What are Leatherjackets? Identifying and treating lawn damage

Leatherjackets are the larvae of the crane fly (daddy longlegs) and one of the most damaging lawn pests in the UK. They feed on grass roots from autumn through to spring, cutting plants off below the soil surface and causing irregular patches of yellowing, dying turf. Treatment is most effective from mid-September to October, when larvae are recently hatched, small, and close to the surface.

What do Leatherjackets look like?

Leatherjackets are grey-brown, legless grubs with a tough, rubbery skin and no visible head. They typically grow to 2.5–3 cm when fully developed. Their tough skin is how they got the name "leatherjackets".

What do Leatherjackets turn into?

Leatherjackets turn into crane flies, also known as daddy longlegs. The adults emerge in late summer, mate and lay their eggs in the lawn, starting the cycle again.

Leatherjackets vs. chafer grubs: how to tell the difference

Both are common lawn pests, but they are different insects with different treatment approaches.

Leatherjackets

• Colour: grey-brown
• Legs: none
• Body shape: straight and cylindrical
• Head: no visible head
• Size: 2.5–3 cm
• Peak damage: autumn to spring

Chafer grubs

• Colour: cream or off-white
• Legs: three pairs
• Body shape: C-shaped
• Head: visible brown head capsule
• Size: 1–2.5 cm, depending on species
• Peak damage: late summer to autumn

Signs of Leatherjackets in your lawn

Look for these signs:

• Irregular yellow-brown patches appearing from late summer onwards
• Grass that pulls away easily from the soil with no roots attached
• More birds on your lawn, such as crows, magpies, rooks and starlings, or foxes digging. They're hunting for grubs just below the surface.
• Damage that worsens in wet autumns following a dry summer

To confirm: cut a square of turf (approx 30 cm x 30 cm), peel it back and inspect the top 5 cm of soil. If leatherjackets are present, you'll find grey-brown legless grubs just beneath the surface. Alternatively, lay a sheet of black polythene over the affected area overnight. Grubs will surface and can be seen the following morning.

If you find cream-coloured grubs with legs and a C-shaped body, you're dealing with chafer grubs instead, and the treatment approach is different. (Link "chafer grubs" to your chafer grub blog.)

Why do some years have worse Leatherjacket infestations than others?

Leatherjacket populations are heavily influenced by autumn weather. Crane flies lay their eggs in late summer, and those eggs need moist soil to survive. A warm, wet September and October creates ideal hatching conditions, and significantly more larvae make it through to winter. Cold, dry autumns tend to result in lower populations. This is why some years see widespread lawn damage across the UK while others pass without issue