Today’s #SEAwednesday post is about an invasive species that is hurting our SEA native trees. The Polyphagous Shot Hole Borer Beetle (PSHB) was in the news today – and it was not good news. The Los Angeles Times reported that PSHB beetles are damaging our trees at an alarming rate. PSHB kill both our native and ornamental trees in Los Angeles County. PSHB, the size of sesame seeds, bore tiny tunnels through the tree trunk and sow fungus in the tunnels to feed their larvae. This process and the fungus in turn kills the host tree.

The only way to control the spread of PSHB is to cut down the diseased tree and carefully treat the wood on-site. It is important to chip the infected wood smaller than 1 inch, as this eliminates habitat big enough for the PSHB to continue thriving. A heat treatment, either through composting or solarizing, is done after chipping to kill the beetle and the fungi.

HOW TO HANDLE INFESTED PLANT MATERIAL

Chip the infested wood to a size less than 1 inch and compost

Chip the infested wood to a size less than 1 inch and solarize

Chip the infested wood to a size less than 1 inch and deliver to landfill to use as Alternative Daily Cover

Cut logs and solarize

Cut logs and kiln-dry

More information on PSHB and Best Management Practices

Los Angeles Times article about the state of our trees in LA County