Moth flight has begun in the Bootheel for ECB, BCW, SWCB, and TAW. I will be posting next week a table of degree days for prediction of second flight, and a table of when (i.e. Calendar Date) and what damage should be occurring in the field. Insect degree days use the same concept as growing degree days for a crop except that each moth can have a difference in total degree days necessary to complete development (i.e. Reach adult stage). Below is an excerpt from Anthony Ohmes, Extension Agronomist for UM, newsletter sent out today.
Black cutworm and true armyworm moths are flying. I have captured both moths in the past 10 days. For true armyworm monitor wheat fields as wheat develops, especially from flag leaf to head emergence. In hay fields monitor cool season grass as it develops through boot prior to cutting. Threshold for both crops is 4 larvae per square foot. Once larvae reach a size greater than an 1 inch, their feeding cycle has completed. For more information on True Armyworm: http://extension.missouri.edu/p/G7115.
For black cutworm, tillage or an early herbicide burndown at 14 days prior to planting reduces the attractiveness of the field to flying moths. Research has shown that most economic damage occurs from larvae already present in the field at the time of planting. Commercially available seed treatments are the first line of defense. It is critical to scout your field early and often, especially if emergence or overall growth is slowed due to weather, for any potential pest outbreaks. Postemergence rescue treatments are warranted when 1-2% or more corn plants are cut below ground or 2 -3% or more plants have been cut above ground and larvae are present. Larvae are gray to black, 1 to 2 inches long when full grown and form a C when disturbed. In cotton, treatment is needed when stand counts fall below 3 plants/foot of row and larvae are present. For more information on Black Cutworm: http://extension.missouri.edu/p/G7112.