Sod webworms have a bivoltine life cycle with four stages: egg, larva, pupa and imago (adult).

With the coming of warmer weather, the larvae will pupate, and moths will appear in late spring or early summer.

Some species also feed on maize, wheat, rye, oats, timothy-grass, and other grasses in pastures, and meadows, with the most damage occurring in areas with permanent sod.

[4] The pupa develops in a silken cocoon attached to soil particles, plant debris and fecal pellets.

The cocoon resembles a small lump of earth, while the pupa itself is pale yellow at first, darkening to a mahogany brown.

[3] Like other snout moths, they have long labial palpi that extend in front of their heads, and fold their wings underneath their bodies, making them slender and harder to see while resting on plants.

[3] To be considered a serious infestation of sod webworms, 12 larvae must be found in a 0.1 square metres (1.1 sq ft) area.

[3] To test this, hollow pans are placed with a pyrethrum or detergent drench and allowed to sit for 10 minutes, then the larvae in the area are counted.

[4] The genus Crambus was erected by Johan Christian Fabricius in 1798, and was originally used to cover species which are now considered to belong to the Noctuidae.