This past week was our 22nd week of monitoring for Ohio pests at the Lep Network and our 6th week reporting on the fall armyworm (FAW). While the statewide average slightly decreased this past week, individual trap counts are still high in some select counties. If FAW reports surpass an average of 7 in your county, we recommend continuing to scout for egg masses and larva in the coming weeks. Counties that should continue scouting for FAW are: Lucas, Sandusky, Van Wert, and Wayne.
Fall Armyworm Averages and Scouting
The statewide average for FAW this past week dipped slightly from 50.6 for the week ending September 8th to 41.2 moths for the week ending September 15th. Counties with the highest averages are Wayne (190.5), Van Wert (63.7) and Lucas/Sandusky (9.0) (Figure 1). This past week, Wayne County saw the highest trap count with 376 fall armyworms in one trap.
As mentioned in last week's newsletter, the fall armyworm is a sporadic pest of corn, sorghum, small grains, pasture grass, and forage crops. The FAW is a tropical pest and therefore not native to Ohio as it overwinters in warm soil in the southern US. Due to its strong affinity for warmer temperatures, infestations are infrequent yet can be damaging when they occur. Expect FAW infestations to become more frequent and potentially more damaging as annual temperatures continue to rise. When scouting for FAW, continue to be aware of larval presence as a spike in this activity is to be expected near the end of September. When scouting for fall armyworm larva, be sure to look for the distinct white, inverted “Y” shape on the front of this pesky pest's head (Figure 2).
For more information on the fall armyworm, visit our current factsheet on FAW: https://ohioline.osu.edu/factsheet/ent-0093
Fall armyworm moth map
Week 6
September 9th to September 15th, 2024
