How to Control Fall Armyworms in Your Lawn

The Fall armyworm is actually a caterpillar, and a common destructive one that are currently more common in the tropical and subtropical areas of Australia.

“The Fall armyworm is one of the worst pests for your lawn,” Nathan says. “It has an insatiable appetite and can decimate your lawn overnight.”  

Identification: The larvae form of the Fall armyworm is most dangerous to turf. Nathan describes the pest as a “green, ugly looking caterpillar with stripes along its back”.

“This hungry caterpillar chews the life out of your lawn, feeding on the leaves and stems of grass, leaving your lawn in stubs. It’s incredibly destructive.”

Early detection and proactive management are essential to prevent widespread infestations.

Select resilient grass varieties: Opt for grass varieties that have shown resilient stance to Fall armyworm. Bermuda grass, couch and zoysia grass are known for their resilience to Fall armyworm infestations. While these varieties still get damaged, they have traits which recover and repair following infestation.

You could also consult with local nurseries or turf experts to identify suitable varieties for your region.

Early intervention: Timing is crucial when applying insecticides as infestations usually occur in the warmer months. Armyworms can also attack other types of plants and vegetables, so early intervention prevents the larvae from causing extensive damage, improving the chances of successful control.

When responding to Fall armyworm infestation, Nathan suggests a two-step approach using a spray for immediate control and an application of a granular product to protect turf, which is effective in reducing the pest from marching across the lawn.

Products such as spray on Indigo Rumbler 100SC 1L (Bifenthrin as active ingredient) and LawnPride Acelepryn Grub Killer Granular 4kg are ideal, and can be found on the myhomeTURF online shop.

Maintain optimal lawn health: A healthy lawn is better equipped to withstand pest pressures. Regular fertilisation, appropriate watering, and proper mowing practices contribute to the overall wellbeing of your turf, making it less attractive to Fall armyworm.

How to Treat Fall Armyworm with Insecticides

What to use:

Chemical options such as Acelepryn or Bifenthrin can be effective against Fall armyworm and can be bought through the myhomeTURF online store. Apply the insecticide according to the manufacturer’s instructions, focusing on areas with visible signs of infestation. Here are our recommendations: 

Indigo Rumbler 100SC 1L (Bifenthrin as active ingredient)

Acelepryn 750ml

 When to apply: Use insecticide at the first sign of Fall armyworm damage. Nathan recommends the best time of day to apply insecticide to the lawn is just before dusk. Ensure to allow enough time to finish the entire lawn treatment before dark.

Lawn Tip: If you have pets, use Acelepryn rather than Bifenthrin as a safer option.

How Long do Insecticides Take to Work? 

Bifenthrin is an insecticide which is active from the time of application. Acelepryn granules can be applied and left as the granule overnight on the plant, then watered the next day. Please ensure you always read the label and only use as directed by the manufacturer. 

Mowing practices: Adopt proper mowing practices to discourage Fall armyworm infestations. Maintain the recommended mowing height for your grass type and avoid removing more than one-third of the grass blades at a time. This helps preserve the vigour of the lawn and minimises stress that could attract Fall armyworm.

Reduce lawn thatch: Fall armyworm larvae often find refuge in thatch layers. Regularly dethatch your lawn to reduce the build up of organic matter, making it less favourable for the pests to establish themselves.

Nathan stresses the importance of bringing your lawn back to health after a pest infestation.

“Apply a wetting agent and use a fertiliser to invigorate your lawn,” Nathan says. “Fall armyworm is a nasty pest but with the right care you’ll have your beloved green lawn back thriving in no time.”

Wetting agent: LawnPride HydraMaxx 2L Hose-On

Fertiliser: LawnPride Kelp ER 2L Hose-On

Acelepryn GR

Indigo Rumbler 100SC 5L

Controlling Fall armyworm in Australian lawns demands a proactive and multifaceted approach. These ravenous pests will quickly destroy an entire lawn if not intercepted, so early detection is key. If you suspect army worms in your lawn, you should confirm with monitoring, and treat your lawn with an appropriate insecticide. Once you have treated the infestation, help to restore your lush lawn with watering and feeding.

For more information on leading pesticide treatments for your home lawn, visit myhomeTURF’s online store.