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Lawn Grub Control, Detection and Prevention

Lawn Grub in the Domestic Lawn

Congratulations on your beautifully lush and green lawn! After weeks of dedicated care, it’s disheartening to notice a small brown patch. At first, you might think a quick sprinkle of water or some fertilizer will do the trick. No need to panic, right? However, over the next few days, that brown patch grows bigger and starts spreading across your lawn. It’s every green keeper’s worst nightmare: lawn grubs. In Queensland, we commonly encounter two types of worms referred to as lawn grubs – White Curl Grub and Army Worm. Continue reading to learn more about methods for effective lawn grub control, detection and prevention.

White Curl Grub

The presence of white curl grubs in lawns is often mistakenly referred to as a “lawn grub” or “witchety grub,” but it’s important to understand that they are actually the larval stage of lawn beetles, specifically scarab beetles. These white curl grubs pose a significant threat to lawns, and their signs of infestation can be easily mistaken for other turf pests, diseases, or disorders.

White Curl Grub
White Curl Grub

When white curl grubs infest a lawn, the consequences are evident: the grass starts to yellow, then progresses to browning, and eventually leads to the lawn’s demise. These grubs voraciously feed on the turf’s root system, causing severe damage. In some cases, the infestation is so severe that you can even roll up the turf as the root system has been completely destroyed.

It’s worth noting that virtually every lawn in Queensland currently has some presence of white curl grubs. An infestation is generally considered problematic when there are 25 or more grubs per square meter. However, if the number of grubs is lower, a normal and healthy lawn with seasonal growth can usually withstand the damage. It’s important to be mindful of external factors that can exacerbate the issue, such as heat or drought conditions.

If you have concerns about white curl grubs, a simple and effective method of grub prevention is to check for their presence as follows: Place a hessian bag or a piece of old carpet on the grass in the late afternoon. Thoroughly wet the bag or carpet and leave it overnight. By the following morning, the white curl grubs will have risen to the surface, allowing you to assess the extent of the infestation.

If you need further guidance or assistance in dealing with lawn grubs, please don’t hesitate to reach out. We’re here to help you with lawn grub control and ensure the health of your lawn.

Army Worm

Army Worm
Army Worm

The second type of lawn grub we encounter is known as the Army Worm. As an adult, the lawn armyworm takes the form of a greyish-brown moth with a wingspan of approximately 35 to 40 mm. The damage caused by these critters differs slightly from that of white curl grubs. Army worms, similar to other caterpillars, primarily feed on the leaves of the turf. The resulting damage often manifests as a distinct line of dying grass marching across your yard. This line of damage typically begins closest to the house, near external light sources that attract the adult moths.

To determine if you have an Army Worm infestation, you can employ the same grub control process as described earlier for white curl grubs. However, it’s important to be aware that if you have already observed significant damage, you’ll need to be strategic with your test placement. The grubs will have likely moved on from the previously affected “dead patch” and may now be active in the still-green areas of your lawn.

If you require further assistance or guidance in dealing with Army Worms or any other lawn-related concerns, please feel free to reach out. We’re here to help you tackle these challenges and maintain a thriving lawn.

Grub Prevention

You may believe that your well-cared-for lawn, the healthiest on the street, is safe from these pests. But here’s some news for you: these bothersome creatures aren’t interested in your neighbors’ messy yards. Lawn grubs have a taste for the finer things and won’t settle for anything less. Unfortunately, it’s often the house with the most impeccable lawn that bears the brunt of their damage.

To safeguard your lawn against lawn grubs and other pests, we recommend Acelepryn GR. This exceptional product provides up to 6 months of continuous protection from lawn grubs and can also eradicate cutworms, armyworms, and sod webworms. Acelepryn is especially suited for larger areas and long-term pest control. The beauty of Acelepryn lies in its ability to provide effective lawn grub control while minimizing any adverse impact on the environment and non-target organisms such as bees and earthworms. Now is the perfect time to apply Acelepryn and shield your lawn from these pests.

When it comes to insecticides, Acelepryn offers season-long control of grubs and caterpillars with just a single application. Its efficiency and long-lasting performance ensure that your lawn remains trouble-free for an extended period. Moreover, Acelepryn is exempt from poison scheduling, reducing personal protection requirements. Additionally, Acelepryn GR is a non-spray option, making it user-friendly and convenient to use.

If you’re specifically dealing with the larvae of Black Beetle, which are typically present from November to March, September is the ideal time to apply Acelepryn for effective treatment.

In autumn, pests like insects and caterpillars can still pose a threat to your lawn. However, with the right choice of insecticide, implementing effectual lawn grub control is easy. Understanding the lifecycle of these pests can assist you in making informed decisions. Products like Acelepryn and Grub Guard offer long-lasting protection against these attacks for many months.


When it comes to dealing with lawn grubs, prevention is key. However, most commercially available pesticides are designed to address existing infestations rather than prevent them. While some granular mixes may offer temporary grub prevention, the question arises: what came first, the chicken or the egg? In this case, it’s the moth! A crucial step is to ensure that your eaves, house, and fences are free from moth nests, which often appear as small cotton-like cocoons. Using a hose and broom to remove these nests can help limit moth activity around your property, although it is not a foolproof solution.

For an existing infestation of lawn grubs, the most effective treatment unfortunately involves the use of chemicals. Bifenthrin and Chlorpyrifos are among the most effective treatments and are available in ready-to-use hose bottles, liquid concentrates for spraying, and granular form for sprinkling and watering in. It’s important to exercise caution with these products, as they can also be harmful to other animals, including children, if they come into contact with them. The optimal time to apply the treatment is late afternoon when birds are less active. Birds are attracted to the dying grubs that come to the surface after treatment. Always remember to read the label and apply the chemical control at the recommended rates. Breaking the lifecycle is essential when treating an infestation. We recommend treating over a two-week period: once on the first day, again on day 7, and once more on day 11. This disrupts the cycle of cocoon, moth, egg, grub, cocoon, and so on.

As a bonus, the active constituents found in these treatments are often present in many commercially used products for treating ants and other insect activity. So, while you rid your lawn of pesky grubs, you may also notice reduced numbers of ants, lawn beetles, African black beetles, and cockroaches.

A natural approach to lawn grub control relies on carnivorous birds. Methods such as flooding the area with water or using soapy water can encourage the grubs to come to the surface, where the birds can hopefully pick them off. However, it’s important to note that this method may yield inconsistent results.

Best of luck with your lawn, and remember to keep a close eye on it for any signs of infestation.

Interested in Learning More?

Centenary Landscaping Supplies provides a full range of effective pest and weed killers, as well as landscaping supplies, for all your lawn care needs. Reach out to our expert team today by contacting us online or calling 07 3373 4999.


UPDATED: 01/05/2024

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