REVISION OF NORTH AMERICAN AGABUS LEACH (COLEOPTERA: DYTISCIDAE): THE OPACUS-GROUP

1996 ◽  
Vol 128 (4) ◽  
pp. 613-665 ◽  
Author(s):  
D.J. Larson

AbstractSpecies of the Agabus opacus- and lineellus-groups, as defined by Larson (1989), are combined and revised as members of the A. opacus-group. The A. opacus-group contains 13 species, namely: A. hypomelas Mannerheim, A. vancouverensis Leech, A. verisimilis Brown, A. vandykei Leech, A. wasastjernae (Sahlberg), A. opacus Aubé, A. confertus LeConte, A. euryomus sp.nov., A. walsinghami (Crotch), A. jimzim sp.nov., A. lineellus LeConte, A. discors LeConte, and A. austrodiscors sp.nov. Agabus wasastjernae and A. opacus are Holarctic and boreal; the remaining 11 species are confined to the Cordilleran region of western North America. Character distribution does not support recognition of subspecies of A. hypomelas, therefore A. hypomelas irregularis Mannerheim is regarded as a synonym of A. hypomelas. A lectotype is designated for A. discors LeConte. A phylogenetic tree of the hypothesized relationships between the species is presented.A key to the species of the group is included. For each species, the following information is provided: synonymy; description and illustration of taxonomically important characters; notes on relationships, variation, distribution, and ecology; and a map of North American collection localities.

Forests ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 751
Author(s):  
Francesco Dovana ◽  
Paolo Gonthier ◽  
Matteo Garbelotto

Phlebiopsis gigantea (Fr.) Jülich is a well-known generalist conifer wood saprobe and a biocontrol fungus used in several world countries to prevent stump infection by tree pathogenic Heterobasidion fungal species. Previous studies have reported the presence of regional and continental genetic differentiation in host-specific fungi, but the presence of such differentiation for generalist wood saprobes such as P. gigantea has not been often studied or demonstrated. Additionally, little information exists on the distribution of this fungus in western North America. The main purposes of this study were: (I) to assess the presence of P. gigantea in California, (II) to explore the genetic variability of P. gigantea at the intra and inter-continental levels and (III) to analyze the phylogeographic relationships between American and European populations. Seven loci (nrITS, ML5–ML6, ATP6, RPB1, RPB2, GPD and TEF1-α) from 26 isolates of P. gigantea from coniferous forests in diverse geographic distribution and from different hosts were analyzed in this study together with 45 GenBank sequences. One hundred seventy-four new sequences were generated using either universal or specific primers designed in this study. The mitochondrial ML5–ML6 DNA and ATP6 regions were highly conserved and did not show differences between any of the isolates. Conversely, DNA sequences from the ITS, RPB1, RPB2, GPD and TEF1-α loci were variable among samples. Maximum likelihood analysis of GPD and TEF1-α strongly supported the presences of two different subgroups within the species but without congruence or geographic partition, suggesting the presence of retained ancestral polymorphisms. RPB1 and RPB2 sequences separated European isolates from American ones, while the GPD locus separated western North American samples from eastern North American ones. This study reports the presence of P. gigantea in California for the first time using DNA-based confirmation and identifies two older genetically distinct subspecific groups, as well as three genetically differentiated lineages within the species: one from Europe, one from eastern North America and one from California, with the latter presumably including individuals from the rest of western North America. The genetic differentiation identified here among P. gigantea individuals from coniferous forests from different world regions indicates that European isolates of this fungus should not be used in North America (or vice versa), and, likewise, commercially available eastern North American P. gigantea isolates should not be used in western North America forests. The reported lack of host specificity of P. gigantea was documented by the field survey and further reinforces the need to only use local isolates of this biocontrol fungus, given that genetically distinct exotic genotypes of a broad generalist microbe may easily spread and permanently alter the microbial biodiversity of native forest ecosystems.


2021 ◽  
Vol 2 (2) ◽  
pp. 395-412
Author(s):  
Patrick Martineau ◽  
Hisashi Nakamura ◽  
Yu Kosaka

Abstract. The wintertime influence of tropical Pacific sea surface temperature (SST) variability on subseasonal variability is revisited by identifying the dominant mode of covariability between 10–60 d band-pass-filtered surface air temperature (SAT) variability over the North American continent and winter-mean SST over the tropical Pacific. We find that the El Niño–Southern Oscillation (ENSO) explains a dominant fraction of the year-to-year changes in subseasonal SAT variability that are covarying with SST and thus likely more predictable. In agreement with previous studies, we find a tendency for La Niña conditions to enhance the subseasonal SAT variability over western North America. This modulation of subseasonal variability is achieved through interactions between subseasonal eddies and La Niña-related changes in the winter-mean circulation. Specifically, eastward-propagating quasi-stationary eddies over the North Pacific are more efficient in extracting energy from the mean flow through the baroclinic conversion during La Niña. Structural changes of these eddies are crucial to enhance the efficiency of the energy conversion via amplified downgradient heat fluxes that energize subseasonal eddy thermal anomalies. The enhanced likelihood of cold extremes over western North America is associated with both an increased subseasonal SAT variability and the cold winter-mean response to La Niña.


1964 ◽  
Vol 21 (5) ◽  
pp. 933-939 ◽  
Author(s):  
Richard H. Rosenblatt

A new species, Pholis clemensi, referred to the family Pholidae, is named and described from 12 specimens taken in southern British Columbia waters and the Strait of Juan de Fuca. Pholis clemensi is compared with other members of the genus, and a key is given to the North American species.


2020 ◽  
Vol 33 (6) ◽  
pp. 2427-2447 ◽  
Author(s):  
Nathaniel C. Johnson ◽  
Lakshmi Krishnamurthy ◽  
Andrew T. Wittenberg ◽  
Baoqiang Xiang ◽  
Gabriel A. Vecchi ◽  
...  

AbstractPositive precipitation biases over western North America have remained a pervasive problem in the current generation of coupled global climate models. These biases are substantially reduced, however, in a version of the Geophysical Fluid Dynamics Laboratory Forecast-Oriented Low Ocean Resolution (FLOR) coupled climate model with systematic sea surface temperature (SST) biases artificially corrected through flux adjustment. This study examines how the SST biases in the Atlantic and Pacific Oceans contribute to the North American precipitation biases. Experiments with the FLOR model in which SST biases are removed in the Atlantic and Pacific are carried out to determine the contribution of SST errors in each basin to precipitation statistics over North America. Tropical and North Pacific SST biases have a strong impact on northern North American precipitation, while tropical Atlantic SST biases have a dominant impact on precipitation biases in southern North America, including the western United States. Most notably, negative SST biases in the tropical Atlantic in boreal winter induce an anomalously strong Aleutian low and a southward bias in the North Pacific storm track. In boreal summer, the negative SST biases induce a strengthened North Atlantic subtropical high and Great Plains low-level jet. Each of these impacts contributes to positive annual mean precipitation biases over western North America. Both North Pacific and North Atlantic SST biases induce SST biases in remote basins through dynamical pathways, so a complete attribution of the effects of SST biases on precipitation must account for both the local and remote impacts.


2005 ◽  
Vol 83 (9) ◽  
pp. 1075-1081 ◽  
Author(s):  
Irwin M. Brodo ◽  
André Aptroot

Protoparmelia hypotremella van Herk, Spier & V. Wirth is reported here as an addition to the North American lichen flora. Fertile material of P. hypotremella was found for the first time, and it is described in detail. The hyaline hair-like appendages on both polar ends of the ascospores, characteristic of the genus, are illustrated for the first time. The species is then compared with Protoparmelia ochrococca , known from western North America, and Protoparmelia oleagina , still known only from Europe. A key to the corticolous species of Protoparmelia is provided.


1969 ◽  
Vol 26 (2) ◽  
pp. 221-228 ◽  
Author(s):  
Ian R. Ball

Dugesia lugubris (Schmidt), a Palaearctic freshwater triclad, is described from North America. A morphological and taxonomic evaluation is presented and comparisons with European material and data are made, confirming the initial diagnosis. The known distribution of the species in North America is discussed in relation to what is known of its distribution and ecology in Europe, and it is concluded that the introduction is probably unique and of recent occurrence. It represents the second authenticated case of passive dispersal by man in the freshwater Tricladida, and is almost certainly a result of the shipping plying between the St. Lawrence River and various European ports. The present findings in no way conflict with the opinions of modern American taxonomists that early records of D. lugubris in North America are the results of mis-identification of Cura foremanii (Girard). A key for the separation of these two superficially similar species is provided.


Botany ◽  
2020 ◽  
Vol 98 (2) ◽  
pp. 91-101
Author(s):  
Andrus Voitk ◽  
Irja Saar ◽  
Renée Lebeuf ◽  
Peter Kennedy

Pseudoomphalina kalchbrenneri is a Eurasian species. In North America the Pso. kalchbrenneri complex is represented by Pseudoomphalina anticostica sp. nov. and Pso. compressipes in the east and Pso. intermedia in the west. Pseudoomphalina farinacea and Pso. felleoides are later synonyms for Pso. compressipes. The somewhat similar Pseudolaccaria pachyphylla occupies a temperate band through Eurasia, confirmed by sequencing in both eastern and western North America. It differs from species of the Pso. kalchbrenneri complex by smaller size, finely granular pileus, non-decurrent gills, and lack of hymenial cystidia. All species of the Pso. kalchbrenneri complex are uncommon, and macroscopically similar. Pseudoomphalina kalchbrenneri and Pso. intermedia can be identified by their distribution (Europe and western North America, respectively) and lack of cystidia. The cystidiate eastern North American Pso. anticostica and Pso. compressipes can be differentiated by the smaller spores of the latter. Pseudoomphalina cokeri is the most ancestral species on the Pseudoomphalina lineage, while Clitocybe thujana and Agaricus apertus (Clitocybe/Clitocybula aperta) fall outside Pseudoomphalina and Pseudolaccaria. We add 21 new sequences to GenBank, including six types (Agaricus compressipes, Clitocybe felleoides, C. farinacea, C. intermedia, C. thujana, Agaricus apertus), and one new species (Pso. anticostica).


1985 ◽  
Vol 117 (11) ◽  
pp. 1287-1366 ◽  
Author(s):  
Valerie M. Behan-Pelletier

AbstractThe Ceratozetidae of arctic western North America, represented by 12 species in 9 genera, are discussed. A new genus, Cyrtozetes, and species, Cyrtozetes denaliensis, are proposed, and Trichoribates copperminensis Hammer, T. polaris Hammer, Svalbardia paludicola Thor, Iugoribates gracilis Sellnick, Diapterobates notatus (Thorell) both adults and immatures, D. variabilis Hammer, Sphaerozetes arcticus Hammer, Fuscozetes sellnicki Hammer, Melanozetes longisetosus Hammer, and Ceratozetes spitsbergensis Thor and C. parvulus Sellnick are redescribed. Immatures of T. polaris, S. paludicola, F. sellnicki, and M. longisetosus are described. Distribution records of Ceratozetes gracilis (Michael) in the western North American arctic are listed. The new combination, Cyrtozetes shiranensis (Aoki and Fujikawa), is proposed.


Sign in / Sign up

Export Citation Format

Share Document