Below is a repeat of an article written in 2014, and this is just a reminder to be checking your pasture grasses for infestations of fall armyworms. I’ve received several reports of treatable infestations occurring in Bermudagrass.
Treatment should be considered when populations exceed three to four larvae per square foot. If fields are ready or near ready for cutting, harvesting is suggested rather than applying insecticide. There are many insecticides labeled for use in pasture, and quite a few have little or no pre-harvest or grazing restrictions. Common options are the synthetic pyrethroids such as Baythroid, Karate/Warrior, or Mustang Max. These work but also have relatively low residual compared with other options such as Besiege, Intrepid, or Prevathon. You might consider biting the bullet and spending a little more money in situations where fall armyworms get an early start in pastures. See the link below for suggested rates.