Article

Leatherjackets and Chafer Grubs – Understanding their lifecycle

Published on 9th January, 2026 by Kate Treen - 4 min read

Leatherjackets and chafer grubs are two of the most damaging lawn pests. Understanding their lifecycles is key to controlling them.

Before we dig into the lifecycles of leatherjackets and chafer grubs, here’s a quick reminder of their key differences:

Feature	Leatherjacket	Chafer Grub
Adult form	Crane fly (daddy long legs)	Chafer beetle
Larval appearance	Legless, greyish brown, tubular (leathery)	C-shaped, creamy white, distinct legs, orange/brown heads.
Lifecycle duration	1-2 years	1-5 years
Primary feeding	Autumn and spring	Late summer, autumn and spring
Visible lawn damage	Yellow/brown drying patches of grass that is easily pulled up.	Similar dying patches, but the turf amy easily be rolled back like a carpet due to severed roots.
secondary damage	Birds (crows, starlings) and mammals (foxes, badgers) that tear up the lawn looking for grubs.	Birds (crows, starlings) and mammals (foxes, badgers) that tear up the lawn looking for grubs.

Leatherjackets are typically 30mm-40mm long

Chafer grubs are usually seen in a C-shape and grow to around 20mm.

Both of these grub pests have the potential to cause and trigger extensive lawn damage. They both live in the soil, and they both eat the roots of grass.

The weakened grass attracts birds and mammals who can easily rip it up to get at the grubs below. This secondary damage can destroy a lawn completely.

Secondary lawn damage from birds and mammals can destroy lawns

Both pests can be controlled with chemical or biological controls at different times of year. Let’s look at their lifecycles and when to apply which control.

Leatherjacket Lifecycle

Stage	Typical timing	Activity	Control
Adult crane fly	July-end-August	Adults emerge from the soil and mate. Females lay their eggs in the turf. They do not feed and only live for a few days.	Acelepryn (professional use only). Effective when used prior to egg hatch.
Egg	Late summer / early autumn	Eggs hatch a few weeks after being laid.	Not effective
Larva (leatherjacket)	Autumn through to the following summer	This is the destructive stage. The larvae hatch and begin feeding on grass roots. They reach their largest and most damaging size in late spring/early summer the following year.	Nematodes. Can be effective when applied during September and October. Acelepryn can be used to control the young grubs straight after hatching, so should be applied before egg laying.
Pupa	Mid to late summer	The fully grown larva pupates in the soil before the adult fly emerges to start the cycle again.	Not effective.

Chafer Grub Lifecycle

Stage	Typical timing	Activity	Control
Adult chafer beetle	Late spring / early summer	Adults emerge from the soil, often swarming to mate. Females lay clusters of eggs a few inches deep in the soil.	Chafer Beetle Traps Uses a pheromone lure to attract the adult beetles.
Egg	Late spring / early summer	Eggs hatch within a few weeks	Not effective
Chafer grub	Summer to the following spring	This is the main damaging stage. Young grubs hatch in mid-to-late summer and feed voraciously on grass roots and organic matter near the surface. As temperatures drop, they burrow deeper into the soil to overwinter. They return to the surface to feed heavily in the spring.	Nematodes Can be effective when applied July to October. Acelepryn can be used to control the young grubs straight after hatching, so should be applied before egg laying.
Pupa	Late spring, April - May	The fully grown larva forms an earthen cell and pupates in the soil before emerging as an adult beetle.