Testing drivers of acoustic divergence in cicadas (Cicadidae: Tettigettalna)

Divergence in acoustic signals may have a crucial role in the speciation process of animals that rely on sound for intra-specific recognition and mate attraction. The acoustic adaptation hypothesis (AAH) postulates that signals should diverge according to the physical properties of the signalling environment. To be efficient, signals should maximize transmission and decrease degradation. To test which drivers of divergence exert the most influence in a speciose group of insects, we used a phylogenetic approach to the evolution of acoustic signals in the cicada genus Tettigettalna, investigating the relationship between acoustic traits (and their mode of evolution) and body size, climate and micro-/macro-habitat usage. Different traits showed different evolutionary paths. While acoustic divergence was generally independent of phylogenetic history, some temporal variables’ divergence was associated with genetic drift. We found support for ecological adaptation at the temporal but not the spectral level. Temporal patterns are correlated with micro- and macro-habitat usage and temperature stochasticity in ways that run against the AAH predictions, degrading signals more easily. These traits are likely to have evolved as an anti-predator strategy in conspicuous environments and low-density populations. Our results support a role of ecological selection, not excluding a likely role of sexual selection in the evolution of Tettigettalna calling songs, which should be further investigated in an integrative approach.     

Phylogenetic systematics of Colotis and associated genera (Lepidoptera: Pieridae): evolutionary and taxonomic implications

We investigated the genetic diversity and phylogenetic placement of the butterflies in the genus Colotis and eight related pierid genera using sequence information from two mitochondrial and two nuclear genes. To establish the status of species, we initially barcoded 632 specimens representative of all genera and most species and subspecies in those genera. A subset was then selected for phylogenetic analysis where additional gene regions were sequenced: 16S rRNA (523 bp), EF‐1α (1126 bp) and wg (404 bp). DNA barcode results were largely congruent with the traditional classification of species in the Colotis group, but deep splits or lack of genetic divergence in some cases supported either species‐level differentiation or synonymy. Despite using information from four genes, the deeper nodes in our phylogeny were not strongly supported, and monophyly of the ‘Colotis group’ and the genera Colotis and Eronia could not be established. To preserve the monophyly of Colotis, we revive the genus Teracolus for three outlying species previously in Colotis (i.e. Colotis eris, Colotis subfasciatus and Colotis agoye), as well as the genus Afrodryas for Eronia leda. The position of Calopieris is unresolved although it appears to be well outside the molecular variation in Colotis (s.l.). A dispersal/vicariance analysis suggested that major diversification in Colotis (s.str.) occurred in Africa with subsequent dispersal to India and Madagascar.     

Integrative taxonomy reveals phenotypic plasticity in the freshwater mussel Contradens contradens (Bivalvia: Unionidae) in Thailand,with a description of a new species

The freshwater mussel Contradens contradens (Lea, 1838) occurs in most types of freshwater habitats throughout Thailand. The species shows extensive variation in shell morphology, which has led to the recognition of six different subspecies. In this study, the validity of these six subspecies plus one unknown species was assessed using an integrative taxonomic approach. Geometric morphometric analyses revealed significant differences in shell shapes among these six nominal morphological subspecies, although a considerable degree of overlap was detected in some groups. In contrast, the phylogenetic tree obtained from the concatenated data of mitochondrial COI and nuclear H3 gene sequences and molecular species delimitation analyses revealed only three supported clades. These clades are proposed herein as three distinct species, and strongly corresponded to the biogeographically disjunct drainage systems in Thailand. They consisted of the (i) C. contradens clade found in the Chao Phraya Basin and other rivers that drain into the Gulf of Thailand, (ii) C. crossei clade that is restricted to the Middle Mekong Basin, and (iii) a clade containing only the newly discovered species from Huai Luang River in the north-east of Thailand, which is described herein as Contradens rolfbrandti Jeratthitikul & Panha, sp. nov. Speciation among these congeners was probably caused by the restriction of gene flow due to the past geomorphology of the river systems. The intraspecific variation in the shell shape detected here does not reflect the evolution of the mussel, but rather is evidence of phenotypic plasticity.http://zoobank.org/urn:lsid:zoobank.org:pub:649B6093-E1DD-4FD8-8185-A4696C43AD36; http://zoobank.org/urn:lsid:zoobank.org:act:777DDE86-8397-4FF3-AA78-0BE0F34611F4     

Revision of the systematics of the genus Calliptamus Serville 1831, (Orthoptera: Acrididae: Calliptaminae) in Algeria using morphological,chemical, and genetic data

Summary. The genus Calliptamus contains swarming orthopterans that cause serious damage in Algerian agricultural systems. However, it remains difficult to identify species within this genus; a thorough understanding of the group’s systematics and the utilization of novel taxonomic criteria are needed. We used morphological analysis along with two other methods of species identification – chemotaxonomy with cuticular compounds and DNA barcoding involving the COI gene – to classify 81 individual grasshoppers collected at two different sites in the Sétif region (northeastern Algeria). The chemotaxonomic analyses yielded ambiguous results, but DNA barcoding allowed us to differentiate two Calliptamus species found in Algeria: Calliptamus barbarus (Costa 1836), and Calliptamus wattenwylianus (Pantel 1896). Several morphological criteria used in identification keys appear to reflect differences among morphotypes rather than differences between species, and their taxonomic specificity is not supported by the barcoding data. The number of spines on the hind tibia is the only morphological criterion that reflected genetic differences between species; it is thus considered to be a taxonomically useful feature for identifying species in this genus.     

Morphological, vocal and genetic divergence in the Cettia acanthizoides complex (Aves: Cettiidae)

We used morphological, vocal and molecular (one mitochondrial and two nuclear loci) data to re-evaluate the taxonomic status of the taxa acanthizoides , concolor , and brunnescens in the Cettia acanthizoides (J. Verreaux, 1871) complex. We conclude that all three are valid taxa, and that acanthizoides of China and concolor of Taiwan are best treated as conspecific, whereas brunnescens of the Himalayas is better considered as a separate species. The degree of morphological, vocal, and genetic differentiation is variably congruent among all taxa; the recently separated acanthizoides and concolor differ slightly in plumage and structure but are indistinguishable in vocalizations, whereas the earlier diverged brunnescens and acanthizoides/concolor differ only slightly more in morphology but to a much greater degree in vocalizations. We stress the essential nature of taxonomic revisions as a prerequisite for the biodiversity estimates required for conservation planning.  © 2007 The Linnean Society of London, Zoological Journal of the Linnean Society , 2007, 149 , 437–452.     

An integrative approach to species delineation incorporating different species concepts: a case study of Limnadopsis (Branchiopoda: Spinicaudata)

The unambiguous delineation and identification of species remain central problems in systematic and taxonomic studies. Species delineation depends on the data utilized and the species concept applied. In recent years, morphology‐based species delineation has been complemented by DNA sequence data, leading to an integrative taxonomy. Such integrative approaches, however, are hampered by the partial incongruence of the various data types with certain species concepts. In this study, we delineated Australian Limnadopsis species employing one mitochondrial (cytochrome c oxidase subunit I, COI) and one nuclear (elongation factor 1α, EF1α) marker and a morphological character apparently part of the specific mate recognition complex, and therefore potentially indicative of reproductive isolation. By integrating the data over various species concepts (e.g. the ‘biological’, ‘Hennigian’, ‘recognition’, ‘phylogenetic’ and ‘evolutionary’ species concepts), the delineation of most species becomes straightforward and unambiguous. Conflicts are particularly interesting as they reveal different aspects of speciation considering the various species concepts. Our study emphasizes the benefits of a truly integrative approach to taxonomy. By combining molecular data with morphological characters indicative of reproductive isolation, it is possible to delineate species integrating not only different data types, but also different underlying species concepts. Overall, 11 Limnadopsis species could be delineated, including all eight currently recognized species, and three so far undescribed species. Most species were congruently delineated under all species concepts. A strict application of the evolutionary species concept, however, would have further split L. parvispinus into two species on the basis of the COI data. In addition, Limnadopsis tatei is consistently split into two sympatrically occurring species under all applied species concepts. © 2011 The Linnean Society of London, Biological Journal of the Linnean Society, 2011, 104 , 575–599.     

Host specificity and variation in oviposition behaviour of milkweed stem weevils and implications for species divergence

1. An herbivore's life-history strategy, including optimization of resource use, is constrained by its evolutionary history and ecological factors varying across the landscape. 2. We asked if related and co-distributed herbivore species maintain consistency of host preference and oviposition behaviours along the species' range. We surveyed two putative species of milkweed stem weevils, Rhyssomatus lineaticollis and R. annectens, which co-occur alongside their hosts, Asclepias syriaca and A. incarnata. 3. We confirmed the two species status of weevils, supported by differences in morphology and a bilocus gene phylogeny. Furthermore, we found that species divergence recapitulated the weevils current host plant use. 4. We found oviposition variation within and between species. R. annectens poked the stem haphazardly or girdled it before oviposition. Meanwhile, R. lineaticollis primarily trenched stems in the north, but poked or girdled in the south. Variation in oviposition patterns could be a response to variation in host plant defenses. 5. In nature, weevils strictly oviposited on their respective host plants, while in bioassays, R. lineaticollis exhibited strong preference for A. syriaca and R. annectens fed equally on both host plants. 6. Overall, our results support that milkweed stem weevils are strict specialists but might be undergoing changes in host use. R. lineaticollis specializes on A. syriaca but has two distinct modes of oviposition. Meanwhile R. annectens seems to be more accepting of other hosts. We hypothesize that these weevils might be shifting host use associated with changes in host plant distributions.     

Taxonomy of family Plakinidae (Porifera: Homoscleromorpha) from eastern Pacific coral reefs,through morphology and cox1 and cob mtDNA data

Sponges belonging to the class Homoscleromorpha have become a pivotal group to help understand early metazoan evolution. However, their complex systematics and cryptic habitat (e.g. dead coral, or under/amongst coral rubble or rock), hinders the recognition and classification of species. An extensive study carried out in coral reefs from the Mexican Pacific coast, Revillagigedo and Clipperton Islands, yielded 21 specimens and five species of Plakinidae: Plakortis albicans, Plakinastrella clippertonensis, P lakina muricyae sp. nov. , P lakina paradilopha sp. nov. , and P lakortis clarionensis sp. nov. Fragments of cytochrome c oxidase subunit I (cox1) and cytochrome b (cob) mtDNA were sequenced to generate DNA‐barcoding of some species and to determine their phylogenetic relationships with other homosclermorphs. Molecular and morphological data placed Plakina muricyae sp. nov. together with the morphologically related species Plakina monolopha (Plakina monolopha‐complex), whereas Plakina paradilopha sp. nov. seems to belong to the Plakina dilopha complex. According to spicule morphology and size, Plakortis albicans had been considered to be in the Plakortis simplex‐complex. However, this was not supported by our molecular data and Plakortis albicans clustered with Plakinastrella sp. here. This is the first time that the standard cox1 ‘barcoding fragment’ has been analysed for the systematics of Plakinidae, which showed to Plakina as a monophyletic group, which is congruent with the morphological hypothesis. The genus Plakina is here recorded for first time from Mexican Pacific waters. A taxonomic key for Homoscleromorpha species from the eastern Pacific region is also included. © 2014 The Linnean Society of London     

Wheat curl mite and dry bulb mite: untangling a taxonomic conundrum through a multidisciplinary approach

Two economically important eriophyoid mites, Aceria tosichella (wheat curl mite; WCM) and Aceria tulipae (dry bulb mite; DBM), were frequently confounded in the world literature until the late 20th Century. Their morphological similarity and ambiguous data from plant‐transfer and virus‐transmission trials contributed to this confusion. Until recently, there was a general lack of knowledge about the existence of species complexes and it was not possible to accurately genotype tested mites. In the present study, two WCM genotypes of divergent host specificity (MT‐1 and MT‐2) and one DBM genotype were tested for the acceptance of Poaceae, Amarylidaceae, and Liliaceae species that were reported or suspected as hosts of WCM or DBM. The MT‐1 lineage colonized all tested plants. Onion‐ and garlic‐associated DBM populations did not colonize tulip and wild garlic, suggesting that host‐acceptance variability exists within A. tulipae s.l. Morphometric analysis did not discriminate closely‐related MT‐1 and MT‐2 genotypes but completely separated both WCM genotypes from DBM based on the larger overall body size of the latter. Three morphological traits combined to discriminate between the DBM and MT‐1 genotypes, both of which can infest Amarylidaceae bulbs. In total, these combined DNA sequence, host‐acceptance, morphometrical results unambiguously separated two WCM and one DBM genotypes. Similar studies on additional lineages of both WCM and DBM should ultimately dispel previous taxonomic confusion between these two species. © 2013 The Linnean Society of London, Biological Journal of the Linnean Society, 2014, 111 , 421–436.     

DNA barcodes as a tool in biodiversity research: testing pre-existing taxonomic hypotheses in Delphic Apollo butterflies (Lepidoptera,Papilionidae)

Numerous studies have demonstrated that DNA barcoding is an effective tool for detecting DNA clusters, which can be viewed as operational taxonomic units (OTUs), useful for biodiversity research. Frequently, the OTUs in these studies remained unnamed, not connected with pre-existing taxonomic hypotheses, and thus did not really contribute to feasible estimation of species number and adjustment of species boundaries. For the majority of organisms, taxonomy is very complicated with numerous, often contradictory interpretations of the same characters, which may result in several competing checklists using different specific and subspecific names to describe the same sets of populations. The highly species-rich genus Parnassius (Lepidoptera: Papilionidae) is but one example, such as several mutually exclusive taxonomic systems have been suggested to describe the phenotypic diversity found among its populations. Here we provide an explicit flow chart describing how the DNA barcodes can be combined with the existing knowledge of morphology-based taxonomy and geography (sympatry versus allopatry) of the studied populations in order to support, reject or modify the pre-existing taxonomic hypotheses. We then apply this flow chart to reorganize the taxa within the Parnassius delphius species group, solving long-standing taxonomic problems.     

Ecologically relevant cryptic species in the highly polymorphic Amazonian butterfly Mechanitis mazaeus s.l. (Lepidoptera: Nymphalidae; Ithomiini)

The understanding of mimicry has relied on a strong biosystematic framework ever since early naturalists first recognized this textbook example of natural selection. We follow in this tradition, applying new biosystematics information to resolve problems in an especially difficult genus of tropical butterflies. Mechanitis species are important components of Neotropical mimetic communities. However, their colour pattern variability has presented challenges for systematists, and has made it difficult to study the very mimicry they so nicely illustrate. The South American Mechanitis mazaeus and relatives have remained particularly intractable. Recent systematists have recognized one highly polytypic species, whereas earlier work recognized the melanic Andean foothill races as a distinct species: Mechanitis messenoides. Recent molecular evidence suggests M. mazaeus and M. messenoides are genetically well differentiated, but evidence of morphological and ecological differences indicative of separate species was still lacking. Thus, it remains to be conclusively demonstrated whether this is an extreme case of a polymorphic mimetic species, or whether distinct co‐mimetic lineages are involved. Here we provide evidence that M. mazaeus and M. messenoides are ecologically distinct and identify consistent morphological differences in both adult and immature stages. These ecological and morphological differences are correlated with mitochondrial sequence data. In spite of some overlap in almost all traits, wing shape, adult colour pattern, and larval colour pattern differ between the two species, in addition to clutch size and larval host use in local sympatry. Although three well‐differentiated mitochondrial DNA (mtDNA) haplogroups were identified within these two species, one for M. mazaeus and two within M. messenoides, no morphological or ecological differences were found between two mtDNA haplogroups, both of which appear to belong to M. messenoides. We conclude that M. mazaeus and M. messenoides are distinct although highly polymorphic species, each with multiple sympatric co‐mimetic forms, and suggest that further work is needed to clarify the identity of other phenotypes and subspecies of Mechanitis. © 2012 The Linnean Society of London, Biological Journal of the Linnean Society, 2012, 106 , 540–560.     

Utility of DNA taxonomy and barcoding for the inference of larval community structure in morphologically cryptic Chironomus (Diptera) species

Biodiversity studies require species level analyses for the accurate assessment of community structures. However, while specialized taxonomic knowledge is only rarely available for routine identifications, DNA taxonomy and DNA barcoding could provide the taxonomic basis for ecological inferences. In this study, we assessed the community structure of sediment dwelling, morphologically cryptic Chironomus larvae in the Rhine-valley plain/Germany, comparing larval type classification, cytotaxonomy, DNA taxonomy and barcoding. While larval type classification performed poorly, cytotaxonomy and DNA-based methods yielded comparable results: detrended correspondence analysis and permutation analyses indicated that the assemblages are not randomly but competitively structured. However, DNA taxonomy identified an additional species that could not be resolved by the traditional method. We argue that DNA-based identification methods such as DNA barcoding can be a valuable tool to increase accuracy, objectivity and comparability of the taxonomic assessment in biodiversity and community ecology studies.     

基于形态和分子数据的中国锈迷孔菌属一新种

结合形态学特征和分子序列分析发现采自内蒙古自治区和黑龙江省兴安落叶松树上一新种——蒙古锈迷孔菌,对此种进行了形态描述和特征图示,并讨论了该新种与其近缘种之间的异同。     

Morphological variation of Aechmea distichantha (Bromeliaceae) in a Chaco forest: habitat and size-related effects

Plants show different morphologies when growing in different habitats, but they also vary in their morphology with plant size. We examined differences in sun- and shade-grown plants of the bromeliad Aechmea distichantha with respect to relationships between plant size and variables related to plant architecture, biomass allocation and tank water dynamics. We selected vegetative plants from the understorey and from forest edges of a Chaco forest, encompassing the whole size range of this bromeliad. Plant biomass was positively correlated with most architectural variables and negatively correlated with most biomass allocation variables. Understorey plants were taller and had larger diameters, whereas sun plants had more leaves, larger sheath area, sheath biomass and sheath mass fraction. All tank water-related variables were positively correlated with plant biomass. Understorey plants had a greater projected leaf area, whereas sun plants had higher water content and evaporative area. Plasticity indices were higher for water-related than for allocation variables. In conclusion, there were architectural and biomass allocation differences between sun- and shade-grown plants along a size gradient, which, in turn, affected tank water-related variables.     

Deep genetic divergences in Aoraki denticulata (Arachnida, Opiliones, Cyphophthalmi): a widespread 'mite harvestman' defies DNA taxonomy

Aoraki denticulata (Arachnida, Opiliones, Cyphophthalmi, Pettalidae), a widespread 'mite harvestman' endemic to the South Island of New Zealand, is found in leaf littler habitats throughout Nelson and Marlborough, and as far south as Arthur's Pass. We investigated the phylogeography and demographic history of A. denticulata in the first genetic population-level study within Opiliones. A total of 119 individuals from 17 localities were sequenced for 785 bp of the gene cytochrome c oxidase subunit I; 102 of these individuals were from the Aoraki subspecies A. denticulata denticulata and the remaining 17 were from the subspecies A. denticulata major. An extraordinarily high degree of genetic diversity was discovered in A. denticulata denticulata, with average uncorrected p-distances between populations as high as 19.2%. AMOVA, average numbers of pairwise differences, and pairwise F(ST) values demonstrated a significant amount of genetic diversity both within and between populations of this subspecies. Phylogenetic analysis of the data set revealed many well-supported groups within A. denticulata denticulata, generally corresponding to clusters of specimens from single populations with short internal branches, but separated by long branches from individuals from other populations. No haplotypes were shared between populations of the widespread small subspecies, A. denticulata denticulata. These results indicate a subspecies within which very little genetic exchange occurs between populations, a result consistent with the idea that Cyphophthalmi are poor dispersers. The highly structured populations and deep genetic divergences observed in A. denticulata denticulata may indicate the presence of cryptic species. However, we find a highly conserved morphology across sampling localities and large genetic divergences within populations from certain localities, equivalent to those typically found between populations from different localities. Past geological events may have contributed to the deep genetic divergences observed between sampling localities; additionally, the high divergence within populations of A. denticulata denticulata suggests that the rate of COI evolution may be accelerated in this taxon. In contrast, the larger subspecies A. denticulata major shows much less differentiation between and within sampling localities, suggesting that it may disperse more easily than its smaller counterpart. The fact that the remarkable genetic divergences within populations of A. denticulata denticulata from certain localities are equivalent to divergences between localities poses a challenge to the rapidly spreading practice of DNA taxonomy.     

Otostephanos (Rotifera,Bdelloidea, Habrotrochidae) with the description of two new species

Abstract

We present a morphological feature-based key for the genus Otostephanos and describe two new species, O. jolantae sp. nov. and O. ukrainicus sp. nov. For O. jolantae sp. nov. we analysed the intraspecific morphological variability and provided the barcodes of mtCOX1 mitochondrial gene. Further, we developed a method to standardize measurements for the Philodina type of corona and trophi measurements of bdelloids. Otostephanos jolantae sp. nov. is a large rotifer with a smooth cuticle and bright red-orange gut; it can be distinguished from the known species by a high triangular upper lip with a tongue-like tip not divided into lobes, spade-shaped swollen rump, and 6/6 dental formula. It is found in Sphagnum collected in Poland, Ukraine and the Czech Republic. Otostephanos ukrainicus sp. nov. has a long body covered with coarse-grained cuticle on the last two neck segments, trunk and rump; it is distinguished by long narrow head and neck, saccular-like swollen trunk, spade-like rump, and a tiny foot. Unlike the other species of this genus, it has band-like upper lip with two narrow, sharp protrusions separated by an interspace, unusually small spurs and trophi with 5/5 major teeth. Thus far, it is only found in Ukraine, in pine and oak forest litter. http://zoobank.org/urn:lsid:zoobank.org:pub:9FC484E3-67F5-43A9-8478-A7BE14FBE5E33