GARDENING: Lawn-eating caterpillars could return this fall

A colleague and good friend, Dr. Curtis Young, Allen County (Lima) said he is trapping significant numbers of them in his monitoring traps. The number of adult moths in the traps were high enough to warrant a warning from Curtis to be on the lookout.

The problem in 2021 happened because no one knew they were feeding until it was too late.  The early instars (stages) of the armyworms are quite tiny and feeding injury isn’t obvious. However, after about five to six instars, they consume an entire blade of grass quickly.

If the populations are high enough, they can consume an entire lawn almost overnight — at least it feels that way. If there is no more turf to eat, the consume each other!

The caterpillar attack in 2021 was likely due to the moths catching a good strong storm wind out of the south. They landed in most parts of Ohio.  They originate in South America and migrate north on storms.

The closest site trapping the adult male moths nearest to the Miami Valley is Curtis’. Most of the traps around the state are in northwest Ohio.  However, Allen County is not that far from us so it’s a good idea to start inspecting the lawn.

There are a couple of different methods to check for armyworm caterpillars. Note, that if you have a lot of starlings feeding in the lawn, you want to check.  Inspect the turf blades closely in the area where the birds are feeding.  Look for tiny caterpillars.

Another method is to put a tablespoon of dish soap in a gallon of water and pour it on a small area of turf. If caterpillars are present, they soon surface and are visible.

Lawns should be treated with a product that lists caterpillars on the label. Lawn products that contain the active ingredients bifenthrin, beta-cyfluthrin, lambda or gamma-cyhalothrin, permethrin, deltamethrin, or other pyrethroids. Please, always follow the label instructions.

Try to treat the caterpillars early when they are small. As I mentioned, it seems as though they can eat an entire lawn overnight.

Since there are few to no weeds or clover in the lawns, it’s also safe for pollinators to treat currently.

Finally, you can also look for the brownish moth, however, entomologists are more likely to see the moth than you or I. I see a lot of brown moths and am challenged to identify them.