Oak wilt

Oak wilt
Aerial photograph of an oak wilt center (St. Paul, MN)
Causal agentsBretziella fagacearum
HostsQuercus spp.
VectorsNitidulidae
EPPO codeCERAFA
DistributionUS
Symptomsleaf discoloration, wilt, defoliation and death

Bretziella fagacearum
Spores produced by the oak wilt fungus (a) Endoconidia (b) Conidiophore
Scientific classification
Domain: Eukaryota
Kingdom: Fungi
Division: Ascomycota
Class: Sordariomycetes
Order: Microascales
Family: Ceratocystidaceae
Genus: Bretziella
Species:
B. fagacearum
Binomial name
Bretziella fagacearum
(Bretz) Z.W. de Beer, Marincowitz, T.A. Duong & M.J. Wingfield
USA counties with oak wilt (2017)
Synonyms
  • Chalara quercina
  • Endoconidiophora fagacearum
  • Thielaviopsis quercina
  • Ceratocystis fagacearum

Oak wilt is a fungal disease caused by the organism Bretziella fagacearum that threatens Quercus spp. The disease is limited to the eastern half of the United States, Central Texas, and Southern Ontario. First described in the 1940s in the Upper Mississippi River Valley. The pathogen penetrates xylem tissue, preventing water transport and causing disease symptoms. Symptoms generally consist of leaf discoloration, wilt, defoliation, and death. The disease is dispersed by insect vectors and to adjacent trees through underground root networks. However, human spread is the most consequential dispersal method. Moving firewood long distances can potentially transport diseases and invasive species.