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Nemasys Leatherjacket Killer (500 m2)

Nemasys Leatherjacket Killer is a leatherjacket treatment containing Steinernema feltiae a species of native entomopathogenic nematode (microscopic worms) which controls infestations of crane fly larvae (daddy long-legs) naturally, safely, and effectively.

There are two application windows in the pests life cycle suitable for applying a leatherjacket treatment. The first window is during the late summer/autumn, from early August to the end of October, with the second window the following spring during March and April.

For best results apply Nemasys leatherjacket treatment to moist turf areas from early August to late October as this targets the pest early in its life cycle when it is more susceptible to control.

For more in depth information, please read the Integrated Management Strategies For Maximising The Efficacy Of Entomopathogenic Nematodes document.


The below infographic is designed to inform the user as to the life stage of the organism throughout the year.

These application windows coincide with the larvae being at a young and susceptible life stage and the soil temperature being above 12ºC, which is the minimum point the nematodes are at their most active in the soil.

During the spring window the larvae will have grown to a stage where effective control of any type is significantly reduced. As a result it is important to note that the required application rate is higher for the spring window compared to the late summer into autumn window.

This means that a pro-active preventative approach to controlling crane fly larvae in turf areas is required. By treating with Nemasys Leatherjacket Killer in the August to the end of October application window, direct damage from the grubs and indirect damage from predators hunting for them in the following spring and summer is avoided.

Chafer Grub - Nematodes Life Cycle

Click to Enlarge

The nematodes work in the soil by seeking out the crane fly larvae and attack the pest by entering natural body openings. Once inside, they release bacteria (Xenorhabdus spp.) that stops the pest from feeding, quickly killing the larvae.

The nematodes then reproduce inside the dead larvae and release a new generation of infective juvenile nematodes. These infective juveniles then disperse into the soil and search for further prey. If sustained this life cycle can lead to significantly reduced leatherjacket populations in subsequent years.

Nemasys Leatherjacket Killer must be used within 3-4 weeks of being received, keep refrigerated until used.

Each pack of Nemasys Leatherjacket Killer contains 250,000,000 nematodes and treats up to 500m2.

We do not sell this product during the period when the larvae are not susceptible to control using nematodes.

To facilitate application at a volume of 2000 ltr/ha the following nozzle is recommended: Flat Fan Nozzle ISO Light Blue 10F110.


Leatherjacket Life Cycle

Leather Jacket Life Cycle Diagram

Further information on the control of leather jackets and chafer grubs with biological controls can be found within this article


How to Apply Nemasys Leatherjacket Killer

Application Rates

  • OPTIMAL CONTROL Window 1 - August to the end of October: 1 pack per 500 square metres.
  • REDUCED CONTROL Window 2 - March and April: 1 pack per 250 square metres.

NOTE: Soil temperatures must always be at least 12ºC at the time of application.


Preparing to Apply Nematodes
1. Order 1. Order Order
Order nematodes to arrive 1-2 weeks prior to forecast application period* to facilitate application in optimum circumstances.
*Aim to apply nematodes 4-5 weeks after peak adult flight time.
2. Store 2. Store Store
Store in a refrigerator at a temperature between 2-6°C.
3. Monitor 3. Monitor Monitor
  • Aim to apply nematodes 4-5 weeks after peak adult flight time.
  • For summer/autumn applications ensure that the soil temperature is > 13°C.
  • For spring applications (chafer grubs only) ensure that the soil temperature is > 8°C.
  • Aim to apply in the morning, in the evening or on a cloudy day.
  • Aim to apply when rain is forecast.
4. Irrigate 4. Irrigate Irrigate
  • Apply 5-10 mm water the evening before treatment.
  • Apply a further 5 mm of water 1-2 hours before treatment.
5. Aerate 5. Aerate Aerate
Use a sarel roller to aerate the soil, facilitating faster movement of the nematodes through the soil profile.*
* It is important that the nematodes come into contact with the soil as quickly as possible; excessive thatch will inhibit this process.
Applying Nematodes
6. Equipment 6. Equipment Equipment
  • Remove all filters from the application equipment. Checking:
    • Lance handle,
    • Top hat filters at the nozzle,
    • Filter bowls within pipes after the pump.
  • Use a suitable nozzle i.e. flat fan nozzle with coarse droplet size.
  • Ensure sprayer is completely clean then fill with half the required amount of clean water.
7. Nematodes 7. Nematodes Nematodes
  • Place the contents of the pack into a clean bucket containing 5 litres of water.
  • Stir well and allow to soak for 20-30 seconds.
  • Stir again and pour the entire solution into the spray tank through its sieve.
  • Top up until the required amount of solution is in the tank.
8. Application 8. Application Application
  • Spray nematode solution immediately onto the prepared surface using a maximum of 12 bar pressure.
  • Apply with a penetrant wetting agent to improve passage into the soil.
9. Post Application 9. Post Application Post Application
  • Irrigate immediately after application using 2-5 mm water to help wash the nematodes into the soil.
  • Ensure the area is kept moist for at least 2 weeks post application.


This product is a biological control which is fully compatible with an Integrated Pest Management (IPM) programme.

  • This product is harmless to people, animals and the environment.
  • Biological controls are living organisms, as a result the exact timing of availability and application may differ according to local environmental conditions. This may cause a slight variance in the life cycle of the target pest species from year to year. Users are advised to closely monitor their local site for signs of pest appearance, susceptible life stages and crop damage.
  • Due to the fact that biological controls contain living organisms they have a short expiry date and should be refrigerated prior to use.

To aid the efficiency of the nematodes into the soil profile, apply with Premier Hydrate Wetting Agent.


For further information regarding Nemasys Leatherjacket Killer, please contact our technical sales team on 01952 641949.




Discounts available on multiple / bulk purchase of these products. Contact the office on 01952 641949.