Sweet Corn
Fall Armyworm Alert!
Fall armyworm (FAW) infestations are increasing in frequency and severity now. While numbers are not extreme, field scouts are reporting infestation rates from 12-30% with some regularity in many parts of central and northern NJ. Cooperating growers in Cape May County (where FAW is typically heaviest) report that FAW is now present in whorl and pre-tassel stage plantings. Because FAW moths are highly mobile, and with southerly winds continuing to dominate, it is important to monitor fields at least weekly for signs of infestation. Whorl stage plants are prime targets for egg laying.
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.