Beneficial Nematodes

What are nematodes?

There are thousands of species of nematodes ranging in size from microscopic to around 1mm in length. They’re often referred to as roundworms though are not closely related to worms. They are multicellular with smooth, unsegmented bodies. They occur naturally in the soil all over the world. They come in various forms including: entomopathogenic (insect parasitic), plant pathogenic nematodes and saprophytic nematodes.
 

What are beneficial nematodes?

Beneficial nematodes (the entompathogenic nematodes) are used in horticulture as a parasite to control invasive insects without any harmful effects on plants, humans, pets or other non-targeted animals and insects. The most common forms of these entompathogenic nematodes are Heterorhabditis and Steinernema.
 

What do beneficial nematodes kill?

There are a vast range of beneficial nematodes, each suited to a particular pest including ants, chafer grubs, fruit flies, carrot root fly, onion fly, goose sawfly, codling moth, leather jackets, slugs, vine weevils, box tree caterpillar, chrysanthemum leaf miner, diaspid scale insects, glasshouse mealybug, glasshouse red (two-spotted) spider, mite, glasshouse whitefly, sciarid fly / fungus gnat larvae, Soft scale, thrips, Cutworms and Wireworm
 

How do beneficial nematodes work?

Beneficial nematodes locate their hosts by detecting carbon dioxide and other waste products. They enter the target host via any available orifice and then release bacteria that multiplies and causes blood poisoning within the host. This leads to a swift death, usually within 24 to 48 hours. This process also converts the host tissue into nutrients that the nematode then feeds on and in turn breeds. As the food source becomes scarce, they move on in search of a new host, leaving no remnants of the original host, unlike chemical based pest control that leaves dead pests
 

Are the released bacteria harmful?

The bacteria cannot survive outside the host and so are not harmful to other organisms or warm-blooded organisms
 

Do nematodes die?

Nematodes can exist for a few weeks at most outside the host body; once they’ve killed off all their host insects they die too. This means repeat applications are required should the pests return. They will also die quickly in temperatures above 35 degrees Celsius
 

Will fertiliser kill nematodes?

Because of its high nitrogen content, fertiliser can reduce the beneficial nematode effectiveness. For this reason, manufacturers recommend that fertiliser not be used two weeks prior to and after nematode application
 

Is there a downside to nematodes?

Whilst they’re beneficial in getting rid of unwanted pests, you need to do your homework to make them effective. You need to ensure that you get the right species for the insect you’re targeting. In addition, as they prey on the larvae stage of the insect, you must learn when the larvae are present. You also have to follow the storage and application instructions meticulously for optimum eradication success
 

How long do beneficial nematodes live?

They have a shelf life of about 2 to 3 months at around 21 degrees Celsius and around 18 to 20 months in a refrigerator at 1 to 2 degrees. However, this varies significantly depending on how they are stored be it a solid formula or powdered form. Each branded product will detail the life expectancy of the nematodes and proper storage instructions
 

Will pesticides kill beneficial nematodes?

Rather than killing the nematodes, some pesticides, when mixed with nematodes, actually provide a better combination killer of insect pests at a reduced cost and with easier application. However, the downside to this is that you need to know which products will work together as they’re not all compatible – you’ll need to research which pesticide to use with which beneficial nematode species before application
 

Can beneficial nematodes harm humans?

These nematodes only target specific insect groups so are not harmful to humans or pets
 

How do you apply nematodes?

• The soil should be moist before application
• Application can be made using standard spray equipment, lances, irrigation lines or even watering cans. Nematodes are quite resistant to pressure so won’t be harmed by the pressure in hydraulic spray equipment as long as it’s below 300psi. However, you need to follow the manufacturers guidelines and follow a few sets of rules:       
  • Spray equipment must be cleaned thoroughly before use with nematodes as chemical residues may be detrimental to them
  • Fine filters should be removed as these can create blockages when applying nematode products
  • If applying via irrigation lines ensure these are free of deposits that may cause blockages     
  • Water temperature should be between 5 and 25 degrees Celsius   
  • The water tank must be constantly agitated throughout the process as nematodes settle out very quickly at the rate of approximately 1cm/minute     
  • It is standard to apply drench treatments at between 5% and 10% of pot volume. For example, a 1 litre pot would require a drench of 50ml to 100ml of diluted product
• Soil temperature should be between 10 and 30 degrees Celsius for at least two weeks after application otherwise the nematodes may perish

 

When should you apply nematodes?

Nematodes are recommended for use whenever larvae or grubs are present. Generally, this is during spring and autumn. However, this can depend upon a number of factors including the type of nematode. They should be applied either early morning or late evening to protect them from them from UV light and drying out
 

Can you mow after applying nematodes?

You should wait a day before cutting the grass after applying nematodes to give them time to find the grubs and begin their work
 

Can you apply nematodes in the rain?

As nematodes like moisture it’s fine to apply them whilst it’s raining. If it hasn’t rained make sure to water the ground thoroughly both before and after application
 

Can you apply beneficial nematodes in the summer?

These can be applied during the summer months but because they’re very sensitive to UV light and temperature, you should apply early morning or late evening when it’s darker and cooler
 

At what temperature do nematodes die?

Nematodes die below 5 degrees Celsius and above 35 degrees Celsius
 

Do beneficial nematodes survive winter?

Nematodes will only survive the winter in a dormant state if the temperature is above 5 degrees Celsius though without a food source to sustain them they will quickly die off
 

Do nematodes kill beneficial insects?

No, they only target specific pests so you must have the right type of nematode for your species of pest. They won’t target other pests or beneficial insects
 

Which nematodes to use for black vine weevils?

ICL Vine Weevil Seeka CT contains the Steinernema kraussei nematodes and provides effective control of black vine weevil larvae in cold to warm temperature ranges of 5 degrees to 30 degrees Celsius. The ICL Vine Weevil Seeka contains the Heterorhabditis bacteriophara nematodes (82%) and an inert carrier with water (18%). It provides control in soil or container-grown crops between 12 and 30 degrees Celsius. These are available in 50 million and 250 million nematode packs

ICL Transporter can be used to optimise the ICL Seeka nematode penetration. ICL's revolutionary penetrant formulation which aids nematode dispersion within the growing media following application. Transporter is a blend of soil surfactants which optimise the distribution of water allowing for a more even spread of your nematode application, putting the nematodes where they are needed and therefore reducing waste

Fargro provide two brands for vine weevil control – Nemasys L and Exhibitline H. Nemasys L contains the Steinernema kraussei nematodes and is an efficient killer that is active down to temperatures as low as 5 degrees Celsius. This makes it ideal for use from early spring onwards. The Exhibitline H contains the Heterohabditis bacteriophara nematodes and works at temperatures above 12 degrees Celsius. This turns larvae red as it kills them which can be a useful indication of treatment success. For both these products the 50 million pack treats up to 100m2 in pots or 50m2 in open ground. The 250 million pack treats up to 500m2 in pots or 250m2 in open ground. They give control for 4-6 weeks as part of a programme for Vine Weevil control
 

Which nematodes to use for Sciarid fly / fungus gnat larvae?

ICL Fungus Gnat Seeka contains the beneficial nematode Steinernema feltiae. It provides control of fungus gnat larvae as well as Western Flower Thrips and works between temperatures of 10 and 30 degrees celcius. The product is available in units of 50 million and 250 million nematodes. ICL propose a year round application, applied at various intervals throughout the year

Bioline Exhibitline Sf contains the insect pathogenic nematode Steinernema feltiae, as infective juveniles. The nematodes move through water films around soil particles and actively seek out Sciarid fly larvae and fungus gnat larvae. This product is available in units of 50 million, 250 million or 1,250 million nematodes in an inert carrier in sealed trays. They give control for up to 6 weeks protection
 

Which nematodes for leather jackets and cutworms?

Bioline Exhibitline Sc contains Steinernema carpocapse that works at temperatures above 12 degrees Celsius.

Fargro also provide Exhibitline SC that contains Steinernema carpocase.
 

Which Nematodes do we supply?

We can supply a vast range of Beneficial Nematodes including ICL Vine Weevil Seeka CT, ICL Vine Weevil Seeka, ICL Fungus Gnat Seeka, Fargro Nemasys Fruit & Veg, Hb, L, Sc, Sf, Fargro Exhibitline Hb, SC, SF

Contact us for further information on our full range of Beneficial Nematode and other pest control products.