Chafer Grubs and Leatherjackets in Turf: How to Identify, Control and Treat Them

A practical guide to chafer grub and leatherjacket control in sports pitches, golf turf, amenity grass and professional lawns.

Chafer grubs and leatherjackets remain two of the most damaging soil-dwelling pests encountered in UK turf.

This guide is intended for grounds managers, greenkeepers, contractors, amenity turf professionals and experienced lawncare operators who already have a working understanding of turf maintenance and application equipment.

For professional turf managers, successful control is fundamentally a question of pest identification, phenology (the study of how seasonal changes affect plant and animal lifecycles), treatment timing, rootzone conditions and application technique.

The challenge is not simply finding a product that controls the pest. Successful management depends on identifying the correct organism, understanding its life cycle, monitoring adult activity, targeting the most susceptible larval stage and creating the soil conditions in which the chosen treatment can perform.

That makes effective chafer grub and leatherjacket control an exercise in Integrated Turf Management (ITM) rather than reactive pest control.

Both pests can damage turf directly through feeding around the roots and lower plant. They can also lead to significant secondary damage when birds and mammals search for the larvae beneath the surface. Chafer infestations in particular can result in turf being pulled, rolled or dug up as predators search for grubs.

The important point is that by the time severe surface damage becomes obvious, the optimum treatment window may sadly have already passed.

The most effective programme therefore starts before damage appears.

Chafer grub or leatherjacket? Identify the pest first

At Pitchcare we advise that correct identification has to come before product selection.

Chafer grubs

Chafer grubs are the larvae of chafer beetles. They are normally creamy-white with a brown head, have three pairs of legs close to the head and characteristically curl into a C-shape.

Several chafer species may occur in turf, including garden chafer (Phyllopertha horticola) and cockchafer (Melolontha melolontha). Species identification can be important because life cycles, larval development and optimum control timings differ.

Typical symptoms of Chafer Grub infestations:

• yellowing or thinning turf
• a reduction in rooting strength
• turf that lifts more easily than expected
• localised drought-like symptoms
• birds feeding intensively on particular areas
• secondary digging or lifting by mammals

Leatherjackets

Leatherjackets are the larvae of crane flies, or daddy-longlegs. They are grey-brown, elongated and legless, with no obvious head capsule.

They feed on grass roots and around the base of plants, and large populations can result in thinning, yellowing and loss of turf density.

Adult crane flies typically emerge and lay eggs in turf from late summer into autumn, although the behaviour and life cycle vary between species. The two important species for turf management are Tipula paludosa and Tipula oleracea.

Why identification matters

A biological treatment described simply as “nematodes” is not enough information.

Sportnem-H, for example, contains Heterorhabditis bacteriophora and is used for chafer grub control. Sportnem-T contains Steinernema carpocapsae and is used for leatherjacket control.

Different nematode species have different optimum conditions, behaviour and target pests.

Where identification is uncertain, Pitchcare has an experienced team of BASIS-qualified advisers who can help with pest identification, treatment options, product selection and application timing. This is particularly useful where symptoms overlap, more than one pest may be present, or the turf manager is deciding between biological and or conventional control options.

What damage do chafer grubs and leatherjackets cause?

The direct damage caused by larvae is only part of the problem.

Root feeding reduces the ability of turf to access water and nutrients and compromises anchorage. On a sports pitch this can affect surface stability and wear tolerance; on golf turf it can compromise the presentation, aesthetic look and playing quality; and on lawns or amenity turf it may appear initially as irregular yellow or brown patches.

Secondary damage can then magnify the problem.

Birds may peck through the surface to reach larvae, while larger mammals, such as badgers, can cause considerably more physical disruption.

This is one reason preventative management is so important.

Waiting until a playing surface has been physically damaged means you are potentially dealing with three separate issues:

1. a pest population
2. root and plant loss
3. physical surface damage requiring recovery or renovation

So vigilance is key.

How do you know if you have leatherjackets?

Do not assume that every bird feeding on a pitch means there is a leatherjacket problem.

Inspect the turf and establish whether larvae are actually present.

One simple monitoring technique is the overnight sheet test. Water a known area of turf, cover it overnight with a dark sheet, tarpaulin or similar material and inspect the surface early the following morning.

Where leatherjackets are present, larvae may be found at the surface beneath the covering.

On professional turf, consistency matters. Rather than testing one convenient square metre, sample several representative areas:

• known historic hotspots
• apparently unaffected turf
• wetter areas
• sheltered areas
• areas receiving different levels of maintenance or irrigation

Record where and when larvae were found. Over time, this develops into a useful site-specific pest map.

How do you check for chafer grubs?

For chafer grubs, inspect below the surface.

Lift or cut representative samples of turf and examine the rootzone for the characteristic C-shaped larvae.

Record numbers against a defined sample area rather than simply writing “chafers present”.

Repeatable monitoring allows comparisons between locations and seasons and helps determine whether treatment is justified.

It also helps answer the more useful management question:

Which pest is present, where is it concentrated, what stage of its life cycle is it at and is the population likely to compromise the required performance of this surface?

Intervention thresholds should always be interpreted in relation to the required performance of the turf. A population that may be tolerated in golf rough, parkland or low-input amenity grass could be unacceptable on a stadium pitch, golf green, bowling green or elite training surface.

Thresholds should therefore inform the decision rather than be used as an automatic trigger for treatment.

Monitor the adults to predict the larvae

One of the most important changes a turf manager can make is to stop using visible damage as the trigger for action. Is to instead, monitor adult activity.

For chafer beetles, note the start and peak of adult flight. For crane flies, record when adult activity becomes significant and when numbers peak.

Why?

Because adult activity provides an indication of when eggs are likely to be laid and, subsequently, when young susceptible larvae will appear.

Calendar dates provide a useful planning framework, but pest phenology should ultimately determine treatment timing. Adult flight, egg laying, soil temperature and larval development can vary significantly between seasons, locations and individual sites.

The objective is to intercept the population during the early larval instars, when susceptibility is generally higher and before significant root feeding or secondary predator damage develops.

At Pitchcare our current Sportnem-H programme for chafer grub advice is to aim for nematode application approximately four to five weeks after peak adult flight. Our Sportnem-T programme uses the same principle for Leatherjacket treatment.

A simple annual record might include:

• pest species
• first adult observation
• peak adult activity
• pheromone trap counts where appropriate
• soil temperature
• rainfall and irrigation
• first larval observations
• larvae per sample or square metre
• product and treatment date
• post-treatment monitoring
• subsequent turf damage

Over several years, these records become much more valuable than relying solely on a generic calendar.

Are chafer pheromone traps useful?

Pheromone traps can play a useful role in chafer management, but their purpose needs to be understood.

A species-appropriate chafer beetle trap attracts adult beetles using a pheromone lure.

For professional turf managers, its strongest role is often monitoring rather than attempting to eradicate the pest through trapping alone.

Recording the beginning and peak of adult activity can help determine when egg laying is taking place and, therefore, when young larvae are likely to become suitable targets for subsequent control.

For a grounds manager, the information generated by a trap can therefore be more important than the number of beetles physically removed.

How to control chafer grubs with Sportnem-H

Sportnem-H contains the beneficial entomopathogenic nematode Heterorhabditis bacteriophora.

It is used to control susceptible chafer grub larvae in turf.

The nematodes move through moist soil in search of suitable hosts. After penetrating the insect, associated bacteria contribute to killing the grub, after which the nematodes reproduce and another generation can disperse through the soil.

When should Sportnem-H be applied?

Timing is critical. At Pitchcare our guidance identifies mid-July to mid-October as the principal application window for garden chafer larvae.

Cockchafer larvae have a different susceptibility period, identified by our Technical Team as approximately mid-June to the end of August.

Sportnem-H guidance also recommends aiming to treat around four to five weeks after peak adult flight.

These dates should be treated as a framework rather than an excuse to spray according to the calendar.

Species, adult flight, soil temperature, moisture and the development of the early larval instars should determine the final treatment decision.

Step-by-step: applying Sportnem-H for chafer grubs

1. Confirm that chafer grubs are the problem

Inspect the soil and identify the larvae.

Where species or diagnosis is uncertain, seek technical advice before ordering treatment.

2. Monitor adult flight

Record chafer beetle activity and use pheromone traps where appropriate.

The aim is to estimate when susceptible early larval instars will be present.

3. Check soil conditions

Beneficial nematodes are living organisms.

The soil must have sufficient moisture for them to move through the profile and reach their target.

Measure conditions within the rootzone, rather than assuming air temperature or surface moisture represents the environment in which the nematode needs to operate.

4. Prepare the turf

Excessive thatch can impede movement from the leaf surface into the soil.

Where appropriate, shallow aeration such as sarel rolling can assist movement into the profile.

Preparation should be appropriate to the surface and current turf condition; do not cause unnecessary stress simply to accommodate a treatment.

What is Sarel Rolling? This is a specialised turf maintenance technique that uses a spiked drum (called a sarel spiking roller) to puncture tiny holes into the upper layer of the turf without disrupting or tearing the playing surface. It is also useful for irrigation too.

5. Irrigate before treatment

The target zone needs to be genuinely moist, not simply have wet leaves.

Follow the current Sportnem-H instructions for pre-irrigation volumes and timing.

6. Keep Sportnem-H refrigerated

Nematodes are living organisms and need correct storage.

It is vitally important to follow the current storage temperature and use-by instructions supplied with the product and avoid leaving packs in vehicles, warm stores or direct sunlight.

7. Prepare the sprayer correctly

A nematode treatment should not be approached exactly like a conventional pesticide application.

Current Sportnem instructions specify considerations including:

• a completely clean sprayer
• removal of restrictive filters where required
• a suitable coarse-droplet nozzle
• appropriate agitation
• application of the prepared suspension promptly

Always follow the instructions supplied with the particular pack and application system being used. Following these spraying instructions really serve to optimise the outcomes that are required.

8. Avoid strong sunlight

Apply during suitable low-UV conditions, such as early morning, evening or an overcast period.

This also often provides a better opportunity to maintain moisture.

9. Irrigate immediately after application

The nematodes need to move from the foliage and surface into the rootzone.

Follow the Sportnem-H instructions for post-application irrigation and maintain appropriate rootzone moisture during the establishment period.

10. Re-sample the treated area

Do not judge success simply from whether damage appears.

Return to your monitoring points and assess larval populations.

Record the result for next year's programme.

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How to get rid of leatherjackets in turf

Leatherjacket control follows the same fundamental principles: identify, monitor, predict hatch and target young larvae.

For the Sportnem programme, Sportnem-T contains Steinernema carpocapsae.

When should nematodes be applied for leatherjackets?

Pitchcare's current principal treatment window for Sportnem-T runs from mid-September to the end of October.

This is designed to target the early larval instars from the major crane fly species while they are more susceptible to treatment.

A secondary opportunity can exist for newly hatched Tipula oleracea larvae where the pest population and conditions justify treatment, but this is not equivalent to the principal autumn programme and whilst useful control levels may not be as effective.

By spring, Tipula paludosa larvae may already be considerably more developed.

Again, calendar timing should be refined using pest phenology, adult crane fly activity, soil temperature and actual larval development at the site.

Step-by-step: applying Sportnem-T for leatherjackets

1. Monitor crane fly activity

Record adult numbers rather than simply noting that crane flies are present.

The peak matters. This again, if managing over a number of years is where record keeping is key.

2. Confirm leatherjackets are present

Use soil inspection or an overnight sheet test to establish larval activity.

3. Measure soil temperature

Measure the soil rather than relying on air temperature of less than >12 degrees.

The biological activity of the nematode depends heavily on conditions within the treatment zone.

4. Prepare a moist rootzone

Moisture must be present within the upper soil profile rather than simply on the leaf surface.

The rootzone should be capable of supporting nematode movement while remaining adequately aerated. This can often be an issue post drought, so it is key to potentially irrigate in advance where regulations allow.

5. Deal with physical barriers

Where excessive thatch is likely to impede nematode movement, appropriate shallow aeration may improve passage into the soil.

6. Configure the sprayer for nematodes

Follow the Sportnem-T instructions regarding sprayer cleanliness, filtration, nozzles, pressure and agitation.

7. Mix and apply promptly

Maintain appropriate agitation and do not leave the nematode suspension sitting unnecessarily in the spray tank.

8. Apply under low-UV conditions

Early morning, evening or suitable cloudy conditions are preferable.

9. Irrigate immediately

Post-application irrigation helps move nematodes from the plant surface into the treatment zone.

Follow Sportnem-T instructions for water volume and application.

10. Keep the soil moist afterwards

Maintain the rootzone conditions required by the treatment for the recommended post-application period. If lack of rain is an issue, an option can be to use an irrigation equipment to keep the area damp.

11. Monitor again

Use the same sampling locations where possible.

The post-treatment population is one of the most useful pieces of information for planning the following season. For large infestations it may be necessary to apply follow up treatment 21-28 days after the first application.

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Why do nematode treatments sometimes fail?

When biological control disappoints, the explanation is not necessarily that “nematodes don't work”.

Often the problem lies somewhere in the treatment process.

Common causes include:

• incorrect pest identification
• treatment of larvae that are already beyond the most susceptible early instars
• unsuitable soil temperature
• insufficient pre-irrigation
• dry or hydrophobic soil, often after drought
• excessive thatch
• poor movement through the rootzone
• inappropriate sprayer filtration; forgetting to remove filters in nozzles
• excessive pressure
• poor tank agitation
• excessive exposure to sunlight
• delaying application after mixing
• failing to irrigate immediately afterwards
• allowing the rootzone to dry during the following days

This is why buying a pack of nematodes is only one part of the job.

The turf, rootzone, irrigation system, sprayer, pest life stage and timing all form part of the treatment.

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Where does Acelepryn fit into chafer grub and leatherjacket control?

Biological control is not the only tool available to the professional turf manager.

Acelepryn is a professional insecticide containing 200g/L chlorantraniliprole and is authorised for chafer grub and leatherjacket control in specified turf situations subject to the product label.

Acelepryn is authorised for use on specified professional turf areas, including sports pitches, golf greens, tees, fairways and roughs, as well as other managed amenity turf. Under the current label, treatment must be targeted to areas of infestation and is generally limited to 10% of the total area; residential lawns are exempt from this restriction.

The important distinction is that Acelepryn should be positioned preventatively.

The treatment strategy is linked to adult pest activity and anticipated egg hatch so that active ingredient is in place to target the early larval instars.

It is not best viewed as a rescue treatment for large, mature grubs once severe damage has developed.

To support effective and responsible application, professional users should always refer to the current statutory product label and HSE authorisation before treatment. As product approvals, use patterns and regulatory guidance can change, working from the latest information helps ensure the treatment is correctly targeted, legally compliant and optimised for the best possible outcome.

Biological or chemical control: which is better?

This is not necessarily an either/or decision.

Good Integrated Turf Management asks:

What is the target pest, what stage is it at, what is the risk to the grass plant and which intervention is appropriate under the current conditions?

Sportnem-H and Sportnem-T offer biological control options targeted at specific pests.

Acelepryn provides another professional tool where the product label allows its use and where monitoring supports preventative treatment.

Different programmes may use different nematode species, including Steinernema feltiae, Steinernema carpocapsae and Heterorhabditis bacteriophora, each with its own biological characteristics and application parameters.

The lesson for the turf manager is straightforward: follow the programme for the exact product being applied.

Cultural management: reducing the risk to turf

Neither biological nor conventional treatments should sit in isolation from the wider maintenance programme.

Turf that has strong rooting, appropriate nutrition and good physical soil conditions is generally better positioned to tolerate and recover from pest pressure.

Relevant considerations include:

• managing excessive thatch
• reducing compaction
• maintaining appropriate aeration
• ensuring good infiltration
• developing a dense sward
• avoiding prolonged plant stress
• maintaining balanced nutrition
• having sufficient irrigation capacity to support biological treatments

There is a balance to strike.

Nematodes need moisture during treatment, but permanently waterlogged or poorly structured soil is not the objective.

The aim is a turf profile that can be managed precisely: sufficient moisture to support biological activity, combined with adequate aeration, infiltration, rooting and surface performance.

For a golf course or high-quality sports pitch, pest management therefore overlaps directly with rootzone management, organic matter control, irrigation, nutrition and plant-health strategy.

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A practical annual chafer grub and leatherjacket calendar

Exact dates will vary according to location, pest species, weather and seasonal phenology, so monitoring should always refine the calendar.

Spring

• Inspect areas affected in the previous year
• Sample for larvae
• Assess rooting and recovery requirements
• Repair damaged turf where appropriate
• Review the previous year's pest records
• Where relevant, determine whether Tipula oleracea creates a genuine spring Sportnem-T opportunity

May and June

• Monitor adult chafer beetles
• Install appropriate pheromone traps where useful
• Record dates and numbers
• Identify recurring hotspots

June and July

• Continue monitoring chafer flight
• Review whether Acelepryn forms part of the programme on eligible areas
• Base the decision on adult activity, previous pest pressure and the current statutory label rather than waiting for larval damage

July and August

• Monitor for young chafer larvae and early larval instars
• Move into the Sportnem-H treatment period where the chafer species and site conditions are appropriate
• Begin close observation of crane fly activity

August and September

• Record crane fly activity and identify peak flight
• Check soil moisture and irrigation capability
• Prepare application equipment
• Plan autumn leatherjacket treatment rather than ordering reactively after damage

September and October

• Principal Sportnem-T treatment period
• Continue Sportnem-H treatments where appropriate for the target chafer population
• Monitor soil temperatures and larval development carefully

Late autumn and winter

• Re-sample where practical
• Record predator activity and turf damage
• Evaluate treatment success
• Map problem areas
• Use the information to build the following year's programme

Pre-application checklist for nematode treatments

Before opening Sportnem-H or Sportnem-T, ask:

• Have I positively identified the target pest?
• Do I know which life stage or larval instar is present?
• Have I recorded adult activity?
• Is this the correct treatment window for this specific product?
• Is the rootzone soil temperature suitable?
• Is the treatment zone adequately moist?
• Can I irrigate immediately after spraying?
• Can I maintain moisture after treatment?
• Is excessive thatch restricting access to the soil?
• Has any appropriate aeration been completed?
• Is the sprayer completely clean?
• Have restrictive filters been removed where required?
• Is the nozzle suitable?
• Have the nematodes been stored correctly?
• Is the operating pressure appropriate?
• Have the nematodes been stored correctly?
• Can I apply under low-UV conditions?
• Have I planned how efficacy will be assessed afterwards?

If several answers are “no”, it may be better to correct the conditions before applying.

Not sure what is damaging your turf? Ask before treating

Chafer grub and leatherjacket management can become complicated because pest identification, phenology, life stage, soil temperature, moisture and timing all interact.

A treatment that is appropriate in August may be inappropriate several months later. Equally, the correct treatment for chafer grubs is not automatically the correct one for leatherjackets.

If you are unsure whether you have chafer grubs or leatherjackets, when you should treat, or whether Sportnem-H, Sportnem-T or Acelepryn is appropriate, Pitchcare's BASIS-qualified advisers can help assess the options and provide practical technical guidance.

That advice can be particularly valuable when considering:

• pest identification
• pest phenology and life stage
• treatment timing
• product selection
• biological versus conventional options
• nematode handling
• application equipment
• rootzone temperature
• irrigation requirements
• monitoring
• how pest control fits into a wider Integrated Turf Management programme

On high-value turf, obtaining advice before treatment can be considerably more effective than trying to correct a poorly timed application afterwards.

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Five rules for successful chafer grub and leatherjacket control

1. Identify before you treat

Chafer grubs and leatherjackets are different pests.

Make sure you know what is beneath the turf.

2. Monitor adults before damage appears

Adult beetle and crane fly activity can provide the early warning needed to predict egg hatch and target the early larval instars.

3. Target the vulnerable life stage

For both biological and conventional approaches, timing against young, susceptible larvae is fundamental.

4. Treat rootzone conditions as part of the application

For nematodes in particular, soil temperature, moisture, thatch, aeration, infiltration and post-treatment irrigation can determine success or failure.

5. Record the result

Document pest pressure, phenology, timing, soil conditions and post-treatment populations.

Your own site history is one of your most useful ITM tools.

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Frequently Asked Questions

What are chafer grubs?

Chafer grubs are the soil-dwelling larvae of chafer beetles. Turf-damaging species include garden chafer and cockchafer. They feed around grass roots and are normally creamy-white, brown-headed and C-shaped with three pairs of legs.

What are leatherjackets?

Leatherjackets are the larvae of crane flies, commonly known as daddy-longlegs. They are grey-brown, elongated and legless and can damage turf by feeding on roots and around the base of grass plants.

How do I know if I have chafer grubs in my lawn or turf?

Look for loose, thinning or yellowing turf, reduced rooting and unusual bird or mammal activity. Lift representative turf samples and inspect the soil for C-shaped larvae rather than relying on surface symptoms alone.

How do I know if I have leatherjackets?

Inspect the rootzone or use an overnight sheet test on moist turf. Leatherjackets may come to the surface beneath the covering, making populations easier to assess.

How do you get rid of chafer grubs?

Professional chafer grub control starts with species identification, adult monitoring and an understanding of larval phenology. Options can include Sportnem-H containing Heterorhabditis bacteriophora, appropriate pheromone monitoring and, on eligible professional turf, preventative use of Acelepryn in accordance with its current statutory label.

What is the best nematode for chafer grubs?

The answer depends on the product and target species. Sportnem-H uses Heterorhabditis bacteriophora. It should be applied according to its specific treatment window, soil temperature, moisture and application instructions.

When should I apply nematodes for chafer grubs?

Treatment should coincide with susceptible early larval instars. For Sportnem-H this is informed by chafer species, adult flight, soil temperature and seasonal conditions rather than calendar date alone.

How do you get rid of leatherjackets in turf?

Begin by confirming larvae are present and recording crane fly activity. Sportnem-T containing Steinernema carpocapsae can then be used against susceptible young larvae when soil temperature and moisture conditions are suitable.

When is the best time to treat leatherjackets with nematodes?

The principal Sportnem-T treatment period is in autumn, when newly hatched and early-stage leatherjackets are more susceptible. Local adult flight and soil conditions should be used to refine timing.

What soil temperature is needed for leatherjacket nematodes?

Use the current Sportnem-T product instructions and measure soil temperature within the relevant rootzone depth rather than relying on air temperature.

Can Acelepryn control chafer grubs and leatherjackets?

Yes, for professional use in authorised turf situations. Acelepryn contains chlorantraniliprole and should be positioned preventatively against susceptible early larval stages, strictly according to the current statutory label.

Do chafer pheromone traps work?

Pheromone traps can be particularly valuable for monitoring adult chafer beetle activity and helping determine subsequent treatment timing. They should not automatically be regarded as a standalone population-control strategy.

Why do birds keep pecking at my lawn or sports pitch?

Bird activity can indicate soil-dwelling larvae including chafer grubs or leatherjackets, but it should not be regarded as proof. Inspect and sample the turf before choosing a treatment.

Can I apply nematodes with a sprayer?

Yes, but application equipment must be configured appropriately for living nematodes. Follow the exact Sportnem instructions regarding filtration, nozzles, agitation, pressure, application timing and post-treatment irrigation.

Where can I get advice on chafer grub or leatherjacket treatment?

Pitchcare has an experienced team of BASIS-qualified advisers who can provide specialist advice on pest identification, phenology, treatment selection, application timing and wider turf management considerations.

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The key message

Chafer grubs and leatherjackets are at their most difficult when management begins only after the turf is visibly failing.

They become considerably more manageable when the programme starts with monitoring and an understanding of pest phenology.

Identify the pest. Monitor adult activity. Understand the life cycle. Target the early larval instars. Assess the rootzone. Select the appropriate treatment. Apply it correctly. Maintain the conditions required for it to work. Then measure the result.

That is the foundation of effective chafer grub and leatherjacket control on modern sports turf, golf courses, amenity grass and professionally maintained lawns.

And where there is uncertainty, seek technical advice before treating. Correct identification, life-stage assessment and timing are likely to make a greater difference to the outcome than simply reaching for a product once damage becomes visible.