Acute oak decline (AOD) revealed in Kaliwoods this year, with 8-12 dead oaks at the entrance. Gary Batel saw them 2 years ago. It can spread from tree to tree. First defined in 2008-9 in Britain, but evidence from 2006 onwards.
Spread by a beetle that carries the fungus. It involves a number of bacterial
species which cause bark lesions, and a native buprestid beetle Agrilus biguttatus
(oak jewel beetle). The exit holes of A. biguttatus, are characteristically D-shaped, are often visible on the stems of trees on sites affected by AOD. The larval stage of the beetle feeds on the inner bark where it creates larval galleries and this can weaken the tree in severe infestations.
The disease causes a rapid decline in oak trees and can kill them
within 5 or 6 years. The most
obvious symptom is the oozing of a dark, sticky fluid from
cracks in the bark on the stem of affected oak trees.
Kaliwood 