Researchers at the University of Alberta have found that a fungus can make trees resistant to mountain pine beetles, a small insect that causes major damage. The only problem is that this fungus also causes significant damage to infected trees.
Atropella canker, a fungus found primarily in western Canada, can produce toxins on an infected tree that are harmful to pine beetles.
In general, infection with this fungus leads to a change in the tree's defense system, explains one of the study's co-authors, Rashaduz Zaman. In most cases, the infection makes the tree more susceptible to insect and disease attack.
Of five fungi studied, four reduced the resistance of Alberta pines to mountain pine beetles.
However, over the course of the study, atropella cancer was found to be effective in making pine trees more resistant to attacks by the small wood-boring insect, which has already devastated tens of millions of hectares of Canadian forests.
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The small beetle is able to pierce the bark of trees and remove the layer between the bark and the wood. One of the signs of the presence of the insect is the reddish color of pine needles. The photo was taken in 2019 near Hinton, east of Edmonton.
Photo: Government of Alberta
Prevention instead of healing
Atropelle canker is a fungus that affects the trunk of trees. According to Natural Resources Canada, it can cause tree death and is particularly common after wildfires.
Mr Zaman believes that the results of their research are more of a starting point for developing a forest management system and limiting the damage caused by the insect.
So it's not about infecting parts of an entire forest with this potentially deadly fungus in order to increase its resistance to small beetles.
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Atropella canker can cause the tree to slow its growth and even die. Infection is fatal if large canker growths surround the stems.
Photo: Natural Resources Canada
Rather, the results (New window) (in English) show that it is possible to identify the chemical profile of trees resistant to the insect, specifies the doctoral student in forest biology, by analyzing trees infected with the insect are.
According to Richard Hamelin, professor of forest pathology at the University of British Columbia, this is an interesting development.
If it is possible to identify less resistant trees, he believes it would be conceivable to use pheromone traps to attract insects to these trees and then perhaps sacrifice these trees.
He sees this as a way to curb the spread of the insect.
There is no way to eliminate the pine beetle, says Jakub Olesinski, Parks Canada forest health expert.
Pesticides are simply not effective. They cannot be used to control them.
Still far from reality
For the professor, who also holds the position of director of the Department of Nature Conservation and Forestry at the University of British Columbia, it is an interesting study, but we are really far away from real-world applications.
Because the tree's defense system was studied during a fungal attack, he says it is difficult to identify which tree has the profile of being resistant to insects before the atropellar canker begins to cause damage.
If an attack then occurs, it is often too late.
The authors of the study nevertheless expressed the idea of being able to develop a diagnostic tool.
Rashaduz Zaman believes it would be possible to identify which trees might be infected years before the fungus attacks its trunk. As with humans, if they have symptoms they will be tested by doctors.