San Diego, California – Visitors walking through Balboa Park and hikers climbing trails at Mission Trails Regional Park are being urged to act immediately if they spot a destructive invasive beetle capable of killing hardwood trees across San Diego County this spring.
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 the insect burrows deep into trunks, cutting off nutrients and weakening trees long before visible dieback appears.
Balboa Park, Mission Bay Park and waterfront paths around Shelter Island feature clusters of hardwoods that provide shade across heavily visited green spaces. Similar tree cover stretches into Torrey Pines State Natural Reserve, Santee Lakes and neighborhood parks in La Mesa and Chula Vista.
The beetle is glossy black with bright white spots and long black-and-white banded antennae that extend beyond its body. Visitors 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 Santa Ana wind events, creating hazards along trails, park roads and coastal overlooks.
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 season could prevent widespread tree removal and protect San Diego’s urban and coastal canopy into summer.
