Sweet Corn
Fall armyworm (FAW) infestations remain present, although in fields where growers responded with appropriate insecticides, control has been good. Re-infestation is occurring rapidly in Cape May County fields, and is likely happening elsewhere in the southern part of the state. Because FAW moths are highly mobile, it is important to monitor fields at least weekly for signs of infestation. Whorl stage plants are prime targets for egg laying. Delays in treating whorl stage infestations can lead to stunted plants and poor ear size.
Newly hatched FAW larvae cause holes and scratches on leaves that are similar to ECB feeding, except that they tend to be more concentrated and always lead down into the whorl (see photo at left). As the larvae grow, the feeding becomes more destructive, with large ragged holes and obvious droppings deposited in the whorl (see photo at right).
We will provide updates on new FAW appearances and severity as reports come in. FAW are resistant to synthetic pyrethroids. Effective sprays should include IRAC grp. 5 (spinosyns) or IRAC grp. 28 (diamides). The carbamate (IRAC grp. 1A) Lannate is also still effective. Sufficient water should be used in the applications to allow the solution to penetrate the layer of droppings that may have formed above the caterpillar.