True Armyworm and Cereal Leaf Beetle in Cereals

As we continue to scout our cereal crops, reports of cereal leaf beetle and true armyworm in fields are coming in. While most fields are not being found at threshold yet, it is important to monitor your fields and be on the lookout.

 

 

To date, true armyworm  has been reported in small, single patches in cereal fields in Grey, Bruce and Simcoe counties.  It has also been reported in Middlesex, Lambton, Elgin, Oxford, Perth, Haldimand, Brant, and Niagara counties where thresholds have been met and required control. Those crops that are at most risk include cereals, corn and mixed forages and should be scouted every three to four days over the next month.  A detailed overview on identification of true armyworm can be found here.

 

When scouting for true armyworm, the best time to scout is shortly after dusk when larvae are actively feeding. When scouting fields ensure you are walking the entire field and looking at 10 different areas of the field. Count the number of larvae per square foot (30 cm x 30 cm) in each of those 10 areas. Ensure you are also checking the border area directly beside other grassy host crops. If it is cloudy and overcast during the day, you may see the larvae on the head of the plant. If it is a sunny day they will be down on the ground among crop debris or under soil clods. Brown frass may also be present on the plants and on the soil surface.