Lawn pests such as insects and worms are very common throughout the country and can leave your lawn looking brown, burnt, fluffy, or full of holes and in some cases, permanently kill the grass all together. In the Southeast, the most common of these pests are mole crickets, chinch bugs and cutworms.
Upwards of 80% of lawn issues are caused by homeowners. In many cases the mistakes are related to overwatering which leaves the thatch and soil too wet or mowing the grass improperly. When stressed, some plants emit pheromones which attract bugs. Wet thatch can also encourage turf disease which may make your lawn more likely to die when combined with pest damage. Check out this Spring Checklist which contains watering and mowing guidelines to get your lawn healthy before the heat of summer.
Symptoms Descriptions: My grass is soft and spongy, it looks dry or like it’s dying, it’s browning or there are finger-sized ridges or tunnels running through the grass.
Grasses Affected: all grass types are susceptible to mole crickets, particularly bermuda and centipede
About Mole Crickets: These cylindrical-bodied insects are typically 3-5cm in length with small eyes and shovel-like forelimbs highly developed for burrowing. They live and molt (grow) underground and damage the grass roots in two ways: tunneling and eating. Upon damage, the roots dry out or disappear all together and the above grass appears fluffy as it is no longer connected to the ground.
Symptoms Descriptions: My grass was fine yesterday but is half gone today; it looks dry and orange, almost crispy, like it was set on fire, some of the burnt spots look like large doughnuts.
Grasses Affected: this pest is most prevalent in St. Augustine grass
About Chinch Bugs: These tiny insects are multigenerational (several generations can hatch each season) and thrive with large populations, when you find one, there can be thousands. Adults only grow to about 4mm and nymphs can be half the size of a pinhead. Chinch bugs have a long needle like protrusion which they use to inject toxin into the runners or stolons of grass. This toxin liquefies the carbohydrates and converts them into a digestible food source, killing the grass immediately. The chinch bugs then come back to suck out the nutrients, effectively removing all of the moisture in the plant in a rapid fashion which gives it the appearance of being burnt. Chinch bugs are voracious and with their large numbers, can devastate a lawn in short order.
Symptoms Descriptions: My grass looks like it was cut really short by a string trimmer or a mower on the lowest deck setting; there are weird looking areas that don’t seem to be growing; thousands of moths fly out of my yard as I walk through it; it’s a different color than it was yesterday (brown or a different shade of green); there is what looks like sawdust made of grass on the ground and chunks missing or holes in the grass blades.
Grasses Affected: all grass types are susceptible to cutworms
About Cutworms: This term can be used to describe both Fall Armyworms which are most prevalent in bermuda grass or Sod Webworms which prefer zoysia or St. Augustine and Centipede grasses. Both types of worms resemble caterpillars and will eventually become moths which is how they move between various lawns and regions. Adult moths migrating in late summer or early fall, prefer wet overcast conditions, moderate temperatures and high humidity. The moths themselves do no damage to the grass but lay eggs in the thatch which hatch into larvae and become worms. The worms eat grass blades off the runners and are most active in the evening where they will crawl out onto the blades. What looks like grass sawdust is actually frass (the excrement of the worms).
Treatments for most lawn pests include a combination of insecticides and an adaptation to the lawn itself including strategies to reduce excess moisture. The timing of insecticide application can be crucial as treating the pests at the wrong time can be ineffective. For more detailed information on treatment of these lawn pests and more, download a copy of our free e-book: What’s Happening to My Lawn & What Can I Do?