Forage and soybean producers should closely monitor their fields for this pest. Wheat producers may likely avoid any significant damage by planting after the Hessian fly free date. It is likely too late in the growing season for fall armyworms to cause damage to corn or grain sorghum.

Early detection is the key to fighting insect. The pest varies in color from light tan to black with three yellow stripes down its back. The middle stripe is usually darker and the ones on each side are wavy and yellow-red blotched. Fall armyworm has a dark head with a light-colored, inverted "Y" mark on front.

If producers find significant populations of the fall armyworm in their fields, they can apply an insecticide. A list of insecticides for various crops is located in the 2010 Insect Management Recommendations for Field Crops and Livestock, which is accessible online at Johnson cautioned against making any preventative insecticide applications, as these could harm beneficial insects that naturally control the fall armyworm.

Captures of adult corn earworm moths, also known as the soybean podworm, also rose dramatically in Princeton, but their increase wasn't as phenomenal as the fall armyworm. The corn earworm moth trap count for the week ending Aug. 27 was 484, which is up from 82 during the Aug. 20 trap week.

"In the nearly 18 years of monitoring this pest, this is the second-largest capture with the largest being 525 in August 2001," Johnson said.

While it is too late in the season for corn earworm to do any significant damage to corn or grain sorghum, the pest will also feed on soybean pods and seeds. Like the fall armyworm, the moths should turn into caterpillars in a week or two. Soybean producers, especially those with late-maturing varieties, should scout their fields for this pest.