Is your lawn turning yellow, developing bare patches or being dug up by birds and wildlife? Leatherjackets or chafer grubs could be responsible.
Both pests can damage lawns by feeding on grass roots, but they are different insects and require different nematode treatments.
In this guide, we explain how to identify leatherjackets and chafer grubs, recognise the signs of damage and use beneficial nematodes to help control them naturally.
Leatherjackets vs Chafer Grubs: What's the Difference?
| Feature | Leatherjackets | Chafer Grubs |
|---|---|---|
| Appearance | Grey-brown, legless larvae | Cream-white, C-shaped grubs |
| Legs | No legs | Three pairs of legs |
| Adult insect | Crane fly | Chafer beetle |
| Damage | Grass roots and sometimes shoots | Grass roots |
| Common signs | Yellowing, thinning grass | Yellow or loose patches of turf |
| Treatment | Leatherjacket nematodes | Chafer grub nematodes |
| Typical treatment period | Late summer to autumn | Late summer to early autumn |
Treatment timing depends on the pest, soil temperature and nematode product being used. Always follow the instructions supplied with your treatment.
What Are Leatherjackets?
Leatherjackets are the greyish-brown, legless larvae of crane flies, commonly known as daddy long legs.
Crane flies typically lay their eggs in lawns and grassy areas during late summer and autumn, although the exact timing varies by species and weather conditions.
After hatching, the larvae feed on grass roots and sometimes shoots. Feeding can continue through autumn, winter and spring, weakening the grass and making it more vulnerable to dry conditions.
Leatherjackets may also be found in flower beds and other areas of the garden.
How to Identify Leatherjacket Damage
Leatherjacket damage is often noticed from autumn through to spring, when the larvae are feeding.
Common signs include:
- Yellowing or thinning patches of grass.
- Weak grass that pulls away easily from the soil.
- Poor root growth and areas of damaged turf.
- Birds or other wildlife searching the lawn for larvae.
Damage may be more noticeable after mild, wet autumn weather, which can favour leatherjacket activity.
To check for leatherjackets, carefully lift a small section of affected turf and inspect the soil beneath it. Look for greyish-brown, legless larvae.
When Should I Apply Leatherjacket Nematodes?
Leatherjacket nematodes are generally most effective when applied while the larvae are young and actively feeding, often during late summer and autumn.
Depending on the product and conditions, treatment may also be possible in spring. However, older larvae can be harder to control.
Check the recommended soil temperature and application period on your nematode packaging before treating your lawn.
How to Apply Leatherjacket Nematodes
Beneficial nematodes are microscopic organisms that seek out susceptible leatherjacket larvae in the soil. Once they enter a suitable host, they release associated bacteria that help kill the pest.
For effective application:
- Check that the soil temperature is suitable for your nematode product.
- Water the lawn beforehand if the soil is dry.
- Mix the nematodes with water according to the packet instructions.
- Apply evenly using a suitable watering can or compatible applicator.
- Water the treated area as directed to help the nematodes reach the soil.
- Keep the soil moist for the period recommended on the packaging.
Applying nematodes during the evening or in overcast conditions can help reduce exposure to strong sunlight and drying conditions.
Need to treat leatherjackets? Shop Leatherjacket Nematodes.
What Are Chafer Grubs?
Chafer grubs are the larvae of chafer beetles. They are creamy-white, usually curved into a C-shape, with brown heads and three pairs of legs near the front of their bodies.
Adult chafer beetles lay eggs in the soil during the warmer months. After hatching, the larvae feed on grass roots and can cause significant damage to lawns.
Different chafer species have different life cycles, so the best treatment period can vary.
How to Identify Chafer Grub Lawn Damage
Chafer grubs feed on grass roots, which can weaken the lawn and cause yellow or brown patches to appear.
Signs of an infestation may include:
- Yellowing or dying patches of grass.
- Loose turf that can be lifted easily.
- Reduced root growth beneath affected areas.
- Birds, badgers or foxes digging up the lawn to feed on grubs.
To confirm whether chafer grubs are present, carefully lift a section of affected turf and inspect the soil around the roots.
Look for creamy-white, C-shaped larvae with brown heads and three pairs of legs. Unlike leatherjackets, chafer grubs have visible legs.
How Do Nematodes Control Chafer Grubs?
Chafer grub nematodes seek out susceptible chafer larvae in the soil. They enter the grubs and release associated bacteria that kill the host.
Successful treatment depends on using the correct nematode species, applying it when the grubs are at a susceptible stage and providing suitable soil conditions.
When Should I Apply Chafer Grub Nematodes?
Chafer grub nematodes are generally applied in late summer or early autumn, when young grubs are present near the soil surface.
For many UK lawns, the treatment period falls around late July to September, but this can vary depending on the chafer species, weather conditions and product instructions.
Check the recommended soil temperature and treatment window for the nematodes you are using.
How to Apply Chafer Grub Nematodes
Chafer grub nematodes are normally mixed with water and applied to the affected lawn.
- Check the recommended soil temperature and application instructions.
- Make sure the lawn is moist before treatment.
- Mix the nematodes with water as directed on the packaging.
- Apply evenly across the affected area using a suitable applicator.
- Water the lawn afterwards if instructed.
- Keep the soil moist for the recommended period to support nematode activity.
Evening or overcast conditions are often preferable because the soil is less likely to dry out quickly.
Found chafer grubs in your lawn? Shop Chafer Grub Nematodes.
Frequently Asked Questions
Can leatherjackets and chafer grubs be found in the same lawn?
Yes. Both pests can occur in the same lawn. It is important to identify which larvae are present before choosing a nematode treatment, as they require different products.
Will nematodes repair my damaged lawn?
Nematodes help control susceptible pest larvae, but they do not repair grass that has already been damaged. Once the pest problem is under control, the lawn may need time to recover. Severely affected areas may benefit from reseeding and appropriate lawn care.
How long does it take for nematodes to work?
Nematodes can begin infecting susceptible larvae after application, but visible improvements to the lawn may take longer. Results depend on the pest, treatment timing, soil conditions and the extent of the damage.
How should I store nematodes before use?
Follow the storage instructions supplied with your nematodes. Many products require refrigeration and must be used before the expiry date. Do not freeze them, and avoid exposing them to high temperatures.
Are beneficial nematodes safe around children, pets and wildlife?
Beneficial nematode products used for garden pest control are generally considered safe around children, pets and non-target wildlife when used according to the manufacturer's instructions.
Choose the Right Nematode Treatment for Your Lawn
Leatherjackets and chafer grubs can cause similar lawn damage, but identifying the correct pest is the first step towards choosing an effective treatment.
If you find grey-brown, legless larvae, you may be dealing with leatherjackets. If you find creamy-white, C-shaped grubs with legs, chafer grubs are more likely.
At Gardening Naturally, we offer beneficial nematode treatments to help control a range of common garden pests.
Browse our full range of nematodes to find the right treatment for your garden.
For more advice, read our All About Nematodes guide, covering how nematodes work, how to apply them and frequently asked questions.