The invasion of farm armyworms taking over wide fields of forage and lush suburban lawns is of the likes that haven’t been seen in almost 30 years, and the damage has been catastrophic. There is still one question about this year’s infestation that hasn’t been answered: Why are armyworms hitting Ohio so hard this year? Dr. Andy Michel, professor and field crop entomology Extension specialist with Ohio State’s College of Food, Agricultural and Environmental Sciences, is still searching for the answer.
“We have no idea, and it’s humbling for a scientist to say that,” said Michel, who does have some guesses. “One culprit might be warmer winters in areas south of us, which would give more natural survival to fall armyworms as they slowly migrate northward over time, but we just don’t know for sure.”
The name ‘armyworm’ comes from the pests’ behavior of marching across the road from the field they just defoliated to the next green field in its path.
Described by Michel as “one of the world’s nastiest pests,” fall armyworms originated from South America and now they are invasive in Africa and Asia.
Fall armyworms began showing up in Ohio in mid-August in turf and alfalfa fields, along with some reports of damage in soybean fields, and they make quick work of their destruction. In some cases, entire fields were destroyed in a matter of hours. Farmers who haven’t fallen victim to these pests are working quickly to protect their crops.
“Alot of growers are trying synthetic pyrethroids because it is what we have readily available and it is relatively inexpensive,” Michel said. “Farmers are also getting into their forage fields and doing a cutting right away to get what they can from the crop and then start on control measures.”
Dr. Michel warns that this may not be the only time fall armyworms are seen this year, as the process of laying eggs, those eggs hatching, and feeding occurs again by late September.
However, there is one thing that could stop the progress of fall armyworms altogether.
“Fall armyworms are very susceptible to cold weather and especially freezing temperatures,” Michel said. “So, if we don’t start to turn the corner normally this fall, there could be some risk for a third round of feeding. Not so much for corn and soybeans, but more for the forages and potentially some of the wheat fields that might be going in after harvest.”
For more information, read Ohio State’s Unusual Fall Armyworm Outbreaks are Taking Many by Surprise.
Photo credit: Ohio State College of Food, Agricultural and Environmental Sciences