Biology Behind Oak Wilt

Oak Wilt is a vascular disease, meaning it interferes with the tree’s internal water transport system.

The fungus colonizes xylem vessels and triggers defensive responses inside the tree, including tyloses formation, which blocks water movement. While this is part of the tree’s natural defense system described in CODIT (Compartmentalization of Decay in Trees), the blockage can ultimately starve the canopy of moisture.

How Oak Wilt Spreads

    1.    Root Graft Transmission

    •    Common among Live Oaks growing close together

    •    Disease spreads underground from infected trees to healthy trees

    2.    Beetle Transmission

    •    Nitidulid beetles are attracted to fresh pruning wounds

    •    Fungal spores attach to beetles and infect new trees

    3.    Mechanical Damage

    •    Improper pruning timing

    •    Storm damage creating open wounds

Fort Worth’s dense residential plantings often create conditions favorable for root graft spread.