NEWS
Tiny Asian beetle threatens SA trees
T
here is a tiny alien
beetle that is breaking
the hearts of forest and
park managers, and property
owners in Gauteng.
The Polyphagous Shot Hole
Borer (PSHB) or Euwallacea
fornicatus, is an ambrosia
beetle native to Asia that has
been introduced into Israel,
California and, quite recently,
into South Africa.
More than 200 tree species
can be attacked by this beetle.
It is tiny ~ only 2mm long ~
but it carries three species of
fungi between host trees by
carrying spores within a pouch
in its mouthparts. These
ambrosial fungi are inoculated
into host trees and are the
sole nutritional source for the
adult beetles and their larvae.
Unfortunately the fungi also
disrupt the trees' ability to
transport nutrients and water,
resulting in a sick ~ or dead
~ tree.
In addition, holes where the
beetle bored into the tree
become infected and form
oily lesions.
The relationship between the
beetle and the fungus is called
“symbiotic,” meaning that
these two very different
species depend on one
another. The fungus provides
a ready source of food for the
beetle and the beetle provides
the fungus with a free ride to
SALVIA
F rom page 6
Sanbi is conducting erad ica-
tion trials this autumn.
Smallholders are asked to
please report sightings of red
sage to Moleseng Claude
Moshobane, SANBI-DBI: Tel
078 516 8933 and e-mail:
[email protected].
If possible, provide a locality
description, photo and GPS
co-ordinates.
7
www.sasmallholder.co.za
new trees.
More than 100 tree species
can support growth of the
fungi, and 37 species can be
used as a reproductive host
by the beetles.
One of the fungi, Fusarium
euwallaceae, is a moderately
virulent pathogen and is
responsible for causing a
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