Written by Andrew Baber

Scientific Name Spodoptera spp.

What the damage looks like

Skeletons, that’s the easiest way to describe the way your lawn looks after Lawn Armyworm have been through. The Lawn Armyworm is a caterpillar which loves to eat the soft leaf blades of the lawn but is not interested in the harder stems and below ground parts of the lawn. Another typical sign of Lawn Armyworm is part of the reason it gets its name, it advances in a straight line like the armies of old, so the lawn can sometimes have clear distinct lines of advancement of the pest if caught in the early stages.

Lawn “skeletonised” by Lawn Armyworm


General Description of the pest

Lawn Armyworm are common pests of lawns and are often easily indentifiable by the speed and style in which they do their damage as described above. We are not joking, we have seen them destroy large lawns overnight where we found high levels of infestation.

Lawn Armyworm hides just below the surface of the lawn (in the thatch) during the day so are very effective at hiding from a quick scout around for pests, this is because they come out at night to feed. A night-time inspection with a torch is the best way to find them (you might get some looks from the neighbours). Another simpler way is to leave a wet towel on the ground overnight and inspect it in the morning, they won’t realise they haven’t gone underground and you will find them underneath having a nap.

They appear grey to green and even brown in colour with stripes and stars along their body (another reason they get called armyworm). When fully grown they can be up to 4cm long.

Lawn armyworm lays eggs in your soil and can have multiple generations of the pest in the lawn which makes control extremely difficult.


Lawn Armyworm aren’t picky on what type of lawn they feed on and they will strip any lawn type indiscriminately and even eat some of your weeds too! They are however warmer temperature lovers, so the Lawn Armyworm season tends to begin in Queensland and Norther Territory in mid- Summer with them moving further south into New South Wales, Western Australia and ACT as temperatures allow, by late Summer and into Autumn. The season rounds up for most by Autumn but can continue into the winter period for those in warmer tropical areas.

Control of Lawn Armyworm

Don’t wait and apply late. That’s the best advice for treatment of Lawn Armyworm. Due to the speed in which it destroys lawns it’s important you get an application of the correct insecticide on as soon as possible. A secret from the pros though, best results are achieved when the applications are made at dusk or under lights, this means they are climbing through and eating freshly applied product.

Control of Lawn Armyworm with one application is difficult because of the multiple generations hatching from eggs you will see within a year. This means you will need a residual product that isn’t harmful to the environment.

Acelepryn is the gold standard in common lawn pest control problems and where this product provides a solution we recommend you use what the professionals use. It offers a single application for season long grub and caterpillar control.


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