Fighting whitefly naturally and biologically, is that possible? - Yes! Namely with Encarsia formosa. This is because she lays her eggs in the larvae of the whitefly, causing them to die.

Parasitic wasps parasitize eggs of pests

With the white fly, you might think that the name says it all. It is white and flies, but strictly speaking "fly" is the wrong term for the pests of the whitefly (Aleyrodoidea) family. But what can you do if you have this type of lice on your plants? Biological and sustainable control is possible: with the parasitic wasp Encarsia formosa. Find out how to recognize it, how to live it, why it is so effective and how best to use it.

Encarsia formosa parasitic wasps: appearance and lifestyle

Ichneumon wasps of the species Encarsia formosa are about 0.7 mm in size, i.e. much smaller than the name "wasp" suggests and can hardly be seen with the naked eye. At first glance, the small beneficial insects have little in common with the wasps known from the garden. Only the coloring is similar, so the female Encarsia parasitic wasps have a yellow abdomen and a black head and chest, while the males have a purely black body. Both stinging wasps and parasitic wasps belong to the so-called stinging insects (Apocrita), so they are actually related.
To lay eggs, the females need the whitefly as a host, which they can parasitize with their egg. Under optimal conditions, each female lays between 50 and 100 eggs in her lifetime. The larvae pass through various stages in the host, pupate and hatch as adult parasitic wasps about two weeks after laying their eggs.
Originally, Encarsia formosa comes from South and Central America. Nowadays, however, it is bred worldwide and used as an effective beneficial insect, especially against the whitefly.

The Encarsia parasitic wasps are only 0.7 mm in size

Encarsia formosa beneficial against whitefly

The pressing question when it comes to pests is how best to combat them. The whitefly is both in the greenhouse and atHouseplants a common pest. For private users, beneficial insects and biological pesticides are usually the best option. Synthetic plant protection is primarily reserved for commercial horticulture because of the strict usage requirements and the risk for users and the environment. Therefore, this article primarily deals with the effective use of the proven Encarsia formosa parasitic wasp against the whitefly.

Advantages of beneficial insects over pesticides:

  • No residues on the plants and in the soil
  • No waiting times for harvest
  • No damage to plants, humans and animals
  • Unlimited use without special requirements also possible for private users
  • High efficiency when used correctly

In addition to Encarsia formosa there are other beneficial insects that can be used against whiteflies - for example predatory mites (Amblyseius), predatory bugs (Macrolophus ssp.) or lacewing larvae (Chrysoperla carnea). Here at Plantura we have chosen our Plantura Encarsia parasitic wasps to control whiteflies. And with good reason: the Encarsia parasitic wasp is a very successful remedy against whiteflies when used correctly and is therefore one of the most important beneficial insects worldwide. It is now standard in professional commercial horticulture.

The shell of the whitefly turns black after parasitization

How does the parasitic wasp fight whitefly? The Encarsia parasitic wasp is so effective against whitefly because it is nearly fights all stages of development. The females lay their eggs in the last pupal stages of the whitefly. As a result of the parasitization, the whitefly dies and the puparium turns black. The adult parasitic wasp also sucks the hemolymph - the blood of the insects - from the younger larval stages of the whitefly.
Encarsia formosa uses about 15 different species of whitefly as host, including the two most important species Trialeurodes vaporariorum or greenhouse whitefly and Bemisia tabaci, also called cotton whitefly.

Tip: Against the whitefly Aleyrodes proletella the Encarsia parasitic wasp is not a beneficial insect suitable, because it is not parasitized by it. In this case, the parasitic wasp Encarsia is suitabletricolor or approved biological pesticides such as our Plantura pest-free neem. It is gentle on beneficial insects and can be used on many ornamental and useful plants against stinging and biting insect pests.

The coloring suggests that the larvae have been parasitized

Procedure for use as a beneficial insect

When using our Plantura Encarsia parasitic wasps against whiteflies, it is important that they are applied promptly after the plants have been infested with whiteflies. If you choose our Plantura parasitic wasps, you will receive a total of 500 animals on ten cards. In other words, there are 50 animals on each card, which is enough for a total area of about 10 m². We recommend an application between March and October, as there is a sufficient amount of light available for parasitization. In order for the parasitic wasps to be able to take effective action against the whitefly, they must find good "working conditions". This includes the right humidity, sufficient light and an optimal temperature. If these parameters are not sufficiently met, whitefly control will be less successful.

The following also applies: The earlier pests in the plants are discovered and controlled, the less damage can occur. Monitoring the infestation with the help of yellow boards such as our Plantura yellow boards makes sense. In the case of frequent infestations, it makes sense, especially in the greenhouse, to spread parasitic wasps as a preventive measure. Thus, a pest infestation is prevented even before high infestation pressure. A success of the parasitic wasps can be clearly seen after about four weeks.

You can read all about lifestyle, prevention and control with organic pesticides in our article on whiteflies.

Tip: Especially with tomatoes (Solanum lycopersicum), cucumbers (Cucumis sativus) , aubergines (Solanum melongena) and some ornamental plants, the whitefly is often found. Eggs are always laid on the underside of the leaf in a semicircular or circular arrangement.

Whitefly eggs are often arranged in a semicircle or circle

Use parasitic wasps against whiteflies:

  • Immediate ordering of the parasitic wasps after detection of the infestation.
  • After receiving the cardboard strips, apply quickly: Can be stored for a maximum of 2 days at 8 to 12 °C.
  • To increase the success of the fight, you can attack all plants togetherplace a place and use the parasitic wasps collected there.
  • Only open the packaging at the place of use, otherwise any adult parasitic wasps that have hatched will escape.
  • The parasitic wasps develop optimally at a temperature between 22 and 27 °C and a light quantity of at least 4000 lux; for orientation: a desk should be illuminated with 500 to 1000 lux; additional lighting can be useful.
  • In order to achieve the necessary humidity of around 65%, the plants can be sprayed with water every 2 to 4 days.
  • Pesticides should not be used while the parasitic wasps are being used, as they can harm the beneficial insects.

Tip: We recommend spreading our Encarsia formosa only in closed rooms such as greenhouses, rooms or conservatories, as the beneficial insects are outdoors migrate quickly and thus only insufficiently parasitize the pest infestation.

You want to fight whiteflies or other pests outdoors or on the balcony? Read our article on neem for pest control to see how the herbal active ingredient works and is used.

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Gardening Tips