Fall Armyworms Make Unwelcomed Visit to Lincoln Co. Crop Fields
“2016 certainly seems to be a year for fall armyworms,” says Andrew Scruggs, Lincoln County’s Extension Agent for field crops. Fall armyworm, a distant cousin of the more familiar corn earworm, is a type of caterpillar that occurs sporadically year-to-year and can damage a number of agronomically important plants. “So far we have seen damage only on grass crops such as tall fescue and bermudagrass that are being used in pasture or for hay,” Andrew states, “we are hoping the fall armyworm does not find its appetite for soybeans.”
The fall armyworm has reached unusually high levels for the area which Andrew believes is likely due to the combination of wet, cool periods during spring and a dry June and July. “These conditions are not favorable for the beneficial insects that parasitize or feed on the fall armyworm, meaning armyworm populations were not kept in check like normal,” Andrew adds. When in large numbers, they have been known to “march” like an army across a field while scavenging for food, giving them the name “armyworm.”
Unable to survive the cold temperatures in North Carolina, the fall armyworm overwinters in Florida and the Gulf Coast region, slowly migrating its way northward as the temperatures rise. Fall armyworm moths arrive in western North Carolina as early as late July and begin laying eggs on plant foliage, particularly in grasses. One female moth can lay as many as 1000 eggs and multiple generations are produced a season. In as little as two days, the eggs hatch and larve, or caterpillars, emerge and begin feeding on surrounding plants. After feeding for two to three weeks, the armyworms bury into the ground to pupate and after an additional couple of weeks, new moths emerge and take flight once again to continue the cycle.
According to Andrew, fall armyworms also can cause damage to home lawns. “If given the time, armyworms have the potential to eat the entire above ground portions of the grass, resulting in dead patches in the lawn or pasture.” Fall armyworms can be effectively controlled with the proper insecticides but Andrew emphasizes the importance of proper and timely crop scouting, “catching them while they are still small and before too much damage is done is key for maximizing control efforts.” For specific control recommendations or for help identifying fall armyworms, feel free to contact the Cooperative Extension office at 704-736-8461.