This beetle has a toxic relationship with a tree. Fortunately, they know a mushroom

Nature gives rise to fascinating adaptations, which can sometimes lead organisms to live in strange situations.

The relationship between bark beetles, spruce trees and a type of mushroom is a good example. According to a new study published in Proceedings of the National Academy of SciencesBark beetles protect themselves from fungal infections by eliminating antibiotic compounds stored in trees. But the fungus still manages to control the beetles by infecting and killing certain beetle populations.

Examining how each organism has adapted to its neighbors could help scientists create biological treatments for parasites, the researchers said.

No friends here

Spruce bark beetles (The printer himself) are a common pest that burrows deep into a tree, siphoning off nutrients. Although bark beetles are rarely aggressive enough to kill a tree, their presence can threaten those weakened by natural or man-made disasters. Additionally, “little can be done to control most bark beetles once trees have been attacked,” according to one report. report by the California Integrated Pest Management Program.

And then there is the mushroom, Beauveria bassiana. This fungus is neither the friend of the tree nor that of the beetle; as a pathogenic species, it can infect both organisms. The researchers behind the new study wondered whether the beetles could exploit the spruce tree’s rich defensive resources to protect themselves from the fungus.

To find out, the team carried out detailed chemical analyzes of the antibiotics produced by spruce trees to fight fungal infections. Their investigation suggested that the beetles used these compounds for their own defense. Surprisingly, this involved a sophisticated process in which the insects transformed these chemicals into even more toxic substances, with greater capacity to protect against fungal attack.

A strange trio

“We did not expect that the beetles would be able to convert spruce defenses into more toxic derivatives in such a targeted manner,” Ruo Sun, lead author of the study and a biochemist at the Max Planck Institute for Chemical Ecology in Jena, Germany, said in a statement. statement.

The researchers also discovered that the fungi were in turn able to adapt to the beetles’ new defenses. Overall, the tree’s chemical defenses have undergone “multiple transformations and retransformations throughout the food chain, with far-reaching consequences for the evolutionary arms race between hosts, pests and pathogens,” the researchers said.

It is unlikely that any organism involved in this system would knowingly keep others at bay, but it is certainly a natural pest control solution, according to the paper. For example, scientists could take inspiration from the fungus to create more effective pesticides. Some fungal strains “had naturally infected and killed [the beetles]”, Sun said. As such, identifying these strains became the central focus of their research, she added.