Eocene tortoise beetles from the Green River Formation in Colorado,U.S.A. (Coleoptera: Chrysomelidae: Cassidinae)

Abstract The fossil history of leaf beetles (Chrysomelidae) is relatively poorly documented despite an abundance of available material. Of particular interest is the origin and radiation of the diverse tortoise beetles, a derived group within Cassidinae s.l. (=Cassidinae + Hispinae) defined by the exophagous life history and specialized morphology of the immature stages. Cassidinae is also a group with relatively few fossil records that can be assigned with any degree of certainty. Here we report two of the oldest definitive tortoise beetle fossils, Eosacantha delocranioides gen.n. et sp.n. and Denaeaspis chelonopsis gen.n. et sp.n. , from the Eocene Green River Formation (ca. 47 million years old) in northwestern Colorado, U.S.A. Owing to the fine level of preservation, many important features can be observed and are coded into the recent cladistic analysis for the subfamily. Phylogenetic analysis highlights that both genera have affinities with modern lineages, one restricted to the Old World and the other restricted to the Neotropics. Although Cassidinae as a whole extend into the Cretaceous, the available information suggests that the tortoise beetles perhaps originated and diversified during the Early Tertiary. As such, the morphological and biological transitions from the leaf‐mining hispiforms to the distinctive tortoise‐like cassidiforms, with their elaborate defensive larval shields and other unique behaviours, probably took place during the latest Paleocene or earliest Eocene. These Green River fossils are the oldest yet to document the specialized morphology associated with the transition in cassidine feeding and immature biology.     

Molecular phylogenetics and evolution of maternal care in Membracine treehoppers

The treehopper subfamily Membracinae (Insecta: Hemiptera: Membracidae) comprises the majority of genera and species diversity in the New World tropics. These treehoppers exhibit a wide range of social behaviors, making them an excellent group for studying patterns of social evolution in insects. However, to date the tribal and generic relationships have remained unclear. We reconstructed the phylogeny of the Membracinae using a combined mitochondrial (COI, COII, tRNA-Leu, and 12S) and nuclear (Wg) gene data set. A total of 2608 aligned nucleotide sites were obtained for 112 species, representing 25 of 38 currently recognized genera and all four tribes. A strict consensus of five equally parsimonious trees recovered the subfamily and three of its four tribes. The majority rule consensus tree derived from the Bayesian analyses based on the GTR+I+G and mixed-models recovered many clades shared with the parsimony trees and is identical to the single best tree inferred from maximum likelihood analysis, aside from the rearrangement of one node. A comparison of mitochondrial and nuclear genes indicated that Wg provided higher consistency index (CI), data decisiveness (DD), partitioned Bremer support (PBS) than any of the mitochondrial genes analyzed. The combined mitochondrial and nuclear DNA provide strong support for the monophyly of the subfamily and three of its four tribes (Aconophorini, Hoplophorionini, and Hypsoprorini). Membracini is paraphyletic with respect to Hoplophorionini and contains two lineages, the Membracini sensu strictu and the newly resurrected tribe Bolbonotini. Our analyses show that there is a strong phylogenetic component to the evolution of maternal care. Given the widespread occurrence of maternal care within the subfamily, this trait is estimated to have < or = 3 origins, two reversals, and one loss. Our results suggest that the evolution of maternal care in insects may not be as evolutionarily labile as previously thought.     

Phylogenetic relationships of egg parasitoids (Hymenoptera: Eulophidae) and correlated life history characteristics of their Neotropical Cassidinae hosts (Coleoptera, Chrysomelidae)

Egg parasitoids in the family Eulophidae (Hymenoptera) are an important part of the community of insects attacking neotropical leaf beetles in the subfamily Cassidinae. We present a phylogeny of 24 species of oophagous Eulophidae, using the 28S rDNA, the ITS2 rDNA and the cytochrome b genes, applying the NJ, MP, ML and Bayesian tree reconstruction methods on each data set. We ask whether the phylogenetic relationships of the parasitoids are linked with the life history characteristics of their beetle hosts. We show that cladogenesis in the oophagous Eulophidae does correlate with ovipositional behaviour and, to a lesser extent, diet and tribal affinities of their hosts. Additionally using two methods of simultaneous analysis of several gene sets: the Total Evidence method, and the construction of a "supertree" by Matrix Representation Parsimony (MRP), we substantiate the same major phylogenetic relationships within the Eulophidae.     

Maternal care and subsocial behaviour in spiders

While most spiders are solitary and opportunistically cannibalistic, a variety of social organisations has evolved in a minority of spider species. One form of social organisation is subsociality, in which siblings remain together with their parent for some period of time but disperse prior to independent reproduction. We review the literature on subsocial and maternal behaviour in spiders to highlight areas in which subsocial spiders have informed our understanding of social evolution and to identify promising areas of future research. We show that subsocial behaviour has evolved independently at least 18 times in spiders, across a wide phylogenetic distribution. Subsocial behaviour is diverse in terms of the form of care provided by the mother, the duration of care and sibling association, the degree of interaction and cooperation among siblings, and the use of vibratory and chemical communication. Subsocial spiders are useful model organisms to study various topics in ecology, such as kin recognition and the evolution of cheating and its impact on societies. Further, why social behaviour evolved in some lineages and not others is currently a topic of debate in behavioural ecology, and we argue that spiders offer an opportunity to untangle the ecological causes of parental care, which forms the basis of many other animal societies.     

Molecular phylogenetics and evolution of host plant use in the Neotropical rolled leaf 'hispine' beetle genus Cephaloleia (Chevrolat) (Chrysomelidae: Cassidinae)

Here, we report the results of a species level phylogenetic study of Cephaloleia beetles designed to clarify relationships and patterns of host plant taxon and tissue use among species. Our study is based on up to 2088bp of mtDNA sequence data. Maximum parsimony, maximum likelihood, and Bayesian methods of phylogenetic inference consistently recover a monophyletic Cephaloleia outside of a basal clade of primarily palm feeding species (the 'Arecaceae-feeding clade'), and C. irregularis. In all three analyses, the 'Arecaceae-feeding clade' includes Cephaloleia spp. with unusual morphological features, and a few species currently placed in other cassidine genera and tribes. All three analyses also recover a clade that includes all Zingiberales feeding Cephaloleia and most Cephaloleia species (the 'Zingiberales-feeding clade'). Two notable clades are found within the 'Zingiberales-feeding clade.' One is comprised of beetles that normally feed only on the young rolled leaves of plants in the families Heliconiaceae and Marantaceae (the 'Heliconiaceae & Marantaceae-feeding clade'). The other is comprised of relative host tissue generalist, primarily Zingiberales feeding species (the 'generalist-feeding clade'). A few species in the 'generalist-feeding clade' utilize Cyperaceae or Poaceae as hosts. Overall, relatively basal Cephaloleia (e.g., the 'Arecaceae clade') feed on relatively basal monocots (e.g., Cyclanthaceae and Arecaceae), and relatively derived Cephaloleia (e.g., the 'Zingiberales-feeding clade') feed on relatively derived monocots (mostly in the order Zingiberales). Zingiberales feeding and specialization on young rolled Zingiberales leaves have each apparently evolved just once in Cephaloleia.     

A molecular phylogenetic analysis of the Scarabaeinae (dung beetles)

The dung beetles (Scarabaeinae) include ca. 5000 species and exhibit a diverse array of morphologies and behaviors. This variation presumably reflects the adaptation to a diversity of food types and the different strategies used to avoid competition for vertebrate dung, which is the primary breeding environment for most species. The current classification gives great weight to the major behavioral types, separating the ball rollers and the tunnelers, but existing phylogenetic studies have been based on limited taxonomic or biogeographic sampling and have been contradictory. Here, we present a molecular phylogenetic analysis of 214 species of Scarabaeinae, representing all 12 traditionally recognized tribes and six biogeographical regions, using partial gene sequences from one nuclear (28S) and two mitochondrial (cox1, rrnL) genes. Length variation in 28S (588-621 bp) and rrnL (514-523 bp) was subjected to a thorough evaluation of alternative alignments, gap-coding methods, and tree searches using model-based (Bayesian and likelihood), maximum parsimony, and direct optimization analyses. The small-bodied, non-dung-feeding Sarophorus+Coptorhina were basal in all reconstructions. These were closely related to rolling Odontoloma+Dicranocara, suggesting an early acquisition of rolling behavior. Smaller tribes and most genera were monophyletic, while Canthonini and Dichotomiini each consisted of multiple paraphyletic lineages at hierarchical levels equivalent to the smaller tribes. Plasticity of rolling and tunneling was evidenced by a lack of monophyly (S-H test, p > 0.05) and several reversals within clades. The majority of previously unrecognized clades were geographical, including the well-supported Neotropical Phanaeini+Eucraniini, and a large Australian clade of rollers as well as tunneling Coptodactyla and Demarziella. Only three lineages, Gymnopleurini, Copris+Microcopris and Onthophagus, were widespread and therefore appear to be dispersive at a global scale. A reconstruction of biogeographical characters recovered 38-48 transitions between regions and an African origin for most lineages. Dispersal-vicariance analysis supported an African origin with links to all other regions and little back-migration. Our results provide a new synthesis of global-scale dung beetle evolution, demonstrating the great plasticity of behavioral and morphological traits and the importance of biogeographic distributions as the basis for a new classification.     

Life on the fly: phylogenetics and evolution of the helicopter damselflies (Odonata,Pseudostigmatidae)

Ingley, S.J., Bybee, S.M., Tennessen, K.J., Whiting, M.F. & Branham, M.A. (2012). Life on the fly: phylogenetics and evolution of the helicopter damselflies (Odonata, Pseudostigmatidae). —Zoologica Scripta, 41, 637–650. Helicopter damselflies (Odonata: Pseudostigmatidae) form a relatively small, yet highly specialized group of odonates, including the largest extant odonate (wingspan of ～190 mm). Pseudostigmatids are found throughout Central and South America, with the exception of one species that is found exclusively in East Africa. Pseudostigmatids oviposit exclusively in phytotelmata and forage on orb‐weaver spiders, which they pluck from webs. Pseudostigmatids also exhibit unique forms of both broad and narrow wings. Although the ecology of these behaviours and morphological features have been studied, their phylogenetic origins and evolutionary history are unknown. Here, we examine the origins of pseudostigmatid wing forms, oviposition in phytotelmata and spider feeding within a modern phylogenetic context, testing for single origins of each character. Phylogenetic analyses are based on 59 morphological characters and ～5 kb of sequence data. Our findings include a well‐supported monophyletic Pseudostigmatidae and Coryphagrion grandis as sister to the Neotropical genera. The genus Mecistogaster is paraphyletic, with Pseudostigma nested within the clade. The genus Microstigma is supported as monophyletic and forms a sister group relationship to the clade of Megaloprepus and Anomisma. The sister group relationship to Pseudostigmatidae is less clear. On the basis of this phylogenetic analysis, we propose three new tribes (Coryphagrionini, Microstigmatini and Mecistogastrini). As Pseudostigmatidae is monophyletic, the behaviour of gleaning spiders from webs appears to derive from a single origin. There are two origins of broad wings within Pseudostigmatidae. Oviposition in phytotelmata most certainly evolved multiple times within Coenagrionoidea. These findings provide new insights into pseudostigmatid evolution that can be used to generate hypotheses regarding behaviour and morphological adaptation in this unique and threatened group of damselflies.     

利用低拷贝核基因重建菊科紫菀亚科族间系统发育关系

紫菀亚科(Asteroideae)是菊科最大的一个亚科, 包含的种数多于被子植物的绝大多数科。目前, 紫菀亚科族间的系统发育关系主要依赖于叶绿体基因信息, 但是叶绿体基因为单亲遗传, 并不能完整反映进化历史。鉴于杂交现象在菊科普遍存在, 故利用核基因可以反映更完整的紫菀亚科进化历史。该研究首次使用从转录组数据(20个新测+11个从NCBI数据库下载)中筛选出的47个直系同源低拷贝核基因来研究紫菀亚科的系统发育关系, 共选取了29个物种, 代表了紫菀亚科20个族中的13个族。用超矩阵分析方法和溯祖推测分析方法各获得了1个稳定的紫菀亚科系统树, 每个树上绝大多数分支都得到了高度支持, 且2个树之间没有明显的冲突。新的紫菀亚科族间系统发育关系揭示了千里光超族应并入紫菀超族, 春黄菊族可能是千里光族与紫菀族杂交起源的, 金鸡菊族很可能也是杂交起源的。该研究结果显示低拷贝核基因可以更好地解决科以下分类阶元的系统发育关系, 对菊科乃至被子植物其它科的系统发育研究具有重要的借鉴意义。     

Higher level molecular phylogeny of darkling beetles (Coleoptera: Tenebrionidae)

Insect diversity represents about 60% of the estimated million‐and‐a‐half described eukaryotic species worldwide, yet comprehensive and well‐resolved intra‐ordinal phylogenies are still lacking for the majority of insect groups. This is the case especially for the most species‐rich insect group, the beetles (Coleoptera), a group for which less than 4% of the known species have had their DNA sequenced. In this study, we reconstruct the first higher level phylogeny based on DNA sequence data for the species‐rich darkling beetles, a family comprising at least 20 000 species. Although amongst all families of beetles Tenebrionidae ranks seventh in terms of species diversity, the lack of knowledge on the phylogeny and systematics of the group is such that its monophyly has been questioned (not to mention those of the subfamilies and tribes contained within it). We investigate the evolutionary history of Tenebrionidae using multiple phylogenetic inference methods (Bayesian inference, maximum likelihood and parsimony) to analyse a dataset consisting of eight gene fragments across 404 taxa (including 250 tenebrionid species). Although the resulting phylogenetic framework only encompasses a fraction of the known tenebrionid diversity, it provides important information on their systematics and evolution. Whatever the methods used, our results provide strong support for the monophyly of the family, and highlight the likely paraphyletic or polyphyletic nature of several important tenebrionid subfamilies and tribes, notably the polyphyletic subfamilies Diaperinae and Tenebrioninae that clearly require substantial revision in the future. Some interesting associations in several groups are also revealed by the phylogenetic analyses, such as the pairing of Aphtora Bates with Phrenapatinae. Furthermore this study advances our knowledge of the evolution of the group, providing novel insights into much‐debated theories, such as the apparent relict distribution of the tribe Elenophorini.     

Evolutionary constraints in hind wing shape in Chinese dung beetles (Coleoptera: Scarabaeinae)

This study examines the evolution hindwing shape in Chinese dung beetle species using morphometric and phylogenetic analyses. Previous studies have analyzed the evolution of wing shape within a single or very few species, or by comparing only a few wing traits. No study has analyzed wing shape evolution of a large number of species, or quantitatively compared morphological variation of wings with proposed phylogenetic relationships. This study examines the morphological variation of hindwings based on 19 landmarks, 119 morphological characters, and 81 beetle species. Only one most parsimonious tree (MPT) was found based on 119 wing and body characters. To better understand the possible role of the hindwing in the evolution of Scarabaeinae, additional phylogenetic analyses were proposed based on the only body features (106 characters, wing characters excluded). Two MPT were found based on 106 body characters, and five nodes were collapsed in a strict consensus. There was a strong correlation between the morphometric tree and all phylogenetic trees (r>0.5). Reconstructions of the ancestral wing forms suggest that Scarabaeinae hindwing morphology has not changed substantially over time, but the morphological changes that do occur are focused at the base of the wing. These results suggest that flight has been important since the origin of Scarabaeinae, and that variation in hindwing morphology has been limited by functional constraints. Comparison of metric disparity values and relative evolutionary sequences among Scarabaeinae tribes suggest that the primitive dung beetles had relatively diverse hindwing morphologies, while advanced dung beetles have relatively similar wing morphologies. The strong correlation between the morphometric tree and phylogenetic trees suggest that hindwing features reflect the evolution of whole body morphology and that wing characters are suitable for the phylogenetic analyses. By integrating morphometric and cladistic approaches, this paper sheds new light on the evolution of dung beetle hind wings.     

New defensive chemical data for ground beetles (Goleoptera: Carabidae): interpretations in a phylogenetic framework

First reports of major defensive chemicals for ground beetles representing four tribes include: Morionini (formic acid), Dercylini (methacrylic and tiglic acids), Catapieseini (formic acid and decyl acetate) and Perigonini (formic acid and dccyl acetate). Multiple species from Loxandrini were sampled and, shown to contain formic acid, not salicylaldehyde as previously reported. Several hexenoic acid compounds were found in the clivinine genus Schizogenius representing a third class of chemicals for that tribe. Salicylaldehyde was found for the first time in a species of Oodini. Additional species from Pterostichini, Patrobini and Odacanthini were sampled and the results were found to be consistent with previously published reports. The taxonomic distribution of defensive secretions is reviewed for tribes across the family Carabidae. The simultaneous occurrence of hydrocarbons and formic acid is noted in phylogenetically more derived carabids. By mapping chemical classes onto a phylogenetic hypothesis, it is shown that formic acid or other relatively strong irritants are correlated with tribes having a high species diversity in tropical regions, whereas tribes exhibiting higher diversity in temperate regions use milder saturated/unsaturatcd earboxylic acids. Based on this phylogenetic interpretation, the evolution and maintenance of formic acid is interpreted as the result of predation pressures and possibly the evolution of chemical mimicry.     

Subsociality in halictine bees

To look for the occurrence and the significance of brood care in social evolution, I reared six eusocial halictine bee species in laboratory cages enabling the observation of intranest behaviour: Lasioglossum (Evylaeus) laticeps, L. (E.) pauxillum, L. (E.) nigripes, L. (E.) euboeensis, Halictus (Halictus) scabiosae and L. (E.) fulvicorne. All of them were subsocial, each mother caring for her brood. Brood cells were sealed after oviposition with earthen plugs; they were then reopened, visited and closed again. These observations plus the reports in the literature on eleven eusocial species indicate that seventeen species of eusocial halictine bees provide parental care, i.e. are subsocial. Brood care, subsociality, is strongly associated with eusociality. To study reversal from eusociality to subsociality, I have reared the non-eusocial form of two species within which there are or have been eusocial forms: Halictus (H.) rubicundus and Lasioglossum (E.) fratellum. They are secondarily solitary, having lost worker brood. However, both species still show brood care. This suggests that in transitions to eusociality, brood care antedated eusociality. To further examine this issue I reared two truly solitary species that are not derived from eusocial ancestors: Lasioglossum (E.) villosulum and L. (L.) quadrinotatum. Unlike secondarily solitary species, females of both these species close their brood cells after oviposition and ignore their progeny thereafter. This association strongly suggests that the subsocial route with maternal brood care is the route to eusociality in halictine bees.     

Unexpected reactions of a generalist predator towards defensive devices of cassidine larvae (Coleoptera, Chrysomelidae)

Studies of multitrophic interactions show that insect faeces may act as a defensive device against predators, as kairomone source for attraction of antagonists and as a significant energy source for micro-organisms. In the present study, we investigated effects of larval faeces from leaf beetles of the subfamiliy Cassidinae towards a generalist predator, the ant Myrmica rubra. Most cassidine larvae collect their faeces together with exuviae as so-called abdominal defensive shields on two movable spines at the posterior tip. The effects of these abdominal shields towards M. rubra were studied in three cassidine species, which feed mono- or oligophagously upon tansy (Chrysanthemum vulgare): Cassida denticollis and C. sanguinosa which possess such faecal shields and, for comparison, C. stigmatica with shields made of exuviae only (=skin shield). Bioassays revealed that larvae with both faecal and skin shields were attacked by the ant M. rubra more often than larvae whose shields had been removed. This attractiveness of shields towards ants contrasts with other studies, which found that abdominal shields of chrysomelid larvae act as defensive mechanisms against generalist predators like ants. To characterize the attractive cues of the shields, we studied possible chemical and physical stimuli. Olfactometer bioassays with M. rubra and chemical analyses revealed that plant-derived volatiles from faecal shields of C. denticollis attracted the ant, whereas odour from skin shields of C. stigmatica did not. Skin shields also emitted volatiles which derived from tansy, but in much lower quantities. Exclusion of contact to surface chemicals of a faecal shield reduced the ants' aggressive behaviour, whereas a change in the moisture content of a faecal shield had no influence. Visual stimuli cannot be ruled out as enhancing the ants' reaction towards faecal shields with their attractive volatiles, and are suggested to play a major role in the ants' response towards skin shields. This novel attractive effect of the abdominal shields of cassidine larvae is discussed, especially with respect to host plant chemistry and possible functions of the shields that might outweigh the negative consequences of the attraction of the predator M. rubra. Received: 22 June 1998 / Accepted: 2 November 1998     

Body Size Diversity and Frequency Distributions of Neotropical Cichlid Fishes (Cichliformes: Cichlidae: Cichlinae)

Body size is an important correlate of life history, ecology and distribution of species. Despite this, very little is known about body size evolution in fishes, particularly freshwater fishes of the Neotropics where species and body size diversity are relatively high. Phylogenetic history and body size data were used to explore body size frequency distributions in Neotropical cichlids, a broadly distributed and ecologically diverse group of fishes that is highly representative of body size diversity in Neotropical freshwater fishes. We test for divergence, phylogenetic autocorrelation and among-clade partitioning of body size space. Neotropical cichlids show low phylogenetic autocorrelation and divergence within and among taxonomic levels. Three distinct regions of body size space were identified from body size frequency distributions at various taxonomic levels corresponding to subclades of the most diverse tribe, Geophagini. These regions suggest that lineages may be evolving towards particular size optima that may be tied to specific ecological roles. The diversification of Geophagini appears to constrain the evolution of body size among other Neotropical cichlid lineages; non-Geophagini clades show lower species-richness in body size regions shared with Geophagini. Neotropical cichlid genera show less divergence and extreme body size than expected within and among tribes. Body size divergence among species may instead be present or linked to ecology at the community assembly scale.     

Molecular phylogeny of rootworms and related galerucine beetles (Coleoptera: Chrysomelidae)

The Galerucinae (Coleoptera: Chrysomelidae) sensu stricto (true galerucines) comprise a large assemblage of diverse phytophagous beetles containing over 5000 described species. Together with their sister taxon, the flea beetles, which differ from true galerucines by having the hind femora usually modified for jumping, the Galerucinae sensu lato comprises over 13 000 described species and is the largest natural group within the Chrysomelidae. Unlike the flea beetles, for which robust hierarchical classification schemes have not been erected, an existing taxonomic structure exists for the true galerucines, based mostly on the works of the late John Wilcox. In the most recent taxonomic list of the Galerucinae sensu stricto, five tribes were established comprising 29 sections housing 488 genera. The majority of the diversity within these tribes is found within the tribe Luperini, in which two genera, Monolepta and Diabrotica, are known to contain over 500 described species. Here, we extend the work from previous phylogenetic studies of the Galerucinae by analysing four amplicons from three gene regions (18S and 28S rRNA; COI) representing 249 taxa, providing the largest phylogenetic analysis of this taxon to date. Using two seven‐state RNA models, we combine five maximum likelihood models (RNA + DNA for the rRNAs; three separate DNA models for the COI codon positions) for these partitions and analyse the data under likelihood using Bayesian inference. The results of these two analyses are compared with those from equally weighted parsimony. Instead of choosing the results from one optimality criterion over another, either based on statistical support, tree topology or philosophical predisposition, we elect to draw attention to the similar results produced by all three analyses, illustrating the robustness of the data to these different analytical methods. In general, the results from all three analyses are consistent with each other and previous molecular phylogenetic reconstructions for Galerucinae, except that increased taxon sampling for several groups, namely the tribes Hylaspini and Oidini, has improved the phylogenetic position of these taxa. As with previous analyses, under‐sampled taxa, such as the Old World Metacyclini and all sections of the subtribe Luperina, continue to be unstable, with the few taxa representing these groups fluctuating in their positions based on the implemented optimality criterion. Nonetheless, we report here the most comprehensive phylogenetic estimation for the Galerucinae to date.     

A comprehensive molecular phylogeny of tiger beetles (Coleoptera,Carabidae, Cicindelinae)

Tiger beetles are a remarkable group that captivates amateur entomologists, taxonomists and evolutionary biologists alike. This diverse clade of beetles comprises about 2300 currently described species found across the globe. Despite the charisma and scientific interest of this lineage, remarkably few studies have examined its phylogenetic relationships with large taxon sampling. Prior phylogenetic studies have focused on relationships within cicindeline tribes or genera, and none of the studies have included sufficient taxon sampling to conclusively examine broad species patterns across the entire subfamily. Studies that have attempted to reconstruct higher‐level relationships of Cicindelinae have yielded conflicting results. Here, we present the first taxonomically comprehensive molecular phylogeny of Cicindelinae to date, with the goal of creating a framework for future studies focusing on this important insect lineage. We utilized all available published molecular data, generating a final concatenated dataset including 328 cicindeline species, with molecular data sampled from six protein‐coding gene fragments and three ribosomal gene fragments. Our maximum‐likelihood phylogenetic inferences recover Cicindelinae as sister to the wrinkled bark beetles of the subfamily Rhysodinae. This new phylogenetic hypothesis for Cicindelinae contradicts our current understanding of tiger beetle phylogenetic relationships, with several tribes, subtribes and genera being inferred as paraphyletic. Most notably, the tribe Manticorini is recovered nested within Platychilini including the genera Amblycheila Say, Omus Eschscholtz, Picnochile Motschulsky and Platychile Macleay. The tribe Megacephalini is recovered as paraphyletic due to the placement of the monophyletic subtribe Oxycheilina as sister to Cicindelini, whereas the monophyletic Megacephalina is inferred as sister to Oxycheilina, Cicindelini and Collyridini. The tribe Collyridini is paraphyletic with the subtribes Collyridina and Tricondylina in one clade, and Ctenostomina in a second one. The tribe Cicindelini is recovered as monophyletic although several genera are inferred as para‐ or polyphyletic. Our results provide a novel phylogenetic framework to revise the classification of tiger beetles and to encourage the generation of focused molecular datasets that will permit investigation of the evolutionary history of this lineage through space and time.     

Phylogenetic interrelationships,taxonomy, and reductive evolution in the Neotropical electric fish genus Hypopygus (Teleostei,Ostariophysi, Gymnotiformes)

A phylogenetic reconstruction of the Neotropical electric fish genus Hypopygus based on 47 parsimony‐informative morphological characters is presented. A series of synapomorphies support the hypothesis of monophyly of Hypopygus, and partially resolve species‐level relationships within the genus. Hypopygus species are recognized here as miniaturized fishes based on two criteria; first, a derived condition of diminutive body size, and; second, the presence of a suite of reductive morphological characters, including partial or total losses, simplifications, and reductions of the anal‐fin rays, scales, cranial bones, and laterosensory canal system. Reductive characters associated with miniaturization comprise 45% of the total number of characters in the phylogenetic reconstruction of the genus. Miniaturization and reductive morphological evolution in Hypopygus are discussed here in the phylogenetic context. A taxonomic revision of Hypopygus is presented, in which five new species are described, two species previously assigned to the genus are redescribed, and a single known species of Stegostenopos is redescribed and included in Hypopygus as a junior synonym. Distribution maps and a key for all eight valid species of Hypopygus are provided, based on the examination of 5014 catalogued museum specimens. © 2011 The Linnean Society of London, Zoological Journal of the Linnean Society, 2011, 163 , 1096–1156.     

Phylogeny and evolutionary history of the blister beetles (Coleoptera, Meloidae)

Meloid beetles are well characterised by both morphological and biological features. Previous phylogenetic hypotheses based on morphological characters assumed the repeated parallel evolution of complex biological novelties. In this work relationships among several taxa of the four subfamilies and almost all tribes representing meloid diversity are examined by using mitochondrial (16S) and nuclear (ITS2) DNA sequences, in 25 genera (using Anthicidae as outgroup). Secondary structure of 16S and ITS2 rRNAs were modelled. ITS2 structure represents a synapomorphic condition for the family and informative characters at the tribal level. Phylogenetic hypotheses based on separate and combined analysis of the 16S and ITS2 rDNA sequences, and morpho-biological characters were tested, and compared with previous morphological classifications. Molecular dating allowed an outline of the main steps of the evolutionary history of Meloidae, which evolved during Early Cretaceous and then radiated considerably with the adoption of hypermetaboly and parasitic behaviour, and with repeated, parallel evolution of larval phoresy on its hosts.     

Oil-producing flowers within the Iridoideae (Iridaceae): evolutionary trends in the flowers of the New World genera

Background and Aims

Oil-producing flowers related to oil-bee pollination are a major innovation in Neotropical and Mexican Iridaceae. In this study, phylogenetic relationships were investigated among a wide array of New World genera of the tribes Sisyrinchieae, Trimezieae and Tigridieae (Iridaceae: Iridoideae) and the evolution of floral glandular structures, which are predominantly trichomal elaiophores, was examined in relation to the diversification of New World Iridaceae.

Methods

Phylogenetic analyses based on seven molecular markers obtained from 97 species were conducted to produce the first extensive phylogeny of the New World tribes of subfamily Iridoideae. The resulting phylogenetic hypothesis was used to trace the evolutionary history of glandular structures present in the flowers of numerous species in each tribe. Hypotheses of differential diversification rates among lineages were also investigated using both topological and Binary-State Speciation and Extinction methods.

Key Results and Conclusions

Floral glandular structures and especially trichomal elaiophores evolved multiple times independently in the American tribes of Iridoideae. The distribution pattern of species displaying glandular trichomes across the phylogeny reveals lability in the pollination system and suggests that these structures may have played a significant role in the diversification of the Iridoideae on the American continent.