Does your lawn look like it went dormant overnight? You may have armyworms!
Armyworms are turf damaging insects that have their name due to the way they travel through the lawn eating the green blades from the grass. These little guys are actually caterpillars. The adult armyworm is a nocturnal moth active during humid, warm summer evenings. The adult female lays her eggs in masses of 50 to more than 100 on the grass blades. The eggs hatch over the course of a few days and begin feeding immediately on the turf foliage and tender stems. As the larvae increase in size they will feed for two or three weeks on your turf stand. In severe cases the larvae can cut the entire turf stand down to ground level, leaving nothing but brown circular patches. During the day the army worm larvae will stay closer to the soil surface in the shade. The larvae Burrowing 2 to 8 centimeters down into the soil, the larvae begin the pupate stage, which last about 9 days. Using soil debris, leaves and silk, the army worm assembles a loose cocoon over their body preparing for their next stage. After a preoviposition period of three of four days the adult female will emerge and lay her eggs and continue to do so for the next four to five days. The adult army worm will live anywhere from 7 to 21 days.
At first sign of damage in your lawn it is important to identify what is causing the decline. If the armyworm is the culprit, an insecticide application needs to be made quickly to stop them in their tracks to prevent further damage.