What are nematodes?
Nematodes, commonly referred to as roundworms, are a diverse group of worms belonging to the phylum Nematoda. Nematodes are characterized by their unsegmented, cylindrical bodies, and they come in a variety of sizes, ranging from microscopic to several inches in length. Nematodes play various roles in ecosystems. Some are free-living, feeding on organic matter in soil or water, and are essential for nutrient recycling. Others are called parasitic nematodes, infecting plants, insects, animals, or humans. There are about 25.000 named species, but estimated numbers of species are in the millions. Nematodes are also referred to as roundworms, threadworms, and eelworms.
Types of nematodes
In agriculture the most important types of nematodes are parasitic nematodes. More specifically insect-parasitic nematodes and plant-parasitic nematodes.
Insect-parasitic nematodes, often referred to as entomopathogenic nematodes or beneficial nematodes, are a group of parasitic nematodes that have a unique relationship with insects. These nematodes are natural predators of various insects and play a crucial role in biological pest control, making them beneficial for agriculture and horticulture. These nematodes are not harmful to humans, animals, or plants but are highly effective in controlling harmful insects.
Plant-parasitic nematodes are a group of parasitic nematodes that infest and damage plants, leading to significant agricultural and horticultural problems. These nematodes are detrimental to crop health and can cause yield losses. They feed on plant roots, disrupting the plants' ability to take up water and nutrients, which ultimately affects their growth and productivity.
The most common types of plant-parasitic nematode are root-knot nematodes, cyst nematodes, lesion nematodes, spiral nematodes and dagger nematodes.
Beneficial nematodes for pest control
Nematodes for pest control, often referred to as entomopathogenic nematodes or beneficial nematodes, are microscopic roundworms that serve as natural agents for biological pest control. Beneficial nematodes are highly specific in their choice of hosts and do not harm beneficial insects, humans, or animals. Common pests targeted by these nematodes include various larval insects like grubs and weevils (Coleoptera larvae), caterpillars (Lepidoptera), fly larvae (Diptera), Thrips (Thysanoptera) and many other soil-dwelling pests.
Benefits of nematodes
Using beneficial nematodes for pest control offers several key benefits:
- Fast-acting biological solution
- Resistance proof - pests cannot build resistance
- Can be applied with regular spray equipment
- Compatible with most pesticides
- Leaves no residue
What pests do nematodes control?
Beneficial nematodes are effective biological agents for controlling a wide range of harmful insects and pests. Nematodes are the natural enemies of grubs and weevils, caterpillars, thrips, wireworms, leatherjackets and a large group of fly larvae, such as fungus gnats, crane flies, shore flies, onion flies and more. Nematodes are a perfect fit within IPM programs due to their compatibility with most pesticides. They reduce the reliance on chemical pesticides and promote sustainable and eco-friendly pest management practices. Here are some of the common pests that beneficial nematodes can control:
Beneficial nematodes effectively control grubs. Grubs are the larval stage of various beetle species, including Japanese beetles and June beetles. They are creamy-white, C-shaped, and typically found in the soil, where they feed on the roots of grasses and other plants. Grubs are notorious pests in lawns, gardens, and soft fruits, as their feeding can lead to significant damage to plant roots, causing wilting and brown patches in the grass.
Specifically, the beneficial nematode species Heterorhabditis bacteriophora is used for grub control. These nematodes parasitize grubs by entering their bodies and releasing symbiotic bacteria, which quickly kill the grubs. Beneficial nematodes are a natural and eco-friendly method of managing grub populations in lawns and gardens, reducing the need for chemical pesticides.
Koppert provides nematode solutions tailored to specific market segments. Larvanem is designed for a variety of greenhouse crops, Sportnem-H is ideal for lawns, and Capyphor is specifically for outdoor crops.
Beneficial nematodes prove to be a valuable tool for controlling thrips, which are tiny insects known for their ability to damage a wide range of crops and ornamental plants. Thrips feed on plant sap, leaving behind silvered or discolored patches and causing distortion or scarring of leaves and flowers.
Nematodes are most effective against thrips at the soil-dwelling larval, pre-pupal and pupal stage. Larvae found on plants and adults are also susceptible to nematode infection, depending on the crop architecture and the environmental conditions. To use nematodes for thrips control, they are typically applied to the soil in the root zone of infested plants, ensuring that they come into contact with the thrips pupae.
For thrips control, the most commonly used species of beneficial nematodes is Steinernema feltiae. Koppert provides nematode solutions tailored to specific market segments. Entonem is designed for a variety of greenhouse crops and urban green. As part of an integrated pest management Capirel is designed for thrips control in allium crops.
For caterpillar control, beneficial nematodes are very effective allies. Nematodes are most effective against caterpillars at their vulnerable larval stages (larvae of butterflies and moths). Caterpillars are voracious pests that can cause significant damage to various crops and ornamental plants. Several species of beneficial nematodes are effective in controlling caterpillars, including Steinernema feltiae and Steinernema carpocapsae.
Koppert provides nematode solutions tailored to specific market segments. The choice of nematode species may depend on the specific caterpillar species affecting the target plants and the environmental conditions. Application timing is crucial to target caterpillars in the soil or on plant surfaces.
Sportnem-T effectively manages caterpillars and cutworms in lawns, Capsanem is tailored for controlling caterpillars in greenhouse crops, while Casea and Capirel are the go-to choices for caterpillar control in orchards, berries, outdoor vegetables, and urban trees. Entonem is designed for use across a range of greenhouse crops and urban green spaces.
Nematodes can be used to effectively control fungus gnats, small flies that can be a problem in greenhouse and indoor plant environments. Fungus gnat larvae feed on organic matter in the soil and can damage plant roots.
Steinernema feltiae is a commonly used nematode species for fungus gnat control in greenhouse and outdoor crops. The nematodes can be applied to the soil or growing media, ensuring they come into contact with the fungus gnat larvae.
Koppert provides nematode solutions tailored to specific market segments. Entonem effectively controls fungus gnats in a variety of greenhouse crops and urban green spaces. Scia-Rid is the preferred choice for controlling fungus gnats in mushroom cultivation.
Beneficial nematodes are effective in controlling crane flies which is a common pest in lawns and turfgrass. Crane fly larvae, also known as leatherjackets, can cause significant damage by feeding on grass roots.
Steinernema carpocapsae is a commonly used nematode species for controlling craneand leatherjackets. The nematodes are typically applied to the soil in areas where these pests are active, ensuring they come into contact with the target larvae. This eco-friendly approach to pest control reduces the need for chemical pesticides and helps maintain healthy lawns and turfgrass.
Koppert provides nematode solutions tailored to specific market segments. Sportnem-T is used for the control of craneand leatherjackets in lawns. Capsanem is the solution for controlling crane and leatherjackets in both protected and outdoor crops, and urban greens. Casea is the choice for crane fly and leatherjacket control in outdoor vegetables.
Nematodes can also be used for the control of shore flies, which are common pests in greenhouse and indoor plant environments. Shore fly larvae can damage plants by feeding on root hairs and organic matter in the growing media. Steinernema feltiae (Entonem) and Steinernema carpocapsae (Capsanem) are commonly used nematode species for shore fly control in greenhouse and outdoor crops. The nematodes can be applied to the growing media to ensure they come into contact with the shore fly larvae.
Nematodes can be used effectively to control wireworms, which are the larval stage of click beetles. Wireworms are known for their destructive feeding habits, as they can damage the roots, seeds, and underground plant parts of various crops.
Both Heterorhabditis bacteriophora and Steinernema carpocapsae are commonly used nematode species for controlling wireworms. The nematodes are typically applied to the soil before or during planting to ensure they come into contact with the wireworms.
Casea and Capyphor are used for wireworm control in outdoor vegetables, such as potato and processing tomatoes.
Nematodes can also be employed to control onion fly and bean seed fly, which are common pests affecting onion and other bulb crops. These flies lay their eggs near the base of the plants, and the resulting larvae, known as onion maggots, can cause significant damage by tunneling into and feeding on the bulbs.
Steinernema feltiae is a commonly used nematode species for onion fly and bean seed fly control. The nematodes can be applied to the soil around plants to ensure they come into contact with the fly larvae. This natural and environmentally friendly approach to fly control reduces the need for chemical pesticides and helps protect onion and bulb crops from underground pest damage.
Koppert offers Capirel nematodes to control onion fly and bean seed fly in many field crops, such as onions and beans.
How do nematodes work?
Beneficial nematodes use a fascinating strategy for parasitizing and killing their host insects. Here's how they work:
- Seeking out hosts: Entomopathogenic nematodes actively search for potential insect hosts. They are attracted to their hosts by detecting chemical cues emitted by the insects, such as carbon dioxide, heat, and specific chemicals.
- Host penetration: Once they locate a suitable host, the nematodes enter the host's body through natural openings, such as the mouth, spiracles (insect breathing tubes), anus or soft cuticle areas. Some nematodes release enzymes to help digest and soften the host's cuticle, allowing them to enter.
- Symbiotic bacteria release: Once inside the insect host, the nematodes release symbiotic bacteria, such as Xenorhabdus or Photorhabdus species, into the insect's body cavity. These bacteria are essential for the nematode's parasitic strategy. The bacteria quickly multiply, causing septicemia (a lethal blood infection) in the host insect.
- Bacterial infection: The bacteria secret toxins and antimicrobial compounds that kill the host insect within a few days. The host becomes immobile and eventually dies due to the bacterial infection.
- Feeding and reproduction: The nematodes feed on the multiplying bacteria and absorb the nutrients released by the bacterial activity. This provides nourishment for the nematodes and supports their reproduction. As the bacterial population within the host insect continues to grow, so do the nematode populations. The nematodes reproduce, developing through multiple juvenile stages into mature adults.
- Emergence: After consuming the host insect's tissues and the bacteria, thousands of new nematodes emerge from the dead insect's body. These newly emerged nematodes are now ready to seek out new hosts and continue the cycle.
Beneficial nematodes species
Several species of beneficial nematodes are commonly used in biological pest control. These nematodes play a vital role in managing insect pests and are considered beneficial for agriculture, horticulture, and integrated pest management programs. Some of the well-known beneficial nematode species include:
- Steinernema feltiae: These cold tolerant nematodes are effective against a wide range of soil-dwelling pests, including fungus gnats, vegetable root flies, root weevils, and other insect larvae. They are commonly used in greenhouse and nursery pest management and are becoming more and more popular in orchards and outdoor vegetable crops.
- Steinernema carpocapsae: This species is known for its effectiveness against pests such as wireworms, various caterpillars, and weevil and beetle larvae. Its ability to adapt to different temperatures makes it a good choice for controlling caterpillars in various crops.
- Heterorhabditis bacteriophora: These nematodes are particularly effective against soil-dwelling insects like Japanese beetle, white grubs, and root weevils. They are used in turfgrass management and for controlling pests in several vegetable crops, blueberries, and other soft fruit crops.
How to apply nematodes
The application of beneficial nematodes is a straightforward process that ensures they come into contact with the target insects. Nematodes can be applied by foliar or soil application, depending on the target pest. Here's a general guideline on how to apply nematodes (always check the label for detailed application advice):
- Choose the right nematode species tailored to your specific pest problem
- Determine the required nematode quantity based on the infestation severity and treatment area and as indicated on the product labels
- Store nematodes in a refrigerated environment to maintain their effectiveness until the day of application
- Create a nematode suspension by mixing them with water following provided instructions
- In case of soil application: Ensure the soil or growing media is adequately moist (not waterlogged) to facilitate nematode movement. Also take the soil temperature into account (see product labels for detailed information)
- In case of foliar application, the air relative humidity is another important factor to consider to maximize success (>75%)
- Ideally, apply nematodes during periods of moderate UV light, such as early morning or late afternoon, and avoid high sun intensity
- Spray nematodes evenly using various methods like sprayers, irrigation systems, drones etc. to help nematodes reach pest larvae
- Consider follow-up applications based on pest severity and nematode species
- Monitor and adjust your treatment plan as needed
Beneficial nematode products
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Frequently Asked Questions
Nematodes are microscopically small (0.6 to 1 mm), unsegmented worms that occur naturally in the soil throughout the world.
Yes, there are entomopathogenic nematodes (insect parasitic), plant pathogenic nematodes, and saprophytic nematodes. The entomopathogenic nematodes are natural enemies of a lot of insects.
No. Plant pathogenic nematodes cause harm to plants. However, entomopathogenic nematodes are 100% safe for plants, animals and humans. This is because only insects can be host to this group of nematodes. By far the most nematodes belong to the group of saprophytes. These nematodes are harmless and live of dead organic matter to provide a rich soil life.
Nematodes are actively looking for a host or using an ambush strategy to reach their host. Once in contact with a host, they try to penetrate it through a body opening. In the host, the nematodes release a bacterium that can kill the host very quickly. This bacterium also causes the host to be converted into food for the nematodes. This food enables the nematodes to complete their life cycle.
Yes. The most common entomopathogenic nematodes belong to the genus Heterorhabditis or Steinernema. In addition, there are a number of other genera and species, but they are found in much smaller quantities.
No. This group of bacteria is only harmful to insects and cannot survive outside an insect or in warm-blooded organisms.
No. Nematodes cannot survive at very low temperatures and certainly not outside a host. Only if the nematode is in the host and the temperature is not too low is there a small chance that the nematodes can overwinter. However, this is never to the extent that enough nematodes are available in spring to be able to have a sufficiently controlling effect.
It depends. Some pests are susceptible to nematode infection in both larval and adult stages, some only during the larval stages (and some only as adults). As a general rule, nematode are most effective against young larvae, especially in the case of large insects.
In nature they live in soil and are therefore effective against soil pests, but for several above ground pests foliar applications show good efficacy, provided the fields/greenhouses offer the optimal temperature and humidity conditions required. For instance, nematodes can be used against palm tree pests, caterpillars, thrips, Nesidiocoris, asparagus beetle, Tuta absoluta and several fruit moths and beetles.
Nematodes - Application
Please contact your advisor for the pest/target lists. This list is not exhaustive as we are routinely running bioassays to discover new targets.
Nematodes should be applied with water. Once resuspended in water, the nematode suspension can be dispersed using spraying/irrigation systems most commonly used in agriculture and gardens: airblast sprayer, boom sprayer, drones, backpack sprayer, a watering can or others. They can also be dispersed via drip irrigation systems with a preference for high pressure ones and be injected through a Dosatron/Venturi injector. Remove filters if finer than 0.3 mm. If there is any doubt, remove all filters.
The pressure on the nozzle may not exceed 20 bar (190 psi), with conventional large volume nozzles.
Nematodes are sensitive to drought. When they are introduced into a dry substrate/soil they will die. Also when the soil dries out very quickly after application. In addition, they use moisture in combination with soil particles to move. Dispersion is not possible without a water film.
As long as the soil is not dry, the nematodes will survive and search for a host. It is therefore important to leave the soil moist for a few weeks after application of nematodes.
No. In particular in clean rock wool slabs they cannot maintain well and they will flush with the drain. (Pot) soil, on the other hand and if not too dry, is always good.
Heavy clay soil is also not optimum for nematodes. In this case, repeated applications are needed.
Nematodes can also be used against several foliar pests (f.e. caterpillars, thrips). Their efficacy will be strictly connected to survival time on the leaves. To ensure the best results, we therefore recommend to use the nematodes when:
- Relative humidity is high (>75%); early mornings or evenings
- Solar radiation is low; early mornings or evenings
- Temperature is ideally within 15°C – 25°C (59 - 77°F)
- An adjuvant is recommended (ask your local consultants for compatible adjuvants)
Preferably around 15 – 20 °C (59 - 68 °F) but certainly not above 25 °C (77 °F). Above 30 °C (86 °F), nematodes will die quickly.
Be careful with recirculation pumps that may quickly warm up the spray tank water above 30°C, especially in hot seasons.
Once nematodes are resuspended in water, the total volume of the suspension must be sprayed immediately. Therefore a suspension cannot be saved.
If the suspension is not mixed, the nematodes will sink to the bottom and die of oxygen deficiency. Therefore, a suspension must always be kept in motion or aerated.
pH values between 4-8 and EC values up to 5 are safe for nematodes.
Nematodes are quite insensitive to many types of pesticides and can thus be sprayed easily after a pesticide treatment or even sometimes tank-mixed. For a complete list of side effects, check the Koppert Side Effect List or download the app. Tank mix with foliar fertilisers must be avoided.
Under optimum conditions, a nematode can kill an insect in 24-48 hours. Under field conditions, a nematode will first have to look for a host. The effect of treatment is thus strongly dependent on how quickly a nematode has found a host.
Infected larvae will change color because of the growth of the bacteria and nematodes. In case of Heterorhabditis pink-reddish and Steinernema yellow-brownish. Under practical conditions, infected insect larvae will quickly become slimy and thus will no longer be found. In practice, the decrease of pest pressure is the only indication that the application has been effective.
Under the optimum conditions, nematodes can, depending on their energy reserves, stay alive in the soil for a few weeks and look for a host.
Nematodes - Regulations
Nematodes are considered as natural enemies in most countries, so for applying nematodes no license is required.
Nematodes are considered as natural enemies in most countries, so for applying nematodes no license is required. They are therefore exempt of pesticide regulations. However, some countries may require local permits. Check with your local Koppert consultant and/or your local authorities if any doubt.
In many countries they are considered as natural enemies (macro organisms) and can therefore be used in organic farming. Local registration requirements and retail demands can differ, so always check the local situation in your country.
Our nematode products Entonem and Capsanem are OMRI listed, meaning that this formulation has been reviewed by OMRI against the USA and Canadian organic standards. Other products are in the certification process. Please contact the local Koppert subsidiary for more info.
Nematodes - Packaging and formulation
In order for the nematodes to survive during transport and storage they need to be packed in a carrier material. This biodegradable carrier material allows a good solubility and a long shelf life for a living product.
No the carrier material is not harmful to humans.
No the carrier material is biodegradable and not harmful to the environment, fish, micro-organisms and soil organisms. In addition the carrier material disintegrates quickly in the environment, releasing its natural compounds.
Nematodes - Storage
The product must be stored in a ventilated refrigerator between 2-6°C (35-43°F). Upon receipt of the nematodes, generally shipped in cool boxes, it is highly recommended to remove them from the cool box as soon as possible and store them preferably unstacked, in a fridge or a ventilated cold room, between 2 to 6°C (35-43°F). This will maximize the nematodes shelf life. Freezing will be lethal.
If impossible to remove them from the cool boxes, keep the cool boxes lid open upon receipt and place the product in a cold room as soon as possible.
Nematodes can be stored in a ventilated refrigerator until the expiry date. For long storage, it is recommended to avoid stacking up the packs in order to maintain a good air circulation.
No. However, we can no longer guarantee that the indicated numbers of nematodes on the pack are still active. As a result, the efficacy can no longer be guaranteed. It does not mean that, i.e. 1 week after “use by “date, no effects are to be expected.