Large Shift in Symbiont Assemblage in the Invasive Red Turpentine Beetle

Changes in symbiont assemblages can affect the success and impact of invasive species, and may provide knowledge regarding the invasion histories of their vectors. Bark beetle symbioses are ideal systems to study changes in symbiont assemblages resulting from invasions. The red turpentine beetle (Dendroctonus valens) is a bark beetle species that recently invaded China from its native range in North America. It is associated with ophiostomatalean fungi in both locations, although the fungi have previously been well-surveyed only in China. We surveyed the ophiostomatalean fungi associated with D. valens in eastern and western North America, and identified the fungal species using multi-gene phylogenies. From the 307 collected isolates (147 in eastern North America and 160 in western North America), we identified 20 species: 11 in eastern North America and 13 in western North America. Four species were shared between eastern North America and western North America, one species (Ophiostoma floccosum) was shared between western North America and China, and three species (Grosmannia koreana, Leptographium procerum, and Ophiostoma abietinum) were shared between eastern North America and China. Ophiostoma floccosum and O. abietinum have worldwide distributions, and were rarely isolated from D. valens. However, G. koreana and L. procerum are primarily limited to Asia and North America respectively. Leptographium procerum, which is thought to be native to North America, represented >45% of the symbionts of D. valens in eastern North America and China, suggesting D. valens may have been introduced to China from eastern North America. These results are surprising, as previous population genetics studies on D. valens based on the cytochrome oxidase I gene have suggested that the insect was introduced into China from western North America.     

Phylogeographic history of the woodwardioid ferns,including species from the Himalayas

The woodwardioid ferns are well-represented in the Northern Hemisphere, where they are disjunctly distributed throughout the warm temperate and subtropical regions of North America, Europe, and Asia. To infer the biogeographic history of the woodwardioid ferns, the phylogeny of Woodwardia was estimated using rbcL and rps4 sequences from divergent distribution regions including the Himalayas. Phylogenetic results support Woodwardia as a monophyletic group with Woodwardia areolatae and W. virginica as basal, these two species from eastern North America diverged early, which are sister clades to the remaining species from America, Europe, and Asia. Based on analyses of the fossil records of these species for divergence times, Woodwardia species were estimated to have diverged initially in the Paleogene of North America. After its New World origin, a greater diversification and expansion of Woodwardia occurred in eastern Eurasia, with the European arrival of Woodwardia radicans during the Middle Miocene. Compared to earlier reports, a migration back into North America via the Bering land bridge is consistent with these data.     

A New Fishfly Species (Megaloptera: Corydalidae: Neohermes Banks) Discovered from North America by a Systematic Revision,with Phylogenetic and Biogeographic Implications

The taxonomy of Megaloptera from the Nearctic region is fairly well known and their faunal diversity has been largely surveyed, even in relatively remote regions. However, the evolutionary history of Nearctic Megaloptera is still poorly known with phylogenetic and biogeographic studies lacking. In this paper, we report a new fishfly species of the endemic North American genus Neohermes Banks, 1908, increasing the total number known of species to six. This new species (Neohermes inexpectatus sp. nov.) is currently known to occur only in California (USA) and is apparently confined to the Northern Coastal Range. The new species resembles the three Neohermes species from eastern North America based on the relatively small body size and the presence of female gonostyli 9. However, our phylogenetic analysis using adult morphological data recovered the new species as the sister species to the remaining Neohermes, which includes two species from western North America and three from eastern North America. According to the present interspecific phylogeny of Neohermes, with reconstructed ancestral areas, the initial divergence within the genus was found to take place in western North America, with a subsequent eastward dispersal. This likely lead to the modern distribution of Neohermes in eastern North America with the closure of the Mid-Continental Seaway, which separated western and eastern North America in the Mid-Late Cretaceous (100–80 MYA) and finally disappeared at the end of the Cretaceous (70 MYA). The uplift of the Cordilleran System probably accounted for the divergence between the eastern and two western Neohermes species.     

A taxonomic study of campylopus schimperi and C. subulatus (Bryopsida: Dicranaceae) in North America

Campylopus schimperi is known in North America from Oaxaca, Colorado, British Columbia, Yukon, Alaska, Baffin Island, Gaspé Peninsula, and Newfoundland, and reported from Greenland. No specimens of the previously reported C. subulatus were found from North America and this species should be excluded from the North American bryophyte flora. A quantitative study and critical review of the characters distinguishing these two species indicate that leaf laminal cell shape and length, and costal anatomy are the most definitive taxonomic features. The distributional range of C. schimperi in North America suggests a close association with unglaciated areas and hypothesized glacial refugia.     

Vuilleminia erastii sp. nov. (Corticiales), an amphi-Beringian species and revision of the occurrence of Vuilleminia comedens in North America

Vuilleminia is a basidiomycete genus the species of which have resupinate, corticioid fruiting bodies. It is apparently a North Hemisphere genus, and the majority of its species are distributed in Europe and western Asia. In North America, there are two reports of Vuilleminia comedens. Detailed study of North American specimens and comparisons with additional collections led to the conclusion that they belong to a new lineage named Vuilleminia erastii sp. nov., whose distribution extends from western North America to East Asia, Siberia, and Finland. The species is recognized by the decorticating fruiting bodies with preference for species of Betulaceae in the boreal zone, relatively small allantoid basidiospores, and little-developed cystidia with apical appendix.     

Putative source of the invasive Sirex noctilio fungal symbiont, Amylostereum areolatum, in the eastern United States and its association with native siricid woodwasps

Two genotypes of the fungal symbiont Amylostereum areolatum are associated with the invasive woodwasp Sirex noctilio first found in North America in 2004. S. noctilio is native to Europe but has been introduced to Australasia, South America and Africa where it has caused enormous losses in pine plantations. Based on nucleotide sequence data from the intergenic spacer region (IGS) of the nuclear ribosomal DNA, the A. areolatum genotypes found in North America are most similar to genotypes found in Europe, and not to genotypes from the southern hemisphere. Although two IGS strains of A. areolatum were found in North America it cannot be stated whether A. areolatum was introduced to North America from Europe once or twice based on our study. Genetic groupings formed by sequencing data were in most cases supported by vegetative compatibility groups (VCGs). Other siricid woodwasp species in the genus Sirex are native to North America. The North American native Sirex edwardsii emerging from the same tree as S. noctilio carried the same strain of A. areolatum as S. noctilio. The North American native Sirex sp. ‘nitidus’ collected outside the geographical range of S. noctilio carried a unique strain within A. areolatum. Our findings of A. areolatum in the native North American species, S. sp. ‘nitidus’, contrast with the previous view that A. areolatum was not present in North America before the accidental invasion of S. noctilio.     

Intercontinental dispersal of Typha angustifolia and T. latifolia between Europe and North America has implications for Typha invasions

The full effects of biological invasions may be underestimated in many areas because of cryptogenic species, which are those that can be identified as neither native nor introduced. In North America, the cattails Typha latifolia, T. angustifolia, and their hybrid T. × glauca are increasingly aggressive invaders of wetlands. There is a widespread belief that T. latifolia is native to North America and T. angustifolia was introduced from Europe, although there has so far been little empirical support for the latter claim. We used microsatellite data and chloroplast DNA sequences to compare T. latifolia and T. angustifolia genotypes from eastern North America and Europe. In both species, our data revealed a high level of genetic similarity between North American and European populations that is indicative of relatively recent intercontinental dispersal. More specifically, the most likely scenario suggested by Approximate Bayesian Computation was an introduction of T. angustifolia from Europe to North America. We discuss the potential importance of our findings in the context of hybridization, novel genomes, and increasingly invasive behaviour in North American Typha spp.     

The species of Coleosporium (Pucciniales) on Solidago in North America

Species of Coleosporium (Pucciniales) are rust fungi that typically alternate between pines and angiosperms. In North America, species of Coleosporium often infect Solidago (goldenrods), although their taxonomy on these hosts is unresolved. Joseph. C. Arthur and George B. Cummins regarded these as a single species, Coleosporium solidaginis (fide Arthur) or C. asterum (fide Cummins), but later inoculation studies demonstrated the presence of more than one species, distinguishable by their aecial hosts. A more recent taxonomic study of Coleosporium found that specimens on Solidago identified as C. asterum in North America were not conspecific with the type, which is from Japan, prompting the present study. Herein, we conducted a systematic study on ca. 60 collections of Coleosporium infecting species of Asteraceae from North America using regions of ribosomal DNA and morphology of teliospores and basidia. Our data indicate at least three species of Coleosporium occur on Solidago in North America, C. solidaginis, C. montanum comb. nov., which is proposed for the taxon that has commonly been identified as C. asterum in North America, and C. delicatulum, all of which can be differentiated by morphology of their basidia. In addition, the challenges of marker selection for molecular barcoding of rust fungi is discussed.     

The Megophthalmidia (Diptera,Mycetophilidae) of North America including eight new species

Megophthalmidia Dziedzicki is a small leiine genus (Mycetophilidae) with seven species described from the Neotropics and ten species from the Palearctic region. Two species of Megophthalmidia have been reported for North America. Recent collecting of Mycetophilidae in California and Arizona, however, shows current North American diversity of Megophthalmidia is at least on par to other regions of the world. Eight new species of Megophthalmidia are described here, increasing the number of Nearctic Megophthalmidia species to nine. Included is a particularly atypical member of the genus, M. saskia sp. n., which expands the genus concept of Megophthalmidia. Of the two species previously recorded for North America, only one actually belongs in the genus. Megophthalmidia occidentalis Johannsen, is fully described and illustrated. The other named species, M. marceda (Sherman) is illustrated and transferred to the genus Ectrepesthoneura Enderlein. A lectotype is designated for this species. A key to the species of Megophthalmidia of North America is provided. The biology of these flies is not yet known. Three of the new Megophthalmidia species – M. lenimenta, M. misericordia, and M. radiata – are only known to occur within small protected areas within the California State Park and UC Natural Reserve systems.     

Priority areas for the conservation of the genus Abies Mill. (Pinaceae) in North America

Fir forests (Abies, Pinaceae) are dominant in temperate regions of North America; however, they have experienced high degradation rates that can threaten their long-term continuity. This study aimed to identify the priority areas for the conservation of the genus Abies in North America. First, we modeled the species distribution of the 17 native species through ecological niche modeling, considering 21 environmental variables. Then, we defined the priority areas through multi-criteria analysis, considering the species richness, geographic rareness, irreplaceability, habitat degradation, and risk extinction. We also built six scenarios, giving more priority to each criterion. Finally, we identified the proportion of the extent of the priority areas covered by protected areas. Elevation, precipitation seasonality, and winter precipitation influenced the distribution of most of the Abies species. When considering equal weights to each criterion, the priority areas summed up 6% of the total extent covered by the Abies species in North America. Most priority areas were located on the West Coast of the United States, the Eastern Sierra Madre, Southern Sierra Madre, Sierras of Chiapas and Central America, and the Trans-Mexican Volcanic Belt ecoregions. In these ecoregions, the Abies species are restricted to small areas facing high degradation levels. Only 16% of the area covered by the Abies species in North America is protected, mainly under restrictive schemes such as National Parks and Wilderness Areas. The priority areas identified could be the basis for establishing or enlarging protected areas. The preservation of the genus Abies could also maintain other ecological features and processes such as biodiversity, forest resources, and environmental services.     

Exploring the Formation of a Disjunctive Pattern between Eastern Asia and North America Based on Fossil Evidence from Thuja (Cupressaceae)

Thuja, a genus of Cupressaceae comprising five extant species, presently occurs in both East Asia (3 species) and North America (2 species) and has a long fossil record from Paleocene to Pleistocene in the Northern Hemisphere. Two distinct hypotheses have been proposed to account for the origin and present distribution of this genus. Here we recognize and describe T. sutchuenensis Franch., a new fossil Thuja from the late Pliocene sediments of Zhangcun, Shanxi, North China, based on detailed comparisons with all living species and other fossil ones, integrate the global fossil records of this genus plotted in a set of paleomaps from different time intervals, which show that Thuja probably first appeared at high latitudes of North America in or before the Paleocene. This genus reached Greenland in the Paleocene, then arrived in eastern Asia in the Miocene via the land connection between East Asia and western North America. In the late Pliocene, it migrated into the interior of China. With the Quaternary cooling and drying, Thuja gradually retreated southwards to form today’s disjunctive distribution between East Asia and North America.     

Redescription of the geologically youngest albanerpetontid (?Lissamphibia): Albanerpeton inexpectatum Estes and Hoffstetter, 1976, from the Miocene of France

Albanerpeton inexpectatum Estes and Hoffstetter, 1976, the type species of Albanerpeton and the geologically youngest albanerpetontid, is rediagnosed and redescribed based on a large collection of jaws and frontals from Miocene fissure fills near La Grive-Saint-Alban, southeastern France. Intraspecific variation is documented in these elements, and is attributed to growth and individual differences. Synapomorphies of the upper jaws indicate that A. inexpectatum a) belongs in a clade whose members are otherwise known from the Upper Cretaceous-Paleocene of North America and b) is the sister species of an undescribed North American Paleocene species. The presence of A. inexpectatum in the Miocene of France is postulated to be the result of an Early or Middle Tertiary dispersal of an unknown ancestral species from North America into Europe. Cranial apomorphies of A. inexpectatum are interpreted as having strengthened the skull for burrowing in rocky soil and feeding.     

DomesticatedChenopodium of the Ozark Bluff Dwellers

Previous suggestions that prehistoric agriculturalists of the Ozark Bluff Dweller culture utilized a fully domesticated form ofChenopodium have been confirmed. Comparative examination of infructescence and fruit structure indicates that archaeological material is assignable toC. berlandieri ssp.nuttalliae, a product of Mexican agriculture. Large-fruited chenopod remains from other sites in eastern North America, often identified as those of wild species, may also belong to the Mexican domesticated form. A related, wild species of northeastern North America,C. bushianum, shows similarities to the Mexican weed-crop complex that may reflect prehistoric genetic interaction. This is the first documented report of domesticatedChenopodium from prehistoric North America.     

Mitochondrial DNA based phylogeny of the woodpecker genera Colaptes and Piculus,and implications for the history of woodpecker diversification in South America

The woodpecker genus Colaptes (flickers) has its highest diversity in South America and the closely related genus Piculus is restricted to South and Central America. Two species of flickers occur in North America, and one species is endemic to Cuba. We conducted a Bayesian phylogenetic analysis of three mitochondrial encoded genes (cyt b, COI, 12S rRNA) and confirmed that the two genera are paraphyletic. Three species historically classified as Piculus are actually flickers. We found that the Cuban endemic C. fernandinae is the most basal species within the flickers and that the Northern Flicker is the next most basal species within the Colaptes lineage. The South American clade is most derived. The age of the South American diversification is estimated to be 3.6 MY, which is synchronous with the emergence of the Isthmus of Panama. The pattern of diversification of South American flickers is common among South American woodpeckers. Although woodpeckers have their greatest diversity in South America, we hypothesize that woodpeckers (Family Picidae) originated in Eurasia, dispersed to North America via the Bering land bridge, and multiple lineages entered South America as the Isthmus approached its final closing.     

Phylogenetic diversity of true morels (Morchella), the main edible non-timber product from native Patagonian forests of Argentina

Morchella species are edible fungi in high demand and therefore command high prices in world markets. Phenotypic-based identification at the species-level remains inadequate because of their complex life cycles, minor differences and plasticity of morphological characteristics between species, and the lack of agreement between scientific and common names. In Patagonia–Argentina, morels are associated with native forests of Austrocedrus chilensis (Cordilleran or Chilean cypress) and Nothofagus antarctica (ñire) and several exotic conifers that were introduced from western North America. Little is known about their taxonomy and phylogenetic relationships with other species in the genus. This work focused on the identification of collections of Morchella from Patagonia and their phylogenetic relationships with other species from the Northern Hemisphere. The comparison was made by analysis of DNA sequences obtained from four loci: the nuclear ribosomal internal transcribed spacer region (ITS) and the partial RNA polymerase I gene (RPB1) for the complete collection; and ITS, RPB1, RNA polymerase II gene (RPB2), and translation elongation factor (EF1-α) for the species-rich Elata Subclade. Analyses of individual and combined data sets revealed that Patagonian morels belong to the Elata Clade and comprised three strongly supported species-level lineages from both Patagonian native forest, and exotic trees introduced from western North America. One lineage was identified as Morchella frustrata phylogenetic species Mel-2, which is known from the USA and Canada. The second lineage, which appeared to be ‘fire-adapted’, was identified as Morchella septimelata phylogenetic species (Mel-7), which is also known from the USA. This species was collected from burned native forests mainly composed of A. chilensis and N. antarctica but also Pseudotsuga menziesii (Mirb.) Blanco, which is native to western North America. The phylogenetic analyses suggested that the third species from Patagonia was nested within the species-rich Elata Subclade and represents a new species-level lineage (informally designated Mel-37) within Elata Clade. The present collections from Patagonia constitute the southernmost latitude from which Morchella has been reported to date. The identification of two Argentine morels as North American taxa is therefore a remarkable biogeographic pattern. In view of the hypothesis that the Elata Clade originated in western North America, we speculate that at least two of the lineages colonized South America from North America via long distance dispersal, migration or, more likely, they were introduced with the exotic tree species that they were collected near.     

Foliar pathogens of Populus angustifolia are consistent with a hypothesis of Beringian migration into North America

Populus angustifolia, the narrowleaf cottonwood, is considered one of two native species of Populus section Tacamahaca restricted to western North America. Efforts to construct a definitive phylogeny of Populus spp. are complicated by ancient hybridization, but some phylogenetic analyses suggest P. angustifolia is more closely related to Asian congeners than to Populus trichocarpa, the other species of Populus section Tacamahaca in western North America. Because hosts and their obligate symbionts can display parallel phylogeographic patterns, we evaluated the possibility of a Beringian migration into North America by an Asian ancestor of P. angustifolia by determining the distributions, host preferences, and, in some cases, closest phylogenetic relatives of fungal leaf pathogens of P. angustifolia. Phyllactinia populi, a common foliar pathogen on Populus spp. in Asia but unknown on P. trichocarpa, was found on P. angustifolia in multiple sites. Mycosphaerella angustifoliorum, also unknown on P. trichocarpa, was commonly collected on P. angustifolia. Conversely, many common foliar pathogens of P. trichocarpa in western North America were not found on P. angustifolia; only Melampsora×columbiana and Drepanopeziza populi were common to both Populus species. Phylogenetic analyses revealed that M. angustifoliorum was not part of the diversification of Mycosphaerella on Populus that includes all other Mycosphaerella species on Populus in North America: Mycosphaerella populicola, Mycosphaerella populorum, M. sp. 1, and M. sp. 2. The latter two undescribed species represent a newly discovered diversification of M. populorum in western North America. Overall, the leaf pathogen community of P. angustifolia is consistent with a Beringian migration into North America by the ancestor of P. angustifolia.     

Biology and host specificity ofChamaesphecia hungarica andCh. Astatiformis (Lep.: Sesiidae) two candidates for the biological control of leafy spurge,Euphorbia esula (Euphorbiaceae) in North America

Leafy spurge (Euphorbia esula (s.1.)) is an herbaceous perennial and serious weed of Eurasian origin that has been accidentally introduced into North America. The two European root-boring mothsChamaesphecia hungarica andCh. astatiformis are univoltine and overwinter as mature larvae. Both species have a lower survival rate on leafy spurge than on their field hosts, and thus are not optimal candidates for the biological control of leafy spurge. However, the rate of larval development and larval growth on the target weed and on the two field hosts is nearly the same. The experimental host range of both species is restricted to a few species in the subgenusEsula within the genusEuphorbia. The two species occupy different habitats in the steppe biome and are targeted for similar leafy spurge habitats in North America.