Everything you need to know about ichneumon wasps

Hannah
Hannah
Hannah
Hannah

I am particularly interested in garden wildlife which is why I did my Master's degree with a focus on "animal ecology". I am convinced that beneficial insects and wildlife are a sustainable and effective alternative to many of the products we use on our plants. I am also a passionate birdwatcher and rarely go for a walk without my binoculars.

Favourite fruit: kiwi, apple and redcurrant
Favourite vegetables: tomatoes and green beans

How big are ichneumon wasps? Can ichneumon wasps sting and are they dangerous for humans or animals? Read on to learn the answers and how to identify parasitic wasps.

Ichneumon wasp resting on a log
ichneumon wasps are small beneficial insects that do not have much in common with their stripy namesake [Photo: emka74/ Shutterstock.com]

Although ichneumon wasps (Ichneumonidae) are Hymenopterans and their name may make us think of the stripy insects that like to disrupt our picnics, they are in fact not actual wasps. Instead, ichneumon wasps are an insect group of their own and they have an important characteristic in common: they parasitise other insect species. This means they lay their eggs on a host insect, making ichneumon wasps natural enemies of herbivorous insects, along with predators such as beetles. That way, parasitic wasps control numerous species considered pests – both naturally and by being selectively bred. The most common species used for natural pest control is the ichneumon wasp from the genus Trichogramma. This species is specialised in moths and can, for instance, be used to get rid of food and clothes moths.

How to identify ichneumon wasps

Identifying ichneumon wasps is quite tricky, as most of them are very small and there are many different species. Their bodies are similar to the real wasps we know so well – except that they are much smaller and cannot sting.

How big are ichneumon wasps?

Depending on the species, ichneumon wasps are just under a millimetre up to a few centimetres in size. The species of the genus Trichogramma are only 0.3 – 0.4 millimetres.

What do adult ichneumon wasps look like?

Adult ichneumon wasps have two pairs of wings, two compound eyes, antennae and a typical “wasp waist”. The female ichneumon wasp has a large ovipositor that looks like a sting but it is far too unstable to pierce the skin. Instead, they use it to lay eggs and to position them very precisely – a bit like the needle of a syringe.

What is the ichneumon wasp’s life cycle?

Ichneumon wasps lay their eggs directly into the eggs or larvae of the host insect. Here, their own larvae start to grow, causing the host itself to die. When new ichneumon wasps hatch, they in turn look for a new host.

What do ichneumon wasp larvae look like?

Ichneumon wasp larvae are small, maggot-shaped and have no legs. However, they are difficult to spot as they develop inside their host.

What do ichneumon wasp eggs look like?

Due to their incredibly small size and because they are laid directly onto the host insect, little is known about the appearance of ichneumon wasp eggs.

What do ichneumon wasps eat?

The larvae of the ichneumon wasp feed on their host, causing it to die. Adult ichneumon wasps feed on pollen and nectar.

Are parasitic wasps dangerous?

Ichneumon wasps are not dangerous to humans or pets such as dogs or cats. Due to their high specialisation, they only parasitise their host insects and are not interested in other organisms. As soon as they have hatched, they immediately search for new hosts and leave everything else well alone.

Can ichneumon wasps sting?

You need not be afraid of being stung by an ichneumon wasp because they do not have a sting. The females have a large ovipositor for laying eggs but it is not strong enough for stinging.

Ichneumon wasps as beneficial insects

For many known pests there is a corresponding ichneumon wasp, which means they can be specifically bred and used for natural pest control. Due to their high degree of specialisation and because they cannot reproduce without the host insect, they are very effective and die after successful elimination of the pest itself. People have been making use of this handy life cycle since the beginning of the 20th century.

Using parasitic wasps to get rid of moths

Ichneumon wasps of the genus Trichogramma have been bred to control moths and can be used to get rid of pantry moths and clothes moths.

Our Plantura Mini-Wasps parasitise the eggs of food and clothes moths, making them a sustainable and safe alternative to chemical sprays. These tiny beneficial insects come in carded dispensers and get straight to work after hatching.

Advantages of ichneumon wasps for moth control:

  • Natural and environmentally-friendly method without the use of chemicals
  • Harmless to humans, animals and clothing
  • Very effective and thorough method when applied correctly
  • Odourless
  • Easy to use
  • Free and reliable delivery

Our Plantura Mini-Wasps against pantry moths and clothes moths come in carded dispensers containing 2000 eggs each, which hatch shortly after delivery. This amount is enough to cover about one square metre, so the number of cards required depends on the size of the affected area. For a moth infestation in a normal sized kitchen, we recommend using 4 cards.

Mini-Wasps against Pantry Moths - Natural Moth Control
Mini-Wasps against Pantry Moths - Natural Moth Control
  • Effective & chemical-free biological control for pantry moths
  • Highest quality parasitic wasps
  • Not harmful to humans or pets

When getting rid of moths, it is important to keep at it! Ichneumon wasps need to be introduced several times to break the moth’s life cycle and to get rid of an infestation entirely. We recommend introducing cards 4 times in total for food moths and 6 times for clothes moths. To make this process as smooth as possible, we will deliver a fresh set of our Plantura Mini-Wasps against clothes moths right to your doorstep at 14-day intervals. That way, you can be sure of having new wasps right when you need them.

Mini-Wasps against Clothes Moths - Natural Moth Control
Mini-Wasps against Clothes Moths - Natural Moth Control
  • Effective & chemical-free biological control for clothes moth
  • Highest quality parasitic wasps
  • Not harmful to humans or pets

How long do ichneumon wasps live?

At room temperature, ichneumon wasps can survive for about 7 – 10 days before dying and literally disintegrating. They can only reproduce with moth eggs, which they need for the larvae to develop. Therefore, after successfully controlling the moths, the last generation of ichneumon wasps dies without leaving any offspring.

Tip: After using ichneumon wasps, wipe the shelves with a damp cloth and wash your clothes to remove any small traces of the beneficial insects.

Learn more about ichneumon wasps in our article, Ichneumon wasps against lice and whitefly.

Subscribe to the Plantura newsletter