Army Worm - Prevention and Cure

The army worm is actually a moth larva and is a caterpillar, rather than a worm.  Army worms can cause severe damage to lawns and are notoriously difficult to get rid of.  So how do you know if your lawn has been attacked by army worms and what can you do to get rid of them and prevent further attacks?  Read on for more information.

Does my lawn have army worms?

These annoying pests attack your lawn by eating through the soft new root growth of the grass plants, leaving dead and dying patches on your lawn that seem to grow bigger day by day.  The adult moths are active during spells of warm summer weather and can lay hundreds of eggs overnight beneath the grass leaves.  The eggs hatch out into caterpillars, which then burrow down into the shallow grass roots to feed on them.

Of course, once the caterpillars have disappeared beneath the surface of the lawn, they're hard to spot.  A good way of confirming your sick lawn diagnosis is to place a wet paper bag or some soaked newspaper on the lawn in the evening.  Turn the paper over the following morning and the army worms can be seen hiding underneath.

How can you get rid of army worms?

You can buy army worm chemical killer products from good garden centres in the form of granules, sprays, and hose-on treatments. 

For maximum effect always apply the product to the lawn in the evening.  This is because the army worms hide deep underground during the day to avoid the heat, moving upwards to the shallow grass roots to feed as the temperature drops in the evening. 

How can you prevent an army worm attack?

The best way of discouraging army worms is by keeping your grass growing continually and evenly, without any sudden flushes of new growth.  This is because older, tougher roots are not as appetising to the army worms and are therefore less likely to attract them.

To achieve this even growth, feed your lawn regularly with a slow-release fertiliser product during the cooler, dryer months of the year.  Don't fertilise when the weather is warm and damp and the grass will naturally put on a growth spurt.

Some types of grass are more resistant to the army worm than others.  If you're planting a new lawn, consider using Buffalo grass, Tropika or Zoysias, all of which have very coarse roots and a typically constant growth rate, making them unattractive to these pests.

In conclusion

If you think your lawn may be suffering from army worm attack, follow the advice above to halt the pests' progress and prevent further infestations.