Don’t let armyworms waylay your wheat or canola

By Tom Royer, Extension Entomologist

Heath Sanders could not have made a more prophetic statement for this Extension Entomologist than when he said: “we learn something new about canola every year”. I have learned something new every year that I have been working with canola, and this year is starting to confirm his “prophesy” once again.

This has been a banner year for fall armyworms. They built up populations early, and migrated into Oklahoma earlier than “normal”, attacking sorghum and pasture grasses. Now, they are ready to attack wheat (once it emerges) and possibly, are marching in to graze on newly emerged canola. Dr. Angela Post, OSU Extension Weeds specialist reported that there were caterpillars that appeared to be either beet armyworm or fall armyworms attacking canola. We are getting confirmation on their identity, but regardless, producers need to be vigilant and protect their fields.

I have already discussed their management in wheat http://entoplp.okstate.edu/pddl/pddl/2015/PA14-41.pdf, but now need to alert canola producers about them attacking seedling canola and eliminating stand.

Look for “window pane” damage in young canola plants and/or cut plants. At this time, with canola so small, armyworm and cutworm caterpillars cannot be allowed the chance to reduce stand. The suggested treatment threshold is 1 or more armyworms per row-foot.

Look for window pane damage in young canola plants. Treatment threshold is one or more worms per foot of row.

Look for window pane damage in young canola plants. Treatment threshold is one or more worms per foot of row.

Consult CR-7194 Management of Insect and Mite Pests of Small Grains and CR-7667 Management of Insect and Mite Pests in Canola for specific insecticides that are registered for control. Keep in mind that beet and fall armyworms can sometimes be difficult to control, so vigilance is needed by follow-up scouting following an application to make sure control is achieved.

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About Amanda De Oliveira Silva

I joined Oklahoma State University in 2019 as an Assistant Professor and Small Grains Extension Specialist and was promoted to Associate Professor in 2025. My program integrates applied research and Extension with the goal of improving the productivity, profitability, and sustainability of wheat production systems. While much of my work is rooted in Oklahoma and the Southern Great Plains, the questions I study—how agronomic management, crop physiology, and plant nutrition interact to influence yield, grain quality, and nutrient use efficiency—are relevant to wheat-growing systems around the world. By working closely with producers, industry partners, and researchers, my goal is to develop practical, science-based solutions that help growers navigate production challenges and improve the resilience of their farming systems.

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