Sven Bradler

Sven Bradler
Georg-August-Universität Göttingen | GAUG · Department of Morphology, Systematics, and Evolutionary Biology

Dr.

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85
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2,245
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January 2010 - present

Publications

Publications (85)
Article
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The genus Agathemera Stål, 1875 comprises eight species of robust wingless stick insects occurring largely on the slopes of the Andes across Chile, Argentina, and Bolivia, although some species can be found downward to coastal forests (Dominguez et al., 2009; Vera et al., 2012) (Fig. 1). These insects emit a repellant secretion from their large pro...
Article
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Although species are central units for biological research, recent findings in genomics are raising awareness that what we call species can be ill-founded entities due to solely morphology-based, regional species descriptions. This particularly applies to groups characterized by intricate evolutionary processes such as hybridization, polyploidy, or...
Article
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Background Phasmatodea are well known for their ability to disguise themselves by mimicking twigs, leaves, or bark, and are therefore commonly referred to as stick and leaf insects. In addition to this and other defensive strategies, many phasmatodean species use paired prothoracic repellent glands to release defensive chemicals when disturbed by p...
Preprint
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Independent evolution of similar traits in lineages inhabiting similar environments (convergent evolution) is often taken as evidence for adaptation by natural selection, and used to illustrate the predictability of evolution. Yet convergence is rarely perfect. Environments may not be as similar as they appear (e.g., habitats scored the same may be...
Preprint
Full-text available
Background Phasmatodea are well known for their ability to disguise themselves by mimicking twigs, leaves, or bark, and are therefore commonly referred to as stick and leaf insects. In addition to this and other defensive strategies, many phasmatodean species use prothoracic repellent glands to release defensive chemicals when disturbed by predator...
Article
Full-text available
With the recent advance in molecular phylogenetics focused on the leaf insects (Phasmatodea, Phylliidae), gaps in knowledge are beginning to be filled. Yet, shortcomings are also being highlighted, for instance, the unveiling of numerous undescribed phylliid species. Here, some of these taxa are described, including Phyllium iyadaon sp. nov. from M...
Article
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Phylliidae are herbivorous insects exhibiting impressive cryptic masquerade and are colloquially called “walking leaves”. They imitate angiosperm leaves and their eggs often resemble plant seeds structurally and in some cases functionally. Despite overall morphological similarity of adult Phylliidae, their eggs reveal a significant diversity in ove...
Article
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Seit Beginn der Grass-Root-Initiative #IchBinHanna um die prekären Beschäftigungsverhältnisse von Forschenden unterhalb der Professur sind weit über 300 Diskussionsbeiträge in Zeitungen, Büchern, Fernsehsendungen und Podcasts erschienen [1]. Auch der VBIO berichtete über die zunehmend besorgniserregende Situation des wissenschaftlichen Personals [2...
Data
Additional file 4. Supplementary discussion of phasmatodean phylogenetic relationships.
Data
Additional file 1: Figure S1. Maximum Likelihood phylogeny based on the best-scoring tree with nodal support (UFBoot and SH-aLRT) at each node (Files S1 and S2). Lock symbols represent constrained clades (B1 constraints). Character states for wings and ocelli are depicted at tips for females and males. Figure S2. Ancestral state reconstruction...
Data
Additional file 2: File S1. Best scoring ML tree with UFBoot support values in newick format. File S2. Alternative ML tree with SH-aLRT support values in newick format. File S3. BI tree with B1 constraints in nexus format. File S4. BI tree with B2 constraints in nexus format. File S5. BI tree with B3 constraints in nexus format. File S6. Final conc...
Data
Additional file 3: Table S1. Phylogenetic signal. Results of phylogenetic signal estimations using D statistics and Pagel's lambda, and the comparison of the observed number of evolutionary transitions for each trait against a randomised character matrix. Wings = presence of wings (macropterous or micropterous), Flight = potential capability of fli...
Article
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Background The re-evolution of complex characters is generally considered impossible, yet, studies of recent years have provided several examples of phenotypic reversals shown to violate Dollo’s law. Along these lines, the regain of wings in stick and leaf insects (Phasmatodea) was hypothesised to have occurred several times independently after an...
Article
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Die #IchBinHanna-Debatte des vergangenen Jahres hat die vielfach prekären Beschäftigungsverhältnisse wissenschaftlichen Personals sowohl national als auch international mit großer Wucht in die Medien transportiert. Mittlerweile ist das Thema auf der politischen Bühne angekommen. Die Diskussion der Versäumnisse und möglicher Lösungsansätze ist in vo...
Preprint
Full-text available
The re-evolution of complex characters is generally considered impossible, yet, studies of recent years have provided several examples of phenotypic reversals shown to violate Dollo’s law. Along these lines, the regain of wings in stick and leaf insects (Phasmatodea) was hypothesised to have occurred several times independently after an ancestral l...
Article
Full-text available
The insect order Phasmatodea is known for large slender insects masquerading as twigs or bark. In contrast to these so-called stick insects, the subordinated clade of leaf insects (Phylliidae) are dorso-ventrally flattened and therefore resemble leaves in a unique way. Here we show that the origin of extant leaf insects lies in the Australasian/Pac...
Article
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The morphology of the antennal hearts in the head of Phasmatodea and Embioptera was investigated with particular reference to phylogenetically relevant key taxa. The antennal circulatory organs of all examined species have the same basic construction: they consist of antennal vessels that are connected to ampullae located in the head near the anten...
Article
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Stick and leaf insects (Phasmatodea) are large terrestrial herbivorous arthropods known for masquerading as plant parts such as bark, twigs and leaves. Their evolutionary history is largely shaped by convergent evolution associated with adaptive radiations on geographically isolated landmasses that have repeatedly generated ground-dwelling ecomorph...
Article
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While the leaf insects (Phylliidae) are a well-supported group within Phasmatodea, the genus Phyllium Illiger, 1798 has repeatedly been recovered as paraphyletic. Here, the Phyllium (Phyllium) celebicum species group is reviewed and its distinctiveness from the remaining Phylliini genera and subgenera in a phyloge- netic context based on morphologi...
Article
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Stick and leaf insects are an emerging model system for exploring evolutionary biology, with a vibrant and increasing community of scientists dedicated to using these insects as research tools. In 2016, part of this community met in Orlando, Florida (USA) during the 25th International Congress of Entomology (ICE) and participated at a symposium hel...
Article
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Within the last two years, the leaf insects of the genus Phyllium of both the islands of Java and Sumatra have been reviewed extensively based on morphological observations. However, cryptic species which cannot be differentiated morphologically may be present among the various populations. Since it has frequently been demonstrated that analyses ba...
Article
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Phasmatodea comprises over 3,000 extant species and stands out as one of the last remaining insect orders for which a robust, higher-level phylogenetic hypothesis is lacking. New research suggests that the extant diversity is the result of a surprisingly recent and rapid radiation that has been difficult to resolve with standard Sanger sequence dat...
Article
Published in Zoologica — Original Contributions to Zoology (ISSN 0044-5088): Abstract Attachment devices with different microstructure and surface microstructure evolved on the tarsi of hexapods. In biomechanical studies it was shown for a few species that different types of structure have different attachment properties. However, it is yet unclea...
Article
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Achrioptera is a taxon of extremely large and exceptionally colorful stick insects endemic to Madagascar and the Comoros Archipelago. We studied the phylogenetic position of the Achriopterini, comprising the genera Achrioptera and Glawiana, based on a multigene phylogeny and concluded that it is a sister group to other Madagascan phasmids (Anisacan...
Article
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Stick and leaf insects (Phasmatodea) are large, tropical, predominantly nocturnal herbivores, which exhibit extreme masquerade crypsis, whereby they morphologically and behaviorally resemble twigs, bark, lichen, moss, and leaves. Females employ a wide range of egg-laying techniques, largely corresponding to their ecological niche, including droppin...
Article
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Insects have developed specialized structures on their feet for adhering to surfaces, with stick and leaf insects or Phasmatodea exhibiting an unexpectedly high diversity of these structures. In Phasmatodea, attachment on different substrates is achieved by two types of pads on the legs: the euplantulae on the tarsomeres and the arolium on the pret...
Chapter
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Stick and leaf insects (order Phasmatodea) are a mesodiverse lineage of large terrestrial herbivores with predominantly tropical distribution and few species inhabiting more temperate regions. The phylogenetic position of the Phasmatodea among the lower neopteran insects has been debated for many years, with basically every orthopteroid insect orde...
Article
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Orthoptera, or Saltatoria, represents the most diverse insect group among the lower neopterans or Polyneoptera. The present study provides a detailed comparative investigation of the skeletal and muscular thoracic morphology of 23 orthopteran species. For the first time, we investigate unstudied ensiferan key taxa including Gryllacrididae (raspy cr...
Article
Schizodactylidae, splay-footed or dune crickets, represents a distinct lineage among the highly diverse orthopteran subgroup Ensifera (crickets, katydids and allies). Only two extant genera belong to the Schizodactylidae: the winged Eurasian genus Schizodactylus, whose ecology and morphology is well documented, and the wingless South African Comicu...
Article
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Genes acquired by horizontal transfer are increasingly being found in animal genomes. Understanding their origin and evolution requires knowledge about the phylogenetic relationships from both source and recipient organisms. We used RNASeq data and respective assembled transcript libraries to trace the evolutionary history of polygalacturonase (pec...
Article
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Background Secondary winglessness is a common phenomenon found among neopteran insects. With an estimated age of at least 140 million years, the cave crickets (Rhaphidophoridae) form the oldest exclusively wingless lineage within the long-horned grasshoppers (Ensifera). With respect to their morphology, cave crickets are generally considered to rep...
Article
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Phasmatodea, commonly known as stick and leaf insects, represents a mesodiverse lineage of polyneopteran insects, standing out as one of the last traditional insect orders for which a robust, higher-level phylogenetic hypothesis is lacking. Recent studies demonstrated that often geographical distribution rather than traditional classifi cation and...
Article
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Background: The study of islands as model systems plays a key role in understanding many evolutionary processes. Knowledge of the historical events leading to present-day island communities is pivotal for exploring fundamental mechanisms of speciation and adaptation. The remote Mascarene archipelago (Mauritius, Réunion, Rodrigues), considered to be...
Article
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An area around Brje pri Komnu in the Karst region of Slovenia has been visited between 1995 and 2009 usually for about 10 days in June or July. During these visits Orthoptera have been studied in some detail emphasizing species identification and acoustic behaviour. A species list is provided and - focussing on sibling species - some identification...
Article
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Stem-group Phasmatodea, known as the Susumanioidea, are previously established from the Jurassic through the Paleocene. Here, we extend this record to the early Eocene with five new fossils: two forewings from the Klondike Mountain Formation exposures at Republic, Washington, United States of America, and three partially complete specimens from the...
Article
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The eggs of stick and leaf insects (Phasmatodea) bear strong resemblance to plant seeds and are commonly dispersed by females dropping them to the litter. Here we report a novel egg-deposition mode for Phasmatodea performed by an undescribed Vietnamese species of the enigmatic subfamily Korinninae that produces a complex egg case (ootheca), contain...
Article
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We describe two new species of Clitarchus Stål from Northland, New Zealand. Clitarchus rakauwhakanekeneke sp. nov. is described from the Poor Knights Islands and Clitarchus tepaki sp. nov. is described from the Te Paki / North Cape area and the Karikari Peninsula at the northernmost tip of New Zealand. Two new synonymies are proposed including Cli-...
Article
The phasmatodeans or stick and leaf insects are considered to be a mesodiverse insect order with more than 3000 species reported mainly from the tropics. The stick insect subfamily Necrosciinae comprises approximately 700 described species in more than 60 genera from the Oriental and Australian region, forming the most species-rich subfamily tradit...
Article
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Fossil species that can be conclusively identified as stem-relatives of stick- and leaf-insects (Phasmatodea) are extremely rare, especially for the Mesozoic era. This dearth in the paleontological record makes assessments on the origin and age of the group problematic and impedes investigations of evolutionary key aspects, such as wing development...
Conference Paper
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Ensiferans (crickets and katydids) form an extremely diverse and species-rich lineage among the “Lower Neoptera” or Polyneoptera. Numerous studies based on morphological and molecular data have led to largely incongruent results, and the phylogenetic relationships within the Ensifera still remain unresolved. For instance, the phylogenetic affinitie...
Article
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In a morphological ontology the expert's knowledge is represented in terms, which describe morphological structures and how these structures relate to each other. With the assistance of ontologies this expert knowledge is made processable by machines, through a formal and standardized representation of terms and their relations to each other. The r...
Article
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The origin of winged insects (Pterygota), one of the planet’s most diverse lineages of organisms, is assumed to lie in the Devonian, but as an extremely sparse fossil record impedes our understanding of their early diversification, any well-preserved insect fossil from this time would be particularly valuable1. Garrouste et al.2 described an arthro...
Article
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Friedemann K., Wipfler B., Bradler S. and Beutel R.G. 2011. On the head morphology of Phyllium and the phylogenetic relationships of Phasmatodea (Insecta). —Acta Zoologica (Stockholm) 00: 1–16. External and internal head structures of Phyllium siccifolium are described in detail. The findings are compared with conditions found in other phasmatodean...
Article
Full-text available
The origin of winged insects (Pterygota), one of the planet's most diverse lineages of organisms, is assumed to lie in the Devonian, but as an extremely sparse fossil record impedes our understan-ding of their early diversification, any well-preserved insect fossil from this time would be particularly valuable 1 . Garrouste et al. 2 described an ar...
Article
A detailed study of the exoskeleton and musculature of the phallic organ of Oxyartes lamellatus (Kirby, 1904) (Phasmatodea: Necrosciinae) is here presented – the first study of this kind for Phasmatodea. The asymmetrical phallic organ shows a highly complicated morphology, with several sclerites and many formative structural elements, of which a sc...
Article
The recently described Gallophasma longipalpis from Earliest Eocene French amber is considered to be a key fossil taxon that phylogenetically links 'Mesozoic Phasmatodea' with extant stick and leaf insects. However, our re-evaluation of the evidence provided for this placement reveals that Gallophasma does not possess any unambiguous synapomorphies...
Article
The recently described Gallophasma longipalpis from Earliest Eocene French amber is considered to be a key fossil taxon that phylogenetically links 'Mesozoic Phasmatodea' with extant stick and leaf insects. However, our re-evaluation of the evidence provided for this placement reveals that Gallophasma does not possess any unambiguous synapomorphies...
Article
The Lanceocercata are a clade of stick insects (Phasmatodea) that have undergone an impressive evolutionary radiation in Australia, New Caledonia, the Mascarene Islands and areas of the Pacific. Previous research showed that this clade also contained at least two of the nine New Zealand stick insect genera. We have constructed a phylogeny of the La...
Article
Full-text available
We describe a new genus and species of stick insect from Northland, New Zealand, Tepakiphasma ngatikuri, gen. nov., sp. nov. We have classifi ed this genus as a member of Phasmatidae, Phasmatinae, Acanthoxylini, and due to the presence of certain key synapomorphies it is phylogenetically placed within the Australasian clade Lanceocercata. A number...
Chapter
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Kommen sie nie zurück? Sie – gemeint sind Merkmale und Eigenschaften unserer Vorfahren oder der Vorfahren einer jeden anderen Spezies – Merkmale und Eigenschaften, die im Zuge der Evolution verloren gingen. Sie gingen aber nicht verloren, wie man etwa seine Brieftasche verliert. Diese Merkmale waren dem Besitzer einfach nicht mehr von Nutzen, sonde...
Article
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The 'tree lobsters' are an enigmatic group of robust, ground-dwelling stick insects (order Phasmatodea) from the subfamily Eurycanthinae, distributed in New Guinea, New Caledonia and associated islands. Its most famous member is the Lord Howe Island stick insect Dryococelus australis (Montrouzier), which was believed to have become extinct but was...
Conference Paper
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Similarities between species can arise in two fundamentally different ways. Either each species has retained a comparable trait from their common ancestor, or each has acquired it independently. Although the first possibility might seem far more likely, convergence is a common phenomenon. Here we present evidence for the independent origin of the “...
Article
Full-text available
Stick and leaf insects (insect order Phasmatodea) are represented primarily by twig-imitating slender forms. Only a small percentage (≈1%) of extant phasmids belong to the leaf insects (Phylliinae), which exhibit an extreme form of morphological and behavioral leaf mimicry. Fossils of phasmid insects are extremely rare worldwide. Here we report the...
Article
Recently several conflicting hypotheses concerning the basal phylogenetic relationships within the Phasmatodea (stick and leaf insects) have emerged. In previous studies, musculature of the abdomen proved to be quite informative for identifying basal taxa among Phasmatodea and led to conclusions regarding the basal splitting events within the group...
Chapter
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Article
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The evolution of wings was the central adaptation allowing insects to escape predators, exploit scattered resources, and disperse into new niches, resulting in radiations into vast numbers of species. Despite the presumed evolutionary advantages associated with full-sized wings (macroptery), nearly all pterygote (winged) orders have many partially...
Conference Paper
The euphasmatodean slick and leaf insects comprise all Phasmatodea with the exception of the Nearctic genus Timema (Bradler S 1999 Cour Forsch-Inst Senckenberg 215: 43). Their eggs are hard-shelled and strongly resemble seeds. In the majority of species the eggs are flicked actively from the ovipositor or passively dropped to the ground (Bedford GO...
Article
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Die Gespenstschrecken oder Phasmatodea sind eine etwa 3000 Arten umfassende Teilgruppe der geflügelten Insekten, die weltweit in allen tropischen und subtropischen Gebieten beheimatet ist. Ihre Stellung im System der Insekten wird kontrovers diskutiert und ist bislang weitgehend ungeklärt (KRISTENSEN 1975). Gleiches gilt für die internen Verwandtsc...