Zoysia grass is a popular warm season lawn grass known for its ability to stand up to heat, drought, heavy foot traffic and a variety of other challenges. However, zoysia grass is not immune to everything. If not properly cared for, zoysia can become thin or develop bare spots due to pest damage. Understanding what insects and animals commonly feed on zoysia grass is the first step toward protecting your lawn.
Insects That Eat Zoysia Grass
Several insects target zoysia grass as a food source. The most common zoysia-eating pests include:
- Armyworms
- Billbugs
- Chinch bugs
- Grubs
- Mole crickets
- Sod webworms
- Spittlebugs
- Zoysia moths
These insects can damage zoysia grass in different ways. Chewing insects like armyworms and webworms feed on grass blades. Sucking insects like chinch bugs pierce individual grass plants and feed on the fluids inside. Grubs feed on grass roots below ground. Others like mole crickets and billbugs target both above and below ground parts of the grass.
Armyworms
Several armyworm species feed on zoysia grass. These caterpillars grow up to 1 1⁄2 inches long and hide near the ground during the day. At night they come out to feed. Armyworms chew grass blades, stripping them down to the sheaths. As they feed, armyworms leave behind greenish-brown fecal pellets. Severe armyworm infestations can completely destroy grass in affected areas.
Billbugs
Billbug adults are beetles that look like small weevils. The larvae are cream-colored grubs with orange heads that live underground. Billbugs chew holes in grass stems and also feed on roots. This causes zoysia grass to turn yellow and die in scattered patches across the lawn.
Chinch Bugs
Chinch bugs are sucking insects that extract fluids from grass stems and crowns. Feeding by chinch bugs turns zoysia grass yellow. It first shows up as yellow patches in sunny areas. Chinch bug populations sometimes migrate from nearby wheat or hay fields once those crops are harvested.
Grubs
Several beetle species have grubs that feed on grass roots. These C-shaped white larvae damage zoysia by chewing through the roots. This causes the grass to die in irregular patches. Birds pulling up grubs leave holes and bare spots behind. Skunks and raccoons also dig around in the lawn looking for grubs to eat.
Mole Crickets
Mole crickets get their name from the underground burrowing tunnels they create while searching for food. They emerge at night to feed on grass stems and roots. Mole cricket feeding activity causes zoysia grass to turn yellow and die off in irregular areas.
Sod Webworms
The larvae of lawn moths, sod webworms chew through grass stems near the crowns. Their feeding damage causes zoysia turf to turn brown. Heavy webworm infestations can kill grass or thin out a zoysia lawn. When disturbed, the small green to brown caterpillars wiggle backwards into the grass to hide.
Spittlebugs
Spittlebug nymphs suck nutrients from grass stems and produce white foamy spittle as a protective cover. Feeding by spittlebugs turns zoysia light green or yellow. Adults resemble froghoppers and do little damage to the lawn.
Zoysia Moths
Zoysia moth caterpillars feed on zoysia leaves at night, chewing out notched holes in the blade edges. High populations can cause widespread thinning or dieback. Zoysia moths complete two or three generations per year.
Animal Pests
Certain animals also feed on zoysia lawns. Birds, rodents, and others can damage zoysia in different ways as they search for food.
Birds
Several bird species eat zoysia seeds and pull young grass shoots. Geese grazing on zoysia can remove significant amounts of turf. Crows pull out new grass plugs. Birds also eat grubs, leaving random bare spots dotted across the lawn.
Deer
Deer feed on zoysia grass, particularly in spring and summer. Excessive grazing by deer or other ruminants kills the grass down to the crown. Repeated deer traffic across the lawn can wear paths through zoysia over time.
Moles
Moles tunnel just below the soil surface searching for grubs and earthworms. The raised ridges and holes left behind can dislodge or smother grass. Voles also make surface tunnels through the lawn that can damage zoysia.
Rabbits
Rabbits nibble on zoysia blades and stems. Their feeding gives the grass a ragged, chewed appearance. Rabbits tend to avoid zoysia when other greens are available, but may rely on it in winter or drought conditions.
Raccoons
Raccoons dig in lawns hunting for insect larvae like grubs. They pull up patches of grass in search of food. Raccoons also forage for grass seeds and new shoots.
Rodents
Gophers, ground squirrels, voles and mice burrow through lawns eating roots, seeds and tender shoots along the way. Their tunnels can disrupt and smother grass.
Diseases
In addition to pests, zoysia grass is prone to certain lawn diseases under the right conditions:
- Brown patch
- Dollar spot
- Large patch
- Leaf spot
- Melting out
- Nematodes
- Rust
- Take-all root rot
Fungal diseases like brown patch, dollar spot, large patch and leaf spot attack the blades and stems of the grass. Excess moisture and high humidity favor these diseases. Rust diseases thrive in alternating wet and dry conditions. Melting out and take-all root rot are fungal diseases that infect the roots and crowns.
Plant-parasitic nematodes are microscopic roundworms that feed on grass roots. Their feeding activity damages the roots and reduces the turf’s ability to take up water and nutrients. Nematode feeding weakens grass and causes spotty yellowing.
Weeds
Weeds compete with zoysia grass for light, moisture and nutrients. Certain weeds also produce natural weed killers that suppress grass growth. Some common zoysia weeds include:
- Bermudagrass
- Carpetweed
- Chickweed
- Clover
- Crabgrass
- Creeping Charlie
- Dandelion
- Henbit
- Knotweed
- Nutsedge
- Plantain
- Spurge
Perennial grassy weeds like bermudagrass and crabgrass thrive in the same conditions as zoysia. Broadleaf weeds such as clover, spurge and plantain grow as individual plants scattered through the lawn.
Over-Fertilization
Applying too much nitrogen fertilizer can damage zoysia grass. Excess nitrogen causes succulent, tender growth that is more susceptible to problems. It can also lead to thatch buildup, which encourages diseases, insects and weeds.
Pet Waste
Urine from dogs and other pets contains high amounts of nitrogen. When concentrated in one spot, it can burn zoysia grass leaves and kill the lawn. Always remove pet waste promptly before damage occurs.
Foot Traffic
Frequent foot traffic across the same path wears down zoysia turf over time. Heavy foot traffic compacts the soil, restricting air, water and nutrient absorption by the grass.
Shade
Too much shade encourages zoysia problems like diseases and moss growth. Without sufficient sunlight, thin and bare patches may develop due to reduced growth and vigor.
Poor Soil Conditions
Compacted, acidic or infertile soil prevents zoysia roots from spreading easily. Grass in poor soils struggles to access air, moisture and nutrients. This leads to weakened turfgrass more prone to pest issues.
Drought Stress
Lack of moisture makes zoysia grass less tolerant of insect and disease problems. Drought-stressed grass draws pest invasions. Make sure to provide zoysia with about 1 to 1 1⁄2 inches of water per week in the absence of rain.
Low Mowing
Cutting zoysia too short leaves it more vulnerable to stresses. Mow zoysia no lower than 1 to 2 inches high. Short mowing removes more photosynthesizing leaf surface and opens the lawn to increased weed competition.
Thatch Buildup
Thatch is a spongy layer of dead grass stems and roots accumulated at the base of the turf. Excess thatch prevents water, air and nutrients from reaching the soil. It also harbors insect and disease pests.
Damage Prevention
The best way to protect zoysia grass is to maintain optimal growing conditions that encourage strong turfgrass. Here are some tips:
- Mow at the proper height – 1 to 2 inches is ideal.
- Leave clippings on the lawn to return nutrients.
- Fertilize moderately in spring through fall.
- Control thatch buildup through core aeration.
- Monitor for pests and treat early before extensive damage occurs.
- Fix drainage issues and improve poor soils.
- Raise mower height and water during droughts to reduce stress.
Contact a lawn care professional for help designing a maintenance program tailored specifically for zoysia grass. Protect your investment by keeping zoysia healthy and pest-free.
Conclusion
Zoysia grass provides a versatile warm-season lawn but still faces threats from a variety of insects, animals, diseases, and environmental stresses. Pay close attention to changes in the appearance of your zoysia to identify issues early before they damage large areas. Routinely inspect for signs of chinch bugs, grubs, armyworms, diseases and other problems. Addressing issues promptly can help protect zoysia quality. Proper mowing, irrigation, fertilization and other care creates optimal growing conditions to keep zoysia thicker and better able to resist pest invasions. A healthy zoysia lawn is the first line of defense against damage and decline.