San Francisco, California – Visitors walking through Golden Gate Park or hiking coastal trails near Lands End are being urged to act immediately if they spot a destructive invasive beetle capable of killing hardwood trees across San Francisco.
According to the U.S. Forest Service and the California Department of Food and Agriculture, the Asian longhorned beetle attacks maple, birch, willow, poplar and elm trees. Officials warn that the insect tunnels deep into tree trunks, weakening them internally before visible dieback appears.
Golden Gate Park, the Presidio and neighborhoods from the Richmond District to Noe Valley feature ornamental and native hardwoods that provide shade, reduce erosion and buffer coastal winds. Similar tree cover lines trails at Twin Peaks and across the Golden Gate Bridge into the Marin Headlands.
The beetle is glossy black with bright white spots and long black-and-white banded antennae extending beyond its body. Hikers may notice perfectly round exit holes in trunks or sawdust-like material collecting at the base of trees.
If infestations spread, weakened limbs could snap during gusty Pacific systems, increasing hazards along trails and park roads.
Officials urge residents and park visitors to kill the beetle on sight if safely possible and report sightings immediately to state agriculture authorities. Early detection this spring could prevent widespread tree removal and protect San Francisco’s urban canopy into summer.
