Dr. Taylor Scarr, a provincial forest entomologist with the Ministry of Natural Resources in Sault Ste. Marie, was on hand at the Adventure Inn here last Wednesday to answer questions about the jack pine budworm infestation in Rainy River District.
The jack pine budworm caused severe defoliation of nearly 90,000 hectares of forest in parts of the district this past summer and ignited concern that many trees could be in danger.
“We want to provide the info to the public,” Dr. Scarr said, noting the comment and review period of the proposed Insect Pest Management Program is 60 days.
After that, Dr. Scarr explained the MNR will decide which of the following four actions should be taken to handle the situation:
•Salvage harvest (specifically harvesting only the trees that have died or are in danger of dying as a result of the budworm outbreak);
•Re-directed harvest (changing harvesting schedules to deal with infested areas first, putting off the harvest of other areas for a later date);
•Use of insecticides (controlling the population levels of insects with the use of the biological insecticide Bacillus Thuringiensis subspecies Kurstaki, commonly known as Btk); or
•No treatment (relying on either the weather or the many species of birds, spiders, and other predators that feed on the tiny insect to keep the budworm population in check).
Dr. Scarr talked a lot about the use of Btk, and noted he had several questions on the topic.
“One question asked was if Btk affects animals,” he said, adding the bacterium does not harm mammals—only caterpillars of specific insect species.
“And most aren’t out yet,” he remarked.
If a decision is made to use Btk, Dr. Scarr said it likely would be sprayed during the first week of June.
The Ministry of the Environment has allowed Btk to be sprayed right to the water’s edge. “There is no buffer zone,” Dr. Scarr explained. “It’s considered safe.”
An information sheet developed by Health Canada, which was handed out at the information session, stated “Btk has been used on millions of acres of wooded areas and agricultural crops in many countries.”
Dr. Scarr noted the bacterium will not kill all the budworms.
“It will kill enough to keep the trees green and to get over the outbreak,” he said. “But there will still be some budworms.”
The four possible actions outlined to relieve the impact of the jack pine budworm outbreak have been developed based on experience, Dr. Scarr noted.
He explained samples of second-instar larvae are taken from branches. If there is more than 54 on a one-metre branch, it is expected to get severely defoliated.
Dr. Scarr had a sample in a small glass container to show those on hand for the open house. He noted it is common to see 100-200 second-instar larvae, and in one particular case 600 were counted.
“We had a positive response,” he added about the seminar, noting there was an excellent turnout.
“No one wants to see their wood supply affected,” he said.
Fort Frances Times
Local News from Across the Rainy River District
