Insect pests multiply very quickly indoors. There are no natural predators to keep the insects in check, so you have to be very diligent about checking for symptoms. Keep an eye out for leaves that become discolored or curled and for plants that look limp even when they’re watered. Learn to spot the following common houseplant pests.
House Plant Bugs
1. Spider Mites leave telltale webbing, especially on the inner joints of plants and in plants with lush foliage. The tiny mites are about the size of a pinhead and injure plants by sucking their juices. Attacked leaves will have yellow stippling. As the infestation gets worse, the leaves will turn totally yellow and brittle and quickly die.
To get rid of spider mites, thoroughly spray the affected plants with insecticidal soap. Repeat as recommended on the label.
2. Mealy Bugs are small cottony white blobs, usually attached to the plant at the stem joints, but they may also be found along the stems. They make themselves at home and slowly feed off the plants by sucking. Plants infested with mealy bugs often look like they are drying out, even when they've been watered.
Mealy bugs are very hard to get rid of. If you catch the problem early, cut out the infested branches. You can also dab the mealy bugs with a cotton swab soaked in rubbing alcohol. If you plants become severely infested, it would be best to just get rid of them. The mealy bugs are only going to spread.
3. Scales are small insects that attach themselves to the stem of a plant and cover themselves with a hard, oval-shaped shell. Like mealy bugs, they slowly suck the sap from plants, leaving them too weak to sustain themselves.
Also like mealy bugs, they are very hard to get rid of. Pesticides often don’t penetrate their hard shells. You may have some luck rubbing the scales off with your nail. Young scales have to crawl unprotected to a new location to set up shop, and can be sprayed at that time with insecticidal soap. The soap has only minimal use against the protected adults.
4. Aphids look like small green, white, yellow or black spots that can surface on all parts of a plant. Aphids can reproduce so quickly that an infestation will cover the plant in days.
Aphids are soft-bodied insects and can be killed quite easily by a strong blast of water or repeated sprays of insecticidal soap. But they are persistent and you will need to remain diligent to rid your houseplants of these pests.