Acute Oak Decline and Agrilus biguttatus: The Co-Occurrence of Stem Bleeding and D-Shaped Emergence Holes in Great Britain
File(s)
Published version
Author(s)
Type
Journal Article
Abstract
Acute Oak Decline (AOD) is a new condition affecting both species of native oak,
Quercus robur and Quercus petraea, in Great Britain. The decline is characterised by a distinctive
set of externally visible stem symptoms; bark cracks that “weep” dark exudate are found above
necrotic lesions in the inner bark. Emergence holes of the buprestid beetle, Agrilus biguttatus are
often also seen on the stems of oak within affected woodlands. This investigation assesses the extent
to which the external symptoms of these two agents co-occur and reveals the spatial and temporal
patterns present in affected woodland. Annual monitoring in eight affected woodlands showed that
stem bleeding and emergence holes frequently occur on the same trees, with new emergence holes
significantly more likely to occur when trees already have stem bleeds. Trials with coloured prism
traps confirm A. biguttatus was present at all experimental sites. Beetle emergence is linked primarily
to a few heavily declining trees, indicating that susceptibility may vary between hosts and that those
with reduced health may be predisposed to AOD. Stem bleeds occur on trees in close proximity to
the locations of trees with exit holes.
Quercus robur and Quercus petraea, in Great Britain. The decline is characterised by a distinctive
set of externally visible stem symptoms; bark cracks that “weep” dark exudate are found above
necrotic lesions in the inner bark. Emergence holes of the buprestid beetle, Agrilus biguttatus are
often also seen on the stems of oak within affected woodlands. This investigation assesses the extent
to which the external symptoms of these two agents co-occur and reveals the spatial and temporal
patterns present in affected woodland. Annual monitoring in eight affected woodlands showed that
stem bleeding and emergence holes frequently occur on the same trees, with new emergence holes
significantly more likely to occur when trees already have stem bleeds. Trials with coloured prism
traps confirm A. biguttatus was present at all experimental sites. Beetle emergence is linked primarily
to a few heavily declining trees, indicating that susceptibility may vary between hosts and that those
with reduced health may be predisposed to AOD. Stem bleeds occur on trees in close proximity to
the locations of trees with exit holes.
Date Issued
2017-03-17
Date Acceptance
2017-03-14
Citation
Forests, 2017, 8 (3)
ISSN
1999-4907
Publisher
MDPI AG
Journal / Book Title
Forests
Volume
8
Issue
3
Copyright Statement
© 2017 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access
article distributed under the terms and conditions of the Creative Commons Attribution
(CC BY) license (http://creativecommons.org/licenses/by/4.0/).
article distributed under the terms and conditions of the Creative Commons Attribution
(CC BY) license (http://creativecommons.org/licenses/by/4.0/).
License URL
Subjects
Science & Technology
Life Sciences & Biomedicine
Forestry
decline
predisposition
Agrilus
prism traps
EMERALD ASH BORER
QUERCUS-ROBUR L
WOOD-BORING INSECTS
COLEOPTERA BUPRESTIDAE
PLANIPENNIS
TREES
DROUGHT
EUROPE
MECHANISMS
PATHOGENS
Publication Status
Published
Article Number
87