Fungi may help some tree-killer beetles turn a tree’s natural defense system against itself. The Eurasian spruce bark beetle has massacred millions of conifers in forests across Europe. Now, research suggests that fungi associated with these bark beetles are key players in the insect’s hostile takeovers. These fungi warp the chemical defenses of host trees to create an aroma that attracts beetles to burrow. This fungi-made perfume might explain why bark beetles tend to swarm the same tree. As climate change makes Europe’s forests more vulnerable to insect invasions, understanding this relationship could help scientists develop new countermeasures to ward off beetle attacks. …This ability of bark beetles to overcome the powerful defense system of conifers has led some scientists to wonder if fungi might be helping. …Combining pheromones with fungi-derived chemicals might be the secret to entice more beetles into traps, making them more effective.