August 28, 1997
(Forest Resources and Agrifoods)
Kevin Aylward,
Minister of Forest Resources and Agrifoods advises that the
operational part of the 1997 hemlock looper control program has
ended. The program, which was carried out under licence from the
Department of Environment & Labour, began on July 4 and ended
on August 3, 1997.
"Although the
weather was less than ideal for operations," commented the
minister, "approximately 4,200 hectares of infested forest
were treated in western and northern Newfoundland with the
biological insecticide, B.t. (Foray 76B)."
Over the next few
weeks, ground crews will dismantle the spray bases and store
equipment. Field crews all continue to collect data on insect
numbers and defoliation in sample plots. Once the looper larvae
finish feeding, the annual defoliation survey carried out by the
department will commence to map the 1997 insect damage. After all
data is collected, analyzed and evaluated, the effectiveness of
the program will be determined. Results are expected in late
September.
Mr. Aylward
expressed concern for the increase in the population of balsam
fir sawfly in western Newfoundland in 1997. First detected in
1991, the population has grown to where the 1997 infestation
forecast was for 54,000 hectares to be defoliated, more than
double the 1996 recorded defoliation of 19,700 hectares. Much of
the infestation is occurring in silviculturally treated areas.
Also of concern is the increase in the yellowheaded spruce sawfly
in central Newfoundland which is causing defoliation on young
black spruce, and more importantly on black spruce plantations.
Some 500 hectares were affected in 1996.
"The increase
in sawfly infestation is of growing concern for both government
and industry who have invested in these silviculturally treated
areas where the sawfly has been detected," stated Mr.
Aylward. "There is currently no biological insecticide
solution to these insects. Bacillus thuringiensis (B.t.), which
is used routinely for hemlock looper, is not effective against
sawflies. Therefore, my department must look into alternative
methods of control."
The Newfoundland
Forest Service, the Canadian Forest Service and the two pulp and
paper companies are pursuing an integrated approach to sawfly
management. This approach involves examining the ecology of
infested areas, determining existing natural controls such as
viruses, parasites, and natural predators as potential long term
solutions, and determining the impact of the sawfly infestation.
However, to date, an effective integrated control strategy for
the sawfly has not been found. Currently, the only chemical
insecticide for sawfly control in aerial forest pest management
is fenitrothion. The department is evaluating what immediate
control options that are available.
"We have had a
very successful year in minimizing the infestation of hemlock
looper," said Mr. Aylward, "and I trust that research
on long term and short term control for other potentially
damaging pests like the balsam fir sawfly and the yellowheaded
spruce sawfly will ensure that we are ready and able to protect
our forests and ensure its long term sustainability."
Contact:
Hubert Crummey
(709) 637-2424
Anna Buffinga
(709)729-3750
|