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Fungus Fly Killer Nematodes


What Are Fungus Gnats?

The Fungus Fly, also known as the Sciarid Fly, can cause severe damage to many plants including house plants and plants being propagated. These tiny flies will lay eggs in compost or soil, from which larvae develop. The larvae often feed on young plants and seedlings at propagation and are a very common pest in house plants. Damp conditions and organic plant matter will provide an ideal breeding ground for the larvae, which will feed on plant roots causing damping off and seedling collapse. The larvae, at large numbers, can also spread soil-borne diseases such as Pythium. Once the larvae develop into adults they become nuisance pests, forming small clouds of flies when disturbed. 

What Are Fungus Fly Killer Nematodes & How Can They Help?

Fungus Fly Killer contains Steinernema feltiae nematodes for the effective biological control of Fungus / Sciarid Fly. The nematodes enter the larvae via a natural opening, like the mouth, and feed on the contents of the larvae. A natural bacterium is produced by the nematodes inside the larvae, which kills it. Infected larvae will be completely broken down by the nematodes. The nematodes also reproduce inside the larvae, releasing more nematodes into the surrounding area. 

When Should I Apply The Nematodes?

Apply your Fungus Fly Killer Nematodes when damage to plants is observed or when Fungus Fly activity has been observed. Fungus Fly can occur all year round and can be treated at any time they occur.

How Many Nematodes Do I Need?

The Fungus Fly Killer Nematodes are available in 6 different pack sizes as detailed below:

- 1 x 5 million nematodes to treat up to 10m2 (or up to 25 house plants)

- 1 x 10 million nematodes to treat up to 20m2 (or up to 50 house plants) 

- 1 x 25 million nematodes to treat up to 50m2

- 2 x 25 million nematodes to treat up to 100m2

- 1 x 250 million nematodes to treat up to 500m2

- 2 x 250 million nematodes to treat up to 1000m2

What Conditions Do The Nematodes Require?

Choose a humid or wet day to apply your Fungus Fly Killer Nematodes. Nematodes are UV-sensitive and will not survive long when exposed to bright, sunny conditions. Apply the nematodes early in the morning or early in the evening in order to utilise the optimum humidity levels.

Soil or compost temperatures should be above 10℃ for the nematodes to be active. 

How Do I Apply The Nematodes?

For small packs (5 and 10 million):

1. Open and empty contents of the 5 million sachet into a 0.5 litre (500ml) bucket, or container, of lukewarm water and mix thoroughly. For a 10 million unit mix the solution in a 1 litre bucket (1000ml) and mix.

2. Add nematode concentrate to a watering can and add water. This should be at least 0.5 litre of water for the 5 million pack concentrate, and add at least 1 litre of water for the 10 million pack concentrate.

3. Mix the concentrate solution and extra water for one minute to distribute the nematodes evenly in the solution. Apply immediately after mixed.

4. Pour and apply the solution into the Houseplant pots, seed trays, or containers, directly into the growing media / compost, using all the solution between the treated pots.

For larger packs (25 million plus):

1. Open and empty the contents of your 25 million sachet of nematodes into a bucket or container of 2.5 litres of water and mix thoroughly.

2. Add 0.5L of the nematode concentrate to a watering can or sprayer (hand held sprayers should suffice, with filters removed, or use our specific nematode applicator, the Nema Super Sprayer, for optimum nematode application) with up to 8L of water.

3. One pack of 50sqm nematodes will make 5 watering cans (including concentrate solution).

4. Spray the soil or compost and ensure plenty of the solution is applied directly onto the Fungus Fly larvae. If applying to pots, make sure nematode solution reaches root zone at the bottom of the pots. 

One watering can treats up to 10sqm, and the entire solution treats up to 50sqm.

Ensure the soil is moist for 2 weeks since application.

Repeat applications may be required after 4 weeks to prevent the build up of fresh Fungus Fly larvae.

Full application instructions are provided on delivery. 

Can I Store Nematodes?

You can store unopened nematode packs in a fridge but it is best to ensure you apply your nematodes as soon as possible for the best results.

Fungus Fly Killer Nematodes are harmless to humans, pets and wildlife, and safe to apply to edible plants.

Use Our Yellow Sticky Traps To Catch Adult Fungus Flies

Black adults of Fungus / Sciarid Fly can reach high levels. It is best to use some of our yellow sticky traps in combination with your nematode treatment to prevent the build up of a large infestation. See our Eco Sticky TrapsYellow Sticky TrapsExtra Large Yellow Sticky Traps, or our Mini Sticky Traps (for smaller pots).

See Also Our Hypoaspis Miles Predators For Complete Fungus Fly Protection 

Hypoaspis miles are small predatory mites that inhabit the soil or compost surface around the plant stem and feed on the eggs and larvae of Fungus / Sciarid Flies. Utilise these predators in combination with your Fungus Fly Killer Nematodes for the complete protection against Fungus Fly infestation. The Hypoaspis miles product listing can be found here.

Customer Reviews

Based on 9 reviews Write a review

Customer Reviews

Based on 21 reviews

just thought there be more of it

Hi Annette,

Thanks you for your comments and for shopping with us. We have changed the formulation of our nematodes so they are supplied with less excess carrier material. The nematodes were previously packaged in a clay based formulation but are now supplied in a gel. This gel leaves virtually no residue following application and is also 100% organic, containing no microplastics. Alternative suppliers may still package their nematodes with bulkier carrier material but this does not mean there are a higher quantity of nematodes contained within. Our nematode counts remain the same but we have simply disregarded the excess carrier material in favour of a more eco-friendly and cleaner solution. I hope your application and treatment was successful, and if you require any further assistance please just let our brilliant customer service team know and they'll be happy to help.

Kind regards, Julian Ives [Director, Dragonfli]


Excellent cleared all the fungus gnats within 2 weeks.


Problem sorted, thanks very much!

Saved my plant from the bin!

I had a problem plant in the office for months and nothing would get rid of them, sprays were useless. It was on the verge of being thrown out the window by staff when the flies exploded in population. One shot of this and they were gone within days, to be fair I did use the whole packet on one plant. Worked perfectly!


Worked really well.