- Nematodes: Profile, Appearance & Co.
- Nematodes as beneficial insects
- Application of nematodes: timing, procedure and duration of action
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Nematodes act as beneficial insects against many plant pests. But what are nematodes and how do you use them correctly?
Nematodes offer the possibility of controlling a large number of pests biologically. When using nematodes, however, you should always keep in mind that they are living organisms. We will show you which pests you can use nematodes against and how to proceed correctly. In this article you will find all the information you need for a successful nematode operation.
Nematodes: Profile, Appearance & Co.
Nematodes, also known as elk, are translucent to white in color and cannot be seen with the naked eye. Over 20,000 different species are known to date. Depending on the species, nematodes have very different properties. The small roundworms feed species-specifically on plants, bacteria, algae, fungi, predatory or dead animals, for example. Many are also parasitic, such as roundworms, trichinella, and whipworms, all of which are also nematodes.
The nematodes (Nematoda) relevant for plant cultivation are small roundworms that are less than a millimeter in size. Depending on the specialization of food intake, they can be harmful or beneficial to plants. Some species can infest vegetables and other plants as pests. If you have problems with nematodes, then our article on nematodes as pests will certainly help you.
Nematodes as beneficial insects
Now what makes some nematodes effective beneficials? Nematodes can actively move and spread in the soil. This ability gives the nematodes a greater chance of encountering prey in the garden. Their small size enables the nematodes to penetrate the interior of the pests via body openings and thus kill them. They then use the pest bodies to reproduce. Threadworms have many smaller allies when it comes to pest control: they are special bacteria that live in symbiosis with the nematodesLife. When a nematode and a suitable prey meet, the nematode injects the bacteria into the victim. These then digest the pest from the inside out - the nematode can then use the prey as food and multiply. The nematodes then leave the dead pest and look for a new host. In this way, the nematodes can remain in the soil for months under good conditions.
Another advantage is that the use of nematodes has no negative side effects for your plants or the environment. Incidentally, in almost all cases it is the pest larvae and not the adult pests that are attacked by the nematodes.
The high biodiversity of nematodes allows many different pests to be addressed, for example:
- Mourning Gnats
- Once weevil
- Guglings
- Ants
- Snails
- Cherry Fruit Flies
- Box tree moth
- Mole Crickets
- Thrips
- Meadow Crane
Application of nematodes: timing, procedure and duration of action
For a successful use of nematodes a few points should be considered:
- Before you can use nematodes, it is important that you find out which pest it is. Only certain nematodes can be used against various pests.
- The right time of year to apply nematode treatment depends on the pest and the weather. Because if it is too cold or too dry, the nematodes are not active. Since usually only the larvae of the pest in the soil can be controlled, the time should be chosen so that the pest is in the larvae stage. Below we give you the best times to combat the most common pests.
- The soil temperature must be right for the respective nematode species. If the temperatures are too low, the nematodes stop their activity completely. Most species can be used at a soil temperature between 12 and 28 °C.
- Nematodes are sensitive to UV light. For this reason, you should avoid spreading the roundworms during the day. The evening or early morning is better.
Where to buy nematodes? You can purchase various nematodes on the Internet in specialized shops or by ordering cards from garden centers. In our Plantura online shop you can also find three different types of nematodes that protect against the most common pestsact, pray. You will then receive the nematodes directly in your mailbox as durable larvae in a powder that serves as a carrier substance.
In order to maintain this dormant state, it is important that you store the nematodes in the refrigerator until use. You can find out how long you can store the nematodes on the product packaging. Our Plantura nematodes can be stored for up to 6 weeks before use.
What is the correct way to use nematodes? Mix the powder containing the nematodes with water. The exact mixing ratio can be found on the product packaging. You should moisten the area to be treated well with water before applying the nematodes. The suspension can now be spread evenly over the area to be treated using a watering can. You can also read about the size of this area on the product packaging. After application, you should rinse the treated area with water to flush the nematodes into the soil. While the nematodes are doing their work, you should make sure that the soil is always moist. However, it is essential to avoid waterlogging.
Tip: For pests with a multi-year development cycle, such as garden beetles or mole crickets, we recommend using the nematodes for several years in a row.
What about the duration of action of nematodes? You can find the first dead larvae in the soil after just a few days. Under very good conditions, the introduced nematodes remain in the soil for several months, but their numbers are constantly falling. Optimal pest control is only given in the first four weeks after application.
Tip: For example, if larvae of the vine weevil (Otiorhynchus) have been successfully infested and killed by nematodes, they will turn red-brown. This is how you can check if the application worked.
Summary: How to Use Nematodes Properly
- The time of treatment depends on the pest and can be found on the package insert.
- The floor temperature must be between 12 and 28 °C continuously.
- Apply the nematodes in the morning or evening.
- Mix the purchased powder and nematodes with water.
- Use the watering can to spread the nematodes on the moistened soil and then water them in.
- Keep the soil moist for at least two weeks,to encourage the nematodes.
Nematodes against fungus gnats
The adult fungus gnats (Sciaridae) actually do not damage any plants. However, the larvae of the fungus gnat stay in the ground and feed, among other things, on young roots. In this way, the larvae can harm the plants. Indoor plants in particular are often attacked by fungus gnats. We have compiled helpful tips for you on the subject of fighting fungus gnats in our article.
The nematode species Steinernema feltiae (SF nematodes)has proven effective against fungus gnats. Steinernema feltiae can be used on indoor plants all year round and outdoors from a soil temperature of 12 °C. We present our Plantura SF nematodes in more detail on this page.
In the event of a severe infestation or if you want to be on the safe side, we recommend using it in combination with a biological agent based on neem oil. Our Plantura organic sciarid-free neem allows you to get rid of sciarids naturally.
Nematodes against vine weevil
Nematodes can also control vine weevils, more precisely their larvae in the soil. Provide rhododendron (Rhododendron), ivy (Hedera helix), hydrangea (Hydrangea) and other plants are spared the dreaded pit damage of the vine weevil, HB nematodes can be used. The nematode species Heterorhabditis bacteriophora can be applied from a soil temperature of 12 °C and is used for reliable and biological control of the vine weevil. We recommend applying our Plantura HB nematodes between April and May or alternatively between August and September. You can find more information on vine weevil control by nematodes in our special article.
Nematodes against grubs
Cheugs are the larvae of scarab beetles such as June beetles (Amphimallon solstitiale), May beetles (Melolontha melolontha) or rose chafers (Cetoniinae). They can cause damage if they multiply in large numbers on lawns. The complete and permanent control of grubs can sometimes take years with the stubborn larvae - especially with the May beetle. The reason for this lies in the many larval stages of the grubs, not all of which are responsible for the effect of spraysare susceptible
A biological control option is the use of HB nematodes against cockchafer, June beetle and rose chafer larvae. Since only the first two young growth stages of grubs are effectively controlled, the time of control is very important, as is the right nematode species: Heterorhabditis bacteriophora can be used between July and September against grubs from June beetles, garden leaf beetles and somersault beetles.
Nematodes against ants
Ants are not actually pests and are part of a he althy garden. But if you get the upper hand on terraces or paths, you may have to fight them. In this case, just like with fungus gnats, you can use our Plantura SF nematodes of the species Steinernema feltiae. The nematodes disturb the ants, causing them and their brood to leave the treated area.
Ants can be a nuisance, especially in the house. When fighting ants in your home, we recommend that you use a biological agent. A particularly harmless agent for humans and animals is, for example, our Plantura ant agent InsectoSec®, which uses pure kieselguhr as an active ingredient.
Nematodes against snails
As every hobby gardener knows, slugs can cause considerable damage in the garden. You can also use nematodes to control snails. The special advantage: snails multiply particularly strongly in damp weather. The nematodes also need moist conditions to develop well.
To combat snails effectively, you should use the nematode species Phasmarhabditis hermaphrodita. The optimum soil temperature is between 12 and 25 °C. Another advantage is that the harmless Roman and house snails are spared.
Roundworms against other pests
The nematode Steinernema feltiae is not only effective against fungus gnats and ants, but also against the larvae of the cherry fruit fly. However, the effect is not nearly as good as with the fungus gnat. The cherry fruit fly larvae can only be combated at the moment when the larvae migrate from the infested cherry into the soil. Therefore, the nematodes must be applied to the soil in such a way that they are actively present in the soil during this period. A good time to do this is early June.
In order to be able to use nematodes against the box tree moth, theNematodes are integrated into a specific wetting agent. This is the only way for them to come into direct contact with the larvae of the box tree moth.
The nematode species Steinernema carpocapsae is suitable for box tree moth control. You will find precise information on the correct application on the product packaging. The optimal treatment time is two weeks after you have discovered the first adult animals. To determine this point in time, we recommend a moth trap.
For effective and environmentally friendly control of the box tree moth, we can also recommend a remedy based on the Bacillus thuringiensis, which is also alive. Such a remedy is, for example, our Plantura Zünslerfrei XenTari®.
Too many mole crickets (Gryllotalpidae) can become very annoying in the vegetable patch. The nematode species Steinernema carpocapsae can be used against mole crickets. Here, the adult animals are infested and killed. The optimal period for combating is between March and July from a soil temperature of 12 °C.
Buckets can be a problem, especially in the lawn. Biological control is possible with our Plantura SC nematodes against meadow gnats. The larvae of the crane fly are killed by the nematode species Steinernema carpocapsae. The best time to combat this is about two weeks after the high point of the crane fly's flight, between September and October.
Nematodes can also be used against thrips (Thysanoptera). Flower thrips (Frankliniella occidentalis) is one of the most common species and a problem, especially in greenhouses or indoors. Steinernema feltiae attacks the flower thrips pupa and kills it. Control can therefore take place all year round.
In addition to nematodes, there is a whole range of other animal helpers that will help you keep pests in check in the garden. We present other exciting beneficial insects in the garden in our overview article.