Foresters
advise keeping a close watch on beetles
By Karen Brasher
MSU College of Forest Resources
MISSISSIPPI
STATE-- Take high temperatures, drought and forest fires, add the
woody debris caused by Hurricane Katrina and the result is the recipe
for South Mississippi’s worst bark beetle outbreak
in more than a decade.
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Glenn
Hughes, a forestry specialist with Mississippi State
University's Extension Service, points to the damage
from pine bark beetles that are destroying this tree
at Elks Lake in Forrest County. (Photo by Marco Nicovich)
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“Pine trees are severely stressed due to the hurricane and the drought
that followed,” said Glenn Hughes, Mississippi State University Extension
Service forester. “Pine bark beetle populations exploded immediately
after Katrina as beetles infested snapped pine trees. Last fall, these beetles
moved into isolated live trees due to the post-Katrina drought.”
This
summer’s drought is rated severe or extreme for South Mississippi
and has resulted in increased numbers of forest fires, adding to the
stress on trees, Hughes said.
Coastal
areas subjected to the storm surge from Katrina have the greatest
tree mortality, with thousands of dead trees documented in the area.
“This is particularly troublesome because the individuals who have lost
their homes may be living in temporary trailers and in many cases have exhausted
their financial reserves,” Hughes said. “They now find that their
pine trees are dead or dying.”
There
are different types of pine bark beetles, and some are more destructive
than others. According to Hughes, the majority of pine bark beetle
infestations so far have been in timber snapped or downed by Katrina.
“Ips, or Engraver beetles, about half the size of a grain of rice, infest
downed timber, living between the bark and the wood,” he said. “The
problem occurs when Ips beetles begin attacking live trees that are stressed
by drought, lightning, or other factors. Damage is generally restricted to
a few trees, but can affect several acres. This damage can be costly to both
forest landowners and homeowners.”
A
second type of pine bark beetle, the southern pine beetle, is rated
the most destructive pine bark beetle in the South. It fortunately
has not been seen in great numbers this year and is typically not a
problem in South Mississippi.
A
third type of bark beetle is the black turpentine beetle, which generally
is found in the lower 8 feet of the tree, often around wounded areas
on the bark. This bark beetle is the least destructive of the three,
Hughes said, and the easiest to control. It is also the largest of
the three, about the size of a grain of rice.
“The most effective prevention technique involves maintaining healthy
pine trees,” he said. “For forest landowners, this consists of
thinning at the appropriate time to reduce stress and thus insect attacks.”
Homeowners
may need to water trees once a week during a drought period. Watering
trees with 1 inch of water each week during a drought is better than
more frequent, less intense watering.
Hughes
said landowners should pay close attention to their trees so those
infested can be identified and removed promptly. Signs of infestation
by bark beetles include the needles turning from dark green to yellowish
green to reddish brown. Another telltale sign is the appearance of
globs of sap on the bark called “pitch tubes.” These indicate
where the beetle bored into the tree.
Mark Anderson, general manager of Hattiesburg-based Karnes Tree Service
and certified arborist, has assisted more than 50 landowners this summer
in removing trees from landscapes due to storm damage, drought and
bark beetles.
“Black turpentine beetles colonized trees damaged during the hurricane
clean-up that occurred this spring,” Anderson said. “Once the black
turpentine beetles come in, the Ips and southern pine beetles are not too far
away.”
Southern
pine beetles are moving from tree top to tree top in the landscape
and spraying has little to no value, Anderson added.
Homeowners
should look for any signs of stress in the crown of the trees and
contract with a tree service to remove infested trees promptly.
“Inaction will allow the beetles to move to neighboring pine trees, infesting
them, and resulting in more dead trees and greater removal costs to the homeowner,” Anderson
advised.
Beetle
activity typically increases in the fall as temperatures moderate,
Anderson said, so the bark beetle situation may get worse before it
gets better.
“Needles on many trees infested by beetles are just starting to turn,
so landowners and homeowners need to become familiar with signs of infestation
in order to identify, treat, and stop the beetles,” he added.
A
series of evening meetings are being planned in South Mississippi
to educate landowners and homeowners about the threat from bark beetles,
as well as control measures. For information on upcoming meetings,
contact Hughes at (601) 794-0671.
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Released:
Aug. 24, 2006
Contact: Dr. Glenn Hughes, (601) 794-0671
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