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.

• Klíčová slova
• Entomochoric fungi, Geosmithia morbida, Pityophthorus juglandis, subcortical beetles, symbiosis,
• MeSH
• biodiverzita * MeSH
• brouci klasifikace   mikrobiologie   MeSH
• DNA fungální genetika   MeSH
• druhová specificita MeSH
• fenotyp MeSH
• fylogeneze MeSH
• hmyz - vektory mikrobiologie   MeSH
• Hypocreales klasifikace   izolace a purifikace   MeSH
• nemoci rostlin mikrobiologie   MeSH
• stromy mikrobiologie   MeSH
• zavlečené druhy MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, U.S. Gov't, Non-P.H.S. MeSH
• Geografické názvy
• Colorado MeSH
• Kalifornie MeSH
• Názvy látek
• DNA fungální 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.

• Klíčová slova
• Bionectriaceae, North America, ectosymbiont, subcortical beetles, symbiosis,
• MeSH
• biologické pigmenty metabolismus   MeSH
• DNA fungální chemie   genetika   MeSH
• elongační faktor 1 genetika   MeSH
• fylogeneze MeSH
• Hypocreales klasifikace   genetika   izolace a purifikace   fyziologie   MeSH
• mezerníky ribozomální DNA chemie   genetika   MeSH
• nosatcovití mikrobiologie   MeSH
• RNA ribozomální 5.8S genetika   MeSH
• RNA-polymerasa II genetika   MeSH
• sekvenční analýza DNA MeSH
• shluková analýza MeSH
• tubulin genetika   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Research Support, U.S. Gov't, Non-P.H.S. MeSH
• Geografické názvy
• Spojené státy americké MeSH
• Názvy látek
• biologické pigmenty MeSH
• DNA fungální MeSH
• elongační faktor 1 MeSH
• mezerníky ribozomální DNA MeSH
• RNA ribozomální 5.8S MeSH
• RNA-polymerasa II MeSH
• tubulin 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
• biodiverzita * MeSH
• borovicovité klasifikace   mikrobiologie   parazitologie   MeSH
• brouci klasifikace   mikrobiologie   MeSH
• fylogeneze MeSH
• hmyz - vektory mikrobiologie   MeSH
• hostitelská specificita MeSH
• Hypocreales klasifikace   genetika   izolace a purifikace   fyziologie   MeSH
• molekulární sekvence - údaje MeSH
• nemoci rostlin mikrobiologie   parazitologie   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Evropa MeSH

Geosmithia spp. (Ascomycota: Hypocreales) are dry-spored fungi that occur in galleries built by many phloeophagous bark beetles. This study mapped the diversity, host spectrum and area of distribution of Geosmithia spp. occurring in galleries of bark beetle species with a Mediterranean distribution. Eighty-six wood samples of 19 tree species infested by 18 subcortical insect species were collected from across the Mediterranean Basin during the years 2003-2006. Geosmithia spp. were found in 82 samples of angiosperms and two host trees from the family Juniperaceae infested by 14 bark beetles and the bostrichid Scobicia pustulata, suggesting that the association of Geosmithia and phloeophagous bark beetles is very widespread in the Mediterranean. Geosmithia isolates were sorted into 13 operational taxonomic units (OTUs) based on their phenotype similarity and phylogeny of their ITS regions of rDNA (ITS1-5.8S-ITS2). The OTUs represent five known species (G. flava, G. langdonii, G. lavendula, G. pallida, G. putterillii) and seven undescribed taxa. Most of the bark beetles were associated with on average 1-2.5 OTUs per sample. G. lavendula, considered very uncommon in nature, was found as a common associate of bark beetles. Six out of 13 OTUs were found to be distributed in the Mediterranean but not in neighbouring areas of temperate Europe suggesting that Geosmithia spp. have a geographically limited distribution, probably due to their dependency on the geographically limited area of their vectors. The proportion of generalists and specialists among Geosmithia spp. was smaller compared with data from temperate Europe. A possible explanation is the effective dispersal of Geosmithia by polyphagous bostrichids across the niches defined by mutually exclusive bark beetles.

• MeSH
• brouci klasifikace   růst a vývoj   MeSH
• cévnaté rostliny mikrobiologie   parazitologie   MeSH
• DNA fungální analýza   izolace a purifikace   MeSH
• druhová specificita MeSH
• fenotyp MeSH
• fylogeneze * MeSH
• Hypocreales klasifikace   genetika   růst a vývoj   izolace a purifikace   MeSH
• kůra rostlin mikrobiologie   parazitologie   MeSH
• Magnoliopsida mikrobiologie   parazitologie   MeSH
• mezerníky ribozomální DNA analýza   MeSH
• molekulární sekvence - údaje MeSH
• sekvenční analýza DNA MeSH
• technika náhodné amplifikace polymorfní DNA MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Středomoří MeSH
• Názvy látek
• DNA fungální MeSH
• mezerníky ribozomální DNA MeSH

Geosmithia spp. (Ascomycota: Hypocreales) are little-studied, dry-spored fungi that occur in galleries built by many phloeophagous bark beetles. This study mapped the distribution and environmental preferences of Geosmithia species occurring in galleries of temperate European bark beetles. One hundred seven host tree samples of 16 tree species infested with 23 subcortical insect species were collected from across Europe during the years 1997-2005. Over 600 Geosmithia isolates from the beetles were sorted into 17 operational taxonomic units (OTUs) based on their phenotype similarity and phylogeny of internal transcribed spacer (ITS) region of rDNA (ITS1-5.8S-ITS2). The OTUs represent six known species and eight undescribed taxa. Ninety-two samples infested with subcortical insects were characterized by the presence/absence of OTUs and the similarity among the samples was evaluated. Geographically distant populations of the same beetle species host relatively uniform Geosmithia communities across large geographic areas (ranging from southern Bulgaria to the Czech Republic). This suggests effective dispersal of Geosmithia spp. by bark beetles. Clustering of similar samples in ordination analysis is correlated predominantly with the isolation source (bark beetles and their respective feeding plant), but not with their geographical origin. The composition of the Geosmithia OTU community of each bark beetle species depends on the degree of isolation of the species' niches. Thus, Geosmithia communities associated with regularly co-occurring bark beetle species are highly similar. The similarity decreases with decreasing frequency of beetle species' co-occurrence, a pattern resembling that of entomochoric ophiostomatoid fungi. These findings suggest that: 1) communities of Geosmithia spp. are vector-specific; 2) at least in some cases, the association between Geosmithia OTUs and bark beetles may have been very stable and symbioses are likely to be a fundamental factor in the speciation of Geosmithia fungi; and 3) that even nonsticky spores of Geosmithia are suitable for maintaining an insect-fungus association, contrary to previous hypotheses.

• MeSH
• brouci klasifikace   růst a vývoj   MeSH
• cévnaté rostliny * mikrobiologie   parazitologie   MeSH
• DNA fungální analýza   izolace a purifikace   MeSH
• ekosystém * MeSH
• fenotyp MeSH
• fylogeneze MeSH
• Hypocreales klasifikace   genetika   růst a vývoj   MeSH
• kůra rostlin * mikrobiologie   parazitologie   MeSH
• Magnoliopsida * mikrobiologie   parazitologie   MeSH
• mezerníky ribozomální DNA analýza   MeSH
• podnebí MeSH
• RNA ribozomální 5.8S genetika   MeSH
• technika náhodné amplifikace polymorfní DNA MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Evropa MeSH
• Názvy látek
• DNA fungální MeSH
• mezerníky ribozomální DNA MeSH
• RNA ribozomální 5.8S MeSH