Fungus Gnat – GNATNEM

Fungus Gnat – GNATNEM


GNATNEM® Fungus Gnat treatment actively seeks out and kills fungus gnat larvae that live in the soil and cause damage to the root system of plants. It is suitable for household pots through to commercial applications. It is used as both a preventative and curative treatment.
Contains: Steinernema feltiae as infective juveniles.

When using as a curative treatment for an existing problem, best results are obtained by two separate applications 10-14 days apart. Ensure that you have ordered enough product to allow for these two applications.

GNATNEM® Beneficial Nematodes (Steinernema feltiae) are natural predators. They have been shown to be the most effective solution for the control of fungus gnats. Easily applied, the microscopic nematodes actively seek out and kill fungus gnat larvae before they do damage, then breed within the dead larvae, and this new generation will emerge to continue the control process. Fungus Gnat larvae cannot develop resistance to Beneficial Nematodes.

These natural predators won’t harm people, pets, plants or beneficial insects or organisms.

Numerous plants are susceptible to damage from Fungus Gnats, especially during their early growth stages.

While adults are more commonly noticed and can be a nuisance, they do little physical damage to the plants, however they can transmit harmful diseases.

The larvae cause the most damage, by feeding on and damaging the root system. This can result in reduced yields, yellowing of plants, or in worst cases can result in the total loss of plants. They also carry fungal spores from plant to plant which can result in the spread of diseases such as Pythium, Phytophthora and Chalara.

Fungus gnats spread through flying adults, and can also be brought onto location through larvae contaminated soil. Adults are able to find their way from outside into growing areas through gaps in protection, and can continually re-infest in this way.

The fungus gnat adults live for about 3 weeks, and will lay around 300 eggs during this time. Generations will overlap, with mixed lifecycles at any one time, which complicates control options. Larvae quickly build up resistance to chemical control methods, and these chemicals can also negatively impact on the plant growth particularly in younger plants.

Apply at a rate of 50 million nematodes per 100 m2 as a curative or 50 million nematodes per 200 m2 as a preventative.

Best results are obtained by scheduled routine preventative treatments. This will not allow populations to build up and damage can be prevented. Season long control can be achieved with regular preventative applications. Preventatively apply once a month as a guide.
For smaller areas or if using for a heavy infestation, apply a third of the pack at a time, 7-10 days apart to ensure that no product is wasted. Application by this method is better than over-applying in a single dose.

Soil temperature should be a minimum of 12C at the time of application for the GNATNEM Fungus Gnat nematodes to be active.

Apply by watering can, pump sprayer or knap sack after removing any fine filters (< 0.5 mm). They can also be applied with some brands of hose end sprayers.

Store any unused product properly sealed and in a household refrigerator (4-8C) for up to 3-4 weeks after arrival. The product must not be frozen at any time. Store lower in the refrigerator away from any chill zones.

Additional information


15 Million (Propagation), 25 Million (Small), 50 Million (Large), 150 Million (Triple Pack), 200 Million (Four Pack)


Contains: Steinernema feltiae as Infective Juveniles.


Ideally, the product should be used when fresh, however with care, this product may be stored flat and properly sealed in a household refrigerator between 4oC and 8oC for up to three weeks. The product must not be stored at less than 4oC for ANY period.

How are Beneficial Nematodes applied?

Beneficial Nematodes are applied like any conventional spray application via a back-pack sprayer, boom spray, watering can or venturi hose end sprayer. Just remove any fine filters (less than 0.3mm). There is no need for any protective equipment as required for chemical applications.

Whilst the application of Beneficial Nematodes is easy, the correct handling of the product and timing of the application is critical to its success. Please read and follow the shipping instructions carefully.

How often will I need to apply Beneficial Nematodes?

A single application will control the current generation of larvae within the growing media. To treat an existing problem, we suggest purchasing enough for a subsequent application in 10-14 days for best results.

As fungus gnats can re-enter, the best approach will depend on individual situations and the user’s past experience. A preventative approach is recommended where fungus gnat adult re-entry is an issue.

When should Beneficial Nematodes be applied?

Beneficial Nematodes can be applied as a preventative treatment (before damage is noticed), throughout the year. Or a curative treatment when damage or adults are first sighted.

Will Beneficial Nematodes damage beneficial soil organisms?

Definitely not! Beneficial Nematodes are naturally occurring organisms that are mass reared. They will not affect earthworms, microbes or any other beneficial organisms.



Handling Instructions:

  1. The product is best used on arrival, however with care, this product may be stored for a limited period.
  2. The nematodes come in a cellulose powder solution and in a dehydrated and hibernated state.
  3. The product may be stored in a refrigerator at between 4oC and 8oC for up to three weeks. The product must not be stored at less than 4oC for ANY period.

Application Instructions:

  1. Only apply Beneficial Nematodes at Do NOT apply outside at other times, even if overcast! Application within a UV filtered environment during daylight hours is ok.
  2. Ensure that the soil temperature exceeds 12o
  3. Ensure that the area to be treated has been irrigated and that the soil is moist.
  4. Allow 20-30 minutes re-hydration before applying nematodes.
  5. Spray the area as evenly as possible. In some cases, greater evenness may be achieved by spraying in a cross-hatch pattern, ensuring that the suspension is agitated or stirred at 5 minute intervals, as the nematodes will settle to the bottom of the vessel.
  6. Irrigate well immediately after treatment, and maintain moist soil conditions for the next 7 to 10 days.

Application Rate:

Curative – When applied as a curative for an existing pest problem, a higher dosage is required as indicated in the treatment application coverage. As a curative, two applications are recommended for best results, to apply half of the quantity ordered on arrival and the other half in 10-14 days. Either make sure you have ordered enough product for this second application or schedule to order again in this period – for best results.

Apply at a rate of 50 million nematodes per 100 m2.

Preventative – As a preventative apply as part of a structured periodic application or in advance of historical seasonal infestations. Apply at a rate of 50 million nematodes per 200 m2.

Apply as evenly as possible with enough water during or after application to maintain a moist environment in the top layers of the growing medium.

Application Methods:

Watering Can

Nematodes are easily applied with a watering can.

  1. Fill a watering can with plain water, and apply to the area to be treated to determine either what percentage of that area it will cover, or measure how many square metres. As an example – if the full watering can covers 1/5 of the area to be treated, you will need 5 full cans for total coverage. If it covers 25m2 out of an area of 125m2, you will need 5 full watering cans.
  2. Using tepid water, prepare for a stock solution easily measurable into the number of watering cans required to assist with even application. For the best ratio we suggest approximately 500ml per standard 9 litre watering can. For the example above, 500ml x 5 cans = 2.5 litres of water required. A used ice cream container is an easy option for the stock solution, or a bucket for larger areas. Add the nematodes to be used to the stock water and gently mix.
  3. Allow 20-30 minutes for the nematodes to re-hydrate.
  4. Agitate the nematode stock solution to re-suspend the nematodes, and add the appropriate proportion of the stock to the watering can. In the above example, this would be 1/5 of the stock, or 500ml. Fill up the can with tap water.
  5. Apply evenly to the treatment area, agitate occasionally to ensure nematodes have not sunk to the bottom of the can to ensure even dispersion.
  6. Repeat steps 4 and 5 until all solution is used, and the total treatment area has been covered.
  7. Ensure all solution is used within one hour of initial stock mixing.
  8. Some carrier cellulose may not fully dissolve and can block watering can holes, so monitor and clear holes as necessary. If the flow from the can is too strong, taping up some of the holes can assist with control.
  9. Once all the solution is used, for best results again lightly irrigate the area that has been treated (a hose is ok) to assist in washing the nematodes into the media.

Hose End Sprayer (Venturi)

Nematodes can be applied with a suitable venturi sprayer with a click on hose fitting. This can be easier for larger areas. A suitable sprayer will have an aperture hole that enters the spray head no smaller than 2.5 mm.

  1. Ensure that all components of the sprayer are properly connected, and pre-irrigate the treatment area with water only in the sprayer only to determine the flow rate and approximate coverage timing. Ensure all the area to be treated has been pre-watered.
  2. As a general guide, a typical sprayer with a 1 litre reservoir will cover 100m2
  3. Using tepid water, prepare a stock solution easily measurable into the number of full sprayer bottles that will be required. For a 1 litre sprayer we suggest no more than 25 million nematodes to 1 litre of water or the mixture will become too thick.

Apply in across hatch pattern by going over the treatment area twice in two different directions.

  1. Continue to spray evenly until all of the product has been used. Agitate by shaking the sprayer regularly to avoid the nematodes settling to the bottom of the reservoir and assist with even application

Pump Sprayer

Nematodes can be applied with a pump up style sprayer using low pressure.

  1. Pre-irrigate the area to be treated well prior to nematode application
  2. Ensure that all filters have been removed.
  3. Add the required nematodes for the intended treatment area to be covered to the sprayer container, and fill with required level of water
  4. Allow to stand for 20-30 minutes for the nematodes to re-hydrate
  5. Continue to spray evenly until all the product has been used. Make sure that you shake or otherwise agitate the solution every couple of minutes to aerate the solution and stop the nematodes settling to the bottom.
  6. Lightly irrigate with clear water within 30 minutes of applying to avoid nematodes drying out on the surface of the media or the foliage.




GNATNEM® is available all year. During periods of high demand, slight delays in product availability may be experienced.


Whilst the product is best used fresh, it can be stored flat in a refrigerator at between 4 and 8 degrees celsius for 3-4 weeks. Door racks are best to avoid any chance of product freezing. This product must not be frozen for ANY period.



  • Only apply Beneficial Nematodes at dusk outdoors. Do NOT apply at other times, even if it is overcast, as they cannot tolerate high UV light ie direct sun. If applying within a UV protected greenhouse, this restriction does not apply.
  • Do not apply when the ambient air temperature exceeds 32°C, or the soil temperature exceeds 25°C or is below 12°C as the nematodes will become stressed or will be inactive.
  • Avoid high or drying winds as this will dehydrate the nematodes.
  • Ensure treated area is irrigated both before and after application as the nematodes require moisture for movement and need to be washed off into the soil where the pest is.
  • Apply your nematodes as evenly as possible as they don’t travel far.
  • Maintain moist soil conditions for not less than two weeks after treatment (to ensure a favourable environment for the second generation).



  • Safe for the environment & the family
  • Seek out prey
  • Combat’s chemical resistance
  • These natural predators won’t harm people, pets, plants or beneficial insects
  • Easy to apply
  • Non – polluting



Plant Parasitic Nematodes have a stylet or spear at their head end, rather like a hypodermic syringe, which is used to pierce plant cells and then suck out fluids from within the cells.

The Beneficial Nematodes have no such stylet, and are about as similar to plant parasitic nematodes as human beings are to goldfish.



Definitely! Beneficial Nematodes are naturally occurring organisms that are mass reared.

They will not affect earthworms, microbes or any other beneficial organisms.

They are “totally safe”. The APVMA has exempted Entomopathogenic Nematodes from registration in Australia. The Beneficial Nematodes are supplied in a cellulose-based carrier.



Beneficial Nematodes are resistant to most chemicals as they are protected as infective juveniles by a sheath.

Even chemicals that have shown an effect have only had a transient effect if placed in contact with for a short period of time. pH will have no affect and Electrical Conductivity (EC) is not an issue with the infective juveniles.



At low temperatures the nematodes will be inactive but will resume activity once temperatures have risen. They will only be permanently harmed if frozen.

At too high a temperature, the nematodes will dry out and can perish.

Consider that soil media temperatures will probably be higher than air temperatures in most cases.



Beneficial Nematodes are supplied in a cellulose-based carrier and can be applied with any equipment traditionally used for spray applications. Always remove filters finer than 0.5mm (500mm). They can be applied with a watering can, pump sprayers, trigger sprayers or simple click on, hose end venturi sprayers.

Stir every 5 minutes where agitation doesn’t exist as they will settle.



Beneficial Nematodes move around in a film of moisture. Applying with more water is better but consider that you need to deliver the nematodes near the surface for some products.

The other important point is to apply the correct amount of nematodes as evenly as possible over the given area with enough water to achieve permeation and not excessive run off.

Beneficial Nematodes will work best in moist soil, bare ground, and in areas with minimal vegetation.

They are reported to work great in kennels with cement floors. The ground must be kept wet so a quick daily spraying would be beneficial.



The key to prolonged success is the application of routine and preventative treatments. As fungus gnats can move in from untreated areas, and have several generations present at once, the problem can arise again.  A routine scheduled application can assist for continued control and damage minimisation.



The Beneficial Nematodes attack the Fungus gnat larvae stage within the soil to stop the life cycle. Adults may still be present due to emergence prior to treatment. They may also be entering the area from an untreated area, either internal or external.



You sure can!  

Please call 02 6284 3844, or send us an email via the Contact Us function


GNAT Brochure PV2

Application & Handling Termite 50M

Coverage m2

Propagation Pack –               $44.00 – Covers 25/50m2
Small Pack –                          $66.00 – Covers 50/100m2
Large Pack –                          $99.00 – Covers 100/200m2
Large Triple Pack –              $264.00 – Covers 300/600m2
Large Four Pack –               $308.00 – Covers 400/800m2


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