Illustration of a billbug
Illustration of a billbug
adult billbug
adult billbug
adult billbug

Billbugs are particularly troublesome lawn pests because both the adult insect and its immature larvae damage grass. Adult billbugs chew holes into grass blades and deposit eggs inside. When larvae hatch, they eat grass from the inside out and continue eating from the roots to the tips. By the time homeowners see the results, large areas of lawn may already be lost.

Identification: Billbugs get their name from the adult insect's long, curved, bill-like snout. A type of weevil, mature billbugs may grow up to 1/2 inch in length. Depending on the species, their hard shells range in color from clay-brown to near black; all have an unusual pitted texture. Billbug larvae are white with reddish-brown heads and look very similar to white grubs, another common lawn pest. However, billbug larvae do not have legs; white grubs do.

Signs/Damage: Billbug damage can be hard to diagnose. Grass begins to turn brown in early summer, but it's easily mistaken for drought damage, fungal disease or grass dormancy. Test your lawn by pulling on an affected area. Billbug-damaged grass breaks off at the soil line and is usually accompanied by lots of powdery sawdust-like excrement. Dig or pull apart grass to inspect the roots and crown, and the legless larvae are easily seen.

Control: Effective billbug treatment calls for a multi-pronged approach. Target adults in early spring before they lay their eggs, and treat newly hatched larvae before they can damage lawns extensively. Late-season treatments target larvae and adults, which may overwinter in thatch and leaf debris . GardenTech® brand offers effective options to kill and control billbugs and keep protecting for up to three months:

  • Sevin® Insect Killer Granules kill and control adult billbugs and their larvae above and below the soil line. Apply the granules with a regular lawn spreader, and then water immediately to release the active ingredients into the soil.
  • Sevin® Insect Killer Concentrate works with a pump-style sprayer for targeted spot treatments or extensive coverage of larger lawn areas where you expect billbug problems to occur.
  • Sevin® Insect Killer Ready to Spray simplifies thorough coverage of lawns and home perimeters. Attach it to a regular garden hose, and it mixes automatically as you spray.

Tip: Poor lawn maintenance contributes to billbug problems from year to year. Follow good mowing practices and dethatch regularly to help keep billbugs at a minimum.

Always read product labels and follow the instructions carefully.

GardenTech is a registered trademark of Gulfstream Home and Garden, Inc.

Sevin is a registered trademark of Tessenderlo Kerley, Inc.


"Nutgrass Billbug - Sphenophorus cariosus" by Judy Gallagher licensed under CC BY 2.0

"Billbug - Sphenophorus sp." by Fyn Kynd licensed under CC BY 2.0

"Billbug - Sphenophorus sp." by Fyn Kynd licensed under CC BY 2.0

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