Fight mealybugs (mealybugs) successfully

An infestation with mealybugs can be seen in the white, cotton-wool-like webs with which this pest surrounds itself. These can mainly be found on the shoots, stems and on the leaves of the respective plants. In some types of plants, such as orchids and cacti, they can also be found on the root neck or in the root area and on the flowers. There they suck off plant sap and secrete poisonous secretions and honeydew, which weakens the plant in question considerably and ultimately leads to tissue damage and the shedding of the leaves.
The honeydew secreted by the lice can be recognized by sticky spots on the plant. It is not uncommon for sticky, white spots on the inside of the respective planter to indicate an infestation. The mealybug can also transmit various viral diseases that weaken the plant in question. A particularly strong infestation with this pest usually results in the death of the entire plant.

Causes of an infestation

• One cause can be unfavorable site conditions.
• The location may be too warm, too dark, or the air too dry.
• This is why an infestation occurs particularly frequently in winter.
• Another cause can be a fertilization that is too nitrogenous.
• Often you bring in mealybugs when you buy new plants.
• Before buying, it is important to pay attention to a possible infestation.
• This helps significantly to prevent an infestation.

Mealybugs on orchids

The orchid varieties Phalaenopsis and Cattleya in particular are attacked by the mealybug, whereby all parts of the plant can be affected. Most of the time it attacks the leaf axils. Some types of this pest also damage the root ball.

Symptoms

An attack on orchids is indicated by discoloration on the leaves. As a result, the leaves begin to wither. Deformation of both the leaves and the flowers occurs, and ultimately leaf loss. If the infestation is severe, the white webs of the mealybugs are distributed over the entire plant. In addition, the leaves are stuck together by the honeydew.

Combat

• Immediately isolate affected orchids from the rest of the plant population!
• This is essential to prevent it from spreading.
• Natural enemies such as ichneumon wasps, ladybugs or lacewings are helpful.
• The Australian ladybird in particular is bred specifically for pest control.
• These beneficial insects are available from beneficial insect suppliers who send them by post.
• The lice can be wiped off the leaves of the orchid with a cloth soaked in alcohol.
• If necessary, repeat the whole thing for a few days.
• Infested flowers must be cut off completely.
• The lice can also have attacked the roots.
• Therefore, move the orchids into fresh substrate as quickly as possible.
• To do this, take the plant out of the plant pot.
• Then completely free the old substrate from the roots.
• Then rinse the roots thoroughly under running water.
• Also clean the plant pot thoroughly or replace it with a new one.
• Now put the orchid in a clean pot with fresh substrate.
• Handel offers special pesticides against mealybugs.
• Oily sprays are not suitable for orchids.
• Leaves could stick together over a large area and die.
• A sufficient supply of nutrients strengthens the orchids and makes them more resilient.
• As a preventive measure, spray regularly with lukewarm water in summer and winter!
• If all of these measures fail, you may have to part with the plant in question.

Mealybugs and mealybugs on cacti

Cacti are usually very robust and, with proper care, also relatively resistant to attack by pests or diseases.
However, unfavorable environmental conditions, such as excessive humidity and insufficient light, increase the risk of infestation. The same applies to excessive nitrogenous fertilization and non-observance of the rest period of cacti in winter. As with all other plant species, mealybugs can also be introduced into cacti when they are bought.

Symptoms

An infestation with mealybugs can also be seen on cacti by the white wax secretions of the animals. Since this pest spreads very quickly, an entire cactus collection can be affected under certain circumstances. The egg cocoons of the lice are mainly found in relatively inaccessible places. This can be between the mother plant and the child, as well as between the ribs and on the root neck, but also between the graft and the grafting base.

Combat

• First isolate affected cacti from other plants!
• You cannot collect the pests because of the spines.
• Special pesticides are available in stores to combat it.
• These also need to be sprayed into inaccessible areas on the cactus.
• Treatment should be repeated at regular intervals.
• This is necessary to reach all animals.
• If the infestation is less severe, the plant protection solution can also be applied with a firmer brush.
• Cactus can also be dabbed daily with a brush soaked in alcohol.
• Spraying with pure denatured alcohol is also possible.
• Be careful when doing this!
• The outer wax layer of the plants should not be damaged.
• Repeat until nothing of this pest can be seen anymore!
• Regularly check for renewed infestation days and months later.
• In the case of a slight infestation, a strong jet of water can also be helpful.
• However, you can only reach the above-ground parts of the plant and not the roots.
• In order to capture the entire plant, plant protection sticks are ideal.
• These should work specifically against the mealybugs.
• They are put into the substrate and the substances are absorbed by the plants.
• If the mealybugs and mealybugs then suck up the sap, they die.
• Agents with a systemic effect, such as Lizetan Combigranulat, can also reach lice that are hidden away.
• Depending on the type of agent, these protect against re-infestation for between 8 and 16 weeks.
• Do not use fertilizer while using pesticides!
• Oil-based agents should also be avoided with cacti.

Mealybugs on other house plants – biological control

The control of mealybugs is similar to that of scale insects. First of all, it is always important to move the plants in question to a cooler and lighter location, as well as to separate them from the other plants to protect against the spread of the pest.
Useful insects such as lacewing, ladybird or ichneumon wasp are very effective on all plants. With a few exceptions, non-containing products can be used in the majority of plants. These are usually well tolerated and very effective. If the initial infestation is low, the lice can be collected. If only individual shoots are affected, they should be completely removed.

Soft-leaved plants are particularly sensitive to spraying with oily agents as well as paraffin and soap solutions. They tolerate products containing rapeseed oil much better than those containing mineral oil. Preparations containing mineral oil can cause burns to the plants. To test the tolerance, you should first carry out a test spray on a single leaf or branch.

During the hibernation, you can fight the pests with high percentage alcohol. To do this, soak a cotton swab in the alcohol and then use it to run over the web of lice. The alcohol breaks through the woolen armor of the woolly lice and mealybugs and eventually kills them. However, this method is very complex and for this reason is only worthwhile if the pest still occurs sporadically.

Sometimes you can also use self-made sprays. To do this, mix 12 grams of lamp oil with a liter of water and a few splashes of washing-up liquid. The whole thing is filled into a suitable spray bottle and sprayed on the affected plants twice a day until the lice are gone.

In order to free the roots of lice and eggs, repotting is essential for all plants. The old soil must be completely removed from the roots and the roots rinsed thoroughly with cold water. It is important that neither lice nor eggs get caught in the roots. Then repot the plant. As carefully as you proceed when repotting you should also be in choosing the right location. The optimal supply of nutrients, light and water can support the effectiveness of any remedy. They can also prevent infestation if necessary.

Chemical control

If biological control no longer promises success, the only option left is treatment with an insecticide to possibly save the plant. When using systemic insecticides, its toxicity for humans and other beneficial organisms should be taken into account. Newer insecticides are now more plant-friendly and more effective. So-called systemic remedies are user-friendly and ready for immediate use. They are available in the form of sprays, sticks, sticks or as granules.
Approved systemic agents against woolly or mealybugs are, for example, Dimethoat, Imidacloprid and Thiacloprid. Corresponding agents for spraying usually also contain oils. When spraying, it is essential to ensure a corresponding minimum distance. In addition, the underside of the leaves should not be forgotten when spraying. Many remedies have to be applied repeatedly at certain intervals. This is important because the mealybugs’ eggs cannot be killed. The lice that hatch are then also detected through repeated treatments.

prevention

The plants themselves have certain defense mechanisms to protect against pests, but if they are stressed or weakened for various reasons, this natural protection does not come into effect and the plants become susceptible to both pests and diseases.

In order not to introduce mealybugs and mealybugs, you should make sure that your plants are one hundred percent healthy when buying. However, a well-tended sales room and a competent dealer are not always an indication of high-quality plants. So always look carefully and, if you have the slightest doubt, keep your hands off it, even if apparently only neighboring plants are affected, because this is the only way to avoid or prevent a pest infestation, provided that the subsequent care is correct. Healthy plants are and will remain the very best protection against mealybugs and other pests.

Conclusion
If an infestation with mealybugs is detected too late or if control is started too late, the pest may already have spread to other plants. The affected plants can then usually no longer be saved. Therefore, countermeasures should be taken at the first signs of an infestation. The earlier you discover an infestation, the better the chances of success. If insecticides are used for control, the information provided by the respective manufacturer should always be observed. In order to counteract an infestation with any kind of pests, it is advisable to pay attention to optimal environmental conditions at all times.