They're about 1/4 - 3/4 inch long. 1 Response. Larvae are up to 2 inches in length and brown or dull in color. Whiteflies, for instance, are common insect pests of lawn grasses. Grubs, the whitish, soft-bodied C-shaped larvae of beetles like the Japanese Beetle and European Chafers, eat grassroots, killing off the grass. At the root level, you'll see small white tubes made of silky web. Although the damaged lawn areas might look unsightly, the moth larvae rarely cause permanent injury because they don't feed on grass roots. Cultural Control Adult sod webworm moths are usually most noticeable during the summer months and the larvae causes damage to grass that is visible by the early part of fall. Treated areas of your lawn are quickly repopulated by lawn moths from untreated areas. And they are very mobile, flying into your lawn from untreated areas. Tropical sod webworms are one of the most destructive pests of St. Augustine grass and carpet grass. In a minute we’ll show some of the damage here. Any insects that are not readily recognizable can be taken to your local extension office for identification. If there's anyhitng St. Augustine grass does not like, it's being scalped - which causes it to turn brown. To kill sod webworms without resorting to heavy-duty chemicals, we recommend using a pesticide containing BT (Bacillus … Wings are held flat over the back when at rest, giving the insect a triangular appearance. They live in ditches, roadsides, vacant lots, and the shady areas of your lawn. Preventive measures include keeping the turf healthy with adequate irrigation and fertilization. Once they’re in your yard, chinch bugs stay on the move, eating the base of grass stems and destroying one patch of grass before heading for another spot. They are active between early and late summer. These light tan-colored moths will flitter and scatter as you walk through the grass. Tropical sod webworm adults (Figure 2) are brown moths with a mature wingspan of approximately 20 mm (3/4 inch). I hear they eat the roots of St. Augustine grass. At dusk, you might even see the worms themselves. Lawn moth larvae rest on top of the soil during daylight hours and emerge to chew holes in St. Augustine grass blades at night. It lays the eggs, and they hatch to become caterpillar (sod webworm). Using a homemade drench test is the easiest way to flush out and count the larval pests. The adult moth does not damage the grass directly. When you see little brown moths buzzing your lawn, it's time to check your St. Augustine turf grass for sod webworms. The sod webworm caterpillar will eat (chew) various types of grass, especially St. Augustine Grass. The soap irritates the caterpillars, and you can typically spot them as they move to a drier location. Store unused, undiluted product in a dry, cool location. Using a watering can, evenly sprinkle the solution over 1 square yard of unhealthy lawn area. Adult webworm moths are approximately 3/4 inch in length. Fungus on St. Augustine grass shows symptoms such as browning of leaf blades, rust-like growths on grass, and areas of thinning or dead grass in your lawn. Mature caterpillars are ¾ to 1 inch long and … University of California Statewide Integrated Pest Management Program: Lawn Moths and Sod Webworms, University of California Statewide Integrated Pest Management Program: Sod Webworms. Hindwings are white or light in color and plain. Small white moths, often called lawn moths, are a common sight in lawns and grasses throughout North America. Cutworms are another variety of caterpillar which are the larvae of different moth species which can affect St. Augustine lawns. This larval stage is the most damaging of the tropical sod webworm’s life-cycle. Although the moths themselves won't damage the grass blades, their larvae can cause significant damage. Take an open-bottom cylindrical can such as a coffee can with both ends removed and push down into the soil in a patch of lawn that is on the interface of damaged and healthy lawn. The moths themselves don't cause a great deal of damage to grass and other plants, but their larvae do. Sod webworm larvae are actually a number of different species. These damaged spots usually occur in circular patches. Fill the can approximately three quarters full with water and see what insects float to the top. If the moths are sod webworms the product you used should kill the larvae that are eating the grass … Many homeowners will confuse this rot with take-all root rot because of the yellow coloring of the leaves. Adult cutworm moths are approximately 1.5 inches in length with dark brown and streaked forewings. And Saint Augustine lawns are not immune to these pest invasions. Cutworms do their damage by chewing turf blades at their base. Cutworms are another variety of caterpillar which are the larvae of different moth species which can affect St. Augustine lawns. Preventive measures include keeping the turf healthy with adequate irrigation and fertilization… Don't store diluted product for more than 12 hours or it loses its effectiveness. My lawn is St. Augustine. There are several possible reasons why your lawn would be dying. Featuring medium-green to blue-green, broad blades, St. Augustine forms a dense, low-growing turf that suffers few pest problems. Lawn moth larvae have slender, cream-colored bodies with distinct dark brown or black spots running down their backs. University of California Statewide Integrated Pest Management Program: Lawn Insects, Texas A&M AgriLife Extension: Sod Webworm, The Ohio State University Extension Fact Sheet: Sod Webworm Management in Lawns, White Bugs & Circular Patches of Dead Grass. Brown patch fungus proliferates in cool wet conditions. Count the number of caterpillars that appear within 10 minutes of drenching the soil. Adult cutworm moths are approximately 1.5 inches in length with dark brown and streaked forewings. A. Control of both moth species in St. Augustine grass should be targeted at the larval stage. Some of this grass has … Mature caterpillars reach about 3/4-inch long. Harris County Texas. The good news for you is that brown patch disease on St. Augustine grass can be treated easily even using DIY methods as I’ve described in this article. One exception is the sod webworm, the larval form of little brown moths that you can often see flying just above your lawn. They're frequently seen fluttering over the turf in the early evening,” he said. Apply a Bt solution only during dry, warm weather. The adult Crambus vary in color from white to gray, the tropicals … Chinch bugs are another opponent. Annual thatch removal can also prevent the incidence of many lawn pests. He has been published in "The Plain Dealer," "The Repository" and online. The lawn moths are ubiquitous in Pinellas County. Adult tropical sod webworm moths are dingy brown with wing spans of about 3/4 inch. All Rights Reserved. ; June 2003. When St. Augustine grass suffers from this type of fungus, the movement of water and nutrients is unable to get to the roots of the grass, making its leaves turn yellow and die. Although nontoxic to humans, Bt spray can still cause eye or skin irritation. Fold the wings around the body at rest, the tropicals spread their wings, giving a triangular appearance. The moths do no damage to the turf, but the larvae can devastate St. Augustine lawns. Take an open-bottom cylindrical can such as a coffee can with both ends removed and push down into the soil in a patch of lawn that is on the interface of damaged and healthy lawn. Much of what's noticed are leafhoppers which have had a good year living among the local turf. We came in with a sod cutter, cut the grass out, and replaced it with Raleigh St. Augustine. The appearance of moths in St. Augustine lawns is indicative of more serious pests such as sod webworms or cutworms. Many gardeners are seeing moths or what appears to be moths in their lawns. The pests often chew individual blades all the way down to the soil line, and this defoliation can result in irregularly shaped patches of bare soil or brown turf. They are susceptible to cold and do not survive severe winters, thus limiting their most severe damage to south Texas where winters are mild. Q.What should I use to eliminate moths in the lawn? Lawn moth larvae rest on top of the soil during daylight hours and emerge to chew holes in St. Augustine grass blades at night. According to the University of California, you should treat your lawn only if the drench test flushes out 15 or more moth larvae in each square yard. Once a caterpillar consumes Bt-treated grass, the bacteria poisons its digestive tract and the pest stops eating and dies within just two or three days. Insect damage is an incredibly common culprit in struggling St. Augustine lawns. This may need to be done in several areas. The grass above their tunnels browns and dies when the webworms come out of the tunnels to eat the grass. To determine if damage to your St. Augustine lawn grass is indeed sod webworm or cut worm, perform a "float" test. One Bt-based pesticide recommends mixing 1/2 to 4 teaspoons of Bt-based product per gallon of water in a handheld garden sprayer, but carefully read and follow the specific directions on your product's label since instructions vary. Any thoughts/recommendations? We have also seen the damage on Bermuda grass, but to a lesser extent. These nocturnal pests hide in the grass and nearby plants during the day, but will scatter and fly short distances if disturbed. Moths are the adult forms of these serious lawn pests. damage to St. Augustine lawns in the Houston area. from the State University of New York at the Finger Lakes campus in Canandaigua, N.Y. The pests often chew individual blades all the way down to the soil line, and this defoliation can result in irregularly shaped patches of bare soil or brown turf. Combine 2 to 4 tablespoons of liquid dish soap with 1 gallon of water. The moths are the adults that lay the eggs that hatch into the caterpillars that eat our lawns. Damage from sod webworms appears as dead patches in normally green grass in spring and, in general, a thinning of the turf during summer months. ; March 1999, Ohio State University; Sod Webworm Management in Lawns; David J. Shetlar; 1995, University of California; Lawn Moths and Sod Webworms; 2009, North Carolina State University; Cutworms in Turf; Stephen B. Bambara et al. St. Augustine Grass is susceptible to a type of fungus aptly called brown patch fungus. Controlling the caterpillars helps reduce future lawn moth populations.