Geosmithia putterillii

The foamy bark canker is a disease affecting oak trees in California caused by the fungus Geosmithia pallida and spread by the Western oak bark beetle (Pseudopityopthorus pubipennis). This disease is only seen through the symbiosis of the bark beetles and the fungal pathogen. The bark beetles target oak trees and bore holes through the peridermal tissues, making tunnels within the phloem. The fungal spores are brought into these tunnels by the beetles and begin to...