Raffaelea lauricola, a new ambrosia beetle symbiont and pathogen on the Lauraceae

Abstract

An undescribed species of Raffaelea earlier was shown to be the cause of a vascular wilt disease known as laurel wilt, a severe disease on redbay (Persea borbonia) and other members of the Lauraceae in the Atlantic coastal plains of the southeastern USA. The pathogen is likely native to Asia and probably was introduced to the USA in the mycangia of the exotic redbay ambrosia beetle, Xyleborus glabratus. Analyses of rDNA sequences indicate that the pathogen is most closely related to other ambrosia beetle symbionts in the monophyletic genus Raffaelea in the Ophiostomatales. The asexual genus Raffaelea includes Ophiostoma-like symbionts of xylem-feeding ambrosia beetles, and the laurel wilt pathogen is named R. lauricola sp. nov.