Army cutworms damaging wheat

A researcher at the Lubbock Center asked us to tell her what was eating up her ryegrass plots. Suhas Vyavhare and I checked the plots and some wheat fields near Lubbock and found abundant army cutworm larvae. The growth stages are varied from small to about one-inch, so there is plenty of damage yet to come.

Nebraska has a nice 2017 army cutworm alert that states the treatment threshold is four larvae per square foot (for grain production).  Our publication Managing Insect and Mite Pests of Texas Small Grains (page 8) says, "In outbreak years, fields can have 10 - 20 cutworms per square foot." What we saw today was not to that point, but it is still early and many larvae were small and hard to find. Typical damage includes chewing on leaves, cut plants and severed stems.

The first thing you will see when scouting is the leaf damage. During the day, the cutworms will be beneath the soil surface near the plants.

Army cutworm larva.

Clipped stem on 6-inch wheat plant.