Orchids are a beautiful plant to have in your garden whether indoors or outdoors. But you need to protect them from pests especially the dreaded mealybugs which can destroy them in a few days.
You can get rid of mealy bugs fast if you find out about the problem at the early stages. Methods such as plucking by hand or using rubbing alcohol work great at this stage. If it’s a full-blown infestation, it may be too late and you’ll need to dispose of the orchids.
I’ve written a lot more details about the different methods you can use to get rid of mealybugs from your orchids. I’ve also written about ways you can prevent mealybugs from attacking your orchids in the first place.
What are mealybugs?
Mealybugs are tiny, white, cottony insects that you find on orchids and several other plants. They may appear to you as small snowflakes on several parts of the orchids such as leaves, stem, and even the roots.
They are related to scale insects but don’t themselves have any scales. They have a waxy coating on their bodies. The mealybugs harm the orchids by sucking the sap out of them similar to aphids.
This means the plants get a reduced supply of nutrients that will stunt their growth. When the infestation is bad, the plant will die to due the lack of nutrients.
The mealybugs excrete honeydew which tends to attract sooty mold as well as ants. The honeydew may collect on the leaves and block sunlight causing them to wilt and turn yellow.
There are several species of mealybugs but the ones that tend to be most common on orchids are the long tail mealybugs. You can recognize them by their long posterior.
How to get rid of mealybugs
There are many organic and non-intrusive methods you can use to get rid of mealybugs in your orchids. But they work best if you can capture the problem at the early stages when the infestation is just starting out.
If there is a heavy infestation of mealybugs, the orchids may be done for. You can try to use chemical pesticides and insecticides to resolve the issue. But the plant may be too damaged to recover.
The easiest method to get rid of mealybugs in your orchids is to use rubbing alcohol also known as isopropyl alcohol. You can use the one you get at your chemist that contains 70% concentration.
The best mix is to use 50% of this rubbing alcohol with 50% of clean water and put it in a spray bottle. You can then spray it on all the leaves and plant parts you see infested with mealybugs.
You can also use a cotton swab to dip in this solution and gently rub the leaves to remove all the mealybugs and their residue.
You can also add a teaspoon of organic liquid soap that will help the solution spread on the leaves and coat it on the mealybugs.
You’ll need to keep spraying or applying this solution to your orchid plants every week till you see there are no visible mealybugs. And your orchids will start to feel a lot healthier and happy.
Make sure to use rubbing alcohol and not other types such as ethanol as they will be absorbed by the plant and cause problems as they are toxic.
I would also suggest you apply the rubbing alcohol only in the morning and on days when the temperature is below 85 degrees. Too much heat will cause the alcohol to burn and damage the orchid plant.
Use oils and soaps
You can use organic soaps like insecticidal soaps and oils such as neem oil or horticultural oil to get rid of mealybugs. The simplest method is to add a teaspoon of the oil and soap in a liter of water.
Then add some solution to a spray bottle and spray it on the leaves, branches, stem, and soil of the orchid plant.
Before you use this solution on the entire plant, make sure to spray it on a couple of leaves and observe after 24 hours. If there is no reaction on the leaves, you can spray it on the entire plant.
Some of these oils can cause problems on the plant and burn them so it’s best to test them on a few leaves before you use them.
Neem oil is the safest option you can use along with an insecticidal soap. The soap coats the waxy surface of the mealybugs and dissolves it. The neem oil will be absorbed by the mealybugs and will disrupt their growth cycle causing them to slowly die out.
You will need to keep spraying this solution every week because it works slow to kill the mealybug population. You can stop when you no longer see mealybugs on your orchid plants.
I don’t recommend using insecticides because you will end up killing beneficial insects as well. The chemical insecticides may also end up harming the plants if you’re not careful with the amount you use.
But if you have a heavy infestation of mealybugs and don’t know what to do you can try to use them. Make sure to use the ones that are labelled for ornamental plants. Otherwise, it will increase the phytotoxicity in your orchid plants and end up killing them.
Some options you have with chemical insecticides for your orchid plants are acephate, malathion, carbaryl, and diazinon. Make sure to follow the manufacturer’s instructions when using these chemicals on the amount and frequency of use.
You may also need to rotate the use of these insecticides and other methods if you have frequent mealybug infestations. This will help prevent the mealybug population from becoming resistant to them.
Use growth regulators
You have an option to use growth regulators to reduce and eliminate the mealybug population in your orchid plants.
One such growth regulator is kinoprene which is a juvenile hormone. It will interfere with the growing cycles of the mealybugs and reduce their population. You need to use the right amount for this and it does not have any harmful effects on humans or pets.
Another chemical is azadiractin which is a chitin inhibitor. The insects use chitin to develop their exoskeleton. So a chitin inhibitor will cause poor development of such exoskeleton.
This will cause the mealybugs to start dying because their bodies won’t be able to survive long with such poor development.
Attract beneficial insects
This is the method that I like with mealybugs or any other pest infestation in my garden. It’s an organic, natural method that Mother Nature has in place to balance the cycle of life.
Do note that using beneficial insects will reduce the population of mealybugs but it may not eliminate them completely. I am fine with a few pests in my garden as long as they don’t destroy the entire plant.
The beneficial insects that will feast on the mealybug population include wasps, brown lace wings, green lacewings, and lady beetles.
You may be able to purchase some of these insects and release them in the garden. But I like to attract them by growing native plants in the garden close to the orchids.
Pluck them by hand
Another simple, natural, and effective method to remove mealybugs from your orchids is to use your hands and pull them out of the plant.
You can then put them in a bucket containing soapy water to kill them or you can squish them using your fingers. If you feel icky picking them by hand or don’t want the waxy coating on your hand, you can use gloves.
The drawback of using this method is you will only be able to pull out mealybugs that are in the adult or large nymph stage of growth.
Till the ground
It may happen that the mealybugs have infested not only the orchid plants but the potting soil and roots. This can make it harder to get rid of them.
The best thing you can do in this case is repot the plant to another location in the garden that is free from this problem. We have already discussed this.
You can then use a tiller to till several inches of the soil that is having the mealybug infestation. They will be exposed to the surface where insects and birds will feast on them.
You can also spray the rubbing alcohol and soap solution on the mealybugs till you find that they have disappeared from the soil.
Use diatomaceous earth
Diatomaceous earth is a fine, white, powdery material that contains microscopic pieces of shells from the ocean. These fine particles have sharp edges to them.
You can dust diatomaceous earth all over your orchid plants that have a mealybug infestation. The mealybugs soft bodies get cut when they move over the diatomaceous earth. And they won’t survive for very long.
Diatomaceous earth is completely organic and does not harm humans or pets. You only need to take care when spraying the powder as it can get in your lungs and cause irritation. So wear a mask, gloves, eye protection, and thick clothes when spraying it over the orchids.
I prefer that you mix the diatomaceous earth with water and spray it all over the orchids. When the water dries out, the diatomaceous earth will stick to the plants parts and start doing its work.
You will need to apply a layer of the diatomaceous earth at least every week to see the best results as it will take some time to affect the mealybugs.
You’ll also need to apply it again if there is rain in the garden that causes the earlier coating to wash away.
The mealybugs can affect the orchid plant in the leaves, branches, stems, as well as the roots and soil. You may be able to get them out of the foliage with the above methods. But it may be harder to get them out of the soil and roots.
A better solution would be to repot the orchids with new soil. If you are growing them in a pot, this is easier to do as you can use a new pot with a fresh batch of potting soil.
You can take the orchid rootball out of the existing pot by gently tapping on it. Or you can cut open the pot if it’s made of plastic.
Make sure to remove all the mealybugs on the roots by pulling them out with hand and using rubbing alcohol to clear them out. You can then add fresh potting soil to the new pot and put the rootball into it.
If you’re growing the orchid in an outdoor garden, you can transplant it from one location to another free from mealybugs. You can dig around the roots and remove the rootball from the soil.
Follow the same process to remove the mealybugs from the roots by hand as well as using rubbing alcohol. You can now dig a hole in a new location that is of the same depth as the rootball. Place the rootball in the hole and cover it up with soil.
Prune the infested parts
If the mealybug infestation has just started on the orchid, you can prune the parts such as leaves, branches, and roots. Pruning means you cut away the parts of the plant that are infested.
Dispose of the parts far away from your plants otherwise the mealybugs will move on to other plants in your garden.
I would prefer that you burn the parts to be safe. You can use a bypass pruner to clip away the infested parts. This helps you prune the plant with minimal damage.
So there is less chance of any bacterial or viral diseases infecting the orchid. It will also heal a lot faster because the cut is clean.
You should also clean the bypass pruner with rubbing alcohol before and after using it on each and every orchid for pruning.
How to prevent mealybugs
The best way to protect your orchids from mealybugs is to prevent them from reaching the orchids in the first place. I’ve written some steps that are simple but effective in doing this.
Check the orchids before buying
If you are purchasing your orchid plant from a nursery store or garden center, you need to be very careful not to bring mealybugs home. If you do so, the mealybugs will destroy the orchid as well as other plants in your garden.
Check all the leaves, branches, stem of the orchid to ensure there are no visible mealybugs roaming around. You may also need to take the rootball out of the pot to check for mealybugs.
Sometimes, the mealybugs will not be visible but you can check for signs such as sap running out from the leaves or stem, honeydew residue on the plant, or tiny bite holes on the area between the stem and leaves.
After you have bought the orchid home, make sure to quarantine it from the other plants for at least 2 weeks. Check the orchid every day to see if you find any adult mealybugs on it.
You can also take preventive measures like spraying neem oil, horticultural oil, or rubbing alcohol on all parts of the plant. You can do this spraying every week till you are satisfied there are no mealybugs.
Monitor the orchids
I recommend doing a daily check on your orchids and other plants in the morning. This helps check if there are any pest or disease problems starting on the plant.
You can immediately figure out it’s a mealybug infestation starting and take the necessary actions to prevent a full-blow infestation.
Check all the parts of the plant where the mealybugs like to live in. This includes the top and bottom of the leaves, the join where the leaf connects to the stem, and the entire main stem.
If you’re growing the orchid in a pot make sure to check the lips and any cracks on the pot as they are preferred hiding places of mealybugs.
Another common sign of mealybugs is the sticky honeydew they will leave on the plants. You may also check for sticky sap on the leaves and stem that mealybugs tend to feast on.
If you find white, cottony patches on the leaves, stems, and other parts of the orchid, it’s a sign that you have a mealybug infestation.
Keep the garden clean
The next best preventive measure you can take against mealybugs is to keep your garden clean. Don’t allow waste to collect in your garden that could be a breeding ground for pests including mealybugs.
If you are growing orchids in a pot, make sure to sterilize it before use. You can do this by soaking the pot in a solution containing 1 part bleach and 9 parts water.
Keep the pot soaked in this solution for at least 1 hour. You can then rinse it with clean water and let it dry in the sun before adding the potting soil and orchid seedling.
You should also ensure the potting soil you’re using is sterile and free from any pests and diseases. Buy it from a reputed source that will ensure such sterile soil.
You could also solarize the potting soil where you place it inside a black plastic sheet and leave it in the sun for several hours. This ensures the pests and diseases are destroyed before you use the potting soil.
Another way to heat up the potting soil is to place it on a baking sheet in the oven and turn up the heat to 180 degrees. Keep the potting soil in the oven for at least 30 minutes and you’ll have killed pests like mealybugs.