Leatherjacket lawn care: A quick and easy 5-step guide

So, you think your lawn has a Leatherjacket problem. What next?

Leatherjackets are a real thorn in the side of any keen gardener, destroying lawns, small plants and garden borders wherever they go.

If you’ve noticed that blades of grass on your lawn have become yellow and damaged, the cause is probably these pesky critters.

When dealing with problems on your lawn, the best defence is to arm yourself with knowledge and expert help.

That’s why the lawn care professionals at TruGreen UK have put together a quick and easy 5-step guide to help you understand what Leatherjackets are, how they damage your lawn, and – most importantly – how to get rid of them!

Answered in this guide:

  1. What are Leatherjackets?
  2. What causes a Leatherjacket infestation?
  3. How can you identify a Leatherjacket infestation?
  4. What damage do Leatherjackets do?
  5. How do you get rid of Leatherjackets?

1.   What are Leatherjackets?

Leatherjackets are the larvae stage of the life cycle of a Crane Fly (more commonly known as a Daddy Long Legs).

They are small and plump and appear dark grey/brown with elongated tubular bodies and no legs or visible head. They can be up to 30mm long.

Leatherjacket

You’re probably used to seeing Daddy Long Legs during the summer.

This is because this is the time in their lifecycle when they have reached full maturity.

Commonly, the adult Crane Fly/Daddy Long Legs can be found in the tail end of summer and early autumn (around August/September), as this is the time in which they lay their eggs.

2.   What causes a Leatherjacket infestation?

Crane Flies laying eggs in the soil in late summer/early autumn typically leads to an infestation the following year.

Crane Fly eggs hatch a few weeks after they are laid and spend the autumn months feeding on plant roots.

In winter, they hibernate before returning to the surface to finish feeding in the spring

3.   How can you identify a Leatherjacket infestation?

While damage can be seen on the lawn surface in the autumn due to their propensity to overwinter during the colder months, it is in May that damage from Leatherjackets becomes noticeable.

However, as winters have become milder in recent years, damage has been seen at various times throughout the year.

There are tell-tale signs to look for when checking for a Leatherjacket infestation. These are:

  • Birds: Some bird species, like magpies, starlings, crows, and rooks, may search for Leatherjackets beneath lawn surfaces. If you find small round holes in your turf – this may be a sign that birds have inserted their beaks into your lawn in search of Leatherjackets. Be advised, however, that this could also be a sign that birds are looking for chafer grubs.
  • Pupal Cases: When fully grown, Leatherjackets pupate in the soil, and when the adult flies emerge, the pupal case is often partly pulled out of the ground and left sticking up above the lawn surface.
  • Root damage: The damage that Leatherjackets cause in your garden can also reveal them. If seedlings and small plants or vegetables in your flower beds/vegetable patches are dying, this can result from stem damage from Leatherjackets eating plant roots below the soil.
  • Sweating out Leatherjackets: There is also a method of detection that you can try at home, as detailed in this article from Collier Turf Care. This involves soaking the lawn with water using a light-obstructing material like black polythene. This essentially sweats out the larvae and causes them to rise to the lawn surface underneath the cover overnight.

4.   What damage do Leatherjackets do?

Like other lawn pests, the degree of damage done varies depending on population numbers but could result in total loss of your lawn.

As they commonly feed on plant roots, Leatherjackets can kill off your lawn and other plants from below.

Grass can resist minor damage to its root system, so damage may often go unnoticed.

However, if the Leatherjackets exceed the threshold of 25 larvae per square metre, you’ll see significant damage.

If your grass has been growing poorly or you notice the appearance of straw-coloured patches and the ability to pull up the lawn surface, this is probably a sign of an infestation.

5.   How do you get rid of Leatherjackets?

Like the damage caused, the treatment for Leatherjackets depends on the severity of the infestation.

To rid your lawn of Leatherjackets, your best course of action is to contact the professionals at TruGreen Professional Lawn Care UK.

Acelepryn

Recently, the application of a product known as Acelepryn to treat Leatherjackets has also been approved for use on lawns.

This is a leading product in treating lawn pests and can be applied by your local TruGreen lawn care experts.

An insecticide, Acelepryn provides lawn care operators with exceptional broad-spectrum control of pests like Leatherjackets without harming non-targets and benefitting insects both on the plant and in the soil.

It is also been formulated to allow for a high level of pest control while applied at a low rate of product and water application.

It provides the best results when applied to emerging larvae, and its wide application window offers flexibility. Neither rainfall nor additional irrigation is necessary for Acelepryn to provide outstanding pest control.

For optimum control, apply Acelepryn when peak crane fly activity is observed, such as during the egg-laying period.

Nematodes

An alternative treatment we provide is a biological treatment using nematodes.

These are applied by watering them into the turf soil and work to infect Leatherjackets with a bacterial disease.

This will stop them from feeding on the roots of the grass within three days of application and kill off any remaining larvae within 10-14 days.

When is the optimal time for nematode treatment?

When using nematodes to control a Leatherjacket infestation, timing is crucial.

The preferred period for applying nematodes is late summer and early autumn (September and October), as the larvae are at their earliest stage of development and, therefore, more vulnerable.

While spring treatments are less effective, they can still be applied at double strength to stop an infestation.

Furthermore, nematodes are contact-acting and move in water, and will only remain active in a soil temperature above 10ºC.

This means soil must be well-drained and contain plentiful moisture for applications of nematodes to be efficient.

If the damage is too severe, it may be too late for treatment, and your turf may require a complete overseeding with grass seed.

For the best results and advice specific to your lawn, contact the experts at your local TruGreen business.

Need treatment for Leatherjackets?

For expert pest control treatment and guidance, get in touch with professionals at TruGreen.

Our lawncare operatives are equipped to deal with Leatherjackets, no matter the size or scale of the infestation.

For a no-mess, no-hassle lawn care experience, call TruGreen today on 0800 021 3074 or find your nearest business to book your free 14-point lawn analysis and get the best treatment for your lawn today.