Fall Armyworm Flights Increase --- Again!

Fall armyworm (FAW) moth counts are again increasing in the UK-IPM pheromone baited trap at Princeton. This is not completely unexpected. We see some sort of flight increase about this time every year. As to whether or not it is important is really a matter of when the caterpillars appear in relationship to your crops.

At present FAW counts remain lower than the numbers associated with the known outbreak of 2007 and if they continue to a similar number, the peak will be a week or so later. The caterpillars from that peak could be a threat to early planted wheat.

In 2007 several individuals reported large FAW populations in wheat fields. However on the whole these populations were feeding on the volunteer corn and not the wheat. If you find large numbers of caterpillars be sure to distinguish on what they are feeding. Even though the numbers are large they may be (and likely are) doing no harm at all.

The crop most threatened by the fall occurrence of FAW is newly seeded grasses. This could be wheat but are generally, hay fields, lawns and cover for roadsides, construction sites etc. In the very early stages of these seedling grasses FAW can kill the plants. Once a good root system is established plant death is unlikely.

FAW will be present until the first hard frost. These are not cold tolerant insects; they migrate in annually from the gulf coast states. So, once cold weather becomes the standard this insect will disappear.

If insecticidal control were to be needed FAW will not be hard to kill in these seedling systems. Any product labeled for FAW and the crop of interest will provide sufficient control. One really only needs to reduce the population until cold weather arrives. BE very, very wary of replanting. It is often the case that damaged plants will survive and replanting often results in a double stand.