Beetle and Fungus Have 'Gone Rogue,' Threaten Walnut Trees

The walnut twig beetle was once nothing but a nuisance for black walnut trees across the western United States. Now, however, it appears that the beetle has gained a partner in crime - a mutated fungus that infects anywhere the beetles go. This has allowed the once-pests to "go rogue," now inflicting near-irreversible and sometimes fatal damage to these trees and trees like them.