Biological pest control in the house and in the garden makes sense because you do without poison and are doing something good for yourself and the environment. The parasitic parasitic wasps are an excellent help against all kinds of pests.

Ichneumon wasps are valuable beneficial insects in the house and garden

Table of Contents

Show all
  1. the essentials in brief
  2. What are parasitic wasps?
  3. Biological pest control
  4. Buy parasitic wasps
  5. use and application
  6. Lure into the garden
  7. frequently asked Questions

    8. the essentials in brief

    • Ichneumon wasps (€22.99) are parasitic beneficial insects that lay their eggs in the larvae of harmful insects.
    • There are numerous different species, often specialized on specific host species.
    • Therefore, only certain parasitic wasps can be used against moths, aphids, whiteflies, scale insects and other pests.
    • The application should take place over a period of several weeks, whereby the cards from specialist shops containing parasitic wasp eggs are laid out several times.

    What are parasitic wasps?

    When they hear the name "parasitic wasps", many people first think of the real wasps, which are particularly annoying in late summer and can be quite persistent in their search for sweets. However, the useful parasitic wasps have nothing in common with the Vespinae species except for their name (and sometimes also their external appearance - the male animals of some species practice mimicry). Instead, like bees and bumblebees, they also belong to the hymenoptera (lat. Hymenoptera).

    There are around 40,000 different species of parasitic wasps that live in a wide variety of habitats and can look quite different. The smallest varieties reach a body length of less than a millimeter and are practically invisible to the naked eye. Other species can be between one and five centimeters long.

    What all parasitic wasps have in common is their parasitic way of life, because the females always lay their eggs in the eggs of other insect species. The larvae that hatch from these in turn feed on the host larvae and destroy them. Since most species of parasitic wasps have specialized in specific pests in the house and garden, the animals are extremely useful for biological pest control. The adult animals in turn feed mainly on pollen, nectar and honeydew.

    Look

    The parasitic wasps probably owe their name to the fact that the male specimens of some species can actually be confused with the real wasps. However, this is only a tactic known as mimicry, which is intended to protect against predators. In general, you can recognize parasitic wasps by these characteristics:

    • mostly dark brown to black basic coloration
    • often colored (red) or white spots or streaks
    • dark, translucent wings
    • flexible, long wings
    • typical "wasp waist"
    • long ovipositor, which can be as long as the actual body
    • this only occurs in females and is used to lay eggs
    • depending on the species, body length between 0.2 and 50 millimeters

    way of life

    "The action of parasitic wasps may seem brutal, but it is very helpful for humans."

    Ichneumon wasps are among the so-called egg parasites. The female animals have a keen sense of smell, which they use to track down and target the larvae of their host animals - for example moths, butterflies, wasps, beetles, aphids, flies or spiders. They then parasitize their host animals, which proceeds as follows:

    phase of development Happens:
    before egg laying Injecting a toxin into the host larva to paralyze it
    during egg laying Injection of the egg into the host body using the ovipositor
    after egg laying hatching inside the host body as well as pupation; Host bodies are often bloated and dark brown to black in color
    nutrition of the larvae Host body is eaten from the inside
    after pupation the adult parasitic wasps bore a hole through the host's body and slip out from there

    Biological pest control in house and garden

    Ichneumon wasps eat their prey out of the egg

    The parasitic way of life of the parasitic wasps and their specialization on specific pests in the house and garden make the little animals ideal helpers. The beneficial insects not only combat food moths and clothes moths effectively and without any poison, but also aphids and scale insects, whiteflies or butterflies such as the codling moth, leaf miner or the oak processionary moth. In agriculture, the beneficial insects are often used on a large scale, which prevent crop failures caused by pests.

    tips

    If you use parasitic wasps in the garden or greenhouse, be sure to leave the parasitized larvae where they are. A new generation of parasitic wasps is growing here, which will keep you away from another pest invasion.

    Overview: You can use parasitic wasps to combat these pests

    In view of the large number of different species of parasitic wasps and the fact that they often specialize in certain pests, you cannot use just any variety. Depending on which pest you want to fight, these types of parasitic wasps come into question:

    Type of pest to be controlled Suitable parasitic wasp species
    food moths Trichogramma evanescens
    clothes moths Trichogramma evanescens
    aphids Aphelinus abdominalis, Aphdius colemani, Aphidus ervi, Aphidus matricariae
    scale insects Metaphycus flavus, Microterys flavus, Coccophagus lycimnia
    white bow tie Encarsia formosa
    codling moth Trichogramma cacoeciae
    leaf miners Encarsia formosa
    woodworms Spathius exarator

    The tiny Trichogramma species are mostly used in agriculture and in commercial fruit growing. But be careful when using parasitic wasps outdoors: the little animals themselves can be infested with parasites or pathogens, fall victim to toxins or predators (e.g. birds). Then their effect is only limited.

    Ichneumon wasps against bacon beetles?

    Occasionally, the use of parasitic wasps is also recommended against various types of so-called bacon beetle, but there are very different experiences here. Instead, it is better to use camp chalcids (lat. Lariophagus distinguendus) or bacon beetle (lat. Laelius pedatus). These two beneficial species are also egg parasites that do not build their own nests.

    digression

    Are parasitic wasps dangerous?

    Ichneumon wasps are in no way dangerous to humans or pets and can therefore be used without hesitation in the home, in the greenhouse or in the garden. The useful little animals only stay where they can find food and opportunities for reproduction in the form of insect eggs.

    Advantages and disadvantages of parasitic wasps

    Treatment with parasitic wasps has both advantages and disadvantages

    Of course, like so many things, the use of parasitic wasps against pests has advantages and disadvantages. How you weight these is entirely up to you. In principle, however, biological control measures such as the release of beneficial insects make sense, as this saves a lot of poison - and this in turn has positive effects on people and the environment. Don't forget that insecticides always have harmful effects on you and other living beings!

    benefits disadvantage
    non-toxic, without chemicals relatively long treatment time
    Rooms can continue to be used during treatment Due to their short life span, they have to be reapplied regularly
    Ichneumon wasps are easily lured into the garden and settled there strong specialization of individual species on certain pests
    Can be used against many different pests parasitized pest larvae should not be collected or removed
    also preventive use (e.g. on meadow orchards, in storage rooms)
    uncomplicated application

    Where can you buy parasitic wasps?

    You do not buy parasitic wasps in the form of living animals, but as eggs applied to special cards. From these, the finished beneficial insects finally hatch when used and in turn lay their eggs in the larvae of the pests to be combated. The parasitic wasps come from laboratories in which the animals are constantly bred under ideal conditions.

    You can, in turn, order the egg cards in specialized shops on the Internet and from the larger mail order portals such as Amazon and eBay, but you can often also purchase them in garden shops, garden centres, hardware stores, natural shops or drugstores such as DM. Mostly parasitic wasps of the genus Trichogramma are offered, for more specific species you often have to search a little more intensively.

    The advantage of Internet retailers specializing in beneficial insects is that they will send you new egg cards at regular intervals (usually three weeks) and you do not have to constantly try to buy a new one yourself. Since it is not possible to keep them in stock and the cards have to be distributed again and again over a longer period of time, this service makes sense.

    How much do parasitic wasps cost?

    The various providers vary in terms of costs, but on average you should expect around 30 EUR for three deliveries of four cards each. When buying, make sure that the cards contain more than just 300 to 400 parasitic wasp eggs: This number is usually not sufficient for a successful fight against clothes moths and food moths.

    Insert and use parasitic wasps

    This clear video explains very well how the use of parasitic wasps works:

    youtube

    The use of the parasitic wasp cards is very simple: simply lay them out or hang them up and wait. Everything else happens all by itself! However, make sure that you do not use any strong fragrances (such as the essential oils recommended against moths), harsh cleaning agents, etc. during this time, as these also have a negative effect on the parasitic wasps and therefore affect the success of the treatment. Also make sure that the room temperature and humidity do not fluctuate too much, as the parasitic wasps are quite sensitive to this.

    tips

    You should never leave parasitic wasp cards with eggs of the species Trichogramma hanging freely anywhere: These little creatures can only crawl but not fly and therefore need a firm hold.

    Against food moths

    Food moths are a problem in many households and are rarely due to poor hygiene. Usually you simply drag the animals home with the purchase, where they happily reproduce. The infestation is not only unsavory, but also a health risk. Although food moths and their larvae are not poisonous themselves, they can cause allergic symptoms. They also contaminate food with their excretions. There are different types - such as the flour moth (Ephestia kuehniella), the corn moth (Nemapogon granella), the dried fruit moth (Plodia interpunctella) or the rice moth (Corcyra cephalonica) - but all of them can be controlled very well with parasitic wasps.

    And that's how it works:

    1. Buy parasitic wasp cards for food moths.
    2. These should contain around 3000 to 4000 eggs.
    3. Do not store the cards, but attach them as soon as you receive them.
    4. Attach the cards in the immediate vicinity of the infestation found.
    5. You should plan one card for each shelf or drawer.
    6. Repeat the application three times at three-week intervals.

    Also, remove food contaminated with moths and moth eggs to prevent further spread of the plague.

    digression

    You can still do that against moths

    Lavender bags are a good protection against parasitic wasp infestation

    An infestation with food or clothing moths can usually hardly be avoided, since the animals are often brought in with the purchase - a bag of flour contaminated with moth eggs is enough for this! Clothes moths, on the other hand, usually get into the house through a window that is open for ventilation. However, you can take a few precautions to ensure that the little animals don't stand a chance: with food, containers that can be closed well, for example made of glass or metal, help to keep the pests away. Plastic or paper packaging, on the other hand, is unsuitable because the larvae can bore through them. In the closet, fragrances such as lavender, lemon oil, cedar wood and other intense smells drive away the pests.

    Against clothes moths

    The clothes moth (lat. Tineola bisselliella) is a moth that is distributed all over the world. The pest is very small, only growing between six and nine millimeters. Since the larvae feed on keratin, which is a protein found in animal hair fibers, clothing made from natural fibers such as wool are particularly at risk. The moth lays its eggs directly on the clothing and the larvae that hatch from them leave unsightly feeding holes. An infestation can often be recognized by the typical musty smell.

    To successfully combat clothes moths with parasitic wasps, it is best to proceed as follows:

    1. First, remove any clothing that is visibly infested with moths.
    2. This will reduce moth infestation.
    3. Wash the textiles at at least 60 °C or freeze them for 24 hours.
    4. This will also kill the moths and their eggs.
    5. Place the parasitic wasp cards between the items of clothing or attach them to them.
    6. The cards must not hang freely!
    7. Use a card with at least 3000 parasitic wasp eggs per shelf.

    Since clothes moths are very stubborn, you should carry out the treatment over a period of 15 weeks and apply fresh cards a total of six times at intervals of three weeks.

    Ichneumon wasps against pests in the garden and greenhouse

    However, parasitic wasps can not only be used in the apartment or in the house, but also provide useful services in the garden and in the greenhouse. Here you can use the little animals in combination with other beneficial insects - such as ladybirds and lacewings. However, this only works if you do without chemical agents in the form of pesticides, insecticides, etc. outside. These not only kill the pests, but also the desired beneficial insects and thus disrupt the biological balance. The little animals are also suitable for preventing pest infestation on endangered plants such as tomatoes or cucumbers.

    And that's how it works:

    • Lay out the cards with the parasitic wasp eggs as early as April, if possible.
    • Place them directly on the infested or endangered plants.
    • Cards with about ten to 15 eggs per square meter are sufficient for prevention.
    • Of course, to fight a current plague you have to use significantly more animals.
    • The benchmark here is about 3,000 eggs per card.

    Fighting with parasitic wasps works best in summer, when the temperature is constant at 20 to 27 °C and the humidity is around 60 percent. Under these conditions, the parasitic wasps multiply very quickly. If, on the other hand, it is too cold, the treatment often has little or no success - then the more robust pests multiply faster than the parasitic wasps. Therefore, when the temperatures are cooler, use other beneficial insects or limit the use of parasitic wasps to indoor areas or the greenhouse.

    How to attract parasitic wasps to your garden

    Adult parasitic wasps feed primarily on flower nectar and pollen

    Some species of parasitic wasps are native to this country and - provided the living environment is right - can be lured into the garden and settled there with a few tricks. These species are particularly valuable for naturally controlling common garden pests such as aphids and scale insects. In this section you can read what these parasitic wasps need to feel at home in your garden.

    • food sources: Although parasitic wasp larvae live as parasites and are therefore dependent on host animals, adult animals feed primarily on the pollen and nectar of umbelliferae. Therefore, you should preferably cultivate appropriate plants in your garden to attract the animals.
    • Suitable umbellifers: Many herbs and useful plants such as fennel, aniseed, lovage, dill, chervil, carrots and parsnips belong to this group, but also pretty ornamental plants such as the shade-tolerant sweet umbel (Myrrhis odorata), the sun-loving cow parsley (Anthriscus sylvestris) and extremely popular flowering plants such as ivory -Man-litter (Eryngium giganteum), ornamental onions or peonies. Hardly any other type of plant attracts more beneficial insects than this one!
    • insect hotel: Of course, a suitable accommodation should not be missing, even if the little animals do not build nests due to their way of life. An insect hotel (€11.33) near flowering umbellifers, in a sheltered and warm place, attracts numerous other insects. Ichneumon wasps prefer small pieces of wood with tiny drill holes (diameter between two and eight millimeters), which you lay out as early as possible in the year or hang in the trees. These sticks are also often used for wintering.

    Can I breed parasitic wasps myself?

    Typical parasitic wasps found in the garden can be attracted by creating a suitable habitat. Others, such as the Trichogramma species, have to be cultured in the laboratory under suitable conditions. Of course, if you want to save money, you can try it yourself - but the chances of success are not particularly high. Pay attention to these conditions:

    • constant temperatures between 18 and 20 °C
    • Humidity around 60 percent
    • enough moth eggs for food
    • Put moth eggs and parasitic wasps together in a jar
    • Cover jar with linen cloth
    • Incubator is ideal for breeding
    • Starting temperature 25 °C
    • slow drop to 18 °C
    • constantly adding new food (moth eggs).
    • Ichneumon wasps immediately start looking for new eggs after hatching

    The little animals can be produced far more cheaply in industrial laboratories. For a private consumer, breeding parasitic wasps involves a great deal of effort, which is not always crowned with success - the beneficial insects are too sensitive for that.

    digression

    Can I use parasitic wasps and insecticides at the same time?

    No question, the temptation is great when there is a massive moth infestation. However, you should never fight a pest invasion with parasitic wasps and insecticides at the same time! In this case, you would not only kill the pests, but also the beneficial insects that were used. These, in turn, would not be able to fulfill their task at all.

    Instead, stick to the manufacturer's recommendation regarding the amount of parasitic wasp panels used and the recommended duration of treatment, and you'll quickly get rid of your pests.

    frequently asked Questions

    Do the parasitic wasps survive in extreme heat or cold? How do I know if they will survive mailing?

    You can also order parasitic wasps in winter or during the heat of the summer without hesitation. The manufacturer or retailer will adjust the packaging accordingly or send you the shipment at a more convenient time. But no matter what the weather conditions are: Don't leave the parasitic wasps lying around for days (especially not in an outdoor mailbox!), but distribute them immediately upon receipt. A purchase in advance is therefore not possible and also not sensible. You should only buy the little animals if you want to use them directly.

    What happens to the parasitic wasps once the pest has been eliminated?

    You don't have to worry about bringing a new plague of insects into your house or garden with the parasitic wasps. The beneficial animals only survive as long as they have sufficient food and breeding opportunities in the form of their favorite insect eggs. Since most species specialize in certain pests, they die off from the lack of food (ergo when there are no more pest eggs) or migrate to more rewarding areas, such as through an open window.

    How long do parasitic wasps survive?

    Ichneumon wasps only have a very short life span: Depending on the species, the adult animals reach an age of between a few days or weeks. In the case of the Trichogramma parasitic wasps used on food and clothes moths, it is even the case that they live much shorter lives than the moths themselves. For this reason, you must plan the application so that you can use it over a total period of nine or 15 weeks place new cards at intervals of three weeks.

    Can parasitic wasps sting?

    In contrast to real wasps, which spoil your outdoor coffee table in late summer and can sometimes sting if threatened, parasitic wasps are not interested in cakes, people or pets. With their extremely fine sense of smell, the little animals track down the eggs of their preferred host animals and seek them out immediately. However, parasitic wasps do not sting or bite, so there is no danger to humans or animals (at least not unless it is an insect favored by parasitic wasps).

    tips

    The parasitic wasp Lysiphlebus testaceipes is particularly suitable for combating aphids, as the animals emit a scent that is very similar to that of aphids and are therefore not recognized and attacked by ants - who like to keep aphids as "pets".

Category:

Animals in the garden