Healthy Lawns How to Detect Lawn Grubs

how to indentify if you have a lawn grub infestation

There are two main types of lawn grub, each of which can cause devastation to lawns before you are even aware of their presence. Here are some easy ways to recognise and deal with them before they do too much damage.

White curl grub

The first type of lawn grub is the white curl grub. These white, ‘C’-shaped grubs are the larvae of the cockchafer beetle or African black beetle. (Commonly, these grubs are wrongly identified as ‘witchetty grubs’ when observed by home gardeners.) White curl grubs live beneath the soil surface and feed on the healthy roots of grass. Like armyworm, these pests have been known to destroy entire lawn areas completely within a matter of weeks.

Pest Watch identifying lawn grubs white curl grub

How to detect white curl grub

Look for visual signs, such as circular patches in your lawn turning brown or yellow. Your lawn may feel soft and spongy to walk on and you may find grass lying loosely on top of your lawn. (In advanced cases, sections of lawn will be able to be lifted off the surface of the soil like a toupee, as there is no root system left.) For a final confirmation that white curl grubs are present, place a wet hessian bag on your lawn overnight. In the early morning, lift the bag to see if the grubs have come to the surface.


The second type of lawn grub is the armyworm. These army-coloured, khaki- green caterpillars are the larvae of moths of the Noctuidae family. They are a nuisance throughout Queensland and New South Wales and sometimes occur in plague proportions. Armyworm consume the leaves, stems and seed heads of grass. They can decimate entire lawn areas, leaving behind practically nothing but bare earth.

Pest Watch identifying lawn grubs army worm

 How to detect armyworm

If you notice patches of lawn suddenly dying, this could be evidence of armyworm activity. You may also notice small, grey moths flying around your lawn. (These moths are armyworms in their adult stage, looking for a place to lay their eggs.)

Further signs of lawn grubs

You may see wasps hovering over your lawn. Certain species of wasp are a predator of lawn grubs and use them as hosts to feed their young.

Infogram Seasons you can expect Lawn Grub Activity

What time of year

Most lawn grub activity occurs in the warmer times of year from early spring, through summer and into autumn.


How to control lawn grub and armyworm

To effectively control lawn grubs and armyworm in lawns and gardens, use Searles Dead Grub Pro. Searles Dead Grub Pro is a cost-effective broad-spectrum insecticide in easy to apply granules – simply sprinkle onto lawn and gardens and water in immediately after application for optimum results. Active Constituent: Bifenthrin.



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