Biggest Armyworm Invasion in 30 Years Skips Crops to Get Turf

(Bloomberg) -- Fall armyworms are marching across the U.S., turning lush green lawns into dull brown as the invasion spreads from Virginia across the northeastern states and beyond.

It’s the largest infestation entomologist Thomas Kuhar has seen in 30 years, and perhaps the most unique. These pests are often found in crops such as corn, rice and sorghum, though the Virginia Tech professor said this year’s outbreak is selectively targeting lawns and some hayfields while bypassing crops armyworms typically also devour.

“That’s not a normal fall armyworm behavior,” he said in a phone interview. “They should just be devouring things in their path.”

By the time a lawn turns brown, the worm-like larvae have already been camped out there for three weeks to a month. They eventually become moths -- a single female can lay as many as 1,500 eggs. While they typically aren’t much of a problem in a state as far north as Virginia, Kuhar said the moths probably traveled up from the southern U.S. on storm front winds.

Armyworms are a huge problem in countries in Africa. Last year, about 15% of the corn crop in the southern African nation of Zambia was infested, according to the U.S. Department of Agriculture. The invaders also contributed to a 4% decline in China’s corn harvest, sending prices for the grain soaring and forcing the Asian nation to open its strategic stockpiles.

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