23/08/2021
We are getting lots of calls and questions about FALL ARMYWORMS. There is a big outbreak in the state now, and they damage both hayfields and home lawns.
By the time they are in this wandering or marching phase, they are fully mature caterpillars, and will not be around many more days.
But, this time of year, there can be a lot of overlap in generations, so there could be some younger ones still there eating your grass.
In the past, a pyrethroid insecticide, such as bifenthrin (Ortho Bug-B-Gon) or permethrin has worked well against these in the home lawn. You can buy this, or another pyrethroid in a ready-to-use hose end applicator, and this is an easy way to treat smaller lawns.
This year we are hearing some reports of fall armyworms being hard to kill with pyrethroids alone. You can still try the bifenthrin first, but if it does not work, then a Spinosad product (GreenLight, Bonide, Monterey, and others sell this) should work better.
Or you may want to hire a commercial applicator to treat, if necessary.
See page 8 of the following Extension publication for more details on controlling fall armyworms in home lawns. Link: http://extension.msstate.edu/publications/control-insect-pests-and-around-the-home-lawn
