By Blake Jackson
Recent corn earworm (CEW) trap data indicates rising populations in some areas of the state. Notably, York County has reached a 4-5 day spray frequency threshold, while Lancaster County requires spraying every 5-6 days. While other regions may have a seemingly lower risk with a 7+ day spray frequency, vigilance remains critical as trapping efforts are still in their early stages.
Fall armyworm (FAW) presence appears minimal, with only 14 individuals captured in York County traps. Fortunately, effective CEW management strategies typically provide sufficient control for FAW as well.
For producers approaching or exceeding CEW spray thresholds, insecticide options include pyrethroids, diamides, and spinosyns. However, it's important to consider the following:
- Migratory CEW populations may exhibit resistance to pyrethroid insecticides. These resistant populations typically arrive later in the season from southern states.
- Diamides and spinosyns, while effective against CEW, do not provide control for other common corn pests such as sap beetles, brown marmorated stink bugs, Japanese beetles, or adult corn rootworms.
If scouting reveals the presence of these additional pests, incorporating a pyrethroid or the premix insecticide Besiege into your spray program may be necessary.
Early detection is paramount for successful CEW management. Pennsylvania corn growers are encouraged to remain vigilant and conduct regular field scouting to ensure timely intervention.
Photo Credit: gettyimages-dmytro-diedov
Categories: Pennsylvania, Crops, Corn