Galls on oak leaves are harmless growths caused by specific insects. They have different shapes depending on the insect species causing the gall.

The invasive goldspotted oak borer has spread across SoCal, leaving boneyards of dead trees behind. This June, UC ANR and community partners launched an effort to track this pest.

Oak trees are a vital part of both urban neighborhoods and natural ecosystems. Experts issue warning as hidden pathogen ...