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.

Dealing with wet fields, weeds, and pests this week (June 3-7)

This week is shaping up to be a wet one which is a problem for some of the fields that are weedy and too wet for us to get into to spray. Consider increasing rates, and heating up your tank mixes for better weed control on taller weeds when you do get into these fields later. Continue to be vigilant in looking for black cutworm clipping of corn.  The threshold is 3% of plants clipped to warrant a spray. In the potatoes, the first generation Colorado beetles are laying eggs so look for newly hatched larvae next week. Do stem and stand counts this week to determine populations, and weed scouting to see if the hilling operation missed any weeds. Watch out for common ragweed especially as they are very difficult to control if they get larger than 2 inches.

Colorado potato beetle

Colorado potato beetle

Common ragweed

Common ragweed

– Otto Oemig, Agronomist