Sod webworm

Definition

The larval stage of certain grass-feeding moths in the family Crambidae, particularly species of Crambus, Pediasia, and Herpetogramma. These caterpillars construct silk-lined burrows in turf and sod, emerging at night to clip grass blades, and are significant pests of lawns, golf courses, and pasture grasses in temperate regions worldwide. The common name refers collectively to multiple species with similar biology and damage symptoms, not to a single taxonomic entity.

Etymology

From sod (turf, the upper layer of grass and soil held together by roots) + webworm (larva that constructs silken webbing or tunnels).

Example

In late summer, large brown patches in Kentucky bluegrass turf often indicate heavy feeding by greater sod webworm (Pediasia trisecta), whose larvae hide in silk-lined thatch tunnels during the day and surface to feed after dusk.

Synonyms

• lawn webworm
• grass webworm

Related Terms

• thatch
• Integrated Pest Management
• Cutworm
• Armyworm
• white grub
• Crambidae
• turfgrass ecology
• larval shelter

Usage Notes

Sod webworm is a functional common name applied to larvae of multiple genera and species, not a formal taxon. Specialists distinguish species by adult morphology, larval head capsule patterns, and regional occurrence. Damage is often misattributed to drought or other grubs; confirmation requires night inspection or soapy-water flushing to bring larvae to the surface. The silk webbing distinguishes these caterpillars from cutworms (Noctuidae), which lack such tunnels.