As if Kentucky growers don’t have enough to worry about with unfavorable weather affecting their crops, now pests in the form of armyworms have become a concern.
There has been at least one report of true armyworms in pastures in the Lexington area, and moth numbers have increased dramatically in the few weeks. The true armyworm overwinters in Kentucky and can be a serious early-season pest of pastures, small grains, and corn.
But the fall armyworm in western Kentucky discovered recently is different from the true armyworm, keep in mind these are two separate insect pests. Fall armyworms are a migratory pest that re-infests Kentucky each summer and is killed by frost in the fall. It often shows up later in the season after corn has tasseled and lost its attractiveness to this pest. But it has been a recurring pest of pastures, and there have been several outbreaks in pastures the past several years. Total destruction of a field of no-till corn can occur if a severe infestation is allowed to develop without the application of an insecticide rescue treatment. Last week, a significant increase in moth captures in Princeton was recorded, which means we need to watch pastures and late-planted corn in the coming weeks for fall armyworm infestations. UK Entomologist Dr Raul Villnueva says the armyworm is beginning to show up in some crops.
click to download audioThe Kentucky counties affected by this pest so far include Ballard, Lyon, Caldwell, Trigg, Logan, and Warren. Dr Villnueva says catching fall armyworm in its early stages greatly reduces damage to pastures and hay.
click to download audioThe name armyworm derives from its behavior of migrating in large numbers into fields similar to invading armies. If you find fall armyworm, the next step would be to count the number per square foot. If more than two to three per square foot are found in a pasture, it would be time to control them with an insecticide or cut the field.
