Cutworms

Constraint - Cutworms

Description

• There are two species of cutworm that damage crops, Brown/pink cutworm, and common cutowrm (Bogong moth)

• Cutworm larvae are generally plump, greasy in appearance, and smooth bodied

• They have dark heads, dark/red-brown/pink bodies without distinct hairs and can grow up to 40-50 mm long

• Moths vary in colour from dull brown to black with wingspans ranging from 30-50mm

Symptoms

• Patchy damage, with seedlings most affected

• Caterpillars found just under the soil surface

• Plant stems/cotyledons nipped off or completely eaten

Damage

• High density of cutworms can severely damage canola crops

• In some rare cases paddocks of canola can be completely wiped out

• Resowing is often required

Control

Monitoring for cutworm damage is crucial. Careful inspection of the soil around damaged plants may reveal larvae. If required, cutworms are easily controlled with registered insecticides such as organophosphates or pyrethroids. Spraying in the evening is likely to be most effective as larvae are emerging to feed and insecticide degradation is minimised.

 

 

Links and Resources

CESAR - Pestfacts. Cutworms Information on local sightings, habits and behaviour, industry advice, control options, and description. Published 2014.

DAFWA - Identification of pests of Canola. Cutworms Page 11. Description, lifecycle, damage, and control. Published 2005.

GRDC - Best Practice Management Guide. Cutworms Page 48 of 92. Introduction, monitoring, feeding habits, damage caused, lifecycle, and management. Published 2009.

NIPI - Cutworms in Canola Information on finding, monitoring, beneficials, cultural control, thresholds, chemical control, multi-pest considerations, and discussing management. Published 2014.

PIRSA DAFWA & CESAR - I Spy Manual. Cutworms Section 4, pages 7-8. Description/distinguishing characteristics, confused with/similar to, distribution, pest status and risk period, host range, damage symptoms, monitoring and sampling, and management options. Published 2012.