By Blake Jackson
Corn earworm populations are currently moderate across Pennsylvania, with some regions experiencing high numbers. Erie and Lancaster counties are on a 2-3 day spray schedule, while Butler, Juniata, and Lehigh counties follow a 4-5 day schedule.
Other areas have a 5-6 day or greater spray schedule. Recent data indicates that corn earworm numbers have shifted slightly downwards, but fall armyworm populations have increased, necessitating continued management of both pests.
For effective control, growers should refer to the established spray thresholds for corn earworm. The thresholds are as follows: almost absent (1-13 catches per week) calls for sprays every 7 days; very low (14-35 catches) every 5-6 days; low (36-70 catches) every 4-5 days; moderate (71-349 catches) every 3-4 days; and high (more than 350 catches) every 2-3 days.
Conventional control methods include pyrethroids, diamides, and spinosyns, though pyrethroid resistance is becoming more common.
Organic options like Entrust SC and Gemstar LC, along with Bt products, offer alternative solutions. Maintaining habitat for natural predators such as lady beetles and pirate bugs can also aid in pest management.
Recent field monitoring reveals varied earworm infestations. In Rock Springs, Bt corn demonstrated 100% clean ears compared to 70% in non-Bt corn, highlighting the effectiveness of Bt traits in pest control.
The data underscores the importance of using diverse pest management strategies and keeping up with the latest practices to mitigate damage from corn earworms and fall armyworms.
Photo Credit: pexels-nikolett-emmert
Categories: Pennsylvania, Crops, Corn