Cutworm

Both larvae and moths are active at night.

Larvae:

• up to 50mm long
• hairless with dark heads
• darkish bodies, often with longitudinal lines and/or dark spots
• curl into a 'C' shape and remain still if picked up.

Moths:

• dull brown to black patterned wings
• attracted to light.

Armyworms, helicoverpa larvae

Widespread and sporadic.

Attacks all field crops. Crops are at most risk during seedling and early vegetative stages.

• Young caterpillars climb plants and skeletonise the leaves or eat small holes.
• Older larvae commonly cut through stems at ground level and feed on the top growth of felled plants, but they may also climb to browse or cut off leaves.
• Caterpillars nearing maturity often remain underground and chew into plants at or below ground level.
• Early autumn egg-laying results in most damage to young cereals.

• Larvae feed on host plants from hatching through to maturity.
• Mature larvae pupate in the soil.
• Egg-lay to adult emergence is usually 8–11 weeks, depending on species.

Cutworms usually feed in the late afternoon or at night. By day they hide under debris or in the soil.

• Check crops from emergence to establishment.
• Look for patchy areas or where the crop appears thin.
• Scratch away surface soil to look for larvae.

Cutworms are attacked by a number of parasitoid wasp species.

Naturally occurring fungal diseases can reduce populations.

If distribution is patchy, spot spraying may suffice; apply late afternoon to evening for maximum contact with the caterpillars.

Control weeds 3–4 weeks before sowing.