Abstract:
The red turpentine beetle (RTB; Dendroctonus valens) is a bark beetle that is native to Central and
North America. This insect is well-known to live in association with a large number of Ophiostomatalean fungi. The
beetle is considered a minor pest in its native range, but has killed millions of indigenous pine trees in China after
its appearance in that country in the late 1990s. In order to increase the base of knowledge regarding the RTB and
its symbionts, surveys of the beetle’s fungal associates were initially undertaken in China, and in a subsequent
study in its native range in North America. A total of 30 Ophiostomatalean species that included several undescribed
taxa, were identified in these surveys. In the present study, seven of the undescribed taxa collected during the
surveys were further characterised based on their morphological characteristics and multi-gene phylogenies. We
proceeded to describe five of these as novel Leptographium spp. and two as new species of Ophiostoma. Four of
the Leptographium spp. resided in the G. galeiformis-species complex, while one formed part of the L. olivaceumspecies
complex. One Ophiostoma sp. was a member of the O. ips-species complex, while the only new species
from China was closely related to O. floccosum. Two of the previously undescribed taxa from North America were
shown to be congeneric with L. terebrantis, implying that this species was most often isolated in association with the
RTB in North America. The undescribed taxon from North America was identified as O. ips, and like L. terebrantis,
this species was also not recognized during the initial North American survey. Resolving the identities of these taxa
provides essential baseline information to better understand the movement of fungal pathogens with this beetle.
This then enhances our ability to accurately assess and predict the risks of invasions by these and related fungi.
