Livestock and hay producers should be scouting pastures and hay meadows for fall armyworms. Armyworm infestations can wreak havoc on hay fields, pastures, and newly planted fall forages so scout these areas close and often.
Fall armyworms do not overwinter in Arkansas instead the adult moths catch wind currents and gradually move into the state from the south and lay eggs. Fall armyworm damage can appear almost overnight. Infestations can be easily overlooked when the caterpillars are small and eating very little. Once caterpillars grow large and consume more grass, damage becomes apparent. Fall armyworm infestations can be expected through September.
Producers should carefully examine grass blades, stems and organic debris at plant base, and soil surface in a 1 sq. ft. area. It is best to take at least 10 random 1 sq. ft. samples across the pasture or hay meadow. Female fall armyworm moths prefer to lay eggs in areas of abundant growth, so be sure to include a few of these areas in your 10 samples. Also, make note of the size of the armyworms. Knowledge of their size will help producers make sound management decisions. A 1 sq. ft. sampling device made of stiff wire or PVC pipe will make the sampling process much easier. Remember, armyworm outbreaks often occur in waves about 30 days apart, indicating the need for routine scouting.
For more information about armyworms, contact Danny Griffin at the Van Buren County Extension Office.