Mealybugs are a group of insects that are characterized by a soft body with a hard or soft shield. They live as parasites on plants and suck the sap of the plant.
They are located on the underside of leaves, along the veins, and on stems or trunk of the plant where they often go unnoticed because they look like buds or malformations.
Only the larvae move, but once they found a good place, mealybugs stay there.
When a plant is infected, it loses its strength and eventually dies. The affected plant parts turn yellow, deformations are formed and growth is hampered.
Mealybug is a collective name for various soft bodied insects and with a shield. There are about 8,500 species of mealybugs.
Because of their shield, mealybugs are difficult to control with conventional insecticides.
In mild infestation you can kill mealybugs by crushing them and removing manually, but this is not very pleasant.
In case of severe infestation, you can spray the plant with a strong jet of water, but this is only suitable for robust and woody plants.
If the plant is not too large and is grown in a pot, you can immerse it in water and leave it there a little while, till the mealybugs have drowned.
Dab with alcohol:
The simplest method is to soak a cotton ball or disc with alcohol (rubbing alcohol but gin or vodka will also do, do not use a sweet liquor as this may cause mold). Mealybugs are dabbed with cotton wool soaked in alcohol and after 10-20 seconds they can be removed easily by wiping them with the cotton wool.
You may read that you can attack mealybugs with a cotton swab dipped in alcohol, but believe me, you will spend hours doing so. The alcohol evaporates quickly, you will need many swabs, the mealybugs are not well covered by the alcohol and it is not as easy to remove them as with a cotton ball or disc.
Spray with a soapy solution
Prepare a solution of 20 ml cooking oil, 1 teaspoon dishwashing liquid and 250 ml of water. Shake well and fill with water until you obtain a 2 l solution, shake again. Then spray the soapy solution on the mealybugs once a week until the infestation is gone.
Commercial pyrethrin insecticide:
Pyrethrin is a natural insecticide found in the Pyrethrum (hence the name) or Chrysanthemum. It is a neurotoxin that is deadly to insects, slightly toxic to fish but not toxic to mammals.
Pyrethrin is allowed in organic farming.
The biggest problem is that pyrethrin is toxic to all insects, including beneficial insects such as bees. It is best to limit the use to houseplants and greenhouse plants.
It is also possible to fight mealybugs with their natural enemies such as ladybugs and other insects that eat them, but this method is suitable for agriculture and is less convenient on a small scale.