Specimen #11

Beech Bark Disease




Figure 1: Diagram showing the life cycle of Beech Bark Disease.
Please click on picture for an up close view.



Figure 2: Beech Bark Disease of branch collected.



Name: Beech Bark Disease. Fungus: Nectria coccinea
Collection Date:  11th Oct. 2011

Habitat: Fungi found on fallen branches beneath Beech tree. 

Location: Hiram Field Station
Description: Perithecia or fruiting body very small only approximately 1cm or less. Orange-brown in colour and found in clusters on the branch.  

Collector: Olivia Benjamin



Figure 4: Sexual stage of Nectria fungus, showing perthecia.



Ecology and Life Cyle of Beech Bark Disease: Beech Bark Disease is a complex that infects and kills the species of tree the American Beech tree or Fagus grandifolia. This disease is distributed throughout eastern North America and parts of Canada, it was originally introduced from Europe in 1929. The life cycle of disease happens in two stages; the insect and then the fungus. A small (0.5-0.1mm) insect called the Beech Scale or Cryptococcus fagisuga colonize on the beech tree and feed on the sap of the inner bark, causingopen wounds on the tree bark. This stage looks like large amounts of wool covering the bark of the tree. The feeding of the beech scale then allows for the introduction of the fungus called Nectria or Nectria coccinea which is a pathogen. The Nectria fungus then enters the tree killing woody tissue that can sometimes cause cankers on the tree. This fungus allows forms fruiting bodies called perithecia which are round, and orange-brown in colour. Each perithecia has a sac filled with spores that are usually released in fall and are carried by the wind. There is also an asexaul stage of the fungus, which looks like white cushions that produce asexual spores which can also be dispersed by the wind. (O'Brien et. al., 2000)



Figure 3: Asexual stage of Nectria Fungus.


Links
http://michigansaf.org/ForestInfo/Health/BBdisease.htm
http://en.wikipedia.org/wiki/Beech_bark_disease
http://na.fs.fed.us/spfo/pubs/fidls/beechbark/fidl-beech.htm