Therefore, cattle producers are advised to start scouting their pastures to detect fall armyworm infestations before they become widespread. In some geographic areas, extension specialists have already discovered invasions of armyworms, because the insects can t find other forage to devour. The armyworm larvae are generally found seeking shelter in the whorl of the plants, or in ground cover during the daytime. In cases of heavy infestation, armyworms have been known to consume plants to the point that only stubble remains. Infestations are frequently related to the presence of grassy weeds, rye cover crops, neighboring grass or small grain strands which supported the development of a population the previous fall.
Infestations characteristically appear in large numbers all of a sudden.
If they re close together in one spot, and fall armyworms have been reported around, chances are they ve spotted the armyworms. Another sign could also be congregations of birds. On sunny days, scratching the surface of the soil and examining the debris will reveal if armyworms are hiding under the surface. A field damaged by armyworms appears drought stressed, but closer inspection shows ragged leaf tips and scalloped notches out of leaf sheaths. This consumption can destroy a hay crop in some pastures, but will rarely cause plant death, according to Flanders.