Lawn bugs that eat grass roots live beneath the soil surface, where they feed out of sight and cause damage before it becomes obvious. By attacking the roots, they weaken the lawn’s ability to absorb water and nutrients, leading to thinning patches and poor overall growth. This type of damage often appears suddenly, even though it has been developing for weeks.
One of the first signs of root-feeding activity is grass that feels loose or spongy underfoot. Because the roots are damaged or missing, the turf may lift easily from the soil. These weakened areas dry out faster than healthy sections, making the lawn look uneven and stressed.
Root damage also makes lawns more vulnerable to heat and drought. With limited roots, grass cannot store enough energy or moisture to survive harsh conditions. As a result, affected areas may turn brown quickly and struggle to recover, even when watering is increased.
The presence of these underground pests can also attract other problems. Birds and small animals may dig into the lawn while searching for food, creating additional surface damage. This secondary disturbance often worsens the appearance of the lawn and exposes more soil.
Healthy lawn practices help reduce the impact of root-feeding bugs. Proper watering, good soil structure, and balanced nutrition encourage strong root growth that can better tolerate stress. Early attention to thinning or loosening turf can help limit long-term damage and keep the lawn resilient.
Lawn Pests that Eat Grass Roots
White Grubs
White grubs are the larval stage of various beetle species, including Japanese beetles, June bugs, and chafers, and they’re among the most destructive lawn pests. These C-shaped, cream-colored larvae live beneath the soil surface and feed voraciously on grass roots from late summer through fall and again in spring.
Infested lawns develop irregular brown patches that peel back like carpet since the roots have been severed, and you may notice increased wildlife activity as birds, skunks, and raccoons dig up the turf searching for these protein-rich grubs.
Billbugs
Billbugs are weevils whose larvae burrow into grass stems and crown areas before moving down to feed on roots as they mature. Adult billbugs are small, dark beetles with elongated snouts that lay eggs in grass stems during spring and early summer.
The resulting larvae cause patches of dead, brown grass that initially resemble drought stress but don’t recover with watering, and heavily infested areas may have a hollowed-out appearance where the larvae have consumed the root system entirely.
Chinch Bugs
Chinch bugs primarily feed on grass blades and stems by sucking plant juices, but their feeding damage extends to the crown and upper root areas, effectively killing the grass from the ground up. These tiny black and white insects thrive in hot, dry conditions and congregate in sunny areas of the lawn, creating irregular yellow to brown patches that expand outward.
Heavy infestations can destroy entire lawns within weeks, as the bugs inject toxic saliva while feeding that prevents water uptake even in the remaining root tissue.
Mole Crickets
Mole crickets are bizarre-looking insects with front legs adapted for digging that tunnel through soil and feed on grass roots, especially in warm-season lawns. These nocturnal pests are most active during warm, humid weather and create distinctive raised tunnels near the soil surface while their nymphs feed directly on roots and underground stems.
Damaged lawns appear spongy when walked upon and develop irregular brown patches, with the tunneling activity often causing more visible damage than the actual root feeding.
Japanese Beetle Larvae
Japanese beetle larvae, a specific type of white grub, are particularly destructive root feeders that can devastate lawns when present in high numbers. These plump, grayish-white grubs with brown heads feed on grass roots throughout their development, with peak damage occurring in late summer and early fall.
Infestations often appear as dead or dying patches of turf that pull up easily, and a square foot of damaged lawn may contain a dozen or more grubs actively feeding on the remaining root system.
European Chafer Larvae
European chafer larvae are white grubs that feed exclusively on grass roots and can cause catastrophic lawn damage in northern regions where they’re established.
These grubs are similar in appearance to Japanese beetle larvae but tend to feed closer to the soil surface, making lawns particularly vulnerable to secondary damage from animals digging for them. Infested areas turn brown in late summer and fall, and severe infestations can result in complete loss of turf as the entire root system is consumed.
Wireworms
Wireworms are the hard-bodied, yellowish-brown larvae of click beetles that live in soil for several years, feeding on grass roots and underground plant parts. These slender, cylindrical pests are particularly problematic in lawns converted from pasture or fields, where they can persist for years after the initial conversion.
Damage appears as thinning turf and stunted grass growth rather than large dead patches, as wireworms feed methodically on root systems over extended periods, weakening but not immediately killing the plants.
Black Turfgrass Ataenius
Black turfgrass ataenius is a small black beetle whose larvae feed on grass roots in a manner similar to other grub species, particularly targeting golf courses and well-maintained lawns. The larvae are tiny white grubs, much smaller than typical white grubs, and they feed on roots during late spring and summer.
Damage manifests as irregular brown patches in the turf that don’t respond to irrigation, and because of their small size, high populations are needed before damage becomes apparent, often catching homeowners by surprise.
May/June Beetle Larvae
May and June beetle larvae are large white grubs that can remain in the soil for two to three years, feeding on grass roots throughout their extended development period.
These grubs are among the largest turf-damaging larvae and can cause cumulative damage over multiple seasons as successive generations overlap in the same lawn. Infested areas develop brown, dead patches where roots have been completely severed, and the extended life cycle means that even after treatment, residual populations may continue causing damage.
Root Aphids
Root aphids are tiny, soft-bodied insects that cluster on grass roots and feed by sucking sap from the root tissue, weakening the plant’s ability to absorb water and nutrients. These pale-colored pests are often tended by ants that farm them for their sugary secretions, so increased ant activity may indicate a root aphid problem.
Affected lawns show symptoms similar to drought stress, with yellowing, wilting grass that doesn’t improve with watering, and the damage is often patchy as aphid colonies establish themselves in localized areas before spreading.
Ground Pearls
Ground pearls are scale insects whose immature stages feed on grass roots while encased in hard, pearl-like protective coverings that give them their name. These tiny pests are particularly problematic in sandy soils of the southeastern United States, where they attach to roots and feed on plant juices for extended periods.
Infested lawns develop irregular patches of thin, weak grass that gradually expands over seasons, and the pearl-like cysts can persist in soil for years, making ground pearls extremely difficult to control once established.
Cutworms
Cutworms are the caterpillar larvae of various moth species that feed primarily at night, cutting through grass stems at the soil line and also consuming crown tissue and shallow roots. These plump, grayish or brownish larvae curl into a C-shape when disturbed and hide in the soil during daylight hours, emerging after dark to continue their destructive feeding.
Damage appears as small, irregularly shaped brown spots or thinned areas in the lawn, often accompanied by small holes in the turf where the cutworms have burrowed, and their feeding can kill grass plants by severing the connection between roots and blades.
Sod Webworms
Sod webworms are moth larvae that primarily feed on grass blades but also attack the crown and upper root areas when populations are high, causing significant stress to the turf. These tan or gray caterpillars construct silk-lined tunnels in the thatch layer and venture out at night to feed, leaving behind green fecal pellets and notched grass blades.
Heavy infestations can thin the lawn considerably as the webworms damage the critical crown area where roots and shoots meet, and stressed lawns become more susceptible to disease and drought damage.
Crane Fly Larvae (Leatherjackets)
Crane fly larvae, commonly called leatherjackets due to their tough, grayish-brown skin, are worm-like pests that feed on grass roots and crown tissue in cool, moist climates. These larvae are particularly destructive in Pacific Northwest lawns and other regions with mild, wet winters where they remain active year-round.
Damaged turf appears patchy and thin with dead or dying areas that feel spongy underfoot, and like with grubs, you may observe birds and other animals actively pecking at the lawn in search of these plump, protein-rich larvae.