Time to Scout Canola for Bertha Armyworms!

Prepared by John Gavloski, MAFRI Crop Entomologist

Trap counts for adults of bertha armyworm have generally been lower over the past couple of weeks. So populations of the moth stage have peaked and fewer moths are now present. Egg laying should be nearly complete. Some traps had cumulative counts in the uncertain risk category (300-900 moths), and traps near Elm Creek, Sperling, Ridgeville and north of Roblin have counts in the moderate risk category (900 – 1,200 moths). 

A table showing data from the bertha armyworm monitoring program can be viewed on the MAFRI website at:

http://www.gov.mb.ca/agriculture/crops/seasonal-reports/pubs/bertha-report-2013.pdf

 When currently scouting canola fields, look for larvae of bertha armyworm. So far only low levels of larvae have been noticed. Many larvae will still be small and harder to notice. Also note that populations of bertha armyworm can vary greatly between fields within a region, so assumptions regarding a field cannot be made based on findings in nearby fields.

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