Forest & Grassland Health


Cold tolerance and seasonal generations of western pine beetle in CA

Historical temperature records suggest that episodes of western pine beetle winter mortality in California due to extreme cold temperatures are infrequent and mostly restricted to the northeastern parts of the state. Most areas on the west slope of the Sierra Nevada range, especially lower elevations of the ponderosa pine belt, have likely never experienced significant winter mortality of western pine beetle during the period of record. Monitoring in 2017 found no increase in the number of generations of western pine beetle on the Lassen and Stanislaus National Forests compared to historic observations when differences in elevation and latitude are accounted for.

Goldspotted Oak Borer in Southern California

The goldspotted oak borer (GSOB) Agrilus coxalis (Coleoptera: Buprestidae), is a wood borer native to southeastern Arizona, southern Mexico, and northern Guatemala. It is believed to be introduced into California and was first collected in San Diego County in 2004. In 2008, GSOB was linked to continuing oak mortality occurring in San Diego County since 2002 across all land ownerships. It is now also found in Riverside County.

Firewood Movement: Buy It Where You Burn It!!

The movement of firewood can be a source of introduction and dissemination of invasive forest insects and diseases into and around the United States. Pests such as the Asian longhorned...*