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Mealybug matters

I’ve had a lot of bad luck with the mealybug. Plants that have succumbed to this little white bug include a couple of frangipanis (Araliya), a cane palm, a lime tree, a white rose, and more than one succulent. It’s easy for this pest to go unnoticed because the bug attaches itself to the under-side of the leaves of the plant it attacks. Fortunately, there are a few non-toxic ways to get rid of this creature.

So what is a mealybug and what does it do to your plants?

mealybug
via UC Davis IPM

A mealy bug is a small white spider-like creature that travels on the leaves of plants. The male mealy bug does not have wings, the female does. The male mealy bugs are rarely seen as it’s the females who do most of the damage. What these bugs do is suck out the nutrients and the moisture from plants. When they do this, the bugs also produce a wax like substance which is yellow and sticky. This wax-like stuff promotes fungal growth. Which is another way your plants could suffer. 

Now, how will your plants react to this? All the plants that I have had affected by the mealy bug have displayed the same characteristics, so it’s fairly easy to diagnose. Symptoms include stunted growth, yellowing of leaves, rotting flowers (if it’s a fruiting plant, the flowers fail to pollinate successfully), and white fungus on the under-side of leaves. Stunted growth is pretty easy, your plants will fail to grow no matter what you do. No amount of water, compost or sunlight will fix it. This could be the first visible signs that you have mealy bug. Leaves turning yellow and eventually dying and falling is a dead giveaway. Some leaves wither, twist and curl. For example, the frangipani leaves on my plant could grow 4-6 inches long. But when the mealy bug attacked it, the twisted leaves wouldn’t even reach 3 inches.

Treating mealybug and an oil-soap application

Now the good stuff – how do you get rid of this vampire? Well, there are some easy fixes and they can be found in your kitchen. Remember the wax they secrete? It acts as a defense against water. That’s why the rain can’t just knock these critters off plants. So what do we use to breakdown oil? Soap! I use a soap water solution and it works perfectly. Additional items you can use in your solution are pepper (toxic to these bugs), garlic (toxic), Panadol (toxic to bugs but helps the immune system of plants…weirdly) and oil. Why do we use oil again when the bug makes its own wax? – think of this solution water, soap, pepper and oil. The soap water breaks down the wax, the pepper poisons the bug and the oil traps it all in and effectively suffocates them. There is no mixing ratio here, but what I would say is it stay away from laundry detergent. I used laundry detergent once and all my leaves went yellow and died off, fortunately the plant survived and a week later the leaves were back and beautiful. Laundry detergent is much too harsh for the leaves. So I use hand wash, shower gel or any dish wash soap.

Simple. However, the real problem is the eggs They hatch 10 days after being laid. So if you spray your plants with soap solution once and forget about it, 2 weeks later they will be back (read in Schwarzenegger terminator voice). So what I do is spray the plants once a week, just to be safe and it’s worked so far. When the situation is under control you can cut it down to once a fortnight.

How do I spray the solution on the plants? Is there a specific method to do it? – I am glad you asked. I mentioned before the mealy bug likes to hang out on the under-side of the plant. They also travel up and down the juicy new shoots that come up from the soil. So when you do spray the solution, really get the under-side of the leaves soaking wet, treat the trunk, branches and the top soil the same way. Oh yes, spray the top soil as well. This will stop eggs or new hatchlings that have fallen on to the top soil from coming up to the leaves.

So there you go, what a mealy bug is, what it does to a plant, how you can diagnose your plants, and how to get rid of them. Hopefully this helps you to control one of the most destructive indoor plant bugs.

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