Tropical sod webworm

The Tropical sod webworm (Herpetogramma phaeopteralis) is a significant pest belonging to the order Lepidoptera and the family Crambidae. Known for its destructive feeding habits, this moth species causes extensive damage to turfgrass and is a primary concern for lawn care professionals in warm climates.

This pest primarily attacks various species of turfgrass, with a strong preference for Bermuda grass, St. Augustine grass, and centipedegrass. Infestations often go unnoticed during the initial stages, but the rapid feeding rate of the larvae can result in severe thinning of the lawn in a very short period.

The life cycle consists of four distinct stages: egg, larva, pupa, and adult. The adult moth is nocturnal and inconspicuous, often found resting in shrubbery during the day. Larvae develop through several instars, feeding primarily at night and hiding in the thatch layer or soil surface during the daylight hours.

Damage is characterized by irregular patches of brownish, thinning grass. Larvae feed on leaf blades, leaving behind notched edges or completely skeletonized foliage. As the infestation progresses, these patches can coalesce into larger dead areas, severely impacting the health and aesthetics of the turf.

Effective management requires a combination of monitoring and intervention. Cultural practices, such as proper irrigation and avoiding excessive nitrogen fertilization, can make the lawn less susceptible. Chemical control involves the application of professional-grade insecticides during the early stages of larval development to ensure the highest mortality rate.

• Frequent monitoring for frass (larval waste) on the soil surface.
• Maintenance of a healthy, vigorous turf density to withstand pressure.
• Targeted use of systemic insecticides to provide residual protection.