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Carrot beetle

Ligyrus gibbosus[4]

The carrot beetle is a scarab native to the United States. Adults are reddish brown, about half an inch long, and chew on roots and stems just below the soil surface, so the first sign is often a plant that yellows, wilts or falls over.[1][2]

Group
Insect
Order
Coleoptera
Family
Scarabaeidae
US records
32 states
Sources
4 cited
Updated
2026-11-10
Reddish brown carrot beetle on gravelly soil, seen from the side and above
Reddish brown carrot beetle on gravelly soil, seen from the side and above. (c) Colin Croft, some rights reserved (CC BY) — via iNaturalist, CC BY 4.0
On this page
  1. Identification
  2. Where it lives
  3. Biology
  4. Damage and signs
  5. Health risk
  6. Control
  7. Related profiles
  8. Common questions
  9. Sources

How to identify it

  • Adults are reddish brown, rarely shiny black, and about 1/2 inch (11.5 to 16.5 mm) long.[1][2]
  • Under magnification the section behind the head is pitted, with a small bump near its front edge and a shallow dent just behind the bump. The front legs have three teeth on the outer edge.[2]
  • The grubs are white to bluish larvae up to 1-1/4 inches long with a dark head.[1]
  • The genus Tomarus has also been treated as Ligyrus, so the beetle appears under both names, Tomarus gibbosus and Ligyrus gibbosus.[2]

Where it lives

Native and widespread across the United States. The genus ranges from Canada to Argentina and the West Indies.[2]

US map: public records from 32 states since 1990 (GBIF).

Biology and life cycle

The carrot beetle has a one-year life cycle. Adults spend the winter in the soil and come out in spring.[2]

Adults are active at night and fly to lights.[2][1]

The grubs feed on root systems, while adults chew on roots and stems slightly below the soil surface and also feed above ground.[2][1]

Damage and signs

  • In gardens it attacks flowers such as dahlia, iris, lily and sunflower. Foliage yellows and wilts, and plants may be stunted, fall over or die. Stems or leaves at the base of the plant may be chewed.[1]
  • It is also a pest of crops including sugar beets, carrots, potatoes, corn, cotton and sunflowers.[2]
  • Damage to golf course turf was first reported in 2016.[3][2]

Health risk

UC IPM and the Western Australia fact sheet describe it only as a plant pest and list no health risk to people.[1][2]

Control

Keep them out

Keep adults away from plantings. They fly at night and are drawn to lights.[1]

Sanitation

Clear out decaying plant material around garden plants, because it shelters the adults.[1]

Common questions

Why did my sunflowers suddenly wilt and fall over?
Carrot beetles chewing on roots and stems just below the soil can make plants yellow, wilt, fall over or die.[1][2]
Does the carrot beetle only attack carrots?
No. Despite the name, it feeds on many plants, including dahlias, irises, lilies, sunflowers, sugar beets, potatoes, corn and cotton.[1][2]
Why do I see these beetles at my porch light?
Adults are active at night and are attracted to lights.[2]

Sources

  1. UC Statewide IPM Program, “Carrot Beetle (Home and Landscape).” ipm.ucanr.edu/home-and-landscape/carrot-beetle (accessed 2026-11-10)
  2. Department of Primary Industries and Regional Development, Western Australia, “Tomarus gibbosus fact sheet, Scarab Pests to Australia Lucid key (Brumley, Scanlon and Szito, 2020).” keys.lucidcentral.org/keys/v3/exotic_scarab_pests/key/lucid_key_to_scarabs/Media/Html/entities/tomarus_gibbosus.htm (accessed 2026-11-10)
  3. University of Kentucky (Larson, Giese and Potter), “First report of carrot beetle (Tomarus gibbosus) damage to golf course turf (Crop, Forage and Turfgrass Management 2:188, 2016).” scholars.uky.edu/en/publications/first-report-of-carrot-beetle-tomarus-gibbosus-damage-to-golf-cou/ (accessed 2026-11-10)
  4. iNaturalist, “Ligyrus gibbosus taxon page (order and family).” www.inaturalist.org/taxa/1430438 (accessed 2026-11-10)

Updated 2026-11-10. Built from sourced records. Spot an error? Tell us.