Woolly aphids are small and fluffy at first glance, but at second glance they are not so likeable: they suck away at our plants with their little proboscises and damage them permanently. It is therefore important to act quickly when you have to fight mealybugs.
Pests are also part of gardening
First, the good news: You are never alone with a pest infestation. No plant in the garden, on the balcony or in the apartment is safe from them, because there are countless different species. At some point, every plant fan will experience that pests have spread despite good care. But just as quickly as they came, they disappear again with a few tricks.
Mealybugs: A small pest portrait
Mealybugs belong to the mealybug family and have a pronounced preference for the thick foliage of orchids, succulents, citrus trees or olive trees. They also infest houseplants such as ivies, monsteras or ficus species. Woolly aphids can also be found on cacti and palms.
The pests also occur in the garden and in the fresh air on balconies and terraces, but mealybugs are more common indoors or in greenhouses, where it is pleasantly warm for them.
You can easily spot mealybugs, as an infestation is quite noticeable. It looks like light foam or even wool is hanging on the leaves or branches of the plants. The bodies of the female mealybugs are covered with a white to grayish layer of wool or wax. At first glance, the individual animals are difficult to recognize when they form such a “wool pile”. But it also happens that individual mealybugs crawl over a plant. They like to hide on the undersides of leaves, in branch forks and leaf axils.
One sign of a mealybug infestation is honeydew. This is a sticky, colorless coating on the leaves. The mealybugs secrete this, which they have in common with scale insects and also aphids. In the garden, honeydew often attracts ants because they feed on it. When controlling aphids, it is important to remove the honeydew from the leaves, as it can be a breeding ground for various plant-specific fungi, bacteria and viruses. It can be easily wiped off with a damp cloth.
Most often, you do not notice an infestation until it is quite advanced. This is because the eggs of the mealybugs are laid in the webs of wool. When you discover them, you must act quickly to prevent a new generation of lice from developing. The newly hatched larvae are tiny and crawl all over the plant. You won’t be able to spot them until they grow larger – but by then, in the worst case, they will have laid new eggs.
Mealybugs are not dangerous to humans. However, they damage our plants by sucking the cell sap from the leaves and disrupting photosynthesis.
Mealybugs: where do they come from?
You may wonder why pests like mealybugs appear on your plants despite good care. This can have various causes.
Sometimes small care mistakes or an unfavorable location are enough to weaken the plant. Most often, pests appear in the winter quarters, for example, when citrus trees are overwintered too dark or too warm or get drafts. Mealybugs feel at home in low humidity, for example caused by dry heating air.
Many houseplants should also ideally be overwintered in a cool place, but this is often not done for practical reasons. Therefore, they are also more susceptible to being attacked by pests during the low-light months.
Mealybugs can be introduced unnoticed by new plants or even potting soil. A few weeks can pass before they hatch and then you discover them later, so they then seem to appear out of nowhere.
Another cause for the spread of mealybugs is too little space between individual plants or a crown of lemon or olive trees that has grown too densely.
Fighting mealybugs – 3 different ways
Depending on the severity of the infestation, the location of the plants and also your perseverance in the fight, there are different methods to get rid of mealybugs.
- remove them by hand: collect them and wash them off
If you have discovered mealybugs, the first sensible step is to wipe them off with a damp cloth, for example a piece of kitchen roll. You can also use cotton swabs to reach animals that hide in hard-to-reach places. You can also carefully shower the plant or rinse it with a garden hose.
This way you can remove many aphids, but it is necessary to treat the plant more extensively. It is possible that you did not get some of them and the eggs are still on the plant or in the soil. So you have to repeat the procedure regularly or combine it with other measures.
- use home remedies against mealybugs
You have the possibility to fight mealybugs with different home remedies. If gentle and natural remedies are used, this is not only good for your wallet, but also for the plants.
Important: Many different tips can be found on the Internet on how to combat pests. Before using them, think carefully about whether you could damage not only the mealybugs with the agent, but also your plant. For example, vinegar is very aggressive. Spray solutions based on milk are also rather unsuitable, as the milk eventually becomes acidic – not a good idea indoors.
The principle of action of many home remedies is based on spraying the plants with it and smothering mealybugs under a thin layer of oil. Various oils can be used for this purpose: Canola oil, olive oil or sunflower oil.
The oil is mixed with water and an emulsifier (for example, a few drops of dishwashing liquid, preferably an ecological product without fragrances and dyes). Soft soap or curd soap can also serve as an emulsifier. In a spray bottle, shake the mixture well and then spray the plant with it. It is best to place this on a base made of old newspapers, because the liquid drips down.
The oil forms a thin layer under which the pests cannot reach air and they die. The plant would not tolerate pure oil so well, because it also depends on air exchange through its leaves.
For half a liter of such an oil mixture you need, for example, 400 ml of water, 100 ml of oil and 2-3 squirts of dishwashing liquid. Spray the entire plant with it. Cotton swabs can also be used again to apply the mixture wherever there may still be small aphids or their eggs. After about a week, you can repeat the procedure, because surely some aphids could get away.
If the leaves of your plant are too oily, then wipe off the excess oil after a few days. This is especially recommended for plants with rather thinner leaves, as they are more sensitive.
There are other oil preparations that aim to dissolve the wax layer of mealybugs. The animals die as a result. Such an effect can be achieved, for example, with neem oil, orange oil or tea tree oil. The mixtures contain only a little oil, in the case of a light infestation and thin-leaved plants, about 4 ml to a liter of water is enough. Plants with thicker leaves can tolerate even 10 ml per liter. In addition, an emulsifier is still needed so that oil and water can combine. Again, some dish soap, curd soap or soft soap can be used. Many pest treatment products available for purchase are based on neem or orange oil. Mixing them yourself is much cheaper.
By the way, neem oil also has a toxic effect, but it is only dangerous to the pests and completely harmless to humans and beneficial insects. You can also water your plants with the mixture as a preventive measure. The active ingredients get into the leaves and are absorbed there by the aphids. But beware, neem oil is quite smelly.
- chemically fight mealybugs
Sometimes the situation is hopeless: no home remedy works or the pests keep coming back. Treatment with chemical pesticides can be considered if the infestation is limited to ornamental plants, i.e. you do not want to harvest anything. The active substances remain in the plant for quite a long time and in the worst case they can also be found in the fruits! Also, if you have pets or small children who like to nibble on plants or put something in their mouths, you should first try non-toxic home remedies.
One possibility between “natural home remedy” and “chemical club” is methylated spirits. This is a universal cleaning agent, but it is also used as antifreeze in cars. Spirit consists of 90% ethanol, i.e. pure alcohol, but is mixed with agents that make it undrinkable. It is highly flammable and irritates the eyes – so you have to be careful with it. The advantage: methylated spirits dissolve the wax layer of mealybugs and scale insects. For insensitive plants, it is possible to dilute half of the liquid with water and then apply it using a spray bottle or even cotton swabs. Sensitive plants may suffer leaf damage, so test the product on a small area first.
Systemic insecticides are available, for example, in the form of sticks that are inserted into the soil. The poison is absorbed by the pests through the water into the leaves. With such an application, it is important to always keep the soil slightly moist.
The mealybugs keep coming back?
A few tips if success does not last long
Were you able to get rid of the aphids, but they keep coming back? It could be that you didn’t get them all or there were still eggs on the plant or in the soil. Then the next generation hatches and the trouble starts all over again. Therefore, it makes sense to always treat the plant completely and not only where the aphids are at the moment. Wipe all leaves and branches well and make sure that the treatment agent of your choice really reaches all areas.
Before resorting to chemical pesticides, you should also take a closer look at the plant’s location. Is the temperature and humidity right?
Another, but more time-consuming step is to replace the soil. There can also be eggs of the aphids. It makes sense to wait until you want to repot your plant in spring anyway.
Preventing an infestation with mealybugs
An effective means of combating a pest infestation is, above all, to act preventively. The healthier and stronger a plant is, the less attractive it is to pests. The plant is then more resistant and better able to defend itself against the little creepy crawlies, but also against diseases. Of course, this does not mean that a plant is definitely poorly cared for if pests make themselves comfortable on it. Even small factors can be decisive.
To grow healthy and strong, a plant needs sufficient light, water and nutrients. So be sure to find a suitable location and provide it with adequate water, good soil and fertilizer. Especially too warm and too dry air in the winter quarters is like an invitation for aphids & Co to make themselves comfortable on your plant.
Take a look at our texts on wintering the lemon tree and wintering the olive tree.
In the garden, but also on the balcony and terrace, you can prevent pest infestation by making the environment particularly attractive for beneficial insects. An insect hotel and many flowering plants attract beneficial insects that fight pests. Lacewings, in particular, are interesting if you have a problem with mealybugs. Their larvae eat the mealybugs. Lacewings are slightly longer and narrower than normal flies and are bright green. The adult lacewings feed on nectar and pollen.
The use of predatory mites to control pests, even in the home, is unfortunately quite expensive and not so easy to implement successfully. This is because predatory mites are very sensitive to the right temperature and humidity. Theoretically, you would need some measuring instruments to make sure that the predatory mites can survive at all. We therefore recommend resorting to other treatment methods to combat mealybugs.
I have 30 years of experience and i started this website to see if i could try and share my knowledge to help you.
With a degree a Horticulture BSc (Hons)
I have worked as a horticulture specialist lead gardener, garden landscaper, and of course i am a hobby gardener at home in my own garden.
Please if you have any questions leave them on the article and i will get back to you personally.