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NATURE IN
GOOSE ISLAND HIDE AWAY
Nature in
Goose Island |
Living with Goose Island Wildlife
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Nature
News
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Woolly Adelgid Threat to Eastern Hemlock in Goose Island (click
picture to view close-up of a Hemlock Woolly Adelgid
symptom.)
 In
the early 1950’s, a small, aphid-like insect was first
observed feeding on hemlock in Virginia. This insect was
the hemlock woolly adelgid (HWA), Adelges tsugae (Annand),
and an exotic pest native to Asia. The HWA has since
spread to 14 eastern states where it threatens two species
of hemlock--the eastern hemlock, Tsuga canadensis (L.)
Carr. and Carolina hemlock, Tsuga caroliniana Engelm. This
pest is responsible for extensive mortality and decline of
hemlock trees in the eastern U.S. The insect has steadily
spread from its point of introduction and is a serious
threat to survival of hemlocks throughout eastern North
America. Hemlock is an ecologically important tree species
and in many habitats, irreplaceable. Hemlock forests
provide unique habitats for many species of wildlife that
depend on the tree’s dense canopy for food, shelter and
breeding sites. Hemlock is commonly associated with
riparian areas and has been shown to play an important
role in maintaining cool stream water temperatures,
preventing erosion on steep banks, and providing shelter
to wildlife by moderating temperatures in cold winter
months and during hot summer days.
Key Issues: Continued Spread. Currently the HWA infests
about one-half of the native range of hemlock in the East.
It can be found from New Hampshire to northeastern
Georgia and west to central Pennsylvania. The HWA
continues to spread. Without intervention the entire range
of eastern hemlock may become infested. Work is under way
on biocontrols, the most promising of which is a tiny
black coccinellid beetle (Pseudoscymnus tsugae) discovered
feeding on adelgids in Japan in 1992. Years of quarantine
and study convinced researchers that the beetle was safe
for release in the wild. (Other predatory beetles and
mites that prey on the adelgids in Japan and China are
also being studied, but haven’t been approved for
release.) A lab in New Jersey has been mass-rearing P.
tsugae since 1997. Several hundred thousand beetles have
been experimentally released in nearly a dozen states.
Among the places the beetles have been released are a few
parkway locations north of Boone; in Ellicott Rock
Wilderness Area; and, in early June, in the Smokies at
Cataloochee, Laurel Falls and Panther Creek.
Resources:
Georgia Forest Watch
http://www2.gafw.org
www.gainvasives.org/hwa
www.gatrees.org
Georgia Forestry Commission 706-374-6232
www.livingwithbugs.com/merit_insecticide.html
Mark S. McClure
Please let us know if you see any symptoms of woolly
adelgid on your hemlock trees so that we can report it to
the Forest Service or Gilmer County Extension Agent,
Michael Wheeler (706-635-4426) .
For
information about infestations in and around Goose Island
you can also call Eddie Ayers, the Fannin Co. Extension
Agent (706.632.3061) or visit the website:
www.bugwood.org .
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Eastern Tent Caterpillar,
Malacosoma americanum (F.)
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 Importance.-
The eastern tent caterpillar is
primarily an aesthetic problem and has little adverse
effect on the host trees. Species of the genus
Prunus are preferred hosts, with black cherry being the
primary, uncultivated host.
Identifying the Insect. - Full-grown
larvae are between 2 to 21/2 inches (50 to 65
mm) in length. Caterpillars have black heads,
with long, light brown body hairs. The back has
a light stripe, bordered on each side with
yellowish-brown and black wavy lines. The sides
are marked with blue and black spots. Moths have
a wingspread of about 2 to 21/2 inches (50 to
65 mm) and are yellowish-brown, with two
narrow, light lines across the front wings.
Identifying the Injury. - The larvae construct a
white web or tent in the crotch of a small branch. They
consume the entire leaf, except the midrib.
Biology. - Overwintering eggs hatch about the
time black cherry buds open in the spring. Young larvae
begin to construct a tent and enlarge the structure as
they grow. Full-grown larvae construct tough, silken
cocoons. Moths emerge in early summer and lay eggs in
shiny, dark brown masses around small twigs or branches
of host trees.
Control. - Control is not normally necessary.
Defoliated trees usually refoliate after being attacked.
Chemicals can be used to protect fruit trees, or tents
containing the caterpillars may be picked off and
destroyed.
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Pine
"Spittlebug" Cocoons seen all over Goose Island
If you've been noticing "little balls of white stuff" on
the limbs of Goose Island pine trees, the Gilmer County
Extension Agent, Michael Wheeler (706-635-4426) reports
that these "little balls of white stuff" are known as Pine
"Spittlebug" larvae/cocooons. He stated "they are not
typically a problem in the immature state; however, the
larvae does feed on the cambium layer of cells between the
bark and wood and it can cause a branch to die back."
He said
that if you are concerned about your trees/plants that may
be "hosting" the Spittlebug, you could knock them off with
a high pressure waterhose (could this be good for the
tree?) or use an insecticide like Diazanon (sp?).
He said
what we do need to keep an eye out for and be concerned
about is the Southern Pine Beetle. Signs of infestation
are small piles of saw dust around older pine trees;
yellowish to white colored sap oozing from the tree and
something that looks like popped popcorn glued to the
tree. These beetles are smaller than a grain of rice but
can ruin a stand of trees. They usually infest older,
weaker, more vulnerable pine trees first...a good reason
to "take down" any diseased or damaged pines...before they
move to the healthier trees.
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KILLER FUNGUS THREATENS GEORGIA OAK
TREES
Sudden
Oak Death (SOD) disease, caused by a fungus
introduced into California in the early 1990s, now
poses a statewide threat to Georgia’s oak trees
due to infected plants imported to nurseries.
James
Johnson, Forest Health Coordinator for the Georgia
Forestry Commission (GFC), said the fungus (Phytophthora
ramorum) has existed in Europe for many
years, but was only identified in the U.S. when
SOD began killing oaks in California about five
years ago.
The
fungus affects many of the most popular plants
sold in nurseries including camellia,
rhododendron, azalea, pieris, viburnum and lilac.
Johnson said the fungus is not usually fatal to
these plants, but infected spores are spread to
kill members of the oak family.
“The
good news is that there is still time to prevent
the fungus from escaping into Georgia’s oak
population -- but immediate action is needed,”
Johnson said. “Shipments from a Monrovia nursery
in California are now known to be the source of
infected plants in Georgia nurseries that were
unaware of the problem until federal and state
quarantines stopped sales.”
Monrovia plants can be recognized by a green
plastic pot with the name “Monrovia” on the
container and attached tag. GFC officials urge
anyone who purchased Monrovia plants from the
following Georgia nurseries before July 2004 to
take a sample (limb with leaves showing leaf
spots) in a sealed Ziploc bag to the nearest
University of Georgia Extension office for testing
and possible scheduling to remove the plant (all
free of charge).
GFC
officials emphasize that only the described sample
should be taken for testing – and that the entire
plant should not be removed as it could spread the
disease.
Georgia
nurseries in the following counties tested
positive for SOD fungus: Coffers Home & Garden
Inc., Clarke County; Craven Pottery Inc., Banks
County; Deep Springs Nurseries, Whitfield County;
Green Thumb West Nursery & Garden, Columbia
County; Greenbrier Nursery & Gifts LLC, Columbia
County; Island Ace Garden Center, Glynn County;
John Deere Landscapes #173, Fulton County; John
Deere Landscapes #172, Forsyth County; John Deere
Landscapes #57, Gwinnett County; Pike Nursery # 2,
Cobb County; Sago Inc. d/b/a Plant Plus, Coffee
County; Southeastern Wholesale Nursery # 1,
Gwinnett County; Still Lake Nursery Inc., Gwinnett
County; and Shemin Nurseries, Gwinnett County.
These nurseries did not knowingly sell infected
plants and were following state and federal
guidelines at the time of sale. Each has been
recently checked by officials and declared
“disease free.”
For more
information, contact your
Georgia Forestry Commission forester or visit
www.gatrees.org.
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