Two new Geosmithia species in G. pallida species complex from bark beetles in eastern USA

ABSTRACT

Species of Geosmithia are cosmopolitan but understudied fungi, and most are associated with phloem-feeding bark beetles on various woody hosts. We surveyed 207 bark and ambrosia beetles from 37 species in the eastern USA for associated fungi. The community is dominated by species in the G. pallida species complex (GPSC) and included several Geosmithia isolates that appear to be new to science. The new Geosmithia isolates exhibited the characteristic brownish-colored colonies typical for the G. pallida species complex and were phylogenetically resolved as two genealogically exclusive lineages based on a concatenated multilocus data set based on the internal transcribed spacers (ITS) of the nuc rDNA (ITS1-5.8S-ITS2 = ITS), and the translation elongation factor 1-α (TEF1-α), β-tubulin (TUB2), and RNA polymerase II second largest subunit (RPB2) genes. Two new Geosmithia species, G. brunnea and G. proliferans, are proposed, and their morphological traits and phylogenetic placements are presented.

KEYWORDS:

• Bionectriaceae
• ectosymbiont
• North America
• subcortical beetles
• symbiosis

ACKNOWLEDGMENTS

We would like to thank James Skeleton for the help with sampling in Florida.

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Funding

This project was supported by the National Science Foundation, the United States Department of Agriculture (USDA) Forest Service (FS), and USDA Animal and Plant Health Inspection Service (APHIS). The work does not necessarily represent the views of APHIS.