Chafer beetles are a group of scarab beetles whose larvae, known as white grubs, are among the most common causes of lawn damage in North America and Europe. The adults are relatively harmless, but the C-shaped grubs feeding underground on grass roots can destroy turf in patches, and the wildlife that digs them up often makes things worse. Here’s what you need to know to identify them, understand their life cycle, and deal with the damage.
What Chafer Beetles Look Like
Several species fall under the “chafer beetle” label, and they share a similar body plan: compact, oval, and roughly half an inch long. The European chafer is a plain light brown beetle, smaller than a June beetle but larger than a Japanese beetle. Masked chafers are similarly dull-colored, which is part of the problem. Because the adults are unremarkable and short-lived, most people never notice them. The damage shows up weeks later, underground.
The grubs are easier to spot if you know where to look. Dig into the top two inches of soil under damaged turf and you’ll find white, C-shaped larvae between half an inch and one inch long. They have six small legs near the head, a brown head capsule, and visible mouthparts. All chafer grubs look nearly identical to the naked eye. Entomologists distinguish species by examining the pattern of tiny hairs on the underside of the last abdominal segment, called the raster, but for a homeowner the treatment approach is the same regardless of species.
The One-Year Life Cycle
Chafer beetles complete their entire life cycle in a single year, and understanding the timing is the key to managing them. Adults emerge from the ground in late spring and swarm around shrubs and low trees to mate. The adult stage lasts only one to two weeks. During that brief window, each female lays 20 to 40 eggs about two to four inches deep in moist soil.
The eggs hatch within about two weeks, so grubs are present by late July. These tiny larvae immediately start feeding on grass roots, growing through the summer and into fall. In regions with freezing winters, grubs feed until roughly November and then burrow deeper into the soil to wait out the cold. In milder climates they feed all winter. Either way, intense feeding picks up again from March through May as the grubs grow to full size.
In early June, the mature grubs move down to about 10 inches deep, form small earthen cells, and pupate. The pre-pupal stage lasts just two to four days, pupation takes about two weeks, and then a new generation of adults emerges to start the cycle over.
How Grub Damage Looks and Feels
Chafer grubs feed on the roots of turfgrass, so the first symptom looks like drought stress: irregular brown or dead patches that don’t green up even with regular watering. The patches tend to appear in late summer or early fall, right when the grubs are growing fastest. Walk across an infested area and the ground may feel spongy underfoot because the root system holding the soil together has been chewed through.
In severe infestations, the turf has so little root connection left that you can grab a corner and peel it back like a carpet. That’s a clear sign grub populations are high.
Not every brown patch means grubs. To check, cut a one-square-foot section of turf about two inches deep and count what you find. In most home lawns, up to six grubs per square foot is tolerable, and healthy turf can sometimes handle 20 or more before showing visible injury. Golf greens and other closely mowed turf are more sensitive, with a treatment threshold of just one grub per square foot.
The Real Problem: Animals Digging Up Your Lawn
Ironically, the worst lawn damage often comes not from the grubs themselves but from the raccoons, skunks, crows, and coyotes that dig them up. Grub populations as low as five per square foot are enough to attract these predators, well below the level that would actually harm your grass.
Skunks push their noses into the turf and then claw out small cone-shaped holes. When populations are high, dozens of these holes merge into large torn-up patches. Raccoons take a different approach, using their front paws to grip and flip entire pieces of sod, leaving the lawn looking like someone was trying to transplant it. Both animals feed at night, so the damage typically appears overnight with no obvious culprit in sight.
This secondary damage is often the first sign homeowners notice. If you wake up to a lawn full of divots or flipped sod, grubs are the likely reason.
When and How to Treat Grub Infestations
Timing matters more than product choice. Grubs are most vulnerable when they’re small and feeding near the surface, which means late summer is the ideal treatment window for most regions. Treating in spring is possible but less effective because the grubs are larger, deeper in the soil, and closer to pupation.
Biological Control With Nematodes
Beneficial nematodes, specifically a species called Heterorhabditis bacteriophora, are a non-chemical option that targets grubs directly. These microscopic roundworms are applied to the soil in a water solution, where they seek out grubs and infect them with bacteria that kill the larvae within a day or two. You can apply nematodes any time grubs are in the top few inches of soil, roughly April through October, but late summer applications tend to work best because grub populations are high and the soil is warm.
The catch is that nematodes need moisture to survive and move through the soil. Water them in immediately after application and keep the treated area moist for several days. Dry soil will kill the nematodes before they reach the grubs. Not all nematode species sold commercially work against chafer grubs, so check the product label to confirm you’re buying a species with proven activity against turf grubs.
Chemical Treatments
Grub control products sold at garden centers generally fall into two categories: preventive and curative. Preventive products are applied in early to mid-summer, before eggs hatch, and remain active in the soil long enough to kill young grubs as they begin feeding. Curative products are designed for later application, when grubs are already present and causing damage, but they work best on smaller larvae and become less reliable as grubs grow larger in fall.
Whichever product you use, watering it in thoroughly after application is essential. The active ingredient needs to move through the thatch layer and into the root zone where grubs are feeding. A dry application sitting on top of the grass will do very little.
Reducing Grub Problems Long-Term
Healthy, thick turf tolerates grub feeding far better than thin or stressed grass. A lawn with a deep, dense root system can support surprisingly high grub numbers without showing symptoms, while a lawn that’s already struggling will show damage at much lower populations. Regular fertilization, proper mowing height, and consistent watering all help build that resilience.
One simple tactic during egg-laying season (late June through July for most regions) is to reduce irrigation. Female chafer beetles prefer to lay eggs in moist soil, so allowing the top few inches to dry out during this window can make your lawn less attractive as a nesting site. This won’t eliminate grubs entirely, but it can reduce the number of eggs deposited. Resume normal watering after the egg-laying period ends to help the turf recover from any summer stress.
If animal digging is the main issue, addressing the grub population is the most effective long-term fix. Fencing, repellents, and motion-activated sprinklers may discourage raccoons and skunks temporarily, but as long as the grubs are there, the animals will keep coming back.