Sod Webworms (Family Pyralidae)
Description: The larva are greenish color with black spots. The adult stage of the sod webworms is actually a dingy brown moth with a wingspread of approximately 3/4".
Developmental Biology: The eggs are deposited on the blades of grass. They hatch in about 1 week. Thereafter within 3 weeks until pupation, the larvae will due considerable damage to a lawn. The adults will follow 1 week later. They complete their life cycle in 5 to 6 weeks.
General Behavior: Sod webworms feed primarily at night. They remain at the soils surface in a curled position during the daytime hours. It is very rare that you see them feeding during the day. Sod webworms eat the blades of grass in the lawn. This will be noticed as notches chewed unevenly on the tissue of the grass. Damaged areas will appear as yellow or brown patches. Once the caterpillar is fully grown into a moth, the moth will not feed on the grass. Particular grasses affected are Bermuda, St. Augustine, Centipede, Zoysia and Bahiagrass.
Method of Infestation: Eggs are deposited on the blades of grass and an average of 78 degrees for 6 weeks is necessary for the eggs to hatch.
Management: After an inspection reveals the presence of sod webworms, an insecticide needs to be applied. Your professional pest control technician can decide whether a granular application or a liquid treatment is necessary.