Various thresholds of sod webworm numbers that threaten turf damage have been proposed and range from one to 12 per square foot. The general guideline for most Colorado sod webworm infestations is likely to be in the middle of this range. Because cutworms feed more heavily, suggested treatment thresholds for cutworms would be in the lower end of the range. Natural Control Natural controls of sod webworms effectively reduce sod webworm and cutworm populations. Ants, ground beetles, rove beetles and other insect predators are highly effective in controlling sod webworms.
Birds are the most obvious predators.
Starlings, while rearing young, feed on tremendous numbers of sod webworm and cutworm larvae. Flocks of starlings and blackbirds can eliminate infestations in a short period of time. Life stages of the cranberry girdler in Colorado. Chemical Controls Consider insecticide treatments for sod webworms and cutworms only when caterpillar populations are sufficiently abundant to threaten serious injury. Routine sod webworm treatments are not recommended.