By Blake Jackson
Corn earworm populations in Pennsylvania have remained stable but generally high as of August 21, 2024. This has resulted in varying spray schedules across the state, depending on the severity of infestations.
For example, Lancaster County is currently on a tight 2–3 day spray schedule, reflecting particularly high moth activity, while Butler, Centre, Clinton, Erie, Juniata, Lehigh, and York counties are maintaining a 3–4 day schedule.
Mifflin County follows with a 4–5 day schedule, and other counties in the state are on a 5–6 day or longer spray routine.
The prevalence of corn earworms, especially during the reproductive and late vegetative stages of corn, has driven the need for frequent treatments.
Managing corn earworm effectively also helps control fall armyworm populations, which have shown similar levels to the previous week.
To aid in management, specific spray thresholds have been established. These thresholds are based on weekly corn earworm trap counts and help determine the appropriate frequency for pesticide applications.
For example, when the weekly catch is between 71 and 349 months, a 3–4 day spray schedule is recommended. In contrast, populations exceeding 350 moths per week necessitate a more aggressive 2–3 day spray frequency.
Data from August 14 to August 21 show significant variations in trap counts across different counties. For instance, Lancaster County reported a substantial increase at the Landisville site, with counts rising from 291 to 454.
Meanwhile, Erie County's Lake City Rt 5 site reported a high count of 138, further emphasizing the need for vigilant pest management. For more information visit https://extension.psu.edu/2024-sweet-corn-trapping-data
Photo Credit: pexels-nikolett-emmert
Categories: Pennsylvania, Crops, Corn