PEST

NAME
Lawn Armyworm
Spodoptera species

ORDER
Lepidoptera

FAMILY
Noctuidae

Description of the Pest
The larvae are fleshy caterpillars, up to 50mm long, with dark greenish-brown smooth bodies, having a pair of paler lines down their length, with patterns (triangular, in some species) in between. Larvae hide in the thatch of lawns, leaf litter, or under the surface of the soil during the day, emerging to feed at night. Larvae curl up when disturbed. Adults are grey brown moths, with a 40mm wingspan.

     

Appearance and Distribution of the Pest
An Australian native coastal species that is distributed by flying adults that are assisted by wind.

Life Cycle
These insects have a Holometabolouslife cycle, ie. When metamorphosisis observed during the pupalstage.
Eggs are laid in clusters on the undersides of leaves; larvae pupate in the ground.

Period of Activity
Most active during warmer months, with vigorous plant growth following rain.

Damage Caused
Larvae feed in large numbers, chewing on the leaves, stems and flower heads to ground level, and migrating en masse to another area when the food source is exhausted.

Susceptible Plants
Turf grassspecies such as Pennisetum clandestinum(Kikuyu)and Cynodonspecies (Couch) are susceptible. Lawn armyworm will also attack cereal crops.

Cultural Control
Small numbers may be removed by hand.

BiologicalControl
Birds and parasitic wasps feed on mature larvae (ie after initial damage to host has been done), and are thus not an effective control.

Chemical Control
Spray lawn with Carbaryl (do not water in).
Note
Always read the label for registration details and direction of use prior to application of any chemicals.