Mealybugs: What They Are and How To Get Rid of Them

If you have plants, mealybugs can pose a serious threat, especially to young plants. There are hundreds of species of mealybugs in North America, and they feed off plants by sucking the juice from them. They can seriously damage and even kill plants. Preventing and eliminating mealybugs will help protect your plants and ensure they flourish.

Identifying Mealybugs

You can spot mealybugs by their white, cottony appearance. They are small, flat, and waxy with oval, segmented bodies. Mealybugs are quite small, usually between 1/20 and 1/5-inch long. Mealybugs prefer warm temperatures and are often found in houseplants or outdoor plants in warm climates. 

The most common mealybug variety in plants is the citrus mealybug (Planococcus citri). Mealybugs often flock to plant crevices, making them easy to overlook until an infestation occurs. Using a magnifying glass to inspect crevices in your plants can help you spot mealybugs before they spread.

Infestation Signs

White, Waxy Substance on Plants

The first sign of a mealybug infestation is white, cottony, or waxy substances on your plants. “Mealybugs often cluster together in colonies, typically where they lay their eggs and continue to feed,” says master gardener and founder of Pro Gardener Blog, Robert Silver. “These clusters can range in size from small groups to larger masses, resembling fluffy white cotton balls. The presence of these clusters is a telltale sign of a mealybug infestation.”

Sticky Honeydew

Another sign of a mealybug infestation is the sticky honeydew that mealybugs secrete. The honeydew can spur black sooty mold to grow and also attract ants. “The honeydew excreted by mealybugs can attract ants, creating an unhealthy partnership,” Silver says. “These ants will protect the mealybugs from predators, making it even more challenging to control the infestation.”

Wilting Plants

You will also see signs in your plants if you have a severe mealybug infestation. Your plants may grow slowly or abnormally or have wilting leaves. They may twist into contorted shapes or have abnormal flower formations. Fruits, vegetables, and flowers may drop off your plants. “Infested plants often show stunted growth as mealybugs feed on plant sap, depriving the plant of essential nutrients,” Adnan says. “As mealybugs feed on plant sap, leaves may yellow, wilt, or drop prematurely.”

Mealybug Life Cycle

Mealybugs can reproduce rapidly and spread to other plants with the help of insects such as ants. Mealybugs have a life cycle that includes egg, nymph, and adult stages. Mealybugs reproduce in large numbers, with female mealybugs laying between 300 to 600 eggs in their lifetime. 

The mealybug life stages include:

• Eggs. Female mealybugs lay eggs on plants. The eggs are tiny and white and often challenging to see.
• Nymph. Mealybug eggs hatch into nymphs. Nymphs are wingless and resemble small adult mealybugs. Nymphs feed on plant sap and grow quickly.
• Adults. Adult mealybugs are oval-shaped. They’re covered in a white waxy substance that protects them from predators and the environment. Adult mealybugs feed on plant sap and reproduce.
• Sterile male. Some mealybug species produce sterile males. Sterile males do not feed or reproduce. Their only purpose is to mate with females.

The exact timeframe of the mealybug life cycle depends on the type of mealybug. Depending on the species and environmental conditions, mealybugs can complete their life cycle in as little as two weeks. Their ability to quickly reproduce can cause infestations to spread rapidly.

Common Plants Affected by Mealybugs

Plants that are commonly affected by mealybugs grow in warm climates and greenhouses. Some plants that often attract mealybugs include:

• Fruit trees and vines, including citrus fruit trees, grape vines, and fig trees.
• Ferns 
• Ornamental plants such as roses, azaleas, and hibiscus. 
• House plants, including spider plants and succulents.

Overwatering your plants and over-fertilizing them can increase the risk of mealybugs, so make sure you have adequate drainage and follow the recommended feeding and watering schedules for your plants. 

Prevention and Control

Prevention is the first step to combat mealybugs and protect your plants. Regularly checking your plants for signs of mealybugs and isolating any affected plants will help stop the spread of these pests.

Inspect and Isolate Plants as Needed

“Regularly inspect your plants for signs of mealybug infestations,” Adnan says. “Early detection is key to preventing their spread. If you spot mealy bugs, promptly prune and remove affected plant parts. Isolate infested plants to prevent the pests from spreading. Isolating affected plants is crucial to stop the spread of mealybugs. Plants with a severe infestation may need to be discarded to prevent the mealybugs from attacking your other plants. 

Maintain Your Plants

Keeping your plants nourished with the right amount of fertilizer and water can help prevent mealybugs. Mealybugs are attracted to over-watered and over-fertilized plants, so make sure your plants drain well and do not overdo their feeding and watering. Keep your plant areas clean and clear of debris.

“Regularly clear away fallen leaves, plant debris, and weeds, making your garden less hospitable for these pests,” Silver says. “These organic materials can serve as hiding places and food sources for mealybugs. Thoroughly clean your gardening tools as well to prevent the accidental spread of mealybugs between plants.”

Rotate Plants

If you have an extensive plant collection, Silver suggests periodically rotating their positions. Mealybugs tend to settle in certain areas and establish themselves. Rotating plants can disrupt mealybugs’ breeding and prevent infestations from spreading. 

Introduce Natural Predators

Some natural predators can help keep your garden clear or mealybugs. Ladybugs, lacewings, and syrphid flies are natural predators that kill mealybugs. “Encourage beneficial insects like ladybugs and parasitic wasps in your garden, as they feed on mealy bugs,” Adnan says.

Sticky Traps 

You can use sticky traps to stop mealybugs before they crawl into your plants. “Sticky traps, like yellow or blue adhesive cards, can catch wandering mealy bugs before they reach your plants,” Silver says. “You can also create barriers using sticky tape applied around the base of pots.”

Diatomaceous Earth

Diatomaceous earth is a natural substance that you can sprinkle around the base of your plants. It helps deter mealybugs, preventing them from climbing up your plants. 

Neem Oil

Neem oil is another natural remedy to eliminate mealybugs. You can make your own spray by combining 1 to 2 teaspoons of neem oil, 1 to 2 teaspoons of dish detergent, and 1 gallon of water. Spray your affected plants once a week until the mealybugs are gone. 

Chemical Treatments

If you have a severe mealybug infestation that does not respond to your treatments, seek help from a pest control professional. Some insecticides can kill mealybugs but require special care for your plants and the environment. Some pesticides will kill all insects, including beneficial ones, and some are not safe for use indoors or around people. Seek expert advice before using a chemical pesticide.