Confirming Sod Webworm Activity
The surest way to tell if you have sod webworms is to find a suspected area of infestation (brown patches). Get down on your hands and knees, take your two index fingers and part the grass blades in the area between dead and live grass and look for an area with small green pellets. The pellets, called frass, are the excrement of the larvae and indicate that a larva is close by.
Do you have any pictures of the green poo? Is it a dark green pellet?