Something all growers dread is a mealybug infestation. Often said to be one of the hardest pests to kill and get rid of, mealybugs have caused many people a lot of stress as they can destroy plants. Common within the houseplant growing community, mealybugs easily have one of the worst reputations among all pests.
Mealybugs are a wingless, soft-bodied pest which appear as white cottony masses on the leaves, stems and fruit of plants. Closely related to aphids and scale insects, mealybugs can cause a lot of damage and be difficult to get rid of. Mealybugs are often found in moist, warm habitats which makes houseplants a perfect breeding and feeding ground. Prolonged mealybug infestation can lead to disease.
What do mealybugs look like?
Mealybugs are often described as looking like cotton, they actually get their name from the white waxy filaments they produce as a protective barrier as this looks like cornmeal. When grouped together on a plant, mealybugs seem to all blend into one mass of a cotton-like skin which can be confused with seeming like fungus.
Individual mealybugs look like white, fuzzy, ovals that can be anywhere from 1/20th to 1/5th of an inch long. They do not have wings nor an armoured exoskeleton. They are somewhat elongated and segmented and have waxy filaments extending from their hind end, giving the appearance of a tail. Mealy bugs will leave this filament behind as they move around the plant that they are infesting, this is what can get confused with a white fungus.
How do mealybugs damage plants?
Mealybugs can cause damage to plants in several ways:
– They feed by sucking sap from stems, leaves and fruit for the nutrients, this can leave plants with severe wilting and deformed growth.
– They also excrete large amounts of honeydew (this is because the sap they consume has a high sugar content) which can build up on plants and promote growth of sooty mold and cause further damage to plants by restricting photosynthesis.
– This sticky honeydew also attracts ants and can lead to an infestation of them as well.
– Over time leaves will begin to turn yellow and drop and the plant itself can die entirely from a mealybug infestation.
What plants are impacted by mealybugs?
Plants that are often impacted by mealybugs have some properties in common such as producing a sweet sap or being in warm, moist and humid environments.
Common plants affected are:
– Houseplants such as monstera, ferns, ficus, orchids, coleus, palms and philodendrons.
– Fruit trees/plants – especially citrus, figs, berries and grapes.
– Ornamental plants including fuchsia, Cactus, gardenia, jasmine, hibiscus and oleander.
– Plants kept in a greenhouse are also desirable for mealybugs because the warm, humid environment is ideal for breeding and feeding.
The lifecycle of mealybugs
The full mealybug lifecycle lasts around 7-10 weeks. Mealybugs reproduce via eggs, between 200-600 can be laid at once. At higher temperatures less eggs are laid, but there is still enough to increase the population exponentially. These eggs look like a yellowish white cotton mass. The female mealybug will die about 10 days after laying eggs. Young female mealybugs are mobile for their entire lives whereas male mealybugs settle in a white waxy cocoon for the first period of their lives. Male mealybugs also have wings however they are very rarely seen as they do not live very long, only a few days. A new generation of mealybugs can form every 3 months or so however this does depend on the temperature. Several generations of mealybugs can be present at once though, meaning they can multiply very quickly!
What attracts mealybugs?
Mealybugs tend to be attracted to certain plants that are heavy in the juices they prefer to feed on, this means plants that produce a sweet sap. Citrus trees are particularly susceptible, and mealybugs can pose a serious threat to some commercial crops, such as mango as they can breed very quickly and devastate a whole crop. Mealybugs can infest a number of indoor houseplants, particularly tropical species and they are very common within the houseplant growing community.
Mealybugs are attracted to plants with high nitrogen levels and soft growth; they may be more attracted to your plants if you overwater and over-fertilize them.
How do you get rid of mealybugs?
There are a few methods that can be used to get rid of mealybugs, both chemical and organic. Their effectiveness will vary as will the time it takes to eradicate the infestation.
Chemical solutions to get rid of mealybugs
A number of stronger commercial insecticides are able to be used against mealybugs, they can be purchased from most nurseries or on Amazon here. Be cautious when using these chemicals, especially in indoor locations without proper ventilation. Stronger pesticides have varying degrees of toxicity to pets and humans. Generally these solutions will take anywhere from 10-14 days to be completely effective, you will need to reapply 2-3 times during this period.
Using neem oil to get rid of mealybugs
Neem oil is a natural substance derived from seeds of the neem tree. It can be purchased from Amazon here. In addition to its insecticidal properties, neem oil is also a fungicide which is particularly helpful if you have any sooty mold growing as a result of mealybugs. When used as directed, it not only kills insects on contact, but serves as a systemic pesticide by being absorbed into the plant this will act as a repellent to deter future generations. According to the Environmental Protection Agency, neem oil is safe to use on vegetables and other edible plants, as well as ornamentals so it wont have any detrimental effect on you or your family. You will need to follow the directions provided on the package to determine how often you will need to apply the neem oil however you should see noticeable results after a fortnight.
Using insecticidal soap to get rid of mealybugs
Insecticidal soaps are available on the market and can be purchased from Amazon here, or you can make your own by using a common dish detergent such as Ivory Liquid. Try to find a product that is free of perfumes and additives which could further harm plants. Mix the soap in a weak concentration with water (starting a 1 teaspoon per gallon and increasing as necessary). Spray the soapy solution on plants. After 6-8 applications every 3 days or so the mealybug infestation should have been eradicated however if it still remains you might need a stronger product.
Using isopropyl alcohol to get rid of mealybugs
For this method you will need to soak a cotton ball with regular rubbing alcohol and wipe it on the mealybugs, this will both kill and remove them. Before you use this method it is advised to first use a solution consisting of no more than 70 percent isopropyl alcohol, and test it on one leaf before you apply it to the whole plant to make sure the alcohol doesn’t burn it. Repeat the application every day until you no longer have mealybugs, this will likely take anywhere from 1-2 weeks.
Using water to wash away mealybugs
Mealybugs can be dislodged with a steady stream of water. This is best for light infestations on plants outdoors. You will need to use some care and common sense with this method as some plants do not tolerate this kind of vigorous treatment. Repeat the treatment as necessary until all mealybugs are gone.
Using predatory insects to get rid of mealybugs
Lacebugs, lacewings, parastic wasps (Leptomastix dactylopii), and a beetle sometimes known as the “mealybug destroyer” (Cryptolaemus montrouzieri), are natural predators of mealybugs. These are more commonly used for outdoor infestations or in greenhouse situations and are available from commercial online retailers. This likely isn’t the best solution if you have a mealybug infestation on your houseplants as you’ll be inviting more insects into your home.
Making homemade insecticide spray to get rid of mealybugs
To use this method you can make a batch of homemade insect spray by combining 1 garlic bulb, 1 small onion, and 1 teaspoon of cayenne pepper in a food processor or blender and process into a paste. Mix into 1 litre of water and steep for 1 hour. Strain through a cheesecloth and add 1 tablespoon of liquid dish soap. Mix well. The mixture can be stored for up to 1 week in the refrigerator. Spray the solution on the plant parts where mealybugs are present. This natural, homemade solution has been proven to be quite effective, I have even used it myself with great success.
As you can see there are many ways to get rid of mealybugs, both commercial and organic. I have used all of these in the past and can say all of them work. Some do require more work than others however if you don’t like bringing extra chemicals into your home then taking the extra time for the organic methods is definitely worth it.
How do you prevent mealybugs?
Like most pests, the best control for mealybugs is defensive, stopping them from arriving in the first place. Healthy, vigorous plants are less susceptible to infestation than weak, underpotted, and stressed plants. As a general rule, make sure your plants are healthy, and you’re less likely to attract these pests in the first place and if you do attract them, your plants will be better and more equip to fight them and have a lower chance of being negatively affected.
All that being said mealybugs can and will infect even healthy plants from time to time. They can come into your home via new plants. This is actually really common too because greenhouses are the perfect breeding ground for them. Be sure to check any new plant purchases carefully before bringing them into your home and your collection.
There are a number of other strategies can help prevent mealybug infestations on your plants:
– Reducing feeding and watering may sometimes prevent mealybugs since it reduces nitrogen levels and hardens the growth. High nitrogen levels in plants attracts mealybugs.
– Wiping foliage regularly with a leaf shine solution containing neem oil may prevent mealybugs on susceptible plant species as the neem oil acts as a repellent reducing the appetite of bugs in it’s presence.
– With plants that can tolerate such treatment, regular spraying with hard blasts of water can prevent mealybug infestations from taking hold by removing eggs or singular female mealybugs which may try to make a home of your plants. This isn’t ideal for most houseplants.
– For indoor plants that can tolerate it, dropping night time temperatures to 60 degrees Fahrenheit (15.5 Celsius) will discourage mealybugs, which prefer more tropical temperatures. This will not kill any infestation however it will help to prevent breeding and feeding if there are any mealybugs present which you are unaware of.
If an infestation cannot be controlled after two or three weekly applications of insecticide, consider destroying the plant before the mealybugs spread to other plants in your home. Losing one plant is better than losing them all. I find it best to isolate the plant at the first sign of mealybugs. Please also check every other plat you have at the first sign of these pests, it is all to common to be fighting a battle with one plant but losing the war with others at the same time.
What is the difference between mealybugs and scale insects?
Mealybugs are closely related to scale insects, but mealybugs are soft-bodied, rather than having the hard protective shells fond on scale insects. Rather than the fluffy, cottony material, scale insects create a hard, barnacle-like coating on the leaves and stems of plants. The methods for getting rid of scale are very much the same as for mealybugs thought and the methods listed above can also be used for this purpose.
Do mealybugs sting or bite humans or pets?
Mealybugs do not pose any danger of biting or stinging humans or pets; they feed only on the juices of plants and have no interest in flesh.
How long do mealybugs live for?
Female mealybugs lay from 200 to 600 eggs, these can hatch in as little as a few days. Within six to 10 weeks, the hatched insects are ready to lay their own eggs, so an infestation of mealybugs can perpetuate itself almost indefinitely unless they are eradicated. I bet now you see how a mealybug infestation can be so devastating.
Where do mealybugs come from?
Mealybugs will often come into your home because they are attracted to the sweet sap of your plants however the most common way they come into your home is via new plants or even new soil brought inside.
How to kill mealybugs?
Mealybugs can be killed by a variety of chemical or organic methods. All of these methods involve either physically removing the bugs or killing them with some form of insecticide.
Can mealybugs kill your plant?
Yes, they can. If left to breed for too long a mealybug infestation can be detrimental to your plant, even killing it completely.
Can mealybugs fly?
Female mealybugs don’t have wings, so they cant fly. Male mealybugs do have wings and can fly however they are incredibly small and only live for a few days.
So now you know all about mealybugs, what they look like, where they come from and how to get rid of them. They’re pretty scary but not as bad as what everyone makes them out to be. If you find yourself with a mealybug infestation, use the tips in this article to get rid of them and make sure they never come back!