Abstract:The invasive Asian ambrosia beetleEuwal-laceasp. (Coleoptera, Scolytinae, Xyleborini) and anovelFusariumsp. that it farms in its galleries as asource of nutrition causes serious damage to morethan 20 species of live trees and pose a serious threatto avocado production (Persea americana) in Israeland California. Adult female beetles are equippedwith mandibular mycangia in which its fungalsymbiont is transported within and from the natalgalleries. Damage caused to the xylem is associatedwith disease symptoms that include sugar or gumexudates, dieback, wilt and ultimately host treemortality. In 2012 the beetle was recorded on morethan 200 and 20 different urban landscape species insouthern California and Israel respectively.Euwalla-ceasp. and its symbiont are closely related to the teashot-hole borer (E. fornicatus) and its obligatesymbiont,F. ambrosiumoccurring in Sri Lanka andIndia.