The polyphagus shot hole borer (PSHB) is an invasive beerle that forms a symbiosis with a new, as-yet-undescribed Fusarium sp., together causing Fusarium dieback on avocado and hother host plants in California and Israel.  In California, PSHB was frist reported on black locust in 2003, but there were no reords of fungal damage until  2012, when Fusarium was recovered from the tissues of several bakyard avocado trees infested with PSHB in Los Angeles County.  A study was conducted recently to determine the plant host range of the beerle-fungus complex in two heavily infested botanical gardens in Los Angeles County.  Of the 335 tree species observed, 207 representing 58 plant families, showed signs and symptoms consisten with attack by PSHB.  The fungs was revcovered from 54% of the plant species attacked by PSHB, indcated by the presence of the fungus at the site of the enty hole.  Trees attacked by PSHB included 11 species of California natives, 13 agriculturally important species and many common street trees. Survey results also revealed 19 tree species that function as reproductive hosts for PSHB. Additionally, approximately a quarter of all tree indiviuals planted along the streets of southern California belong to a species classified as a reproductive host.  The results suggest that the pest-disease compex could establish in a variety of plant communities locally and worldwide.