17
November/December 2020
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THE DAVEY BULLETIN
DAVEY DONATES
TREE REMOVAL TO
HISTORICAL SOCIETY
The Naperville R/C office removed an 80-year-old red
maple tree, known as the Bliss Maple, from the grounds
of the historic Tanner House Museum for the Aurora
Historical Society.
The maple was dedicated on Arbor Day in 1943 in memory
of Grace Carter Bliss, a well-known local gardener and leader
of the National Federation of Women's Clubs. The tree had
been in decline for several years.
Crew members Alan Masinick, trimmer, Lon McCaslin,
foreman, and Billy Volchko, foreman, assisted with the felling
of the Bliss Maple.
The office also removed dead limbs from a large locust
tree behind the house and trimmed an oak tree that was
interfering with an elm on the property.
The 80-year-old Bliss Maple before it was removed.
There's a new bug in town. The
Mediterranean Oak Borer (Xyleborus
monographus [MOB]), a beetle pest
common in much of the Mediterranean
region of Europe. It was initially found
and identified in Napa County,
California, on valley oaks but has
since been found on blue oak trees.
The beetle, identified in late 2019, has
many similarities to other exotic pests
and ambrosia beetles. Beetles carry
fungal spores which are dispersed
inside the tree in galleries (tunnels
created by the beetle in the wood). The
fungal spores then germinate, colonize
the sapwood, and kill the living cells in
the wood. The fungus kills the tree.
From the ground, look for white saw-
dust around the base of the trunk. Due
Female beetles are light brown in color, only
3mm long (about as big as a rice grain) and
can fly from tree to tree. Male beetles are
wingless and typically do not leave the
tree once they've started burrowing.
NEW BORER DISCOVERED IN CALIFORNIA
to their small size, entry holes can be
hard to spot. But a trained arborist will
notice overall tree decline, including
discoloration of leaves and wilting or
dying limbs in the upper canopy. By
the time most tree owners see the
sawdust, it's too late to save the tree.
"Because it has only been a year
since the exotic beetle was
discovered, here is nothing known
about how deadly this beetle/disease
complex will be or how to manage it.
Being an exotic species from Europe,
there are no established predators
(beneficial insects) to help keep the
beetle populations low enough not to
be a threat to valley and blue oaks
in California," said Len Burkhart,
technical advisor, the Davey Institute.
STEWARDSHIP
PERSEVERANCE
"Additionally, the current drought stress
on native oaks in California makes the
oaks even more prone to bark beetle
attacks than they normally would be.
Arborists need to be aware of this new
threat to our urban and native oaks in
California and the West Coast."
