Look Out for Fall Armyworms in Pastures and Hayfields

— Written By and last updated by Debra West

Our ability to effectively manage armyworms relies heavily upon two things. The first is to be ready for them and always on the lookout during hay season. Stopping to briefly scout fields on a daily basis can and will save a forage crop.

Second, harvesting hay fields or quickly spraying once the insects are spotted will put a halt to damage they can cause. If it’s time to harvest your field anyway, cutting the hay a little sooner is a good plan. However, if harvesting is a still a week or two away and enough armyworms are seen, it is critical to spray.

Also, because animals consume the forage that is sprayed in an armyworm attack, only chemicals labeled for the use on pastures and hay fields should be applied. If a chemical is recommended to you, be sure to double check the label for this reason. There are several chemicals that can be used to control armyworms.

The 2013 North Carolina Agricultural Chemicals Manual recommends using one of the following chemicals for fall armyworms in hay fields: spinosad (Tracer, Entrust), diflubenzeron (Dimilin 2L), methomyl (Lannate), or zeta-permethrin (Mustang Max). For fall armyworms in pastures, recommended chemicals are azadirachtin (Azatin XL Plus, Neemix 4.5), diflubenzeron (Dimilin 2L), spinosad, and carbaryl (Sevin). For true armyworms in pastures or hay fields, use: azadirachtin (Azatin XL Plus, Neemix 4.5), malathion, Bacillus thuringiensis (Agree WG, DiPel DF, Xentari), methoxyfenozide (Intrepid 2F), spinosad, or zeta-permethrin (Mustang Max). Most of the products listed here should be found at you local chemical dealer.

Remember to always be sure to read and follow product label recommendations before purchasing or applying a chemical.

For more information on identifying and controlling armyworms or other forage questions, feel free to call us at the Wayne County Extension Office at 919-731-1525.

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