European Corn Borer
After scouting fields over the last few days I have found larvae and shot holes in leaves. Most activity has been found high in the plant and on the tassel. Tassels are beginning to push up so this is a opportune time for scouting and if needed, insecticide application. So far I haven’t seen anything close to application threshold.
Check out this info sheet on ECB. Take note in MB there is generally only one generation.
When scouting for ECB scout earliest planted fields first. In each field check in 5-10 locations (10 plants in each location) for egg masses and young larvae. The masses are generally found on underside of leaf, leaf midrib, or leaf axil (leaf attaches to stalk). Pull open the whorl to check for larvae feeding. If no masses or larvae are found continue to check every 5-7 days for the next 2 weeks.
Here is a video on scouting for ECB.
Other things to what for are shot holes in the leaves.
Early-stage larvae feed on developing leaves inside the corn whorl. When the leaves emerge a series of small, repeating holes or long, narrow strips are indications that European corn borers may have caused the injury.
More pictures of ECB signs
Last year we saw some ECB damage and combined with hot dry fall stalk breakage was a concern. Picture of a ECB damaged field at harvest.
As you can see there maybe harvest complications and yield losses especially if the stalk breaks below the cob and/or we have a big wind event. ECB may reduce yield by restricting nutrient flow with in the plant as well.
Here is an economic threshold calculator to help determine if you should spray or not.
Once the ECB has bored into the stalk control is difficult one product that has great potential is Coragen which is systemic and will not kill beneficial insects such as bees.
If you have any questions please call or text me.
Also be sure to leave comments about the blog and possible topics you want me to discuss, Thanks Derek