Billbug larvae feed on roots, not foliage, which is why turf health hinges on root care.

What’s on the bill for billbugs? Roots, not leaves

If you’re tending turf in Ohio, you’ve probably noticed those telltale yellow patches that creep across the lawn just when you thought you had things under control. You might reach for a quick explanation, but there’s a small pest that loves the plant’s most vital part: the roots. Billbug larvae aren’t munching on the green blades you see on the surface; they’re digging into the root zone. And that distinction matters a lot.

Let me explain who we’re talking about. Billbugs are a kind of beetle, and the larvae are the soft, white grubs with a brown head that spend their entire larval stage living down in the soil. While the adults are small, the real damage happens below ground, where the larvae feed and grow. Their life is basically a root-centric affair—hence the emphasis on one word: roots.

Primary diet: Roots, plain and simple

Here’s the thing about billbug larvae: their feeding habit centers on roots. That root-focused diet is what makes them particularly nasty for turfgrass. When larvae chew on root systems, the plant can’t drink water or absorb nutrients effectively. That’s what leads to weak patches, thin turf, and the kind of dieback that shows up as yellowing or browning blades in late summer or after a dry spell.

Folks often wonder if foliage is the problem. It isn’t the main issue here. Leaves and blades matter for photosynthesis and vigor, sure, but billbug larvae are in the root zone, not grazing the leaf tissue. Flowers and seeds aren’t a part of their menu either. The root-focused feeding pattern is a red flag that guides how we monitor and, if needed, treat turf damaged by these pests.

Why root damage hurts so much

Roots are the plant’s plumbing. When billbug larvae chew through them, the turf can’t take up water, which makes it look stressed even if you’ve watered adequately. In a busy lawn or a golf course, those patches can spread as neighboring turf tries to compensate and more plants start to struggle. It can be a real uphill battle, especially in Ohio’s hot, dry stretches or after a late-season heat spike.

If you’ve ever sprinkled a patch of turf and seen it go suddenly pale or fail to green up after irrigation, you’re not imagining things. A root-damage pattern can mimic drought stress, disease, or even thatch buildup. The big difference is where the problem comes from: the roots, not just the surface blades.

How to spot billbug trouble without a lab

Detecting billbug trouble starts with looking beyond the leaves. A few practical checks:

• Lift a small patch of turf gently. If the roots look sparse, dark, or decayed, you may be dealing with root feeding. Billbugs don’t always strip every root, but the signs are clear when you pull a plug and see the root system is compromised.

• Look for frass. Tiny, sawdust-like fragments near feeding sites can indicate larvae is present and actively chewing.

• Check for uniform patches that turn brown or yellow from the edges inward. Billbug damage often shows up as irregular, dead-looking patches rather than a clean, uniform brown.

• Inspect both the grass and thatch layer. Heavy thatch can harbor pests, but billbugs do their damage down in the soil, so a close look at the soil and roots is critical.

• Scout at the right time. Adult billbugs are more likely to be active in late spring and early summer, but the larvae that do the real damage are most problematic when they’re small and actively feeding within roots.

A simple monitoring mindset for Ohio lawns

Because Ohio’s climate swings from cool springs to hot summers, a steady monitoring rhythm helps. Keep an eye on patches after periods of heat or drought, then verify with a soil check. If you’re managing a golf course or a larger landscape, routine soil examinations and occasional turf pulls help you catch trouble early rather than after the damage is obvious.

Smart approaches for Ohio turf managers

Once you’ve confirmed billbug activity, you’ve got a few paths to consider. The best choice often depends on how large the damaged area is, how quickly you need results, and the season you’re in. Here are practical, field-tested ideas that fit many Ohio situations.

• Cultural practices that support roots

• Water smartly. Deep, infrequent watering encourages deeper roots. Shallow, frequent watering tends to favor surface-feeding pests and weak root systems. Strike a balance that keeps the root zone healthy without creating soggy conditions.

• Mow at a sensible height. A bit higher mowing reduces stress on stressed turf and helps roots stay robust. It also lowers the chances of surface damage exaggerating the problem.

• Improve drainage and soil structure. Compacted soil invites root stress and makes it easier for larvae to feed undisturbed. Aeration or overseeding with a mix that suits your climate can help by boosting root resilience.

• Manage thatch efficiently. A thin thatch layer provides insulation and can hide pest activity, but a thick thatch can keep roots from getting oxygen. Regular maintenance keeps the root zone breathable.

• Biological helpers that stay quiet but effective

• Beneficial nematodes can be deployed into the soil to target billbug larvae. These microscopic allies seek out the larvae and deliver a harmless sting that kills them. It’s a natural approach that fits well in integrated pest strategies.

• Encourage beneficials. A diverse soil ecosystem—microbes, fungi, and predatory insects—helps keep pest numbers in check. Avoid broad-spectrum products that knock out the good guys along with the bad.

• Targeted chemical options when timing is right

• Soil-applied insecticides can be effective if applied when larvae are small and still feeding near the soil surface. Look for products labeled for billbugs and turf use, and follow the label exactly. Timing matters a lot here, since once larvae grow larger, control becomes harder.

• Neonicotinoid options and other soil-acting products exist, but they’re most effective when used as part of a broader plan that includes cultural and biological steps. Always check local regulations and label directions, especially in sensitive environments or waterways.

• When to treat (timing, not just trying stuff)

• Timing is everything. The earlier you catch feeding in the root zone, the better your chances of recovery. Treatments are generally more successful when larvae are in the early instars, before their feeding causes widespread root damage.

• Don’t chase symptoms alone. Treating a yellow patch without addressing root health can give you a temporary fix at best. Root health is the real lever you pull for lasting turf recovery.

Common-sense reminders and missteps to avoid

• Don’t overdo irrigation in the panic of a patch. Overwatering can worsen root health problems and create conditions that don’t help the turf or the beneficial organisms you’re hoping to rely on.

• Don’t assume any one tactic will solve the whole problem. A mixed approach—cultural care, biological tools, and carefully chosen chemicals when needed—tends to yield the best results.

• Don’t neglect monitoring. The moment you see signs of trouble, start checking roots and soil. Early detection saves turf and frustration.

• Don’t overlook local guidance. Ohio landscapes vary—from Cleveland’s lake-effect zones to the hotter southern stretches. Local extension services offer region-specific insights on when to monitor and what products are most appropriate.

Real-world takeaways for Ohio turf care

If you’re tasked with maintaining lawns, athletic fields, or golf turf in Ohio, understanding what billbug larvae eat helps you frame your response correctly. The root-focused diet explains why you don’t see a complete “eat-the-blades” pattern; you see patches that refuse to green up even with water and fertilizer on hand. Diagnosis starts with looking at the roots, not just the surface blades.

What follows is a practical plan you can actually put into motion. Start with a gentle soil check or turf lift in suspicious areas. If roots are sparse and the plant looks stressed while the surface blades seem ordinary, you’re likely dealing with root feeding. Then pair root-focused monitoring with a strategy that supports healthy roots: smart irrigation, proper mowing, and organic or biological aids where you can. If you need more pressure, consider a soil-applied product following label directions and timing that targets early larval stages. And if you’re ever unsure, reach out to a local turf specialist who knows your soil type and climate.

A quick recap you can nod along to

• Billbug larvae love roots. That’s their main menu and their most damaging pathway.

• Root health is the first thing to protect. Healthy roots keep turf resilient against a lot of stress—and against billbugs.

• Monitor by checking roots, not just leaves. Look for sparse roots, frass, and patchy color changes.

• Use a balanced approach. Cultural care, beneficial organisms, and, when necessary, carefully chosen treatments together offer the best odds.

• Ohio landscapes crave a flexible plan. Local conditions matter, so tailor your approach to your soil, climate, and turf type.

If you’re working with turf in Ohio, the root story stays constant: protect what lies beneath the surface, because that’s what keeps the whole plant standing strong. Billbug larvae may be small, but their impact can feel big if you don’t keep an eye on the root zone. With a mix of proper cultural care, smart monitoring, and targeted controls when appropriate, you can keep your turf healthier, longer, and better prepared for whatever Ohio weather throws its way.

Would you like a practical, field-ready checklist you can print for your next soil check or turf inspection? I can tailor one to your region, your grass type, and your typical mowing and irrigation schedule so you’ve got a simple, actionable guide at hand.