Morphological Taxonomy Research Articles

Morphologic Characterization of Pancreatic Ductal Adenocarcinoma following Post-neoadjuvant Pancreatectomy and Clinical value of Intratumor Heterogeneity.

To evaluate the morphologic landscape of pancreatic ductal adenocarcinoma (PDAC), intratumor spatial heterogeneity, and the resulting clinical impact following post-neoadjuvant pancreatectomy. The clinical value of PDAC morphologic subtypes and intratumor spatial heterogeneity post-treatment remains an open issue. The study cohort included patients who underwent post-neoadjuvant pancreatectomy for PDAC at the University of Verona Hospital Trust between 2013 and 2019. All hematoxylin and eosin-stained slides were reviewed to assess PDAC histomorphology and intratumor heterogeneity. The relationship with other clinicopathological variables, overall survival (OS), and recurrence-free (RFS) survival was evaluated using standard statistics. The study cohort included 400 patients. Histological revision identified ten different morphologic subtypes. Gland-forming PDAC with a conventional pattern was the most frequently identified subtype (41.8%). Overall, 247 tumors (61.7%) showed only one histological pattern and were classified as homogeneous, whereas 153 (38.3%) showed different morphologies and were classified as heterogeneous tumors. The median post-resection survival was 30.1 months (95%CI 26.6-33.5). There was a substantial survival variability according to the morphologic subtype, ranging from 19.1 months in the gyriform subtype to 47.0 months in the papillary subtype. Tumors with a heterogeneous morphology displayed a higher rate of nodal metastases, worse tumor regression metrics, and worse oncologic outcomes relative to spatially homogeneous tumors. This paper provided a morphological taxonomy of residual tumors following post-neoadjuvant pancreatectomy for PDAC. The morphologic subtype and intratumor spatial heterogeneity have relevant prognostic implications and could be included in the pathology report to complement regression metrics.

First Report of Dalbulus maidis (DeLong and Wolcott) (Hemiptera: Cicadellidae) in Oklahoma.

The corn leafhopper, Dalbulus maidis (DeLong and Wolcott) (Hemiptera: Cicadellidae), is an invasive insect that can cause damage to maize (Zea mays L.) in two ways: by direct feeding and the transmission of several plant pathogens. Dalbulus maidis is an invasive and serious economic pest of maize that has spread from its center of origin in Mexico to the southernmost parts of the United States. Prior to 2024, corn leafhoppers had not been documented in Oklahoma, and their spread northward toward the United States corn belt is of significant concern. Here, we provide the first reports of the insect in maize in several Oklahoma counties. Insect specimens were collected at various commercial and experimental field sites by Oklahoma State University research and extension personnel. The identity of the insect species was validated through morphological and molecular taxonomy. The presence records for the corn leafhopper presented here provide valuable information for future monitoring and management efforts of this economically important pest and disease.

Phylogenomics supports a single origin of terrestriality in isopods.

Terrestriality, the adaptation to life on land, is one of the key evolutionary transitions, occurring numerous times across the tree of life. Within Arthropoda, there have been several independent transitions: in hexapods, myriapods, arachnids and isopods. Isopoda is a morphologically diverse order within Crustacea, with species adapted to almost every environment on Earth. The order is divided into 11 suborders with the most speciose, Oniscidea, including terrestrial isopods such as woodlice and sea-slaters. Recent molecular phylogenetic studies have challenged traditional isopod morphological taxonomy, suggesting that several well-accepted suborders, including Oniscidea, may be non-monophyletic. This implies that terrestriality may have evolved multiple times. Current molecular hypotheses, however, are based on limited sequence data. Here, I collate available genome and transcriptome datasets for 36 isopods and four peracarid crustaceans from public sources, generate assemblies and use 970 single-copy orthologues to estimate isopod relationships and divergence times with molecular dating. The resulting phylogenetic analyses support monophyly of terrestrial isopods and suggest conflicting relationships based on nuclear ribosomal RNA sequences may be caused by long-branch attraction. Dating analyses suggest a Permo-Carboniferous origin of isopod terrestriality, much more recently than other terrestrial arthropods.

Performance of DNA metabarcoding, standard barcoding and morphological approaches in the identification of insect biodiversity.

For two decades, DNA barcoding and, more recently, DNA metabarcoding have been used for molecular species identification and estimating biodiversity. Despite their growing use, few studies have systematically evaluated these methods. This study aims to evaluate the efficacy of barcoding methods in identifying species and estimating biodiversity, by assessing their consistency with traditional morphological identification and evaluating how assignment consistency is influenced by taxonomic group, sequence similarity thresholds and geographic distance. We first analysed 951 insect specimens across three taxonomic groups: butterflies, bumblebees and parasitic wasps, using both morphological taxonomy and single-specimen COI DNA barcoding. An additional 25,047 butterfly specimens were identified by COI DNA metabarcoding. Finally, we performed a systematic review of 99 studies to assess average consistency between insect species identity assigned via morphology and COI barcoding and to examine the distribution of research effort. Species assignment consistency was influenced by taxonomic group, sequence similarity thresholds and geographic distance. An average assignment consistency of 49% was found across taxonomic groups, with parasitic wasps displaying lower consistency due to taxonomic impediment. The number of missing matches doubled with a 100% sequence similarity threshold and COI intraspecific variation increased with geographic distance. Metabarcoding results aligned well with morphological biodiversity estimates and a strong positive correlation between sequence reads and species abundance was found. The systematic review revealed an 89% average consistency and also indicated taxonomic and geographic biases in research effort. Together, our findings demonstrate that while problems persist, barcoding approaches offer robust alternatives to traditional taxonomy for biodiversity assessment.

Chemotaxonomy compared to morphological and anatomical taxonomy of five Hibiscus species

Hibiscus is a charismatic genus of the Malvaceae family that is noted for its diversity, lacking identifiable characteristics for distinguishing its various species. Therefore, there is an urgent need to develop authentication methods for genus delimitation and species delineation. The present study aims to discern the taxonomic relationships between the well-known, globally familiar, and economically important five Hibiscus species, namely: H. × rosa-sinensis, H. sabdariffa, H. schizopetalus, H. syriacus and H. tiliaceus based on traditional morphological and anatomical characteristics compared to the contemporary chemotaxonomy. In this context, the leaf-based methanolic extracts of the studied species were analyzed by Gas Chromatography-Mass Spectrometer (GC–MS) to estimate their secondary metabolites similarity. In addition, selected qualitative morphological and anatomical traits including leaf venation patterns, epidermal micromorphology, stomata types and trichomes diversity, petiole serial sectioning (outline, adaxial groove features, vasculature traces arrangement), and midrib characteristics of the studied species were investigated. The results of both chemotaxonomy and traditional taxonomy exhibited a remarkable agreement in the delineation of the five studied species. Specifically, the chemotaxonomy-based dendrogram separates the studied species into two main clusters with the H. sabdariffa as an outlier species in a single cluster and the remaining four species as another cluster with variant distances in its similarity indices. Similarly, the traditional morphological and anatomical characteristics revealed distinct traits for H. sabdariffa compared to the remaining four species. The findings of this study highlight the significance of integrating the structural features with phytochemicals profiling as a potential approach that could be harnessed for the delineation of the taxonomically challenging Hibiscus genus.

Enhancing metabarcoding efficiency and ecological insights through integrated taxonomy and DNA reference barcoding: Acase study on beach meiofauna.

Molecular techniques like metabarcoding, while promising for exploring diversity of communities, are often impeded by the lack of reference DNA sequences available for taxonomic annotation. Our study explores the benefits of combining targeted DNA barcoding and morphological taxonomy to improve metabarcoding efficiency, using beach meiofauna as a case study. Beaches are globally important ecosystems and are inhabited by meiofauna, microscopic animals living in the interstitial space between the sand grains, which play a key role in coastal biodiversity and ecosystem dynamics. However, research on meiofauna faces challenges due to limited taxonomic expertise and sparse sampling. We generated 775 new cytochrome c oxidase I DNA barcodes from meiofauna specimens collected along the Netherlands' west coast and combined them with the NCBI GenBank database. We analysed alpha and beta diversity in 561 metabarcoding samples from 24 North Sea beaches, a region extensively studied for meiofauna, using both the enriched reference database and the NCBI database without the additional reference barcodes. Our results show a 2.5-fold increase in sequence annotation and a doubling of species-level Operational Taxonomic Units (OTUs) identification when annotating the metabarcoding data with the enhanced database. Additionally, our analyses revealed a bell-shaped curve of OTU richness across the intertidal zone, aligning more closely with morphological analysis patterns, and more defined community dissimilarity patterns between supralittoral and intertidal sites. Our research highlights the importance of expanding molecular reference databases and combining morphological taxonomy with molecular techniques for biodiversity assessments, ultimately improving our understanding of coastal ecosystems.

Gambierdiscus carpenteri (Dinophyceae) from Bahía de La Paz, Gulf of California: morphology, genetic affinities, and mouse toxicity

Abstract Gambierdiscus is a marine benthic dinoflagellate genus that currently contains 19 species; some of them are toxigenic, producing ciguatoxins, maitotoxins, and other toxic compounds. The objective of this study was to document the morphological and molecular identification (ITS, 5.8S and 28S of the rDNA) of two strains of Gambierdiscus from La Gaviota Island, Gulf of California, Mexico, and a toxicity test. The shape of the 2′ plate varied between hatchet-shaped and rectangular, that complicated the differentiation between G. carpenteri and G. toxicus. Molecular markers of the three rDNA regions allowed confirmation of the taxonomic identity of G. carpenteri, separating this species from other congeners with high phylogenetic affinity, such as G. excentricus, G. toxicus and G. caribaeus. Studies of the morphological taxonomy of G. carpenteri are scarce; therefore, due to the similarity between species, the combination of morphological and molecular tools is recommended for the identification of species, such as G. carpenteri, G. excentricus, G. toxicus and G. caribaeus. The mouse bioassay showed that the examined isolate was toxic, and it is a potential etiology of ciguatera fish poisoning cases in the region. This study provides the first reliable report and ribosomal sequences of G. carpenteri for the Gulf of California, as well as data on mouse bioassay toxicity.

Biblical Names in Selected Plays of Wole Soyinka: A lexico-semantic Study

This study interrogates the use of biblical names as charactonyms in selected plays of Wole Soyinka, the first Nobel laureate in Africa, with the aim of unearthing their morphological process and sociolinguistic imports in relation to the Holy Bible. The primary data from which extracts were made to illustrate the discussion were four drama texts: The Strong Breed (1963), The Road (1965), Death and the King’s Horseman (1975), King Baabu (2002)- all tragedies, by the same author. The theoretical frameworks adopted were Yule’s (1985) morphological taxonomy and Said’s (1978) postcolonialism. Ten names inundated with biblical elements were purposively selected across-the-board and analysed using the theoretical frameworks. Findings indicated that Soyinka inundated his works with analogy (60%) by deploying six names (Ifada, Sunma, Samson, Simon Pilkings, Olunde, Joseph) patterned after the Holy Bible to illustrate didactic lesson and messianic scapegoatism theme(s). Furthermore, the study revealed that the playwright deployed clipping (20%) through the names Maariya and Tikim, to indicate popular culture among African youth. Finally, the playwright uses biblical names in his works to blend his Christian and traditional background, and as a means of taking indirect swipe at the issue of African complex dispositions to the colonial encounter and its legacies. The work is a contribution to onomastic scholarship in relation to the Holy Bible and African-contact literary texts.

Phylogeny and taxonomic revision of Metacephalus (Insecta: Hemiptera: Cicadellidae) with description of seven new leafhopper species.

Metacephalus Delong and Martinson, 1973 includes leafhopper species from Argentina, Bolivia, Brazil, Colombia, Ecuador (new record), Guyana, French Guiana (new record), Panama, Peru, and Venezuela. In the present revisionary study, we describe seven new species of Metacephalus, propose one species synonymy (M. cinctus as junior synonym of M. facetus), and provide new country records for species, considerably expanding knowledge about species distributions. The study also provides redescriptions and photographs of diagnostic characters for 12 previously described valid species and an identification key to all 21 species of Metacephalus. Molecular phylogenies of Metacephalus species are hypothesized based on maximum likelihood and Bayesian inference analyses of 1,387 bp of mitochondrial Cytochrome Oxidase I and 16S rDNA and nuclear histone H3. Results of the molecular phylogeny generated herein provided a base for understanding character homologies when presenting morphological diagnoses of Metacephalus species and exposed a high level of convergent characters in color pattern and male genitalia morphology usually used in morphological taxonomy of this group of leafhoppers.

Revealing Brownish Mycena Diversity in China: New Discoveries and Taxonomic Insights.

Within the genus Mycena, species exhibiting brownish basidiomata present considerable challenges in identification due to similar coloration. This study underscores the significance of pileipellis types and cheilocystidia characteristics as critical in delimiting brownish Mycena species. To clarify the principal taxonomic characters and their utility in distinguishing between brownish Mycena species, a morphological taxonomy and phylogenetic analysis were performed. Five new species from China were introduced and characterized through a comprehensive morphological anatomy and phylogenetic substantiation: M. campanulatihemisphaerica sp. nov., M. digitifurcata sp. nov., M. kunyuensis sp. nov., M. limitis sp. nov., and M. oryzifluens sp. nov. Discussions of these taxa are supplemented with morphological illustrations. The phylogenetic relationships were inferred using Bayesian Inference and Maximum Likelihood methods based on sequences from the internal transcribed spacer and the large subunit regions of nuclear ribosomal RNA. With the addition of these five new species, the worldwide count of brownish Mycena increases to 94, and a key to the 29 known species of brownish Mycena from China is presented.

The overpowering Role of Morphology in Taxonomy

The aim of the taxonomist is to prepare a natural system of classification bringing out the phylogenetic relationships between plants. To achieve this aim evidence must be collected from all possible angles. External morphology is the first of these and It is quite remarkable that many taxa created on the basis of such studies alone have also been found to be perfectly natural assemblages when other criteria are taken into account.However, a large number of examples may be cited where external morphology has proved inadequate and it is important to study the internal structures. Characters of the cuticle, Stomata, secondary xylem, glands, hairs, pollen grains, embryo sac, endosperm and seed coat have all proved to be of value.To illustrate the significance of internal morphology and embryology a reference will be made, to the following taxa in particular : Ephedra, Exocarpus, Kingdonia, Paeonia, Phyllocladus, Scyphostegia, and Sequoia.(1) Ephedra is more closely related to the cordaites and conifers than to the Gnetales and should be placed in a separate order Ephedrales ; (2) Exocarpus does not belong to the Taxaceae as proposed by one botanist or even close to it, but is a member of the Santalaceae ; (3) The genus Kingdonia should perhaps be removed from the Ranunculaceae and assigned to a new family Kingdoniaceae ; (4) Paeonia cannot be assigned to the Ranunculaceae and is not even related to Helleborus as suggested by Hutchinson ; (5) Phyllocladus is confirmed as a member of the Podocarpaceae all of whose genera are characterized by certain peculiarities in the development of the male gametophyte and the embryo ; (6) The genus Scyphostegia is in no way related to the Urticales, Celastrales or Monimiaceae ; its real affinities are still undecided ; (7) Sequoia gigantea is too different from S. sempervirens to be included in the same genus ; the former must be put in a separate genus Sequoiadendron as recommended by Buchholz.Internal morphology generally corroborates the conclusions based on external morphology. However, it has a special value in cases of controversial nature. Sometimes it fails to provide an immediate solution but reorients our ideas in more fruitful directions.

Characterization of the complete mitochondrial genome of the Libelloides sibiricus (Neuroptera, Ascalaphidae)

Libelloides sibiricus (Eversmann, 1850) is widely distributed in China, Korea and eastern Russia. To date, few studies have been conducted on this species, with the exception of morphological taxonomy studies. In this study, we sequenced the complete mitochondrial genome (mitogenome) of Libelloides sibiricus, which is 15,811 bp in length, with an overall A + T content of 74.8%, encoding 2 ribosomal RNA genes, 22 transfer RNA genes, 13 protein-coding genes, and a control region. The gene arrangement and components of L. sibiricus are identical to those of most other Neuropteran species. TAA is utilized as the termination codon for most PCGs and TAG for nd1, however, nd6 and atp6 used the incomplete termination codon TA- and cox1, cox2, nd5, cytb had termination codons consisting of only T–. In addition, we selected all known 59 species of Neuroptera from NCBI, and used Sialis hamata, Sialis melania, Sialis longidens and Sialis jiyuni (Megaloptera: Sialidae) as the outgroup. Phylogenetic analysis suggested that the mitogenome of L. sibiricus was the most closely related to L. macaronius and all the owlflies formed the monophyletic group within the superfamily Myrmeleontoidea.

First report of the complete mitochondrial genome of Carpomya pardalina (Bigot) (Diptera: Tephritidae) and phylogenetic relationships with other Tephritidae

Carpomya pardalina is known for its potential invasiveness, which poses a significant and alarming threat to Cucurbitaceae crops. It is considered a highly perilous pest species that requires immediate attention for quarantine and prevention. Due to the challenges in distinguishing pests of the Tephritidae family based on morphological characteristics, it is imperative to elucidate the mitochondrial genomic information of C. pardalina. In this study, the mitochondrial genome sequence of C. pardalina was determined and analyzed using next-generation sequencing. The results revealed that the mitogenome sequence had a total length of 16,257 bp, representing a typical circular molecule. It consisted of 13 PCGs, two rRNA genes, 22 tRNA genes and a non-coding region. The structure and organization of the mitochondrial genome of C. pardalina were found to be typical and similar to the published homologous sequences of other fruit flies in the Tephritidae family. Phylogenetic analysis confirmed that C. pardalina belongs to the Carpomya genus, which is consistent with traditional morphological taxonomy. Additionally, Carpomya and Rhagoletis were identified as sister groups. This study presents the first report of the complete mitochondrial genome of C. pardalina, which can serve as a valuable resource for future investigations in species diagnosis, evolutionary biology, prevention and control measures.

A lightweight convolutional neural network (CNN) model for diatom classification: DiatomNet.

Diatoms are a type of algae with many species. Accurate and quick classification of diatom species is important in many fields, such as water quality analysis and weather change forecasting. Traditional methods for diatom classification, specifically morphological taxonomy and molecular detection, are time-consuming and may not provide satisfactory performance. However, in recent years, deep learning has demonstrated impressive performance in this task, just like other image classification problems. On the other hand, networks with more layers do not guarantee increased accuracy. While increasing depth can be useful in capturing complex features and patterns, it also introduces challenges such as vanishing gradients, overfitting, and optimization challenges. Therefore, in our work, we propose DiatomNet, a lightweight convolutional neural network (CNN) model that can classify diatom species accurately while requiring low computing resources. A recently introduced dataset consisting of 3,027 diatom images and 68 diatom species is used to train and evaluate the model. The model is compared with well-known and successful CNN models (i.e., AlexNet, GoogleNet, Inceptionv3, ResNet18, VGG16, and Xception) and their customized versions obtained with transfer learning. The comparison is based on several success metrics: accuracy, precision, recall, F-measure, number of learnable parameters, training, and prediction time. Eventually, the experimental results reveal that DiatomNet outperforms the other models regarding all metrics with just a few exceptions. Therefore, it is a lightweight but strong candidate for diatom classification tasks.

Characterization of the complete mitochondrial genome of Paecilomyces variotii and comparative evolutionary mitochondriomics of 36 fungi.

Paecilomyces variotii has important economic value in stimulating crop growth, biodegradation, and other aspects. Up to now, there are no research reports on its mitochondrial genome. The mitochondrial genome of Paecilomyces variotii was determined with the next-generation sequencing method (Illumina, NovaSeq), and its characteristics were analyzed using various bioinformatics approaches. The length of complete mitochondrial genome sequence of P. variotii is 40,965bp and consists of 14 protein-coding genes, 2 ribosomal RNA genes, 1 ribosomal protein S3 gene, 26 transport RNA genes. The results of phylogenetics analysis using Bayesian inference and Maximum likelihood methods showed that P. variotii belongs to the Eurotiales order in the Thermoascaceae family, and 9 genera within the Eurotiomycetes class were effectively distinguished with high support rates (bootstrap value > 92% and posterior probabilities > 99%). The analysis of synonymous substitution rates and nonsynonymous substitution rates indicated that the Ka/Ks values of the 14 PCGs in the mitochondrial genomes of the two orders in the Eurotiomycetes class ranged from 0 to 0.4333. This study revealed the structural and sequence information characteristics of the mitochondrial genome of P. variotii, and the phylogenetic results strongly support its classification within the family Thermoascaceae, consistent with traditional morphological taxonomy studies. The 14 PCGs in the mitochondrial genomes of the two orders in the Eurotiomycetes class are subject to strong purifying (negative) selection. The results of this research provides an important molecular basis for the development of genomics, evolutionary genetics and molecular markers of P. variotii in the future.

Reassessment of the Phylogenetics of Two Pygmy Grasshopper Generic Groups Tetrix and Systolederus through Mitochondrial Phylogenomics Using Four New Mitochondrial Genome Assemblies.

Mitochondrial genomes offer pragmatic genetic markers to reconstruct evolutionary relationships and inform taxonomic classifications. Here, we present complete mitochondrial sequences for four Chinese pygmy grasshoppers (Tetrigidae), aiming to reevaluate phylogenetic patterns and morphological taxonomy. Our 17,643 bp, 16,274 bp, 15,086 bp, and 15,398 bp mitogenomes of Exothotettix guangxiensis, Formosatettix longwangshanensis, Euparatettix sinufemoralis and Systolederus zhengi, respectively, exhibit archetypal Tetrigidae architecture. We constructed phylogenies using 13 protein-coding loci from 39 Tetrigidae mitogenomes, revealing several genus-level clusters with statistically solid support, conflicts regarding Ex. guangxiensis, F. longwangshanensis merging into Tetrix, and two subclades of Systolederus. The dated divergence analysis indicates over 150 Mya of Tetrigidae ancestry, tracing the Systolederus generic group splits up to ~75 million years ago. Moreover, the Tetrix generic group radiated over 14 Mya across vast distributions, consistent with rapid adaptive dispersals. Our mitochondrial reconstructions suggest that Synstolederus is taxonomically overextended for a single genus, while the distinctiveness of Ex. guangxiensis and F. longwangshanensis from Tetrix appears questionable, and the Tetrix generic group comprises a potential tRNA-Ile coding region. Our integrative mitogenomic approaches will help resolve issues stemming from morphological taxonomy that is reliant on traits that are prone to convergence. This investigation enhances comprehension of Tetrigidae phylogeny and accentuates molecular systematics.

Revisiting the phylogenetic status of a field crab (Decapoda, Brachyura) from Chelari, Malappuram District (Kerala, India): an integrative approach through morphological and molecular taxonomy

Abstract The phylogeny of field crabs has been under profuse discussion for several decades. At this juncture, this paper reassesses the “decades old” phylogenetic status of an edible field crab, hitherto referred to as Paratelphusa hydrodromous, inhabiting the paddy fields of Chelari village (Kerala, India). After Alcock’s (1910) description, there has hardly been any serious attempt at ascertaining its precise taxonomic status. Through an integrated approach, using parsimony analysis and molecular methods, the present study reveals the candidate form’s (species’) closer affinity to the genus Oziotelphusa. Comparison of morphological and molecular characteristics with its closest phylogenetic neighbours (O. biloba, O. wagrakarowensis, O. kerala and O. aurantia) has shown that the candidate form is a taxonomically distinct entity, qualified to be considered as an unreported species; its suggested revised nomenclature is Oziotelphusa chelarensis, reminiscent of the village Chelari. Further, the paper views the relevance of this taxonomic study from conservational angles as well.

The global genetic diversity of planktonic foraminifera reveals the structure of cryptic speciation in plankton.

The nature and extent of diversity in the plankton has fascinated scientists for over a century. Initially, the discovery of many new species in the remarkably uniform and unstructured pelagic environment appeared to challenge the concept of ecological niches. Later, it became obvious that only a fraction of plankton diversity had been formally described, because plankton assemblages are dominated by understudied eukaryotic lineages with small size that lack clearly distinguishable morphological features. The high diversity of the plankton has been confirmed by comprehensive metabarcoding surveys, but interpretation of the underlying molecular taxonomies is hindered by insufficient integration of genetic diversity with morphological taxonomy and ecological observations. Here we use planktonic foraminifera as a study model and reveal the full extent of their genetic diversity and investigate geographical and ecological patterns in their distribution. To this end, we assembled a global data set of ~7600 ribosomal DNA sequences obtained from morphologically characterised individual foraminifera, established a robust molecular taxonomic framework for the observed diversity, and used it to query a global metabarcoding data set covering ~1700 samples with ~2.48 billion reads. This allowed us to extract and assign 1 million reads, enabling characterisation of the structure of the genetic diversity of the group across ~1100 oceanic stations worldwide. Our sampling revealed the existence of, at most, 94 distinct molecular operational taxonomic units (MOTUs) at a level of divergence indicative of biological species. The genetic diversity only doubles the number of formally described species identified by morphological features. Furthermore, we observed that the allocation of genetic diversity to morphospecies is uneven. Only 16 morphospecies disguise evolutionarily significant genetic diversity, and the proportion of morphospecies that show genetic diversity increases poleward. Finally, we observe that MOTUs have a narrower geographic distribution than morphospecies and that in some cases the MOTUs belonging to the same morphospecies (cryptic species) have different environmental preferences. Overall, our analysis reveals that even in the light of global genetic sampling, planktonic foraminifera diversity is modest and finite. However, the extent and structure of the cryptic diversity reveals that genetic diversification is decoupled from morphological diversification, hinting at different mechanisms acting at different levels of divergence.

DNA barcoding, an effective approach for the identification of thrips (Thysanoptera: Thripidae) in citrus orchards

AbstractThrips are serious crop pests with a worldwide distribution. The first step in the design of control methods is accurate species identification. However, the morphological identification of thrips can be complex, especially as there is morphological variation amongst individuals of the same species. Analyzing a fragment of cytochrome c oxidase subunit I (COI) has been used successfully in the identification of insects and other arthropods. Citrus is among the most important crops in the world, and Mexico is one of the largest producers. Despite this, formal reports on the species diversity of thrips found in Mexican citrus orchards are scarce. We explored the species diversity of thrips in selected citrus orchards (of Mexican orange, Key lime and Persian lime), based on morphological taxonomy and on partial sequences of COI. We analyzed 111 thrips specimens, distributed in two genera: Frankliniella, including Frankliniella insularis, Frankliniella invasor and Frankliniella occidentalis; and Scirtothrips, including Scirtothrips citri and Scirtothrips dorsalis. Frankliniella insularis and F. invasor were the most abundant species in Mexican orange (Citrus × sinensis) and Persian lime (Citrus × latofolia) orchards. Scirtothrips dorsalis was the most abundant species in Key lime orchards (Citrus × aurantiifolia). Analysis of molecular variance (AMOVA) and haplotype analyses performed on F. insularis sequences (the most abundant species) showed no significant effect of geographical origin or plant host on its genetic population structure. DNA barcoding is a valuable method to complement the morphological identification of thrips in citrus orchards, allowing more accurate identification to species level.

An Overview of Aquatica Fu et al., a Phylogeny of Aquatic Fireflies Using Mitochondrial Genomes, a Description of Two New Species, and a New Record of Aquatic Fireflies in China (Coleoptera: Lampyridae: Luciolinae).

There are now seven species in the genus Aquatica Fu & Ballantyne, with all but one known from the characteristics of males, females, and larvae. Molecular information is combined with morphological taxonomy for the delimitation of both genus and species. The monophyly of the genus Aquatica is strongly supported in six trees, and its position as sister to the genus Nipponoluciola Ballantyne Kawashima Jusoh et Suzuki is stable across maximum likelihood and Bayesian inference results. Two new species of Aquatica Fu & Ballantyne, A. qingshen sp. nov. and A. xianning sp. nov., described from the features of males, females, and larvae, are closely related within a single clade within the genus Aquatica. Females have distinctively shaped median oviduct plates. A Chinese population identified as A. lateralis was found to be morphologically similar to the Japanese population, but genetic distances suggest that it is a distinctive species. No larvae are associated with this species. Definitions of the aquatic status of Luciolinae fireflies are expanded.