End of Season 2024

Our last monitoring was done on the week of 9/9. Overall, this season saw higher than usual moth numbers in late June and lower than typical in mid August. There was a wide variability in worm population density in the field. Fields we monitored had high number of worms that caused quite a bit of defoliation, approaching threshold in some cases, in late June. However, I heard from some growers and PCAs that did not see many worms in their fields. In the fields we monitored, there were very low number of worms in mid August. Nevertheless, while inspecting fields for our disease survey, we have found fields that had quite a bit of panicle damage, indicating high worm numbers in mid August. 

While the moth numbers can be an indication of overall worm pressure, the most important information the moth numbers convey is the timing of infestations. We have analyzed several years of trapping and we know that the worm peak occurs a week after the moth peak is detected. This is the timing when growers and PCAs need to invest time in monitoring and treating if needed. 

As we close our year of armyworm monitoring, I want to thank growers that allow us to trap moths and collect worms in their fields and Corteva Agriscience for supporting this effort.