
Description
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.
Please note: there is a two week turnaround for delivery on this product.
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. A secondary application in the spring, once soil temperatures exceed 12°C, is possible for serious infestations but efficacy will be reduced due to the stage in the lifecycle of both the pest and the nematode at this time.
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.

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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.
Leatherjacket Life Cycle

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
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1. 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. |
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2. Store Store in a refrigerator at a temperature between 2-6°C. |
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3. Monitor
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4. Irrigate
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5. 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
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6. Equipment
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7. Nematodes
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8. Application
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9. Post Application
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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.
For further information regarding Nemasys Leatherjacket Killer, please contact our technical sales team on 01952 641949.