How To Get Rid Of Lawn Grubs, Curl Grubs, Or Army Worms

28 Jul How To Get Rid Of Lawn Grubs, Curl Grubs, Or Army Worms

Noticed sudden brown patches, soft or spongy turf, or birds pecking obsessively at your lawn? Chances are, you’ve got lawn grubs, and they’re making a feast of your grass.

Lawn grub infestations are a common issue across Australian backyards and commercial properties, especially during the warmer months. 

The good news is that with the right information and a proactive approach, they’re entirely manageable. In this guide, we’ll show you how to spot the signs, understand the pests, and remove lawn grubs, curl grubs, and armyworms before they ruin your turf.

What Are Lawn Grubs?

Lawn grubs are the larvae of various beetles, most commonly the African Black Beetle. These underground pests live just beneath the soil surface, feeding on the root systems of your lawn and causing visible damage above.

The term lawn grub often gets used as a catch-all, but in reality, it includes a few different species:

• Curl grubs, which are C-shaped beetle larvae
• Army worms, which are technically caterpillars, not grubs, but cause similar damage
• Other scarab beetle larvae

Regardless of species, lawn grubs can cause real headaches if left untreated.

What Do Lawn Grubs Look Like?

Identifying these pests is key to getting rid of them effectively. Most lawn grubs:

• Are white or cream-coloured
• Have a soft body with a brown head
• Curl into a C-shape when disturbed
• Range from 10 mm to 40 mm in length, depending on species and maturity

Army worms look different. They are caterpillar-like, greenish-brown with a striped body, and often found wriggling across the lawn surface at dusk.

Life Cycle of Lawn Grubs

Understanding the life cycle of lawn pests helps you treat them at the right time.

• Egg stage: Female beetles or moths lay eggs in the soil or on turf blades
• Larval stage (grub or caterpillar): The most damaging phase, where they feed on turf roots
• Pupa stage: A dormant transition period
• Adult stage: Beetles or moths emerge to restart the cycle

Grubs are most active in spring through autumn. Early detection in the larval stage is crucial to stop damage before it spreads. 

Types of Lawn Grubs

Curl Grubs

Curl grubs are the most common in Australian lawns. These are the larvae of scarab beetles, including the notorious African Black Beetle.

You’ll usually find them in:

• Soil beneath patchy or dying lawn sections
• Root zones, where they feed heavily
• Greater numbers after warm, wet periods

Curl grubs in the lawn can cause extensive root damage quickly. While one or two may not pose a threat, infestations of ten or more per square metre need action.

Army Worms

Armyworms are fast-moving, surface-dwelling caterpillars that can devastate a healthy lawn almost overnight.

It’s important to watch out for greenish or brown caterpillars with pale stripes, clusters of greyish-brown moths at dusk (they lay eggs), or trails of grazed patches appearing suddenly, overnight. 

Getting rid of armyworms requires a fast response, as their feeding period can be short yet aggressive. If you suspect an established armyworm infestation it might be time to contact a professional to help resolve the issue and protect the long-term health of your lawn.

Lawn Grub Comparison Table

Type	Appearance	Signs of Activity	Damage Caused	Active Period
Curl Grub	White, C-shaped larvae with brown heads	Turf rolls up easily, brown patches, spongy feel	Root damage, lawn thinning	Spring to Autumn
Army Worm	Green-brown caterpillars with stripes	Surface grazing, rapid patchy damage, and  moths at dusk	Blade damage, lawn stripped overnight	Late Summer to Autumn

How To Identify Lawn Grubs

Spotting the signs early can save you a lot of stress and costly repairs. Here’s what to look for:

• Bird activity: If magpies, crows or ibis are pecking at your lawn more than usual, they’re likely feeding on grubs
• Brown or dead patches: These may remain even after watering and fertilising
• Spongy turf: The lawn may lift like carpet because the roots have been eaten away
• Moths at dusk: These are often army worm moths laying eggs
• Soapy water test: Mix a bucket of water with dishwashing liquid and pour it over a suspect patch. Within 10 to 15 minutes, any grubs will rise to the surface

Are Lawn Grubs Bad for Your Garden?

Yes, lawn grubs can cause serious damage to your garden. While a small number might not be noticeable at first, a larger infestation can quickly take hold and harm your lawn’s health. These pests feed on the roots of the grass, cutting off its ability to absorb water and nutrients properly. As a result, affected areas often become dry, patchy, and brown, even with regular watering or fertiliser. 

A weakened lawn is also more likely to suffer from weed growth and other pest issues. For homeowners, this can be incredibly disappointing, especially after spending time and money maintaining their outdoor space. In some cases, the damage may be severe enough to require reseeding or laying new turf. That’s why it’s important to act quickly at the any signs of trouble.

Signs of Lawn Grub Infestation

Not sure if grubs are the problem? These are the red flags:

• Patches of lawn are turning brown or yellow and refusing to bounce back
• Turf feels soft or lifts easily underfoot
• You’ve seen increased wildlife digging or pecking at your lawn
• Caterpillars or moths are visible at night or early morning
• Signs of surface grazing or chewed grass blades

If you notice any of the above, it’s time to act.

Lawn Grub Control – How To Kill Lawn Grubs

There are several effective treatments available, depending on the severity of the infestation.

Quick knockdown treatments
For active infestations, use a fast-acting insecticide that targets both curl grubs and armyworms. These treatments work by direct contact and residual action as pests move through the treated area.

Preventative treatments
To avoid re-infestation, apply a preventative treatment in early spring. Products like Acelepryn (granular or liquid) offer up to six months of protection with minimal impact on beneficial insects such as bees and earthworms.

Integrated lawn care
Good lawn health is your first defence. Regular mowing, deep watering, and seasonal fertilising create strong root systems that resist pest damage. Check out our maintenance guide for more lawn care tips.

Contact Seed & Turf for Lawn Grub Removal and Control

Whether you’ve spotted early signs or need a fresh start, Seed & Turf has the solution.

We offer:

• Expert turf advice tailored to your region and soil type
• High-quality, pest-resistant instant turf varieties
• Reliable, Australia-wide delivery

Do not let lawn grubs ruin your outdoor space. Reach out to our team for guidance or a quote. We’re here to help with everything from pest control to lawn replacement.

Contact us today for advice, service, or to get your lawn back in shape.