Predatory mites - pests or beneficials in the house and garden?

Predatory mites as beneficials and pests

the essentials in brief

There are around 5,500 different species of predatory mite.
Some of them are very useful and can be used for biological pest control.
In particular, spider mites, thrips and fungus gnats can be combated with their help.
Other predatory mites are parasitic and torture dogs, cats, rabbits and birds. They absolutely need to be treated.

What are predatory mites?

Predatory mites (Gamasina) belong to the subclass of the mites (Acari) comprising around 50,000 different species. They belong to the zoological class of arachnids (Arachnida). There are around 5500 different species of predatory mite worldwide, but only a few of them have been extensively studied scientifically. Many predatory mites live on the surface of the soil (epigean, as the biologist says), but some also hunt in the vegetation and can therefore be found on plants. Here they are often mistaken for pests. Other species, however, live largely in the ground (endogeic) and are rarely found on the surface.

Tips

If you are not sure whether the small animals on your plants or on the patio are useful or harmful insects, it is best to watch them for a while. They distinguish useful predatory mites from pests by their nimble movements. The hunters are fast and constantly on the move.

Useful predatory mites - pest control without chemicals

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Some types of predatory mites prefer to hunt annoying plant pests and are therefore very suitable for biological pest control. The advantage of using the animals is that they are very effective and you don't have to use any poison. Species of these predatory mite genera are particularly suitable as beneficial insects:

Amblyseius : Species of this genus are very suitable for controlling thrips and whiteflies. In particular, the species Amblyseius barkeri is often used.
Hypoaspis : Predatory mites such as Hypoaspis aculeifer and Hypoaspis miles feed on mosquito species whose eggs and larvae develop in the soil. They can therefore be used well against fungus gnats, for example.
Phytoseiulus : This genus is one of the most species-rich predatory mite genera. The species Phytoseiulus persimilis, which lives on leaves and prefers to hunt spider mites, is often used as a beneficial insect. The animals are particularly successful in viticulture and in greenhouses.
Typhlodromus : Typhlodromus pyri also lives on leaves and hunts spider mites.

The following table shows which predatory mite species you can use against certain pests in the garden, greenhouse and on the windowsill:

Predatory mite species	Used against:	When and how to use:
Amblyseius barkeri	Thrips and soft skin mites	Temperatures above 18 ° C require high humidity
Amblyseius cucumeris	Thrips and soft skin mites	Temperatures above 18 ° C require high humidity for indoor plants
Hypoaspis aculeifer	Sciarid gnats, marsh fly larvae, thrips pupae, springtails, soft skin mites (often found in flower bulbs)	Temperatures between 18 and 25 ° C are ideal
Hypoaspis miles	Sciarids, marsh fly larvae, thrips pupae, springtails	Temperatures between 18 and 25 ° C are ideal
Phytoseiulus persimilis	Spider mites (P. p. Look very similar to spider mites!)	Temperatures between 18 and 25 ° C are optimal, development is twice as fast as that of the spider mites at 22 ° C
Typhlodromus pyri	Spider mites, mainly in fruit and wine growing	occur naturally in fruit trees, but can also be specifically exposed

Digression

Use predatory mites against red poultry mites

The red poultry mite is a blood-sucking parasite that is often found in bird keeping and must be fought persistently. A non-toxic, chemical-free method is the use of predatory mites of the type Hypoaspis miles, which can be easily used in the stable and in the apartment. Incidentally, Hypoaspis miles is not only suitable for combating blood mites, but also snake mites, for example in terrariums. These predatory mites can be used at temperatures of at least 15 ° C.

Buying predatory mites - what to look out for

The question now arises: where do you get these useful predatory mites? You can easily order them online and have them delivered to your home by post. The various providers offer different pack sizes from which you can choose the right one depending on the severity of the pest infestation and the size of the area to be treated. It is best to inquire about suitable delivery units before buying and compare the prices, which can be quite different depending on the provider.

The predatory mites come well packaged in special granules (such as vermiculite) or in bean leaves. These contain the necessary nutrients so that the animals do not starve to death during their journey. As a rule, they survive the delivery very well, but in rare cases the predatory mites can also die, for example because they have been exposed to freezing cold for too long.

Tips

You can use a magnifying glass to check whether the insects are still moving freely after delivery or whether there is no longer any movement. Detailed instructions are usually included in the packaging, as is a brush. With this you transfer the predatory mites to the areas infected with pests.

Breeding Predatory Mites - How It Works

There are some predatory mite species that you don't have to constantly buy, you can breed them yourself at home. This works particularly well with the rather uncomplicated species Typhlodromus pyri, which is usually used against spider mites. For successful breeding you will need:

well sealable plastic cans, content 0.25 liters
plaster
Activated carbon
Food (pollen or live food, e.g. leaf mites)
some bought predatory mites to start with

And this is how predatory mite breeding works:

Mix plaster of paris with some activated charcoal and water.
Pour the plaster mix into the plastic jars.
The fill level should be about a third.
Let the plaster dry.
Poke holes in the can lids with a fine needle.
Put the predatory mites in the vessels.
Add some food using a brush.
Seal the cans.
Then feed the predatory mites once or twice a week.
As soon as the activated charcoal fades, add fresh water with a pipette.

If necessary, you can simply remove the required amount of predatory mites with a brush and insert them.

Application of predatory mites

"Avoid toxic chemicals in the garden, after all, nature provides us with enough effective means."

Combating a pest plague with predatory mites works best if you use the animals preventively or at an early stage. However, if thrips and spider mites have spread strongly or have possibly already developed webs, predatory mites no longer help: now harder guns have to be deployed in order to save the so extensively infested plants.

So that the predatory mites can do their work, you should adhere to these rules when using them:

Expose a sufficient amount of predatory mites. In the case of a slight infestation, at least 20 of these animals per square meter are recommended.
Do not leave the predatory mites in the package after delivery, put them in as soon as possible.
Before doing this, however, read the instructions provided carefully and strictly adhere to the recommendations given there.
Some predatory mite species are very sensitive and need a certain temperature and humidity.
Provide appropriate conditions (especially high humidity!).
Apply the predatory mites directly to the infected areas.
Don't just spill it.
Add predatory mites again after about a week to prevent the pests from returning.

After all pests have been eliminated, the predatory mites either die or feed on pollen and nectar. Use the animals in endangered plants as early as spring if possible to prevent pest infestation.

Tips

In order for the predatory mites to successfully fight the pests, no mite or other pest control agents may be applied at the same time. After all, these make no distinction between pests and beneficial insects and also kill predatory mites.

Predatory mites as pests

In view of the large number of different predatory mite species, there are of course not only useful ones. Some predatory mites make life difficult for humans and animals because they live parasitically on them and feed on flakes of skin, tissue fluids or even blood. Contrary to what is often suggested, however, these are different species, so you do not have to be afraid of the useful predatory mites in your garden.

Signs of mite infestation

An infestation with parasitic species is often noticed by small pustules and redness on the skin, which are often mistaken for mosquito and other insect bites or neurodermatitis. These areas are often itchy. In addition, small blisters or crusts can form. In humans, these symptoms usually only occur sporadically, as this is of no interest as a host for most mite species. Grave mites, for example, are an exception.

treatment

Mites are often found on pets and are a nuisance to them. Dogs, cats, rabbits, birds and snakes are particularly affected. The animals must be treated - if possible by a veterinarian - in order to prevent the symptoms from spreading and worsening. You should also clean the apartment thoroughly, as mite nests are often found in small cracks and crevices, but also in blankets, carpets and even in clothing.

Predatory mites in dogs and cats

If your dog or cat itches and scratches itself noticeably often, it may be due to mite infestation. There are a number of types of mites that torment four-legged friends and cause similar symptoms:

Ear mites : Otodectes cynotis, prefers to colonize the external auditory canal or the skin around the ear. Development from egg to adult animal takes place exclusively in the ear canal. A note is severe itching in the ears and ear infections.
Predatory mites : Cheyletiella mites in particular, but also other species, can infest dogs and cats. These predatory mites are not host-specific, which is why not only Bello, but also the house cat, the child's rabbit or even you yourself can be attacked. If you notice small scales on the skin or in the fur, which are associated with severe itching, mite infestation is possible.
Mange : sarcoptic scabei (var. Canis), also known as grave mites. These animals are highly contagious and cause symptoms that can be mistaken for an allergic reaction. The insatiable, severe itching is typical.

In the event of symptoms, you should immediately consult a veterinarian who will prescribe anti-inflammatory, anti-itch-relieving anti-mite agents for your four-legged friend.

Digression

Can dog mites spread to humans?

In particular, the grave mites, predatory mites that are more common in dogs and outdoor cats, can spread to humans and cause the skin disease scabies. So caution is advised with pets suffering from sarcoptic mange! Furthermore, Cheyletiella mites can be transmitted from dogs to humans and other pets, especially cats and rabbits.

Predatory mites in the home - what to do?

If a mite infestation has been found in your pets, it is very likely that mite nests are also found in your home. Although the animals mostly develop and live on the animal, adult female mites are also viable outside of their host for a long time. In addition, some species of predatory mite do not live directly on the host, but only seek it out to eat. In order to keep the apartment free of mites, these measures are now necessary:

Pull off the bed.
Wash the bedding at 60 ° C.
Vacuum the mattress and treat it with an anti-mite agent.
The same applies to carpets, especially deep-pile variants.
Also wash blankets and pillows.
Stuffed animals should either be washed or frozen for 24 hours.
Ventilate thoroughly several times a day.
The humidity inside the apartment should not be too high.
Seal cracks and the like in the wall and floor, for example with silicone.

frequently asked Questions

What do predatory mites feed on?

What the different predatory mites eat depends on the species. Hunting predatory mites feed primarily on the tissue fluids of other insects, such as spider mites, thrips, sciarid gnats, etc. They also suck out eggs and larvae or, if there is not enough animal food available, feed on nectar and other vegetable matter. These predatory mites are very useful in the garden and are often used to control pests.

The matter is more problematic with predatory mite species, which have specialized in larger prey and live parasitically on dogs, cats or birds. They often feed on blood, but also on other bodily components (e.g. tissue fluid). These animals can cause eczema and other diseases and are therefore undesirable.

Can bird mites also affect humans?

As the name suggests, poultry mites are predatory mites that prefer to attack poultry such as chickens, pigeons and wild birds. The most dangerous for humans is the red poultry mite, a common bloodsucker, which must therefore be controlled systematically.

How dangerous are predatory mites for humans?

Predatory mites cause allergic reactions in humans and animals, which are expressed, for example, in extremely itchy skin rashes. But asthma or scabies caused by grave mites are typical consequences of mite infestation. Fortunately, this only applies to a few species, because only a few of the approximately 50,000 different species of mites are really dangerous to humans.