The army cutworm has one generation per year and spends the winter as a partially grown caterpillar. It will feed on warmer days throughout the winter. In the spring it feeds more frequently and development proceeds more rapidly. As daytime temperatures rise, the army cutworm is found under soil clods and other debris during the day. In spite of spending so much time in the soil, this is a climbing cutworm that always feeds above ground.
After development is complete a small pupation chamber is built several inches below the soil surface. Moths emerge in May and June and migrate to higher elevations in the Rocky Mountains to escape high summertime temperatures. These moths are the "millers" that become a household nuisance following outbreaks. In late summer and early fall the moths return to the plains to lay their eggs in wheat fields and other cultivated areas. With sufficient moisture eggs hatch and larvae of the next generation start feeding as weather conditions permit.
Army cutworms have a very wide host range and will feed on most crops grown. They will feed on just about any green tissue presented to them, although they will show preferences when given a choice. For example, army cutworms have been observed to prefer broadleaf weeds in wheat fields to wheat. When they do damage wheat, they graze in the spring.
Because of the sporadic nature of army cutworm outbreaks, management options are limited to the use of insecticides. Consider treatment if counts are more than four to five per square foot. Pyrethroid insecticides have been the most effective treatments against this pest in university tests. Registered pyrethroids include Baythroid XLR (wheat), Mustang MAXR (wheat), ProaxisR (wheat and triticale) and lambda cyhalothrinR (several products, wheat and triticale).
RRestricted Use Pesticide
Categories: Small grains, Insects, Army cutworm
Date: 3/10/2006