The goldspotted oak borer (GSOB- Agrilus auroguttatus) was found for the first time in

Orange County in December 2014 at one isolated location in Weir Canyon impacting 62 coast live oak (Quercus agrifolia) trees. This new site is approximately

Goldspotted oak borer detections. By C. Washington.

60 miles west of the Idyllwild infestation in Riverside County and 65 miles northeast of the nearest known San Diego County infestation at Mount Palomar. There is no camping nearby; however, firewood may have been brought into neighborhoods within close proximity to the canyon. GSOB appears to have arrived there within the last 5 years as tree mortality was not observed during the initial survey. A coalition of partners is forming to respond to the discovery and determine the extent of the infestation.

The goldspotted oak borer continues to spread locally within areas already infested in San Diego and Riverside Counties.  The California Board of Forestry and Fire Protection unanimously approved the expansion of the GSOB Zone of Infestation in December to include new areas in San Diego County (Palomar and Ranchita) and Riverside County (Pine Cove and Idyllwild). For more information on GSOB, go to gsob.org.

While most biotic forest pests are inactive at higher elevations this time of year, damage from weather-related events is still possible. One example of this is a winter-time foliage desiccation commonly referred to as red belt. The damage occurs when warm air temperatures cause foliage to transpire while frigid soils prevent trees from taking up water. "Red" refers to a dramatic browning of conifer tree crowns across a swath of terrain, while "belt" refers to the band or belt of trees at a given elevation that brown. Before new foliage is produced in the spring, damaged trees can appear dead, causing land managers seeing it for the first time to be caught off guard. Red belt typically occurs in drier and colder eastern California forests and across the west.

Red belt on ponderosa pine, Shasta Co. By D. Owen.

There will be a lot of red trees this spring due to bark beetle activity, but be aware that other conditions can cause trees to look dead, especially in the spring. For a description of red belt and other types of abiotic damage, see USDA Forest Service Ag Handbook 521, "Diseases of Pacific Coast Conifers." California Department of Forestry and Fire Protection Tree Note # 30 provides information on "Identifying Dead and Dying Conifers on Private Land in California."