Most insects pose no threat to plants or grass. However, there are a few lawn insects in Utah that can cause serious damage to your lawn.
Some turf insects infest the soil and attack plants at the root level, some feed on the grass blades, and some do both. Some turf insects suck the juice from the grass blades.
Some of the more common Utah lawn insects that cause damage to Utah lawns include various root, crown, and leaf-feeding insects such as caterpillars; white grubs (which are the larvae of several beetle species); billbugs (which are weevils with white, grub like larvae); sod webworms, armyworms, cutworms and chinch bugs also cause significant damage to Utah lawns.
Surface Feeding Insects
Sod Webworms are the larvae of lawn months. They are light-colored moths, which make short, erratic, darting flights above the lawn and are attracted to lights at night. When resting they fold their wings back closely against their bodies, which gives them a very narrow appearance. These lawn moths lay their eggs in the lawn. In the early evening, they fly over the grass and the females scatter eggs over the lawn. As soon as they are hatched, the larva (Sod Webworm) start feeding on the grass leaves. Sod webworms produce 2-3 generations each year; therefore, the damage is likely to increase as the summer wears on.
Armyworms are also the larvae of moths. They are 1-1/2 inches long; they are greenish and have blackish stripes along each side and down the center of the back. The adults (moths) are brownish gray. Their wings measure about 1-1/2 inches across when expanded. Their feeding causes circular bare areas in lawns.
Cutworms are dull-brown, gray or nearly black caterpillars and are 1-1/2 to 2 inches long. Some cutworms are spotted, others are striped. Usually they hide in the soil during the day and feed at night. They are the larvae of night-flying brown or grayish moths. Cutworms infest lawns occasionally. They feed on the leaves or cut off the grass near the soil.
Billbugs feed on stems and grass leaves. Also see Subsurface feeding insects for more information on Billbugs.
Subsurface Feeding Insects
Subsurface feeding insects are primarily grubs. There are many types of grubs that damage lawns and we can control all of them with our preventative insect application.
Billbugs – The young, or grubs, are small and white, and have hard brown or yellow heads. They feed on the roots of grass. Adult billbugs are beetles 1/5 to 3/4 inch long. They have long snouts, or bills that carry at the tip a pair of strong jaws or mandibles with which the beetles chew their food. The beetles burrow in the grass stems near the surface of the soil and also feed on the leaves.
Grubs are the larvae of various beetle species. They are fat, white with brown heads, have prominent legs with curved bodies measuring up to 1 inch long. Grubs eat the roots of grasses, causing the turf to turn brown and die. Most species require 2-3 years to reach maturity, but some, including the Japanese beetle have a 1-year life cycle. Grub-infested turf will be loose and can easily be pulled back to expose the insects.