Cutworms are surface feeders. Look for gray-brown-black caterpillars between 1/8 and 2 inches long that curl into a C when disturbed.
Cutworms feed at night. If you suspect a problem, scout for them with a flashlight.
To monitor cutworms, mix 2 to 4 tablespoons of dishwashing soap in a gallon of water. Sprinkle over about 1 square yard of turf. Cutworms will come to the surface in about 10 minutes. Flush the area with fresh water to prevent injuring turf.