Watch out for black cutwork feeding!

As I have been out monitoring my black cutworm pheromone traps I am seeing a spike in moth flights, which could eventually lead to serious black cutworm issues in the next following month. DATCP is projecting that May 20th will be the average date when larvae are reaching their maximum damage potential.  One black cutworm can cut down as many as 4 or 5 plants in its larval stage.

With a wide range of hosts black cutworm can be a problem not only in corn but also in soybeans, sunflowers, and other agronomic crops. When scouting be sure to pay attention to low wet areas, patches of fields that have early weed development as well as fields that use reduced tillage systems.

When scouting fields check 10 plants in 10 different areas of the field to record the percent of plants displaying feeding symptoms, if feeding is greater than 3% an insecticide treatment may be considered.

Consult your Allied Agronomy Advisor for control options if you believe you are at threshold. — Josh Johnson, Agronomist

BCW pheromone traps

Pictured above are the black cutworm moths that I found in my pheromone trap.

Cutworm damage

Evidence of black cutworms feeding on young corn plant.


A young corn plant that was cut off by a black cutworm.

Insect activity found today…

Near Galesville today I found my first Western Bean Cutworm Egg Mass. The moth counts are very low this year. We put out 5 pheromone traps and have found very few this season. I also found a fair number of Corn Rootworm beetles feeding on the fresh silks today. Please keep a watchful eye on your corn fields during the critical pollination phase. The published threshold is “when silk clipping is occurring on 25% or more of the plants during pollen shed.” Also, if this field will be corn next year, it is best to plan your management strategy to combat this pest now due to the fact that they will be laying eggs now to attack next year’s corn crop. Please let us know if you have questions on any of these issues. Thank you.

– Rob Shields, Agronomist

Western bean cutworm egg masses.

Western bean cutworm egg masses.

Corn rootworm beetle feeding.

Corn rootworm beetle feeding.

Corn rootworm beetle feeding.

Corn rootworm beetle feeding.