The Integrated Crop Management newsletter from Iowa State University this weekend provided an update on Black Cutworm Moths captured in traps so far this year. Black Cutworm moths migrate on winds from southern states in early spring, then mate and lay eggs. Traps have been placed since the beginning of this month.
Although at least one county in Iowa has reported a peak flight so far this season, ISU said that “…lots of traps are reporting low numbers. Of the 101 traps placed across Iowa, 46 haven’t caught a single moth as of April 23rd.
So, does this mean you should forget about this pest? Not so fast! As with any pest in production agriculture, proper conditions can lead to an infestation. Keep this in mind- one female moth can lay up to 1,300 eggs! According to ISU’s Extension publication, Field Crop Insects, certain corn fields may be at higher risk for damage than others. At risk fields include “poorly drained soils, low lying fields, those next to areas of natural vegetation, and those that are weedy or have reduced tillage.”
In corn, the best time to scout is from mid to late May until corn reaches the V5 stage. Black Cutworm larvae start cutting at around 300 degree days after eggs are laid. If you are concerned that your fields could be infested, scout weekly for this pest until the V5 stage. In soybeans, one should look for missing, discolored or wilted plants- as well as plants with leaf feeding. Depending on soil conditions, the larvae can feed just below ground, or above ground.
Below are pictures of Black Cutworm larvae and moth. If you believe you may have a cutworm infestation, ask your AFS Agronomist about management options! Have a great week.