Species Concept Research Articles

Methods for identifying and measuring the diversity of ectomycorrhizal fungi

Abstract Mycorrhiza is a mutualistic symbiosis between some plant species and a diverse group of soil fungi. Mycorrhizal symbiosis is categorized into discrete types based on the structural differences and the taxonomic position of involved plants and fungi. The main types of mycorrhiza include arbuscular, ericoid, orchid, monotropoid and ectomycorrhiza, the latter being the main focus of this review. Identifying ectomycorrhizal fungi (EMF) is crucial for understanding the ecology and preservation of rare and endangered plants, fungi and habitats. Thus, since the discovery of ectomycorrhiza, new identification methods have been constantly developed. This review tracks the history of EMF identification methods, presents their limitations and aims to discern the frontier of the field. The early methods were based on the morphology and anatomy of EMF, which allowed ectomycorrhizae formed by different EMF to be distinguished. Recognizing the EMF species that formed them, however, was difficult. The introduction of molecular methods that analysed taxon-specific DNA barcodes was a breakthrough in EMF identification, and the internal transcribed spacer gene was adopted as a routine fungal barcoding sequence. Identifying EMF from randomly sampled roots by morphology or polymerase chain reaction (PCR)-based methods results in rare EMF taxa being missed and underreported. This is addressed by bulk sampling combined with environmental DNA metabarcoding methods, which, in turn, yield a lower resolution of taxonomic identification. Most EMF identification methods incorporate PCR reactions, which are biased against some groups of EMF; developing PCR-free molecular methods would constitute a significant advancement. As the traditional concept of species is challenging for fungi, studying EMF functional rather than taxonomic diversity appears to be promising.

Widespread coexistence of genetically distinct morphotypes in theSatyrium longicaudacomplex (Orchidaceae)

AbstractSpecies-level taxonomy is traditionally based on herbarium collections that typically include few, or even single, representatives per site. This can lead to underestimation of diversity when there are sympatric populations of superficially similar plants belonging to different lineages. Satyrium longicauda (Orchidaceae) represents a taxonomic challenge for the delimitation of species boundaries due to the high degree of morphological variation detected within and among populations. Currently, just two varieties are accepted based mainly on length differences of the lateral sepal and nectar spur. However, there is extensive morphological variation within South African populations and evidence for several pollination ecotypes, indicating that this taxon represents an actively diverging species complex. Here, we evaluate intraspecific morphological variation through uni- and multivariate morphometrics and analyse internal transcribed spacer sequences for individuals sampled from 36 sites, including 14 sites where divergent morphotypes occur sympatrically. Morphometric analyses of 1802 individuals revealed the presence of eight morphotypes based on vegetative and floral characters. Up to six morphologically and genetically distinct morphotypes can coexist in sympatry. Morphological and genetic distances among populations were significantly correlated. Phylogenetic analyses of 120 accessions indicated that neither of the two varieties nor S. longicauda as a species is monophyletic, and provided evidence for the monophyly of some of the morphotypes including the newly described S. cernuiflorum. The presence of distinct morphological and genetic sympatric variants, which in several cases scale up to distinct evolutionary lineages, is consistent with the existence of different taxa according to morphological and biological species concepts. Our results therefore confirm that taxonomy based mainly on herbarium collections can grossly under-estimate actual diversity of disparate lineages, although further work is required to finalize taxonomic decisions. These findings have implications for efforts to estimate species diversity in groups that are in the process of diversifying and for conservation practice.

Three forms of killer whales (Orcinus orca) in Antarctic waters

This paper provides field descriptions and biological observations of three different forms of killer whale (Orcinus orca) that occur in Antarctica based on field observations and a review of available photographs. Identifications were based on the relative size and orientation of the white eyepatch and the presence or absence of a dorsal cape. Type A (presumably the nominate form) has a medium-sized eyepatch oriented parallel to the body axis, no dorsal cape, it occurs mainly off-shore in ice-free water, has a circumpolar distribution and apparently preys mainly upon Antarctic minke whales (Balaenoptera bonaerensis). Type B also has an eyepatch oriented parallel to the body axis, but the eyepatch is at least twice as large as in Type A, it has a dorsal cape, mainly inhabits inshore waters, regularly occurs in pack-ice, is distributed around the continent and is regularly sighted in the Antarctic Peninsula area. Although it may also prey upon Antarctic minke whales and possibly humpback whales (Megaptera novaeangliae), seals seem to be the most important prey item. Type C has a small, forward-slanted eyepatch, a dorsal cape, inhabits inshore waters and lives mainly in the pack-ice; it occurs mostly off East Antarctica, and to date it has been recorded feeding only on Antarctic toothfish (Dissostichus mawsoni). Type C appears to be referable to Orcinus glacialis as described by Berzin and Vladimirov (1983). Although similar ecological specialisations have been reported for sympatric killer whale populations in the Northeast Pacific (i.e. an inshore mammal-eater, an inshore fish-eater and an offshore form), the extent of morphological divergence, habitat segregation and, perhaps, reproductive isolation, appears to be more pronounced among Antarctic populations. Although under a Biological Species Concept these forms appear to warrant separate species status, it will be important to show that this interpretation is consistent with results of molecular genetic analyses and additional morphological studies.

Using neutral landscape models to evaluate the umbrella species concept in an ecotone

Using neutral landscape models to evaluate the umbrella species concept in an ecotone

Checklist of the diatoms (Bacillariophyta) from Lake Naivasha, Kenya, with some historical notes.

Lake Naivasha is one of only two large freshwater lakes in the Eastern Rift Valley of Kenya, East Africa. Together with its satellite lakes Crescent Island Crater, Oloidien and Sonachi, it comprises a great variety of pelagic and benthic habitats for aquatic biota, and its sediment record represents a unique archive of past climate change and long-term ecosystem dynamics in equatorial East Africa. This is particularly so because local paleoenvironmental reconstructions can be checked against historical data on the composition of aquatic fauna and flora collected in Lake Naivasha since the early 20th century. Some of the most prominent biological proxies for reconstructing past changes in lakes are diatoms (Bacillariophyta), a group of unicellular autotrophic eukaryotes of which the siliceous skeletons (valves) preserve well in lake sediments and are good indicators for, among others, climate-driven changes in salinity. However, diatom taxonomy and species concepts have changed a lot in recent decades, making it sometimes difficult for non-taxonomists to know which species are concerned in different published studies. This paper provides the currently accepted taxonomic names of the 310 specific and infraspecific diatom taxa reported from Lake Naivasha and its satellite lakes to date, together with their synonyms used in literature concerning these lakes as well as other, commonly used synonyms. Further, a short overview is given of the history of diatom research conducted on materials from Lake Naivasha and its satellite lakes. The present checklist may facilitate the identification and interpretation aspects of future diatom studies on the wider Lake Naivasha ecosystem and on other East African lakes that are less well studied.

Applying the core-satellite species concept: Characteristics of rare and common riverine dissolved organic matter

IntroductionDissolved organic matter (DOM) composition varies over space and time, with a multitude of factors driving the presence or absence of each compound found in the complex DOM mixture. Compounds ubiquitously present across a wide range of river systems (hereafter termed core compounds) may differ in chemical composition and reactivity from compounds present in only a few settings (hereafter termed satellite compounds). Here, we investigated the spatial patterns in DOM molecular formulae presence (occupancy) in surface water and sediments across 97 river corridors at a continental scale using the “Worldwide Hydrobiogeochemical Observation Network for Dynamic River Systems—WHONDRS” research consortium.MethodsWe used a novel data-driven approach to identify core and satellite compounds and compared their molecular properties identified with Fourier-transform ion cyclotron resonance mass spectrometry (FT-ICR MS).ResultsWe found that core compounds clustered around intermediate hydrogen/carbon and oxygen/carbon ratios across both sediment and surface water samples, whereas the satellite compounds varied widely in their elemental composition. Within surface water samples, core compounds were dominated by lignin-like formulae, whereas protein-like formulae dominated the core pool in sediment samples. In contrast, satellite molecular formulae were more evenly distributed between compound classes in both sediment and water molecules. Core compounds found in both sediment and water exhibited lower molecular mass, lower oxidation state, and a higher degree of aromaticity, and were inferred to be more persistent than global satellite compounds. Higher putative biochemical transformations were found in core than satellite compounds, suggesting that the core pool was more processed.DiscussionThe observed differences in chemical properties of core and satellite compounds point to potential differences in their sources and contribution to DOM processing in river corridors. Overall, our work points to the potential of data-driven approaches separating rare and common compounds to reduce some of the complexity inherent in studying riverine DOM.

Objective composition of the legal regime of animal quarantine

The article examines the peculiarities of the object composition of the legal regime of animal quarantine. An important feature of the legal regime of animal quarantine has been established, which is the absence of a single clearly defined object. Such a property can be conventionally called multi-object, and the object is a multi-object, where the main object of the legal regime of animal quarantine is directly the epizootic, the derivative is the animal carriers of epizootics, and the general one is the quarantine territory as the carrier of the quarantine regime. Each of the listed objects has been considered. At the same time, it was established that the formation of a list of particularly dangerous animal diseases belongs to the competence of anti-epizootic bodies, and its definition is characterized by the corresponding transmissibility, when at the international level the list of such diseases that cause epizootics is compiled by the International Epizootic Bureau, and at the national level by each of the participating countries The Ministry of Internal Affairs and Communications creates its own list of quarantine diseases specific to its territory. Attention is focused on the derived object, which recognizes animals as living beings different from humans, endowed with material signs of heterotrophy (feeding on ready-made organic compounds), mobile activity, metabolism, the presence of functional organ systems, the nervous system and feelings. the most general level of objects of the legal quarantine regime is the quarantine territory. It was established that the quarantine zone is generic, and the buffer, infected, and surveillance zone are species concepts, which at first glance looks quite acceptable. Difficulties arise when clarifying the essence and content of these specific categories, because their definition is carried out through the concept that is being defined. That is, buffer, infected, and surveillance zones are determined directly through the general concept of the zone, which complicates their perception, because it requires constant reference to the content of the original general concept. At the same time, the current veterinary legislation does not use the term «territory» to denote quarantine areas, operating with the concepts of quarantine zones. It was established that the belonging of animals to agricultural, domestic and wild causes different features of their quarantine regime.

The species problem in evolution education

An issue that might concern the species problem is the understanding and acceptance of evolution by students. The reason is that some of the modern concepts, which have been developed to define the species category, do not fit the evolutionary theory. In addition, some other concepts are simply criteria for the delimitation of species taxa. In particular, the biological and morphological species concepts, which are present in every textbook and are used almost exclusively in the teaching of evolution, can intensify students’ essentialist perceptions. However, these perceptions could be effectively dealt with the development of the species problem and the nature of species taxa in the classroom, and also the treatment of species as one more level of organization of biological systems during teaching process. This approach is employed in a lesson with a view to contributing to the structure of a fully developed conceptual framework by the students in order to understand the evolution.

Molecular phylogenetic analysis of Tulipa (Liliaceae) from Aksu-Zhabagly Nature Reserve

Barcodes are conserved sequences of genomic, plastid and mitochondrial DNA that can be utilized to uniquely identify an unidentified specimen to its species when conventional identification methods are inapplicable. Among prokaryotic and eukaryotic species, nuclear ribosomal internal transcribed spacer (ITS) sections are one of the most often utilized DNA markers in DNA barcoding and phylogenetic research. In addition to the ribosomal genes, the plastid genes are the most suitable for identifying plant species. The Aksu-Zhabagly Nature Reserve is the oldest nature reserve in Central Asia and is home to 1,312 vascular plant species, 44 of which are categorized as threatened or endangered in Kazakhstan's red data book. In this study, a collection of specimens of uncommon tulip species was compiled, along with their morphological identification and DNA barcoding. The ITS region and parts of the matK and ycf1b genes of tulip plastid DNA were sequenced. The evolutionary link between species of tulips was investigated. Phylogenetic study predicted two Tulipa subclades. Tulipa species have substantially preserved MatK genes. Tulips' ycf1b gene has evolved more slowly than other Liliaceae family members. Nuclear and plastid DNA sequences investigated Tulipa species evolutionary relationships. The findings about the ITS region of nuclear DNA were more definite. Overall, our work shows that genetic data will be important in determining species concepts in this genus, however, even with a molecular perspective pulling apart closely related taxa can be extremely challenging.

Fusarium diversity associated with diseased cereals in China, with an updated phylogenomic assessment of the genus.

Fusarium species are important cereal pathogens that cause severe production losses to major cereal crops such as maize, rice, and wheat. However, the causal agents of Fusarium diseases on cereals have not been well documented because of the difficulty in species identification and the debates surrounding generic and species concepts. In this study, we used a citizen science initiative to investigate diseased cereal crops (maize, rice, wheat) from 250 locations, covering the major cereal-growing regions in China. A total of 2 020 Fusarium strains were isolated from 315 diseased samples. Employing multi-locus phylogeny and morphological features, the above strains were identified to 43 species, including eight novel species that are described in this paper. A world checklist of cereal-associated Fusarium species is provided, with 39 and 52 new records updated for the world and China, respectively. Notably, 56 % of samples collected in this study were observed to have co-infections of more than one Fusarium species, and the detailed associations are discussed. Following Koch's postulates, 18 species were first confirmed as pathogens of maize stalk rot in this study. Furthermore, a high-confidence species tree was constructed in this study based on 1 001 homologous loci of 228 assembled genomes (40 genomes were sequenced and provided in this study), which supported the "narrow" generic concept of Fusarium (= Gibberella). This study represents one of the most comprehensive surveys of cereal Fusarium diseases to date. It significantly improves our understanding of the global diversity and distribution of cereal-associated Fusarium species, as well as largely clarifies the phylogenetic relationships within the genus. Taxonomic novelties: New species: Fusarium erosum S.L. Han, M.M. Wang & L. Cai, Fusarium fecundum S.L. Han, M.M. Wang & L. Cai, Fusarium jinanense S.L. Han, M.M. Wang & L. Cai, Fusarium mianyangense S.L. Han, M.M. Wang & L. Cai, Fusarium nothincarnatum S.L. Han, M.M. Wang & L. Cai, Fusarium planum S.L. Han, M.M. Wang & L. Cai, Fusarium sanyaense S.L. Han, M.M. Wang & L. Cai, Fusarium weifangense S.L. Han, M.M. Wang & L. Cai. Citation: Han SL, Wang MM, Ma ZY, Raza M, Zhao P, Liang JM, Gao M, Li YJ, Wang JW, Hu DM, Cai L (2023). Fusarium diversity associated with diseased cereals in China, with an updated phylogenomic assessment of the genus. Studies in Mycology 104: 87-148. doi: 10.3114/sim.2022.104.02.

The description of Haematococcus privus sp. nov. (Chlorophyceae, Chlamydomonadales) from North America

An enormous body of research is focused on finding ways to commercialize carotenoids produced by the unicellular green alga, Haematococcus, often without the benefit of a sound phylogenetic assessment. Evidence of cryptic diversity in the genus means that comparing results of pigment studies may be confounded by the absence of a phylogenetic framework. Moreover, previous work has identified unnamed strains that are likely candidates for species status. We reconstructed the phylogeny of an expanded sampling of Haematococcus isolates utilizing data from nuclear ribosomal markers (18S rRNA gene, 26S rRNA gene, internal transcribed spacer [ITS]-1, 5.8S rRNA gene, and ITS-2) and the rbcL gene. In addition, we gathered morphological, ultrastructural and pigment data from key isolates of Haematococcus. Our expanded data and taxon sampling support the concept of a new species, H. privus, found exclusively in North America. Despite overlap in numerous morphological traits, results indicate that ratios of protoplast length to width and akinete diameter may be useful for discriminating Haematococcus lineages. High growth rate and robust astaxanthin yield indicate that H. rubicundus (SAG 34-1c) is worthy of additional scrutiny as a pigment source. With the description of H. privus, the evidence supports the existence of at least five, species-level lineages in the genus. Our phylogenetic assessment provides the tools to frame future pigment investigations of Haematococcus in an updated evolutionary context. In addition, our investigation highlighted open questions regarding polyploidy and sexuality in Haematococcus which demonstrate that much remains to be discovered about this green flagellate.

The Russian Backdrop to Dobzhansky's Genetics and the Origin of Species.

Theodosius Dobzhansky was one of the principal 'founding fathers' of the modern 'synthetic theory of evolution' and the 'biological species' concept, first set forth in his classic book, Genetics and the Origin of Species (1937). Much of the discussion of Dobzhansky's work by historians has focused on English-accessible sources, and has emphasized the roles of the Morgan School, and figures such as Sewall Wright, and Leslie C. Dunn. This article uses Dobzhansky's Russian articles that are unknown to English-speaking readers, and his late 1920s to early 1930s correspondence with colleagues and friends in the Soviet Union, to clarify some of the Russian influences on Dobzhansky's evolving evolutionary views, particularly the development of his views on species and speciation. For Dobzhansky, as for Darwin, the problem of species and speciation was crucial for his theoretical explanation of evolution.

Will this umbrella leak? A caribou umbrella index for boreal landbird conservation

AbstractConservation approaches that efficiently protect multiple values, such as the umbrella species concept, have been widely promoted with expected dramatic ecosystem changes. Due to its social and cultural importance, and recent declining trends, boreal populations of woodland caribou have been suggested as potential umbrella species for other declining taxa, such as boreal landbirds. We propose a generic pixel‐based umbrella index that focuses on fine‐grained habitat overlaps. In light of ongoing conservation efforts worldwide implementing area‐based targets (e.g., 30% by 2030), we used a random neutral model as baseline, as opposed to a no‐conservation scenario, which has been used elsewhere. We found that the conservation efficiency of caribou as an umbrella for 71 co‐occurring landbirds—three of which are priority species—in the Northwest Territories, Canada, is generally lower than our random model, as 53% of the species presented negative umbrella index medians with the interquartile range not overlapping zero. We conclude that in cases where area‐based targets drive decision‐making and the issue at stake involves identifying which areas to conserve—not whether to conserve—woodland caribou may be a leaky umbrella for most co‐occurring landbird species and these might need complementary conservation actions to be brought in from the rain.

Integrative approach resolves the systematics of barred wolf snakes in the Lycodon striatus complex (Reptilia, Colubridae)

AbstractWe reviewed the systematics of Lycodon striatus (Shaw, 1802), including all available name‐bearing types of its synonyms after evaluating phylogeographic (genetics), morphological (morphometry, meristic, and hemipenes), osteological and distribution evidence. Lycodon striatus sensu lato is widely distributed throughout South and Central Asia and mimics elapids. Based on phylogenetic analyses of mitochondrial DNA, we demonstrate that populations from (i) eastern and central Peninsular India plus Sri Lanka and (ii) south‐western parts of Central Asia form two different clades representing two distinct species: L. striatus sensu stricto and L. bicolor comb. nov. respectively. These two clades are sisters to L. deccanensis (in the case of L. striatus) and L. jara (in the case of L. bicolor) and together form two main sister radiations. Although the external morphological variability is high in both species, the genetic variability is higher only in L. striatus but not distinct enough to represent more than one species if using the phylogenetic or biological species concept. The phylogeny of the L. aulicus group hints at Sri Lankan L. striatus, likely having evolved in continental Asia through a probable overland dispersal across the Bay of Bengal (present Palk Strait) into Sri Lanka. This dispersal may have been facilitated by low sea levels during the Pleistocene glaciations when Sri Lanka was connected to mainland India. After considering genetic divergence (with a p‐distance of 1.8%–2.1% in the mitochondrial cytochrome b gene) and morphological evidence, we synonymize the Sri Lankan subspecies, L. s. sinhaleyus Deraniyagala, 1955, with L. striatus sensu stricto. The eastern and central Indian L. striatus (i.e. L. striatus sensu stricto) is morphologically distinct and deeply divergent genetically compared to Tajik and Pakistani L. bicolor with a p‐distance of 13.6% in cytochrome b gene (mtDNA). Interestingly, L. bicolor is conspecific (p‐distance 1.4%) with L. mackinnoni, a western Himalayan endemic, and it reveals intraspecific clinal variation.

Re-Examination of the Holotype of Ganoderma sichuanense (Ganodermataceae, Polyporales) and a Clarification of the Identity of Chinese Cultivated Lingzhi

The widely cultivated Chinese Lingzhi is a famous fungus with significant medicinal and economic value, which has commonly been misidentified as Ganoderma lucidum for a long period of time. The scientific binomial of the fungus is always a hotly debated question that revolves around G. lingzhi and G. sichuanense. To interpret the species concept of the taxon, six specific primers for G. sichuanense and one universal primer were designed. Through directed and nested PCRs, we obtained nine ITS sequences from the holotype (HMAS 42798) of G. sichuanense. By genome sequencing, the ITS sequence of the first cultivated Lingzhi (HMAS 25103) was assembled. Based on a phylogenetic study of the genus Ganoderma, the correct name for widely cultivated Ganoderma species in China was confirmed as G. sichuanense, and G. lingzhi should be a later synonym.

Phylogenetic analysis of problematic Asian species ofArtemiaLeach, 1819 (Crustacea, Anostraca), with the descriptions of two new species

AbstractSpecies of Artemia are regionally endemic branchiopod crustaceans composed of sexual species and parthenogenetic lineages, and represent an excellent model for studying adaptation and speciation to extreme and heterogeneous hypersaline environments. We tested hypotheses of whether populations from the Tibetan Plateau belong to A. tibetianaAbatzopoulos, Zhang & Sorgeloos,1998 and whether a population from Kazakhstan is a new species, using other Asian species of Artemia as outgroups. We conducted a multitrait phylogenetic study based on the complete mitogenome, mitochondrial (COI, 12S, 16S) and nuclear (microsatellites, ITS1) markers, and a suit of uni- and multivariate morphological traits. Our results led to the discovery of two new species, one from the Tibetan Plateau (Haiyan Lake) in China (Artemia sorgeloosin. sp.) and a second from Kazakhstan (Artemia amatin. sp.). Our analysis demonstrate that A. tibetiana and A. amatin. sp. are monophyletic, whereas A. sorgeloosin. sp., and A. tibetiana are polyphyletic. Evolutionary relationships based on mitochondrial and nSSR markers suggest that A. tibetiana may have arisen from a past hybridization event of a maternal ancestor of A. tibetiana with A. sorgeloosin. sp. or its ancestor. We present the complete mitogenome of A. tibetiana, A. amatin. sp., and A. sorgeloosin. sp. We also provide a novel taxonomic identification key based on morphology, emphasizing the phenotype as a necessary component of the species concept.

Genetic Variation versus Morphological Variability in European Peatland Violets (Viola epipsila-V. palustris Group).

In Europe, the V. epipsila-V. palustris group comprises V. epipsila Ledeb., V. palustris L., V. pubifolia (Kuta) G. H. Loos (=V. palustris subsp. pubifolia Kuta), interspecific hybrids, and putative introgressants. The genetic affinity of V. pubifolia to V. palustris, and their shared origin via hybridization followed by polyploidization, were confirmed using inter simple sequence repeat (ISSR) markers, restriction site-associated DNA sequencing (RAD-Seq), and a low-copy nuclear gene, GPI, which encodes glucose-6-phosphate isomerase. The other taxa of subsect. Stolonosae were not identified as putative parents of V. pubifolia by GPI. Our analyses indicated that V. pubifolia can be included in the morphological and genetic variation of V. palustris. The ISSR, RAD-Seq, and genome size value separated well V. palustris from V. epipsila and hybrids. The results also reopen the discussion on intraspecific variation in the context of taxa ranks and species concepts. The reduced tolerance of V. epipsila in Europe to changing environmental conditions might result from low genetic differentiation and heterozygosity, as well as the increased number of interspecific hybrids (V. epipsila × V. palustris), and eventually can possibly lead to its extinction. The disappearance of populations/individuals of this species may indicate anthropogenic changes occurring in peatlands.

Challenges and opportunities of strain diversity in gut microbiome research.

Just because two things are related does not mean they are the same. In analyzing microbiome data, we are often limited to species-level analyses, and even with the ability to resolve strains, we lack comprehensive databases and understanding of the importance of strain-level variation outside of a limited number of model organisms. The bacterial genome is highly plastic with gene gain and loss occurring at rates comparable or higher than de novo mutations. As such, the conserved portion of the genome is often a fraction of the pangenome which gives rise to significant phenotypic variation, particularly in traits which are important in host microbe interactions. In this review, we discuss the mechanisms that give rise to strain variation and methods that can be used to study it. We identify that while strain diversity can act as a major barrier in interpreting and generalizing microbiome data, it can also be a powerful tool for mechanistic research. We then highlight recent examples demonstrating the importance of strain variation in colonization, virulence, and xenobiotic metabolism. Moving past taxonomy and the species concept will be crucial for future mechanistic research to understand microbiome structure and function.

A revised taxonomy and estimate of species diversity for western North American Lampetra

Lampreys are an ancient lineage of jawless fish for which the relationships among some lineages are uncertain. We addressed these information gaps for Lampetra species with a focus on western North America. Phylogenetic analysis using all publicly available sequences of two mitochondrial genes—cyt b and COI—supported designation of western North American Lampetra as a distinct genus from Lampetra in Europe, Asia, and eastern North America. Species delimitation analysis of cyt b sequences identified seven species, only three of which are currently recognized. Lampetra ayresii and L. richardsoni, regarded as separate under the “paired species concept,” were not genetically distinct; we recommend synonymizing L. richardsoni with L. ayresii because the latter has precedence, yet continuing to recognize each ecotype using its current common name. Other than the widespread L. ayresii clade, all other species exhibited limited ranges often restricted to one or two locations. Within headwaters of the Willamette River, L. ayresii demonstrated strong genetic structure and lack of gene flow among subbasins, indicating that the subbasin scale may represent an appropriate management unit. However, the appropriate management scale in other areas may differ based on evolutionary histories and gene flow. Subsequent work is needed across western North America to better delineate the ranges of the aforementioned species and to evaluate whether other unrecognized taxa in this lineage may be present.

An enigma of Handianus Ribaut, 1942 (Hemiptera: Cicadellidae: Deltocephalinae: Athysanini): identical host preferences and male calling signals in two morphologically distinctive sympatric species

Handianus eurotiae and H. fartilis distinctly differ in the forewing venation and the male genitalia shape, but have strongly overlapping ranges, do not differ in ecological preferences, feed on the same host plant, Krascheninnikovia ceratoides, and produce almost identical male calling signals. They were never found in the same biotope, although the mechanism of such vicariation is not clear. According to Mayr's biological species concept, such taxa are good species, but Paterson's species recognition concept is inapplicable in this case. Similar examples in Orthoptera and Auchenorrhyncha are considered.