Mealybugs: What to Know

Medically Reviewed by Mahammad Juber, MD on January 17, 2023
5 min read

If you’ve ever seen a small, strange white bug on your houseplants, you may have encountered a mealybug. These odd creatures feed on plants and cover themselves in a wax coating, making it hard to get rid of them. While harmless to humans, they can damage plants, so you’ll want to eliminate them if you find them in your home or garden.

Mealybugs are a tiny, alien-looking insect from the family Pseudococcidae. They often live in colonies and infest plants both indoors and outdoors.

What do mealybugs look like? Mealybugs are small, between 1/8 and 1/4 inch long. Mealybugs are sexually dimorphic, meaning the males and females look distinctly different.

Female mealybugs are the ones you’re likely to notice. They have soft, round bodies and no wings. While their bodies are usually a shade of pink, they often cover themselves with a white, waxy coating that helps protect their bodies from heat and loss of moisture. They usually have white filaments sticking out from their bodies, making them look spiky or bumpy. When the females bunch together on branches, it may look like popcorn.

Male mealybugs look like a completely different species and aren’t seen often. They’re more like gnats, with a set of wings and four eyes. They aren’t covered in wax like the females but often have a long wax tail. 

Some species of mealybugs can reproduce without mating.

Mealybug life cycle. The life cycle of a mealybug will depend on the species.

Some female mealybugs give birth to live young, though most lay eggs. For those that lay eggs, they can lay 200 to 600 at a time. They lay their eggs inside a thick, cottony sack that they usually attach to plant matter like leaves or twigs. These eggs typically take somewhere between three and 16 days to hatch.

When the nymphs, called crawlers, first hatch, they’re usually a shade of yellow, orange, or pink. Not long after birth, they start developing their waxy coating. The nymphs are much more mobile than their adult counterparts, though they look similar to adult females. They’ll go through several phases in the nymph stage before becoming adults. After laying eggs, the female mealybug dies. Depending on the species, the total life cycle for a mealybug is usually between 23 and 75 days.

What do mealybugs eat? Mealybugs have sucking mouthpieces so they can feed on plant sap. They feed on a variety of plants and trees, though citrus trees seem to be most affected. A colony of mealybugs can damage plants as they steal nutrients, causing plants to wilt and stunting their growth.

Mealybugs produce a sweet, sticky substance called honeydew. This honeydew often attracts mold.

So far, over 2,000 species of mealybug have been found worldwide, with about 275 of those living in the U.S. While most of them look similar, some have distinct differences.

Citrus mealybugs (Planococcus citri). Citrus mealybugs are native to Asia but are now found throughout the world. They sometimes have a dark line down their backs. This species feeds on a wide variety of plants, mainly ornamental plants like begonia and tulips, but also on citrus trees. They are the most common mealybug found indoors. Their saliva contains a toxin that may damage plants.

Ground mealybug (Rhizoecus falcifer). Ground mealybugs don’t live on plants, like most mealybugs, but in the soil. They feed on plant roots, especially roots of African violets and other potted plants.

Longtailed mealybugs (Pseudococcus longispinus). As the name suggests, longtailed mealybugs have a long tail filament. While this species looks like it gives birth to live young, their eggs hatch almost immediately after they are laid. They will eat a wide variety of plants.

Madeira mealybugs (Phenacoccus madeirensis). This species of mealybugs has an incredibly varied diet. They’re willing to eat ornamental plants but also fruits, vegetables, and other types of crops. They can damage and deform plants, and their honeydew attracts mold, which causes further damage.

Mealybugs can be found both indoors and outdoors all across the world. They prefer warm, dry weather but can be found indoors if the weather is too cold. 

Mealybugs may cause damage to plants, such as wilting, yellowed leaves and stunted growth. 

Most mealybugs are easy to spot, especially after the first batch of eggs hatches. If your plants are looking ill, check the underside of leaves, the crevice where the leaves meet the stem, and the soil. Mealybugs in these areas might not be as obvious. Keep an eye out for honeydew and black-colored mold.

Female mealybugs can’t fly, and some even struggle to crawl, so they can’t go far. If you’re noticing a sudden surge of mealybugs, it’s likely because they came in on a plant, in pots, or on tools. Check these things before bringing them into your house or leaving them in your garden.

Mealybugs do not pose a health risk to humans but have been known to transmit viruses to plants. A few species have saliva that is toxic to plants.

If you’ve discovered a mealybug infestation, there are a few things you can do to get rid of them:

  • Use tweezers or a cotton swab dipped in alcohol to remove them individually.
  • Wash the plants.
  • Use pesticides like pyrethrins and imidacloprid.
  • Separate infested plants from non-infested plants so the bugs don’t crawl from one to the other.
  • Prune infested areas of the plant, so long as it won’t damage the plant, and dispose of cuttings right away.

To prevent a mealybug infestation, carefully examine all plants before you bring them home, and keep them separate from other plants for about a week. If you often deal with mealybug infestations, consider choosing plants that generally aren’t appealing to mealybugs.

The waxy coating on the mealybug makes it hard for most pesticides to affect them. Systemic insecticides, which are absorbed by plants, are often a better option for mealybugs. When using pesticides or insecticides, follow all instructions and keep them out of the reach of young children and pets.