This past week was our 21st week of monitoring for Ohio pests at the Lep Network and our 5th week reporting on the fall armyworm (FAW). We have seen moth averages climb in key counties including Wayne and Van Wert, respectively. 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: Henry, Lucas, Putnam, Sandusky, Van Wert, Wayne, and Wood.
Fall Armyworm
The statewide average for FAW this past week spiked from only 16.6 for the week ending September 1st to a whopping 50.9 moths for the week ending September 8th. Counties with the highest averages are Van Wert (142.2), Wayne (67.0) and Sandusky (22.0) (Figure 1). Van Wert county saw our highest trap count this week with 934 fall armyworms in one trap (Figure 2).
The fall armyworm is an occasional pest of corn, sorghum, small grains, pasture grass, and forage crops. This tropical pest is 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. The last FAW outbreak in Ohio was recorded only three years ago in 2021 where damage from this moth had substantial effects on alfalfa, clover, turfgrass, fall cover crops and small grain fields. Expect these infestations to become more frequent and potentially more damaging as annual temperatures continue to rise. When scouting for FAW, be aware of larval presence as we expect there to be a spike in this activity near the end of September.
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 5
September 2nd to September 8th, 2024
