Armyworm is around town, showing up in Perth lawns. If your turf looks like an army is chewing on the leaves, or you notice moths at night, have a look in the edge of the eaten grass and see if you can spot them. They won’t be in the area they have already eaten, they will be in the healthy lawn, hence their name.

Armyworm are a problem in your lawn areas normally between autumn and winter, however they are in Perth already this year. The juvenile larvae are initially cream and attain a greenish colour after feeding. Adult caterpillars are brownish with characteristic stripes and black triangular marks along the back and are about 45mm long. When disturbed they roll up into a ball like a slater. Adult armyworm moths are greyish brown with a small wing span.

Female armyworms mate the first night after emergence and two days later they lay their eggs between dark and midnight.

Larvae often feed on the leaf blades, leaving the middle of the leaf, giving it a tattered appearance. They feed only on the soft parts above ground leaving the roots undamaged. The bright green droppings are their castings made up off your lawn leaf!

As the armyworm feeds at night it is best to apply your pesticide in the late afternoon or evening. As the roots are intact the plant is still viable so fertilising with a high nitrogen and iron fertiliser like our Knights Special Mix will promote new leaf growth. The high iron content of our Knights Special Winter Mix will also help if your lawn has gone dormant in winter.

Lawn Doctor have a range of insecticides available at their retail outlet “Backyards to Barnyards” in 1 Dellamarta Road Wangara.