If the leaves of a plant feel strangely sticky and have a few "piles" resembling small cotton balls on them, then it is most likely mealybugs. This is how you get rid of the pests.

Mealybugs are quite easy to spot because of their white color

Table of Contents

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  1. the essentials in brief
  2. detect mealybugs
  3. Endangered Plants
  4. Effectively combat mealybugs
  5. frequently asked Questions

    6. the essentials in brief

    • Mealybugs often hide themselves and their eggs in the plant substrate, in the leaf sheaths or axils. They are often difficult to detect in the early stages of an infestation.
    • The pests protect themselves and their offspring with a layer of wax, which is why many biological control measures do not work or hardly work at all.
    • (Homemade) pesticides based on paraffin oil or alcohol are very well suited for effective control, but not all plant species tolerate them. Orchids in particular are very sensitive.
    • Some beneficial insects such as lacewing larvae or parasitic wasps (€22.99) as well as a bright location and high humidity (especially during the heating period in winter!) help against mealybugs and mealybugs.

    detect mealybugs

    Mealybugs, which are also often referred to as mealybugs or root lice, are stubborn and difficult to control plant pests. They suck on all parts of a plant to get its nutritious sap. In doing so, they not only excrete honeydew, but also toxins that add to the affected plants. The adult animals are surrounded by a waxy layer that protects them from enemies and harmful environmental influences. But it is not only this that makes effective control difficult, but also the rapid rate of reproduction and resourceful survival strategies.

    Mealybugs not only like to hide their eggs where they are difficult to find - for example in the leaf axils, in bracts or in the substrate - they are also able to withdraw when living conditions deteriorate and wait for better times. So do not be too quick to feel safe after supposedly successful countermeasures: the little animals often reappear after a few months of dormancy and spread again en masse.

    Look

    When a mealybug infestation is in its early stages, it is not easy to spot. However, the little animals have a very distinctive appearance, which is why you cannot confuse them. And this is what the pests look like:

    • between one and twelve millimeters in size
    • colored white, pink or light brown
    • covered with a white layer of wax
    • on this there are whitish threads
    • reminiscent of small cotton balls

    In principle, both the adult animals and their eggs and larvae can be found on all parts of the plant. Mealybugs are not only found on the leaves, but also on (soft) shoots and stems, on leaf axils and even on the roots - here they are of course particularly difficult to find.

    damage picture

    Mealybugs leave a sticky residue on the leaves

    On the other hand, the damage to infested plants caused by mealybugs is much less specific. In principle, these can also come from other pests, whereby one and the same plant can of course also be colonized by different types of plant pests. You can tell from these symptoms that something is absolutely wrong and you need to act urgently:

    • Leaves curl up
    • Leaves turn yellow and fall off
    • sticky coating on leaves and other parts of plants
    • this can also drip onto the ground
    • whitish webs on leaves and other parts of plants
    • with root infestation also whitish smear on the inside of plant pots

    The sticky, often dripping coating is what is known as honeydew, which is excreted by mealybugs (and other plant pests as well). Honeydew, in turn, forms the ideal basis for the colonization of sooty mold fungi, which often appear as a result of pest infestation. The affected parts of the plant then look like they are covered with a black goo.

    Excretions and fungi should always be wiped away, as they hinder the plant's photosynthesis and thus its growth

    digression

    This is why it is so important to combat mealybug infestations early on

    Since mealybugs reproduce extremely quickly and the animals are also not very choosy when choosing their host, the infestation is not limited to one plant. Instead, the infection quickly spreads to other growths, which are then also severely weakened. If effective countermeasures are not taken in good time, an affected plant usually dies quickly.

    Which plants are particularly endangered?

    Orchids are often attacked by mealybugs

    In principle, all plants can be attacked by mealybugs. However, hard-leaved plants are particularly sought after by the stubborn pests, especially if they are cultivated indoors - here the living conditions are optimal, especially during the winter months. But the little animals can also be found outdoors, but then more in the hot and dry summer months.

    However, the following plant species are particularly frequently affected:

    indoor plants garden plants
    Aloe Vera (Aloe vera) Apple tree (Malus domestica)
    Weeping Fig (Ficus benjamina) Bamboo (various)
    Elephant foot (Beaucarnea recurvata) Boxwood (Buxus sempervirens)
    Money Tree (Crassula ovata) Hydrangea (Hydrangea)
    Rubber tree (Ficus elastica) Oleander (Nerium oleander)
    cacti (various) Olive tree (Olea europaea)
    Orchids (various) Lemon tree (Citrus × limon)
    Yucca palm / palm lily (Yucca elephantipes)
    Poinsettia (Euphorbia pulcherrima)

    digression

    Why is mealybug infestation so common on orchids?

    Orchids are particularly susceptible to mealybug infestations. This is primarily due to the fact that these popular exotic plants are quite demanding in terms of care, depending on the type and variety. In order to protect the flowering plants from infestation, care for and fertilize them professionally and, above all, ensure an optimally bright location with appropriate temperatures and high humidity. By the way: You usually drag the mealybug infestation into the house with plants that are already infected.

    What helps? Effectively combat mealybugs

    "Know your enemy…then you will defeat him!"

    Since mealybugs are so stubborn, applying a spray once is not enough. Instead, in order to be ultimately (and not just temporarily) successful, you should combine several methods and be one thing in front of one: perseverance! It is particularly important to regularly collect discovered animals, whereby a slightly damp cotton swab is particularly useful in hard-to-reach areas such as leaf axils. It also makes sense to wipe leaves and other plant parts with a damp cloth - baby wipes are ideal for this purpose.

    In addition, be sure to take these steps:

    1. Isolate the affected plant.
    2. Put them in the coolest and brightest place possible.
    3. Of course, both are only possible with potted plants.
    4. Clean the infested parts of the plant and collect the mealybugs.
    5. If the infestation is too severe, cut back the plant (heavily).
    6. Repot the plant in fresh, sterilized soil.

    Appropriate home remedies

    Alcohol and soap are very effective home remedies for mealybugs

    A classic home remedy for mealybugs is denatured alcohol. Of course, you don't use this pure - unless you want to treat an infested cactus - but mix a solution of water, soft soap (44.90€) and spirit. For this you need:

    • a liter of water
    • 15 milliliters of denatured alcohol
    • 15 milliliters soft soap or paraffin oil

    Mix all the ingredients together and spray the affected plants with it about every two days. However, sensitive plants such as orchids should not be sprayed, instead brush the mixture directly onto the affected parts of the plant. Denatured alcohol is so well suited to combating mealybugs because it softens the protective wax shell and makes the animals vulnerable in the first place. In addition, the agent penetrates the body and kills the pests.

    But many a home-made plant extract is also effective against mealybugs and at the same time offers the advantage of fertilizing the plants treated with it and strengthening their defense system. These preparations are particularly suitable against mealybugs and mealybugs:

    suitable plant preparation application
    bracken Simmer 100 grams of fresh leaves in a liter of water for an hour Allow the tea to cool, strain and spray the plants undiluted with the brew
    oregano Pour 1 liter of boiling water over 100 grams of fresh oregano herb or 10 grams of dried oregano and leave to stand for at least 15 minutes let cool, strain (if necessary) and dilute 1:3 with water, spray plants
    nettles Pour a liter of water over 200 grams of fresh nettle leaves (from non-flowering plants!) and leave to stand for eight hours strain and spray plants undiluted
    garlic Chop 50 grams of fresh clove of garlic, pour a liter of boiling water over it, leave for at least half an hour strain, spray plants undiluted

    When preparing, make sure that you cut or chop the plant parts used as small as possible - the better the ingredients that are supposed to drive away the mealybugs then dissolve. Spray the affected plants several times at intervals of no more than two days for this measure to be successful. However, you will only be successful with such herbal sprays if the infestation is just beginning or moderate. However, if the mealybugs have already spread, more severe methods make sense.

    How to rid the roots of mealybugs

    When mealybugs have infested the roots, the plant needs to be repotted

    On the other hand, if the mealybugs are hiding in the roots, you must proceed as follows:

    1. Repot the affected plant.
    2. Carefully free the root system from the substrate.
    3. Rinse it off with a strong jet of water (e.g. in the shower).
    4. Clean and disinfect the planter.
    5. High-proof alcohol, for example, is suitable for this.
    6. Alternatively, you can get a new pot and throw away the old one.
    7. Disinfect the fresh substrate in the oven or in the microwave (instructions: see below).
    8. Pot the plant in the fresh and disinfected substrate.
    9. Pour them carefully, for example with nettle tea.

    Incidentally, the procedure described is not only useful for root lice, but also for a general mealybug infestation. As soon as the pests appear somewhere on a plant, you can safely assume that there are also animals and eggs in the substrate.

    Combat Mealybugs Naturally - Biological Antidotes

    Biological sprays and pesticides - such as neem oil or preparations based on the natural active ingredient pyrethrum - are not suitable for combating mealybugs. The reason for this is the hard wax layer that protects the animals from such influences - the means that are otherwise so successful with other pests fail miserably here. Only the already described use of alcohol and soft soap or paraffin oil is actually effective, because these agents soften the wax and can kill the lice.

    However, both alcohol and paraffin and soft soap have a significant disadvantage: Not all plants tolerate treatment with it, but subsequently die because of it. Therefore, always try an application on a small leaf or something similar first and see how your plant reacts to it. Also make sure not to use the home remedy in direct sunlight - this would result in unsightly spots due to burns.

    Beneficial insects against mealybugs

    However, pests such as the annoying mealybugs can also be combated in other, completely non-toxic ways: The little animals have many predators who are only too happy to eat eggs, larvae and adult lice and thus contain the infestation in a completely natural way. However, when using so-called beneficial insects, there are a few important tips to keep in mind so that this method is successful:

    • do not use insecticides and other toxins at the same time
    • these also kill the beneficial insects
    • at best, do without such agents six weeks before use
    • Use beneficial insects as early as possible
    • in the case of a severe infestation, the beneficial insects cannot keep up with the food
    • then first apply a beneficial agent-friendly agent (e.g. based on rapeseed oil).
    • only then use beneficial insects
    • Strictly follow manufacturer's instructions for amount to be applied, ambient temperature and humidity

    In particular, when it comes to the required number of beneficial insects, it is important to think carefully and weigh them up: If you use fewer of these little animals, they will not be able to fight the mealybug plague. However, if there are too many animals on a plant, they are more likely to eat each other than to attack the pest larvae.

    In particular, the following beneficial insects have mealybugs (and other common pests!) on their menu.

    • Australian ladybug: particularly effective against mealybugs - only 25 of these animals eat all mealybugs on an area of up to 13 square meters, can only be used in closed rooms and from an ambient temperature of 20 °C; adult beetles are delivered, which are placed directly on the infested plants, keeping windows and doors closed (danger of migration!), spraying plants regularly with water, since ladybugs need drinking water
    • lacewing larvae: eat mealybugs between the second and third larval stage, then pupate and fly out of the apartment as adult animals on their own, are supplied by internet dealers in the first larvae stage, repeated use makes sense
    • parasitic wasps: Species Leptomastix dactylopii is specialized on mealybugs, application similar to that of the Australian ladybird, both species can also be used together

    Ichneumon wasps and ladybugs have in common that both are only active in a warm environment. If the temperature is permanently below 15 °C, the use of lacewing larvae makes more sense. Incidentally, you can persuade them to lay eggs again by placing a flat bowl with honey or sugar water on the window sill. In this way, you yourself provide for further beneficial offspring, which in turn keeps the mealybugs in check.

    Beneficial insects in the garden

    Ladybugs love to eat mealybugs

    In addition, the targeted use of beneficial insects is naturally more effective in closed rooms - such as in the apartment, in the conservatory or in the greenhouse - than in the garden, where the animals can migrate. However, such a garden can be designed in a way that is friendly to beneficial insects, so that you can attract lacewings, parasitic wasps, ladybirds and the like, thereby preserving the ecological balance. Many useful insects in the garden also have the advantage that pests don't even have a chance to spread.

    The little animals feel at home in gardens with many native flowering plants, where they can find food in abundance. Flowering hedges, wild plants such as yarrow, chamomile and poppies and umbelliferous plants are particularly attractive. Furthermore, you provide the beneficial insects with a strategically placed insect hotel (€11.33) and one or the other brushwood or heap of stones coveted nesting and wintering places.

    If nothing else helps - take chemical action against mealybugs

    Home remedies and beneficial insects are not always sufficient to combat mealybugs. If the pests have already spread too far, for example if they are in the roots and if the plant is already covered with them, then sometimes only the chemical mace can help. Some preparations are available in specialist shops and on the Internet, which are usually worked into the substrate as sticks or granules and thus get into the plant via the roots. They are uncomplicated to use and also very well suited for indoor use - after all, the toxins don't get into the air this way.

    However, this method only works for plants that have a high water requirement - succulents such as the rubber tree or cacti absorb too little water and therefore too little of the active ingredient.Here you have to resort to sprays. When applying, make sure to keep the recommended minimum distance and don't forget all parts of the plant - including the undersides of the leaves and the leaf axils! - to treat. In addition, the agent must be injected several times, since the eggs are not killed and larvae hatch after one treatment.

    Video:youtube

    Various insecticides are approved and commercially available for home and hobby use. They usually contain one of the following active ingredients:

    • dimethoate
    • Imidacloprid
    • paraffin oil
    • pyrethrins and canola oil
    • Thiacloprid

    digression

    Disinfect new potting soil

    Since mealybugs are often brought into the house through substrate infected with eggs, you should disinfect it if possible and thus render the eggs harmless. To do this, pack the soil in portions at around 600 to 800 watts for five minutes in the microwave or at 200 °C for 20 minutes in the oven, spread out nicely flat on a baking tray. The disadvantage of this method, however, is that useful microorganisms are also destroyed at the same time.

    frequently asked Questions

    What are the causes of an infestation with mealybugs?

    Mealybugs occur particularly frequently during the heating period, as they feel particularly comfortable in dry and warm air. For this reason, it makes sense in winter to keep the air moist with a room humidifier or simply by regularly spraying the indoor plants. Also a strong nitrogen fertilization - especially in the winter months! - Promotes an infestation, as this weakens the plants and makes them vulnerable. Be sure to avoid over-fertilization, as such plants are more likely to be attacked by pests or are generally more susceptible to diseases.

    Are Mealybugs Dangerous to Humans?

    Mealybugs are annoying, but only infest plants. They are therefore not dangerous to either humans or animals.

    Where do the mealybugs come from?

    Most of the time, the pests are simply brought into the house with a new plant. Even if the new acquisition looks healthy, it can still be infested with mealybugs. The animals hide very cleverly in the leaf axils or the bracts or the plant substrate is infested with lice eggs, from which new mealybugs hatch under favorable conditions - such as dry heating air.

    The eggs can rest for months until temperatures and humidity are optimal. For this reason, many do not associate the plague with the newly purchased plant - after all, the time between purchase and the outbreak can be up to a year. The best thing is to immediately repot new plants in fresh, disinfected substrate and then separate them first.

    How fast do mealybugs multiply?

    Mealybugs multiply extremely quickly: A single female can lay up to 600 eggs, from which the first larvae hatch after just a few days. These, in turn, develop so quickly that they begin their harmful sucking activity within up to ten days. In addition, male animals are not absolutely necessary for reproduction, since mealybugs can also reproduce by virginity - i. H. from the 600 eggs of a single female almost only female mealybugs can hatch, which then lay up to 600 eggs and so on… No wonder that there are at least eight generations of mealybugs per year!

    What are mealybugs anyway?

    Mealybugs are also known as mealybugs or root lice. They belong to the mealybug family (lat. Pseudococccidae), which includes around 1000 different subspecies and is distributed worldwide. These are leaf sap-sucking plant pests that prefer to sit on hard-leaved plants. In Germany, the long-tailed mealybug (lat. Pseudococcus longispinus) and the citrus mealybug (lat. Planococcus citri) are particularly widespread. The animals are usually not very specialized, but attack different types of plants.

    How can I strengthen my plants so that mealybug infestations are less likely?

    Healthy plants in a healthy environment are less susceptible to infestation with mealybugs and other pests. Make sure that the humidity is pleasant during the winter months, which is not only good for your respiratory tract, but also for your plants. Be sure to avoid both over-fertilization and under-supply with nutrients - both weaken the plants and make them more vulnerable.

    Furthermore, you can improve the resistance of your plants with special means, for example by spraying them regularly with nettle or horsetail tea. Many a plant lover also swears by homeopathic tonics, which are usually administered with the irrigation water. In general, however, it helps if you plant and care for the plants according to their specific needs.

    tips

    If infested orchids are to be chemically treated, select an explicitly orchid-friendly pesticide. Otherwise, the exotic will not perish from the mealybug infestation, but from an unsuitable pesticide.

Category:

Animals in the garden