Abstract:
Raffaelea (Ophiostomatales) is a genus of more than 20 ophiostomatoid fungi commonly occurring in
symbioses with wood-boring ambrosia beetles. We examined ambrosia beetles and plant hosts in the USA and
Taiwan for the presence of these mycosymbionts and found 22 isolates representing known and undescribed
lineages in Raffaelea. From 28S rDNA and β-tubulin sequences, we generated a molecular phylogeny of
Ophiostomatales and observed morphological features of seven cultures representing undescribed lineages
in Raffaelea s. lat. From these analyses, we describe five new species in Raffaelea s. lat.: R. aguacate, R.
campbellii, R. crossotarsa, R. cyclorhipidia, and R. xyleborina spp. nov. Our analyses also identified two plantpathogenic
species of Raffaelea associated with previously undocumented beetle hosts: (1) R. quercivora, the
causative agent of Japanese oak wilt, from Cyclorhipidion ohnoi and Crossotarsus emancipatus in Taiwan, and
(2) R. lauricola, the pathogen responsible for laurel wilt, from Ambrosiodmus lecontei in Florida. The results of
this study show that Raffaelea and associated ophiostomatoid fungi have been poorly sampled and that future
investigations on ambrosia beetle mycosymbionts should reveal a substantially increased diversity.
