Akif Eskalen steps through the dense, damp leaves in a wooded neighborhood, scrutinizing the branches around him. He's looking for evidence of an attack: tiny wounds piercing the bark and sap dried around them like bloodstains.
The victims are box elders, sycamores and coast live oaks, all in some state of suffering. Eskalen approaches a tree riddled with 1-millimeter holes, as if someone used it for miniature target practice. It's time to nab a perp. He selects a hole, pulls out a large knife and expertly levers out a chunk of wood.
There, in his hand, is a glossy beetle no larger than a sesame seed: the polyphagous shot hole borer.
Though small and sluggish, its appetites are wide and its spread is relentless. It attacks forest trees, city trees and key agricultural trees. It has defied all conventional and chemical weapons. No one seems to have a way to stop it.
Eskalen, a plant pathologist at UC Riverside, wants to contain this invasive bug before it spreads throughout Southern California. Already the beetle has been sighted as far south as San Diego, as far west as Santa Monica, as far east as the Riverside County city of Eastvale.
Eskalen tips the beetle into a glass vial. He detaches a pink spray bottle from his backpack and administers a few lethal squirts of ethanol before twisting the vial shut.
These beetles have a strange M.O. They don't eat wood, like termites; instead, they drill circular tunnels toward the heart of the tree. They carry fungal spores in their mouths and sow them like seeds as they go. Then they harvest the fungus to feed their larvae. It's a deadly partnership: The beetles attack, but the fungus also helps to kill, colonizing the wood tissue and spreading through the plant.