Identify, combat and prevent spider mites from orchids


Spider mites can do serious damage to your orchids. We'll show you what to look out for and how to get rid of the mites.

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In the worst case, vermin on orchids can lead to the death of the plant. In order to be able to act effectively against the pests, it is important to correctly identify them first in order to be able to select the appropriate natural or chemical pesticide. If orchids are infected by mites, these are usually spider mites. Agents that can be used in lice infestation are usually not particularly effective in spider mite infestation.

We'll tell all interested readers first of all what mites can be recognized in orchids. Only in the second step do we then show how this pest can be dealt with in order to save the plant. Environmentally, people and (house) animal friendly means are clearly in the foreground. In addition, all hobby gardeners can take various preventive measures so that spider mites do not infect the plant in the first place.

More information on spider mites

There are approximately 1,200 different types of spider mites worldwide, which belong to a subclass of mites. As a rule, spider mites can be found on the underside of the leaves of orchids and other infested plants. There the mites spin extremely fine, whitish shimmering webs that serve to protect the pests. The mites feed on the juices of the plant, which in turn takes a lot of strength from the infected orchid. If the plant is punctured by the mites, the orchid is damaged. All in all, there is a large variety of spider mites worldwide, which attack very different types of plants. The following spider mites are an economic problem:

  • Red spider
  • Common spider mite
  • Linde spider mite

Appearance of the spider mite

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The body shape of a spider mite is more or less reminiscent of a pear. The tiny length of these mites can be 0.25 to around 0.8 millimeters. This type of mite can also be recognized by a reddish, orange, greenish or yellowish color. The soft-skinned mites also have bristles. A maximum of 16 hair pairs can be seen when you look closely. The spider mite's larvae have three pairs of legs. Adult spider mites, on the other hand, have not just six, but eight legs.

Harmful effects of spider mites

In addition to the delicate, white webs, the spider mites also ensure that the leaves of the infected plant shine silvery. This is the logical consequence of the mites tapping and sucking out the leaves. If the infestation has already reached an advanced stage, the leaves turn brown-black, which indicates their death and the supposed imminent death of the entire plant / orchid. It is easy to explain that this decay is progressing very quickly. After all, only a spider mite stings the leaves of the orchid in extreme cases, a proud 20 times a minute. The tissue cells of the plant leaves therefore do not withstand this load for long, especially with many spider mites.

Don't ignore signs of spider mites!

If there are a lot of speckles with a light yellow color on the leaves of the orchids, this is a solid indication of an attack with spider mites. Now is the time to take action against the pests. If this does not happen, the leaves and then the shoots and finally the entire plant will die. If the infestation is noticed too late, there is no hope that the orchid in question can still be saved. In addition to orchids, the following plants are also commonly affected by various types of spider mites:

  • cucumbers
  • roses
  • Apple
  • pear
  • peach
  • Plum & plum
  • strawberries
  • raspberries
  • gooseberries
  • currants
  • Eiben

It should be noted that spider mites particularly like to pounce on plants that are already weakened. Because then the mites have a much easier game.

Spider mite lifestyle

If you want to successfully combat spider mite infestation, you should know the mites' preferred lifestyle. They love a dry and warm climate. A protected location is also ideal for the spider mites. Although the individual spider mites can only last a few weeks, these pests multiply incredibly quickly. A few mites can quickly become an entire colony. In particular, if the mites have infested an orchid, the location of which is either a plump warm greenhouse or a warm and bright windowsill, they can reproduce all year round.

Spider mites are multiplying rapidly

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For this very reason, there is a risk of spider mite infestation for orchids all year round. A single spider mite can lay up to 100 eggs until it dies, provided the environmental conditions allow it. The females also lay the eggs on the underside of the leaf. It only takes three days for the first mites to hatch from these eggs. In a week or two, the former larvae have become adult mites that can reproduce. That is also why it is so important to get the infestation under control as quickly as possible before the mites can spread to other orchids in their own apartment or in the greenhouse.

Spider mites like it warm

An infestation with spider mites can be observed outdoors, especially in summer. In closed, warm rooms, the spider mite infestation of various houseplants can also become a problem in winter, which is due to the pleasantly warm ambient conditions. The plump heating air ensures that the mites feel good all around and that they reproduce happily. It may well happen that when buying a new houseplant from a specialist dealer or garden center, the spider mites are first brought in and then spread to the existing plants.

Prevent spider mite infestation

Although we would like to take a closer look at the possible measures to combat spider mites on orchids, we would first like to discuss which preventive measures make sense. In view of the living conditions preferred by these pests, it is advisable to ensure that the air humidity is as high as possible. Because this humidity doesn't like spider mites at all. In summer or during heating periods, which are also characterized by a rather dry air, it therefore makes sense to spray the plants regularly with water. This increases the humidity. The plants should also be adequately supplied with water.

New orchids prefer to be in quarantine

In addition, when buying new plants, it is important to ensure that they are not already infected. If it is only a small-scale infection, the spider mites are difficult to see with the naked eye. Therefore, if you want to be on the safe side, prescribe a quarantine to all new plants that are to move into your own apartment. After all, it only takes a few days for the mites to hatch from their eggs.

The mites can then reproduce within a maximum of two weeks. Whether an orchid or other houseplant is actually infected with spider mites can be seen very quickly. If so, the newly purchased plant should first be treated with spider mites before it can join the other existing house plants.

Care - Vigorous plants are more robust

In addition, good care of the existing orchids is a must. After all, the chances of an infection increase if the plant is already weakened. Vigorous, healthy plants that are in the prime of their life, however, can better defy the mites. Regular fertilization also ensures that the orchids are much more resistant to possible spider mites.

In the video, the care measures for orchids are very well explained:

Natural enemies of the spider mite

In addition, the following beneficials are considered natural antagonists of spider mites:

  • predatory mites
  • predatory beetles
  • lacewings
  • ladybug

The promotion of beneficial organisms to protect against a potential infestation with spider mites is, however, only possible in greenhouses and not in one's own living space. Moisturizing the orchid regularly with soft water has proven itself far more successfully in closed rooms. Incidentally, predatory mites can best counter spider mite infestation in the following environmental conditions: temperatures of around 25 degrees Celsius and a humidity of around 75 percent. The earlier the predatory mites are used, the better. They are so effective as a natural remedy for spider mites, because two predatory mites hatch in the same period of time for each spider mite that hatches.

Act actively against spider mites

Examine orchid with magnifying glass and atomizer

So that the orchid has the best possible chance of survival, it is important to recognize and treat the infestation as early as possible. It is therefore advisable to keep a close eye on their leaves every time the plants are watered and fertilized.

Since spider mites are tiny and therefore extremely difficult to see with the naked eye, it is advisable to examine the leaves with a magnifying glass. A water atomizer should also be used. This should be used anyway to regularly moisten the orchids and thus protect them from infestation if possible. Because of the moisture, the fine, white webs can be made more visible before it is too late. If the said speckles or spider mites with their white webs can be seen on the underside of the leaf, it is important to take immediate action against the pests.

Affected plants immediately quarantined

If there is an infestation of an orchid with spider mites, the first thing to do is to move all plants that could also be infected together to another room. Thanks to the quarantine, it can be ensured that the infestation cannot spread to other plants. The quarantine location should not be too warm and humid. Because the pests don't like that at all.

Spider mites don't like moisture

How the pests should then be dealt with depends, among other things, on how strong the infestation is and how resistant the orchid is. A relatively healthy and robust orchid, which only has to deal with a mild infestation, can be rasped off with water. The following instructions must be observed:

  • The best thing to do is to protect the root ball with a bag when you rinse it off.
  • The plant can easily be showered in the shower or bath.
  • Repeat showering of the plant several times every few days to switch off all pests.

Optionally, the entire houseplant can be wrapped in a transparent film bag for a short period after showering. The advantage is obvious: This ensures a high level of humidity, so that the spider mites normally die within a few days or a week at most.

Cut off the affected leaves and shoots

If the pests do not respond adequately to these measures, the affected shoots and leaves can be cut off. However, this should only happen to the extent that the orchid is still viable without the cut leaves and shoots. It is by no means recommendable to put these leaves and shoots on the compost. Because there the pests can continue to multiply. This is particularly problematic because spider mites can become a problem not only for orchids, but also for other plants (even outdoors).

Detect spider mites with finished pesticides

Neem against spider mites

Ready-made pesticides on a natural basis are particularly useful at an early stage of spider mite infestation. Because then there are good chances of being able to cope with the infestation even without the concentrated chemical club and to be able to save the orchid from possible death. Pesticides containing neem, which are easily available in a well-stocked hardware store or garden center, should be the means of choice, provided that the measures mentioned above have either not worked or the use of predatory mites is not a viable alternative.

1 COMPO BIO Insect-free Neem, fight against ... 125 ratings15,99 € 11,54 €To the shop
2 Neem Capsules Bio - Azadirachta Indica - 150g Capsules -… 9 reviews16,90 €To the shop
3 Naturen 7003 Organic Pest Free Neem, 75 ml 72 reviews12,97 €To the shop

Biocides and pesticides

Only when the orchid is on the verge of final ruin will most hobby gardeners want to think about sharper means in the fight against the pests. Before the orchid can no longer be saved, you can try an acaricide, which is also available from specialist dealers. These are extremely potent bio- or pesticides that are offered especially for the control of spider mites. If these preparations are used in greenhouses or outdoors, it certainly makes sense to rely on a preparation that does as little or as best harm as possible to a wide variety of beneficial organisms, such as lacewings or bees.

Discard dead plants

If any rescue attempt has unfortunately failed, the respective orchid should be disposed of. For the reasons mentioned, this plant should not belong to a compost heap. It is better to dispose of the orchid straight away in organic or domestic waste. If the pot of dead orchid is to be used for a new plant, you must ensure that it is free of any mites and their eggs. The former location of the orchid should also be cleared of mites that may have remained, so that other plants are not exposed to the unnecessary risk of infection.