Pest profile

Redbay Ambrosia Beetle

Xyleborus glabratus · Coleoptera: Curculionidae[2]

The invasive redbay ambrosia beetle carries the fungus that causes laurel wilt, a fatal disease of sassafras, redbay and related trees.[1]

Redbay ambrosia beetle, a small dark brown cylindrical beetle, in its tunnel in wood
Redbay ambrosia beetle, a small dark brown cylindrical beetle, in its tunnel in wood. Photo: cgmayers, public domain (CC0), via iNaturalist

How to identify it

  • Beetles leave small round holes under 1/10 inch across, with thin toothpick-like strands of sawdust.[1]
  • Infected trees wilt suddenly, leaves turn reddish-brown and hang on for up to two weeks, and sapwood shows dark streaks.[1]

Look-alikes

Look-alikeHow to tell them apart
Native ambrosia beetlesNative species colonize dead or dying trees, while redbay ambrosia beetle attacks healthy living trees.[1]

Where it lives

Laurel wilt was first found in the US in 2003 and reached southwest Kentucky in 2019; it was in eleven southeastern states by 2020.[1]

US map: public records from 6 states since 1990 (GBIF).

Biology and life cycle

Beetles tunnel in sapwood, lay eggs and farm the fungus as food for larvae and adults, carrying spores to new trees.[1]

Natural spread can reach 34 miles a year; moving infested wood carries it much farther.[1]

Damage and signs

  • Infection from a single beetle can be enough to kill a tree, and sassafras typically dies within several months.[1]
  • Hosts are in the laurel family, including redbay, sassafras, spicebush and avocado; mountain laurel isn't one.[1]

Health risk

It attacks trees; UK Extension mentions no risk to people.[1]

Control

Keep them out

Don't move firewood or debris from infected trees or susceptible species, especially where the disease is confirmed.[1]

Sanitation

Remove and destroy infected trees on site, and contact a county Extension office if laurel wilt is suspected.[1]

Common questions

Why did my sassafras tree suddenly wilt and turn red in summer?
Laurel wilt, spread by redbay ambrosia beetle, causes sudden wilt and reddish leaves.[1]
Can laurel wilt be treated?
UK Extension says no management options are currently available, so limiting wood movement is key.[1]

Sources

  1. University of Kentucky Entomology (ENTFACT), “Laurel Wilt Disease and Redbay Ambrosia Beetle (ENTFACT-459).” entomology.mgcafe.uky.edu/ef459 (accessed 2026-10-06)
  2. iNaturalist, “Xyleborus glabratus taxon page (order and family).” www.inaturalist.org/taxa/321776 (accessed 2026-10-06)

Updated 2026-10-14. Built from sourced records. Spot an error? Tell us.