White Fungus - Mealybug Infestation On Succulent

by Elisabeth Gordon
(Cheltenham. UK)

I have a fleshy indoor pot plant which has developed a horrid white fluffy fungus on it which I can’t get rid of.

It is spreading. It looks seems to have white fine threads on it.
See photos
I’ve tried spraying it and also cutting it back.
Please can you help me.

Answer:

You don't have a fungal problem on your succulent. This is a mealybug infestation. These insects feed on your plant and create this white fluffy looking stuff on your plant. They can multiply quickly and they leave a sticky residue behind which will start to grow a black fungus.

You can treat this with several different organic methods which should get rid of the mealybugs.

1. Use insecticidal soap: You can buy this as a ready made up spray or you can make your own with vegetable oil, dish soap, and water. This will suffocate the bugs.
Spray the whole plant and make sure you also wet the undersides of the leaves. Repeat the treatment after about 10 days to make sure you got all the mealybugs and their eggs.

2. Neem Oil: mix some Neem oil with a few drops of dish soap and water. Again make sure to wet the whole plant. The Neem oil kills the mealybugs and interrupts their breeding cycle.

3. Beneficial insects: lacewings or ladybug larvae feed on pests like mealybugs. They are a good follow up if you had a pest infestation particularly if you have a lot of plants. These pests often fin hiding places in cracks and crevices of the plants or pots. You think you got rid of them... but a few weeks later you will find more of them on your plants. Beneficial insects make sure that this does not happen. You can buy them online and release them around your plants. They will disappear once their job is done.

You can give the plant a rinse with water after a few days to wash off the dead bugs and the sticky residue.
To prevent further pests make sure that your plant is in a bright spot and gets fed and watered regularly. Avoid over-watering which will weaken the plant and makes it susceptible to pests like mealybugs.