping and see one or two mealybugs, my suggestion is not to buy it. It isn’t a life-threatening problem for the orchid, but it’s just a lot of work. There’s always the risk of contaminating your other orchids too—too high of a risk in my opinion.
If you’re an experienced orchid grower or have had mealy bugs in the past with other household plants, you might give it a shot.
I understand—a good orchid is hard to pass by.
If the plant is covered in mealybugs, then kindly place the pot back down and alert the greenhouse. Sometimes with so many plants, they don’t have the time to look at one single plant carefully, and don’t realize there’s a problem.
In no circumstances, take that orchid home.
If you can see the mealybugs on the leaves, then count on having three times that many inside the roots. You certainly aren’t going to unpot the orchid before you buy it.
Walk away without regrets.
If you’re absolutely in love with the orchid, ask the greenhouse to reserve it for you. Pick it up at a later date when the mealybugs have been treated. This probably would be the best option, but still risky. You don’t know what the roots look like.
If mealybugs appear once your orchid is home, there are six home remedies that you can use to eliminate them. We will start with the easiest method, and work up from there. No matter what method you choose, repeat the process within a week, and again the week after that. Spores and “eggs” can be extremely hard to eliminate.
Whatever you do, act quickly.
Mealybugs reproduce faster than rabbits. In one week, you can go from what once was a healthy plant to a now death-stricken plant. Mealy bugs cause extreme leaf and flower deformity. Leaves wilt, never to return to their original state.
How To Rid Your Orchid of Mealy Bugs
The first few solutions are non-toxic and are safe for your orchid, children, and household pets. After these, toward the end of the list, I’ve included solutions that are quite toxic. Make sure you use precaution when working with them.
1. Isopropyl Alcohol 70%
The first method is very simple: get a bottle of rubbing alcohol and a cotton swab.
With the tip of the swab, remove all the mealy bugs manually.
Don’t just remove them and throw them in the trash, because the spores are still airborne. You have to kill them.
This method will not hurt the orchid.
Whatever you do, DON’T take a cotton ball, soak it in alcohol and swipe the leaves up and down, especially on the bottom-side.
This is a spot-touch method. You still want you orchid to be able to breathe. Manually removing the mealybug manually is a bit time consuming, but necessary.
This method will work if your orchid has few visible mealybugs. Even if your orchid is infested with mealybugs, you still need to get the maximum number of adults off your plants. So, Isopropyl Alcohol 70% is your starting place. If you don't have a bottle at home, click here to check the price at Amazon (Affiliate Link).
2. Soap and Water
The second method you’ll want to choose is to make a diluted soapy solution and wash your plant. Mix three cups of liquid soap with one cup of water. You can use baby shampoo, which works very well. What you don’t want is harsh dish detergent that is made to remove grease and heavy, concentrated grease from cooking pans.
Mealybugs will come off when applied a strong jet of water directed at them, but that can be a bit cruel. A more sensitive solution is to take the orchid to the sink or bathtub and mist it down with this soapy solution.
Don’t wash it like you would a oily pan, but mist it with the soapy solution, concentrating where the mealybugs are. Rinse it off thoroughly after 20 minutes of soaking in soapy suds. You need to do this very often, almost every two to three days until all the mealybugs are gone.
Soap actually kills the mealybugs, but to make this work better, add a drop of rubbing alcohol to the solution. To your four-cup solution (three soap and one water) add half a cup of rubbing alcohol. Alcohol breaks down the waxy barrier that keeps the mealybug safe. Once the barrier is broken, the soap acts more efficiently.
Once you have taken the orchid out of its pot, rinse the roots well. Try to eliminate an of the sphagnum moss or broken-down bark parts. Rinse the roots longer than you would normally would.
3. Neem Oil
The third solution will require extra products, but this one is under US$ 10.00 and very easy to find. Neem oil is a mist that you spray on the entire orchid.
It doesn’t kill the orchid or the mealybugs. What?? Yes, that’s right.
It doesn’t kill the mealy bugs, but it interacts with their hormones, preventing larva and pupa to grow. It also interrupts reproduction. Once the neem oil kills off the parent generation, your problem is solved.
You need to reapply it after seven days to inhibit the growth any of the eggs that were missed during the first misting.
Neem oil is not toxic
for animal or plants, but the smell is not the best. It comes from the seeds of the neem tree, popular in India.
It has been used in traditional medicine and ever since 1960 has been introduced into modern botany.
Neem oil is great to have around, not only for mealybugs, but it also interrupts the life cycles of other orchid-destroying insects: aphids, mites and many others. You can check the price here (Affiliate Link).
4. Diatomaceous Earth
Diatomaceous Earth is a fine grade “fossil dust.” This solution is completely safe for animals, since the sharp edges are microscopic. Powder this dust on the top on the potting mix and leave it there. This is also a good preventive measure, to keep mealybugs away before they decide to crawl up your orchid.
The grounded rocks, shells, and other minerals form a fine, white powder: an attractive meal to mealybugs. Once ingested, Diatomaceous Earth shreds the insides of the insects. It also perforates the exoskeleton, making the mealybugs dehydrate.
Diatomaceous Earth will kill anything that eats it, since it’s a powdery glass.
Honey bees, butterflies, and all the good insects that happen to be near and taste a bit of the powder will also die.
Keep that in mind when powdering. You don’t want to kill off good insects.
Yet, it is safe for larger animals and some brands even sell it as an additional cat food.
And you also don’t want razor sharp micro-knives inside your lungs. For this reason, you need to wear a mask
when spraying/powdering your orchid. If possible, go outside to spray this powder on your orchid, and do so in a contained area or box. You can check the price on Amazon here (Affiliate Link).
5. Lady Bugs
If you don’t want to use pesticides and other toxins to rid your mealybug problem, you can order ladybugs
online. There is another beetle that is more mealybug appropriate, Cryptolaemus montrouzieri,
but I’m not a fan of insects… If I have to “buy a bug to kill a bug,” then at least let’s get a cute one. And we all agree that ladybugs are charming. Release 2 to 8 ladybugs on each orchid that is infested.
Since this method will take a few days, this shouldn’t be your primary method of eliminating mealybugs. It is better applied outside, where the ladybugs can keep all your other plants safe, too.
I personally haven’t used this method and, frankly, I doubt that I will. Since I keep my orchids inside in my home office, this is the least practical method in my opinion. You can check the price of Lady Bugs on this Amazon page (Affiliate Link).
6. Commercially Sold Insecticides
This might be your only resort if the infestation has grown too much. Insecticides need to be applied with extreme care and caution. When you go to your local nursery or greenhouse, ask if the insecticide is appropriate for orchids.
Mealybugs also love citrus fruit trees, and many insecticides made for killing mealy bugs work great on those sturdier plants. Orchids are a bit more sensitive,
so keep that in mind when purchasing insecticides. This page about killing little orchid critters
is a good start to understanding pesticides and insecticides.
Thank you for reading this article, and I hope you find a quick, definite solution to get rid of your mealybugs.
If this article was any help, please comment below. Tell me your solutions to treating mealybugs and what has and hasn't worked for you. I'm especially interested in knowing if anyone actually bought ladybugs and how that went. In any case, drop me a "hello" in the comments below just so I know you dropped by.