Cutworms are located in most fields every year, but there have been very few serious outbreaks in the County.
What are the Risks?
The two main species found here are the:
- Redbacked (most common); and
- Pale Western.
Occasionally some glassy varieties will show up in fields of timothy and fescue.
Cutworms are nocturnal larvae that spend their days buried in the soil, thus making them difficult to scout for.
What to Look For
Generally, the first signs of a cutworm problem are bare patches that appear in the crop, seemingly overnight. Upon further inspection you will find healthy plants cut off at ground level or just below the surface. Some species of cutworm may also be leaf feeders and cause damage all the way up the plants.
Redbacked Cutworm and pupae Pale Western Cutworm
Cutworm Field damage Close up of cutworm field damage
Prevention
Due to their nocturnal nature, cutworms can be difficult to manage in canola, and pose a challenge for chemical control. Newer spray technology allows for night spraying which helps to control cutworms and reduce pesticide exposure to beneficial insects.
Here are some other considerations when dealing with this pest:
- Scout fields regularly to provide early detection
- Know which species you are dealing with
- Over time, beneficial insects and diseases will lessen the amount of cutworm infestation
- Apply recommended insecticide at optimum timing using high rates of spray volume to ensure coverage
Related Links
Canola Council Cutworm information
Canola Watch Cutworm management tips
Real Agriculture Cutworm scouting and identification