of the branches may die back as infesEmerald Ash Borer
tation progresses.The bark will split
Emerald Ash Borer (EAB, Agrilus
over dead vascular tissues,and trees may
planipennis) is another exotic beetle that
die within only two years of the onset
was discovered in southeastern
of symptoms. Extensive woodpecker
Michigan near Detroit in the summer
damage is also a symptom of EAB
of 2002.The adult beetles nibble on
attack.
ash foliage but cause little damage.The
larvae (the immature stage) feed on the
Rugose Spiraling Whitefly
inner bark of ash trees, particularly
Rugose Spiraling Whitefly (RSWF
,
green, black and white ash, disrupting
Aleurodicus rugioperculatus) is a nuisance
the tree's ability to transport water and
pest discovered in southern Florida in
nutrients. EAB probably arrived in the
2009 on Gumbo Limbo trees.This
United States on solid wood packing
whitefly appears to have a very broad
material carried in cargo ships or airhost range from palms to woody ornaplanes originating in its native Asia.
mentals and fruits.It is now found along
Emerald Ash Borer is now present in Emerald Ash Borer
the Atlantic and Gulf coasts, primarily
18 Midwest, Northeast and Mid- Photo by Taylor Scarr, Ontario Ministry of Natural Resources, Bugwood.org
where coconut palms grow. Adult
Atlantic states, as well as Ontario and
RSWF congregate on the undersides of the leaves to feed and reproduce.
Quebec, and has killed upward of 60 million trees in those areas.
The most noticeable symptoms of an infestation of this whitefly are the
EAB larvae live under the bark and feed on the vascular tissues. Larvae
create meandering galleries through the phloem, vascular cambium and abundance of the white,waxy material covering the leaves,and also excesetch the xylem, effectively girdling the tree.The tree responds by sprout- sive sooty mold. Like other sucking insects, the RSWF will produce large
ing new (epicormic) branches below the disrupted tissues. Dieback of amounts of "honeydew," a sugary substance, which causes the growth of
the canopy is a symptom of EAB larval infestation as many as one half sooty mold.The actual effect of an infestation on the health of a plant is
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Arbor Age / May/June 2013
7
