Fungi in the genus Geosmithia (Ascomycota: Hypocreales) are frequent associates of bark beetles and woodborers that colonize hardwood and coniferous trees. One species, Geosmithia morbida, is an economically damaging invasive species. The authors surveyed the Geosmithia species of California and Colorado, USA, to (i) provide baseline data on taxonomy of Geosmithia and beetle vector specificity across the western USA; (ii) investigate the subcortical beetle fauna for alternative vectors of the invasive G. morbida; and (iii) interpret the community composition of this region within the emerging global biogeography of Geosmithia. Geosmithia was detected in 87% of 126 beetle samples obtained from 39 plant species. Twenty-nine species of Geosmithia were distinguished, of which 13 may be new species. Bark beetles from hardwoods, Cupressus, and Sequoia appear to be regular vectors, with Geosmithia present in all beetle gallery systems examined. Other subcortical insects appear to vector Geosmithia at lower frequencies. Overall, most Geosmithia have a distinct level of vector specificity (mostly high, sometimes low) enabling their separation to generalists and specialists. Plant pathogenic Geosmithia morbida was not found in association with any other beetle besides Pityophthorus juglandis. However, four additional Geosmithia species were found in P. juglandis galleries. When integrated with recent data from other continents, a global pattern of Geosmithia distribution across continents, latitudes, and vectors is emerging: of the 29 Geosmithia species found in the western USA, 12 have not been reported outside of the USA. The most frequently encountered species with the widest global distribution also had the broadest range of beetle vectors. Several Geosmithia spp. with very narrow vector ranges in Europe exhibited the similar degree of specialization in the USA. Such strong canalization in association could reflect an ancient origin of each individual association, or a recent origin and a subsequent diversification in North America.

• MeSH
• Biodiversity * MeSH
• Coleoptera classification   microbiology   MeSH
• DNA, Fungal genetics   MeSH
• Species Specificity MeSH
• Phenotype MeSH
• Phylogeny MeSH
• Insect Vectors microbiology   MeSH
• Hypocreales classification   isolation & purification   MeSH
• Plant Diseases microbiology   MeSH
• Trees microbiology   MeSH
• Introduced Species MeSH
• Animals MeSH
• Check Tag
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Research Support, U.S. Gov't, Non-P.H.S. MeSH
• Geographicals
• Colorado MeSH
• California MeSH

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.

• MeSH
• Pigments, Biological metabolism   MeSH
• DNA, Fungal chemistry   genetics   MeSH
• Peptide Elongation Factor 1 genetics   MeSH
• Phylogeny MeSH
• Hypocreales classification   genetics   isolation & purification   physiology   MeSH
• DNA, Ribosomal Spacer chemistry   genetics   MeSH
• Weevils microbiology   MeSH
• RNA, Ribosomal, 5.8S genetics   MeSH
• RNA Polymerase II genetics   MeSH
• Sequence Analysis, DNA MeSH
• Cluster Analysis MeSH
• Tubulin genetics   MeSH
• Animals MeSH
• Check Tag
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, U.S. Gov't, Non-P.H.S. MeSH
• Geographicals
• United States MeSH

Species of the genus Geosmithia are associated with insect species, mainly bark beetles. On Ulmus spp., the same beetles are also vectors of Ophiostoma ulmi s.l., the agent of Dutch elm disease (DED), a worldwide elm disease. Aim of this paper is to characterise Geosmithia species associated with elms and/or elm beetles in Europe. Seventy-two strains representative of all morphological taxonomic units were used to build a phylogenetic tree based on ITS, β-tubulin and elongation factor 1-α gene regions. On the basis of molecular and morpho-physiological traits, seven taxonomic entities were identified. In addition to the species previously known our results assigned strains previously identified as Geosmithia pallida to two separate taxa: Geosmithia sp. 2 and Geosmithia sp. 5. Two new species, Geosmithia omnicola and Geosmithia ulmacea, are described. Two strains were assigned to the partially described species Geosmithia sp. 20. Geosmithia species living on Ulmus do not discriminate between elm species, but between different environments. The association between Ulmus and Geosmithia is common, stable, and seems to be related to specific vectors. The relationship between Geosmithia and Ophiostoma would deserve further investigation, as these fungi share the same vectors and habitat for a significant part of their life cycles.

• MeSH
• Coleoptera microbiology   MeSH
• DNA, Fungal chemistry   genetics   MeSH
• Peptide Elongation Factor 1 genetics   MeSH
• Phylogeny MeSH
• Genetic Variation * MeSH
• Hypocreales classification   cytology   genetics   isolation & purification   MeSH
• DNA, Ribosomal Spacer chemistry   genetics   MeSH
• Microscopy MeSH
• Molecular Sequence Data MeSH
• Sequence Analysis, DNA MeSH
• Cluster Analysis MeSH
• Tubulin genetics   MeSH
• Ulmus microbiology   MeSH
• Animals MeSH
• Check Tag
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Geographicals
• Europe MeSH

Fungi from the genus Geosmithia (Ascomycota: Hypocreales) are associated with bark beetles (Coleoptera: Scolytinae), though little is known about ecology, diversity, and distribution of these fungi across beetle and its host tree species. This study surveyed the diversity, distribution and vector affinity of Geosmithia isolated from subcortical insects that colonized trees from the family Pinaceae in Central and Northeastern Europe. Twelve Geosmithia species were isolated from 85 plant samples associated with 23 subcortical insect species (including 14 bark beetle species). Geosmithia community composition was similar across different localities and vector species; although the fungal communities associated with insects that colonized Pinus differed from that colonizing other tree species (Abies, Larix, and Picea). Ten Geosmithia species from four independent phylogenetic lineages were not reported previously from vectors feeding on other plant families and seem to be restricted to the vectors from Pinaceae only. We conclude that presence of such substrate specificity suggests a long and stable association between Geosmithia and bark beetles.

• MeSH
• Biodiversity * MeSH
• Pinaceae classification   microbiology   parasitology   MeSH
• Coleoptera classification   microbiology   MeSH
• Phylogeny MeSH
• Insect Vectors microbiology   MeSH
• Host Specificity MeSH
• Hypocreales classification   genetics   isolation & purification   physiology   MeSH
• Molecular Sequence Data MeSH
• Plant Diseases microbiology   parasitology   MeSH
• Animals MeSH
• Check Tag
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Geographicals
• Europe MeSH

Widespread morbidity and mortality of Juglans nigra has occurred in the western USA over the past decade. Tree mortality is the result of aggressive feeding by the walnut twig beetle (Pityophthorus juglandis) and subsequent canker development around beetle galleries caused by a filamentous ascomycete in genus Geosmithia (Ascomycota: Hypocreales). Thirty-seven Geosmithia strains collected from J. californica, J. hindsii, J. major and J. nigra in seven USA states (AZ, CA, CO, ID, OR, UT, WA) were compared with morphological and molecular methods (ITS rDNA sequences). Strains had common characteristics including yellowish conidia en masse, growth at 37 C and absence of growth on Czapek-Dox agar and belonged to a single species described here as G. morbida. Whereas Geosmithia are common saprobes associated with bark beetles attacking hardwoods and conifers worldwide, G. morbida is the first species documented as a plant pathogen.

• MeSH
• Coleoptera microbiology   physiology   MeSH
• DNA, Fungal genetics   MeSH
• Phylogeny MeSH
• Hypocreales classification   genetics   isolation & purification   physiology   MeSH
• Juglans microbiology   parasitology   MeSH
• DNA, Ribosomal Spacer genetics   MeSH
• Molecular Sequence Data MeSH
• Plant Diseases microbiology   MeSH
• Symbiosis MeSH
• Animals MeSH
• Check Tag
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, U.S. Gov't, Non-P.H.S. MeSH
• Geographicals
• United States MeSH