Do you have mealybugs on your Phalaenopsis orchids and can’t seem to get rid of them no matter what you do? In this post, I’ll describe exactly what to do in order to eliminate those dready mealybugs off your orchids.
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What are Mealybugs
Mealybugs are white and cottony in appearance and you can find then literally anywhere on a Phalaenopsis orchid. On the tops of the leaves, on the undersides of the leaves, on the flower spike and flowers and even in the potting medium!
When inspecting your Phalaenopsis orchids, look everywhere. The first step after you spot mealybugs is to isolate those infested plants and move them away from your other plants because they can spread quickly.
Mealybugs damage your plants by sucking sap out of your plant and they will also excrete a sticky honeydew. The best line of defense against mealybugs is to catch your infestation early on before it gets really bad. Here is what mealybugs look like.
Treating Mealybugs on Orchids
Many people spray their orchids once and then expect the problem to go away. Unfortunately, that’s not sufficient. Make sure you read the entire article, because you must take all these steps for maximum effectiveness.
I like to employ 2 treatments at the same time. The cheapest and quickest way to kill mealybugs is with 70% isopropyl alcohol, and I also recommend adding a systemic insecticide at the same time. Here is the process I recommend.
1. Spray Down Your Phalaenopsis Orchid
If you only see one or two mealybugs, you can dip a Q-tip into isopropyl alcohol (70% isopropyl alcohol will be fine) and touch the mealybug with the Q-tip and it will die immediately. You can easily find 70% isopropyl alcohol at a drug store or grocery store.
If there are multiple mealybugs, especially if they are hiding in leaf crevices, place 70% isopropyl alcohol in a spray bottle and spray down the entire plant, including the undersides of the leaves.
Here is a single mealybug before spraying.
And after spraying, it immediately turned brown and died.
Check your plants at least weekly, and if you see anymore, keep applying the alcohol. You may find yourself spraying weekly for several weeks or longer, depending on the severity of the infestation and how well you are spraying or applying the alcohol.
And just because you don’t see anymore mealybugs, it doesn’t mean that they’re not there. There could be juvenile mealybugs that aren’t visible yet to our eyes so it’s important to take all of these steps.
2. Apply a Systemic Insecticide
In addition to the spraying, I recommend adding a systemic insecticide simultaneously. A systemic insecticide works by absorbing the insecticide from the root system, and then the plant distributes it to the leaves. It essentially protects the plant from the inside out, so it will offer an additional layer of protection. When used in combination with spraying, it is a very effective remedy.
Mealybugs can also infest the potting mix of your orchid, so the systemic will take care of that, and it will prevent you from having to repot your orchid into a fresh growing medium! This is a huge benefit.
There are many on the market, but I like to use the Annual Tree & Shrub Insect Control (link to Amazon) from Bonide. Mix 2 tablespoons (or one ounce) into one gallon of water, and water your orchids with it. If you don’t need that much solution, divide everything by 2 and add 1 tablespoon per 2 quarts of water.
You may only need one application, especially if you catch the mealybugs early, but you can reapply again after a couple of months if you still see mealybugs at that time. (But during the first two months, you’ll want to keep using the isopropyl alcohol regularly every time you see any new mealybugs appear.)
For orchids in sphagnum moss, just top water with your solution and thoroughly soak the moss. Be sure not to dump any of this solution down your drains, though! For orchids growing in bark, I like to soak the bark and roots for 10-15 minutes, and then remove the excess solution.
Follow all safety instruction on the label when using this product. And it does not keep well long-term, so if you mix up your insecticide in water, make sure that you use it up and don’t put it in storage, and don’t dump it down the drain. Use it on your plants only.
3. Monitor Your Orchids
Lastly, monitor your orchids regularly. Check them at least weekly. You may need to continue using the isopropyl alcohol weekly over the period of a couple months. After the initial application of the liquid systemic insecticide, if you still see mealybugs after two months or so, do another application.
The key with pests is to be persistent and systematic. I wish it were as easy as spraying once, but unfortunately it’s not the case.
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