Integrative taxonomy of platygastrine wasps of Germany

In the context of the sixth mass extinction, our understanding of insect decline is severely limited by a lack of information on biodiversity. Many highly abundant and diverse insect groups remain unidentifiable to species or even to genus. The parasitoid wasp superfamily Platygastroidea is one such dark taxon. The taxonomic impediment is especially severe in the Palearctic Platygastrinae due to the proliferation of names with vague concepts. Platygastrine wasps parasitize the hyper-diverse Cecidomyiidae (Diptera), suggesting that their species richness may be correspondingly high. Revisionary work is needed to identify named species and to discover new ones. This work applies integrative taxonomic methods to address the most pressing problems within the subfamily. The research presented in this dissertation focuses on Europe, particularly Germany, which is the current center of insect decline research as well as a historical center of platygastrine taxonomy. As part of this work, historical descriptions and their associated type material were examined and clarified so that further revisionary work can occur. The dissertation is structured in five chapters, of which two are published and three are unpublished. The first chapter reviews 18 genera of Platygastridae described by Arnold Förster (1856), most of which represent distinct and recognizable lineages. The study provides their taxonomic history, diagnostic remarks, English translations, and illustrations of important specimens from the Förster collection in the Natural History Museum Vienna. The collection also includes original exemplar specimens of European species whose types have been lost. Potential neotypes and lectotypes from this material are noted, with the aim of improving nomenclatural stability in the group. Potential neotypes were found for Amblyaspis forticornis (Nees, 1834), Isocybus grandis (Nees, 1834), Platygaster striolata Nees, 1834, and Trichacis tristis (Nees, 1834). Lectotypes will be designated for Platygaster spinigera Nees, 1834, which will be transferred to Leptacis, and for Platygaster corvina Förster, 1861, with Platygaster henkvlugi Buhl, 1996 treated as a junior synonym. Synopeas mutica (Nees, 1834) should be transferred back to Platygaster. The second chapter addresses generic concepts within Platygastrinae sensu Ashmead. Part of Platygastrinae (former Inostemmatinae sensu Ashmead) was reviewed and keyed by Masner & Huggert (1989). However, more than half of the genera in the subfamily, including the vast majority of species, have not been revised. A working key to 14 major world genera, the first of its kind, is provided. An additional six genera and three subgenera of uncertain placement are discussed. The third chapter focuses on nomenclatural problems in the genus Platygaster Latreille, which is the type genus for its subfamily, family, and superfamily. It is also the largest genus in Platygastroidea with nearly 700 species, and recent evidence indicates that it is not monophyletic. It is necessary to establish the identity of the type specimen, as well as the identities of the 13 generic junior synonyms and four subgenera, in order to proceed with taxonomic divisions. The type specimen Scelio ruficornis Latreille, 1805, lost to science for 192 years, was rediscovered. However, it does not belong to the prevailing concept of Platygaster, but to Isocybus Förster, which has extreme taxonomic ramifications. The proposed solution would replace the type species of each genus in order to retain prevailing usage and prevent widespread confusion. A petition is presented to designate Epimeces ensifer Westwood as the type of Platygaster and Scelio ruficornis as the type of Isocybus. In the fourth chapter, the genus Trichacis Förster is revised for Europe. Examination of historical and modern collections combined with DNA barcoding revealed the presence of only a single species in Europe, Trichacis tristis (Nees, 1834), redescribed here. The results suggest that T. tristis has 14 junior synonyms: T. abdominalis (Thomson, 1859); T. bidentiscutum Szabó, 1981; T. didas (Walker, 1835); T. fusciala Szabó, 1981; T. hajduica Szabó, 1981; T. illusor Kieffer, 1916; T. nosferatus Buhl, 1997; T. pisis (Walker, 1835); T. persicus Asadi & Buhl, 2021; T. pulchricornis Szelényi, 1953; T. quadriclava Szabó, 1981; T. remulus (Walker, 1835); T. vitreus Buhl, 1997; and T. weiperti Buhl, 2019. Four species should be transferred to Amblyaspis Förster: T. afurcata Szabó, 1977, T. hungarica Szabó, 1977, T. pannonica Szabó, 1977, and T. tatika Szabó, 1977. Intraspecific variation, biological associations, and taxonomic history are discussed. DNA barcodes are provided and analyzed in the context of worldwide Trichacis and its sister genus Isocybus Förster. The fifth chapter examines platygastrid diversity in Germany in the context of insect decline. DNA barcodes indicate the presence of 178 observed species, with an estimated total of 290. GBOL sampling captured an estimated 93.7% of total species richness, but only 45.8% of rare species. A case study from Isocybus compares historical specimens, DNA barcode vouchers, and ecological data to illustrate the possible decline of a wetland parasitoid species. Altogether, the research demonstrates the importance of historical material, especially type specimens, in understanding biodiversity through time, and provides an essential taxonomic foundation for much-needed modern identification resources for Platygastrinae in the western Palearctic and beyond.Mitten im sechsten Massensterben ist unser Verständnis des Insektenrückgangs durch mangelhafte Informationen über die biologische Vielfalt noch immer stark eingeschränkt. Viele der häufigen und artenreichen Insektengruppen lassen sich nicht bis zur Art oder Gattung bestimmen, verweilen daher im Dunkeln. Platygastroidea, eine Überfamilie parasitoider Wespen, stellt ein solches "dark Taxon" dar. Bei paläarktischen Platygastrinae ist die taxonomische Bearbeitung besonders schwer, da es in einer Vielzahl von Taxa Unklarheiten gibt. Platygastrinae parasitieren die sehr artenreichen Cecidomyiidae (Diptera), was darauf schließen lässt, dass ihr Artenreichtum ebenfalls entsprechend groß sein könnte. Taxonomische Revisionen sind erforderlich, um beschriebene Arten zu identifizieren und neue zu entdecken. Die vorliegende Arbeit nutzt integrative Taxonomie, um die dringendsten Probleme dieser Unterfamilie anzugehen. Der Forschungsschwerpunkt liegt auf Europa, insbesondere Deutschland, das aktuelle Zentrum der Erforschung des Insektensterben, sowie ein historisches Zentrum der Platygastrinen-Taxonomie. Die Dissertation ist in fünf Kapitel unterteilt, von denen zwei veröffentlich und drei unveröffentlicht sind. Das erste Kapitel liefert einen Überblick über die 18 von Arnold Förster (1856) beschriebenen Gattungen der Platygastridae. Informationen über ihre Taxonomie, Anmerkungen zur Diagnose, Übersetzungen sowie Abbildungen wichtiger Exemplare aus der Förster-Sammlung im Naturhistorischen Museum Wien werden bereitgestellt. Die Sammlung Förster enthält zudem wichtige Original-Exemplare europäischer Arten, deren Typen unauffindbar sind. Potenzielle Neotypen und Lectotypen aus diesem Material sind vermerkt, um die nomenklatorische Stabilität der Gruppe zu verbessern. Potenzielle Neotypen wurden für Amblyaspis forticornis (Nees, 1834), Isocybus grandis (Nees, 1834), Platygaster striolata Nees, 1834, und Trichacis tristis (Nees, 1834) gefunden. Lectotypen werden für P. spinigera Nees, 1834, die zu Leptacis gestellt wird, und für P. corvina Förster, 1861, bestimmt, wobei Platygaster henkvlugi Buhl, 1996 als jüngeres Synonym zur letztgenannten Art behandelt wird. Synopeas mutica (Nees, 1834) sollte zurück zu Platygaster gestellt werden. Das zweite Kapitel befasst sich mit Gattungskonzepten innerhalb der Platygastrinae sensu Ashmead. Ein Teil der Platygastrinae (früher Inostemmatinae sensu Ashmead) wurde von Masner & Huggert (1989) überarbeitet und ein Bestimmungsschlüssel bereitgestellt. Viele Gattungen dieser Unterfamilie, einschließlich der meisten Arten, wurden jedoch nicht überarbeitet. Ein Bestimmungsschlüssel für 14 wichtige Gattungen der Welt wird vorgelegt. Weitere sechs Gattungen und drei Untergattungen mit unsicherer Stellung werden diskutiert. Das dritte Kapitel stellt die nomenklatorischen Probleme in der Gattung Platygaster Latreille dar, die Typusgattung der Überfamilie. Mit fast 700 Arten ist sie die größte Gattung der Platygastroidea, die nach neueren Erkenntnissen nicht monophyletisch ist. Das Aufklären der Identitäten des Typusexemplars, 13 jüngerer Synonyme und vier Untergattungen ist wichtig, um mit der taxonomischen Aufarbeitung fortzufahren. Das Typusexemplar von Scelio ruficornis, das 192 Jahre lang für die Wissenschaft als verschollen galt, wurde wiederentdeckt. Der Typus passt jedoch nicht zum vorherrschenden Konzept von Platygaster, sondern von Isocybus. Dies hat bedeutende taxonomische Auswirkungen. Als Lösung wird empfohlen, die Typusarten der einzelnen Gattungen zu ersetzen, um die aktuelle Namensnutzung beizubehalten und Verwirrung zu verhindern. Die Designation von Epimeces ensifer Westwood als Typusart von Platygaster und Scelio ruficornis als Typusart von Isocybus wird vorgeschlagen. In Kapitel vier wird die Gattung Trichacis Förster für Europa überarbeitet. Eine Untersuchung von historischem und neuem Sammlungsmaterial in Kombination mit DNA-Barcoding offenbarte das Vorhandensein einer einzigen Art in Europa, Trichacis tristis (Nees, 1834), die hier neu beschrieben wird. Die Ergebnisse zeigen, dass T. tristis 14 jüngere Synonyme hat: T. abdominalis (Thomson, 1859); T. bidentiscutum Szabó, 1981; T. didas (Walker, 1835); T. fusciala Szabó, 1981; T. hajduica Szabó, 1981; T. illusor Kieffer, 1916; T. nosferatus Buhl, 1997; T. pisis (Walker, 1835); T. persicus Asadi & Buhl, 2021; T. pulchricornis Szelényi, 1953; T. quadriclava Szabó, 1981; T. remulus (Walker, 1835); T. vitreus Buhl, 1997; und T. weiperti Buhl, 2019. Vier Arten sollten zu Amblyaspis Förster gestellt werden: T. afurcata Szabó, 1977, T. hungarica Szabó, 1977, T. pannonica Szabó, 1977 und T. tatika Szabó, 1977. Intraspezifische Variationen, biologische Assoziationen und die taxonomische Geschichte werden diskutiert. DNA-Barcodes werden bereitgestellt und im Kontext der weltweiten Arten von Trichacis und ihrer Schwestergattung Isocybus Förster analysiert. Im fünften Kapitel wird die Diversität der Platygastriden in Deutschland im Hinblick auf das Insektensterben untersucht. DNA-Barcodes weisen auf das Vorhandensein von 178 Arten hin, bei einer geschätzten Gesamtzahl von 290 Arten. Die Studie erfasste geschätzt 93,7 % des gesamten Artenreichtums, aber nur 45,8 % der seltenen Arten. Eine Untersuchung der Gattung Isocybus mittels historischer Belege, DNA-Barcodes und ökologischer Daten zeigt den potentiellen Rückgang einer Parasitoidenart. Diese Arbeit demonstriert, wie wichtig Sammlungen, insbesondere Typusexemplare, für das Verständnis der Artenvielfalt im Laufe der Zeit sind und liefert die taxonomische Grundlage für die dringend benötigten modernen Bestimmungshilfen der Platygastrinae in der westlichen Paläarktis und darüber hinaus

An integrative description of a population of Mesobiotus radiatus (Pilato, Binda & Catanzaro, 1991) from Kenya

In a moss sample collected from Mount Kulal in Kenya, a new population of Mesobiotus radiatus was found. Given that the original description of M. radiatus was based solely on the morphology observed by light microscopy and measurements based mostly on a single individual, here we describe the new population by means of integrative taxonomy and a large sample size. We provide an integrative description comprising a comprehensive set of morphometric and morphological data from light and scanning microscopy as well as nucleotide sequences of three nuclear fragments (18S rRNA, 28S rRNA, ITS-2) and one mitochondrial fragment (COI). Mesobiotus radiatus is most similar to M. binieki, M. coronatus, M. patiens, M. perfidus, M. philippinicus, M. pseudocoronatus, M. pseudopatiens, M. rigidus, M. simulans, and M. wuzhishanensis, but differs from them mainly by egg morphology and morphometry, and some characters of adult specimens

Integrative taxonomy of Iberian Merodon species (Diptera, Syrphidae)

The genus Merodon Meigen, 1803 (Syrphidae, Diptera), with more than 50 European species, is primarily distributed in the Mediterranean region, there being 34 species that occur in the Iberian Peninsula. The morphological variation found within some species from the Iberian Peninsula prompted us to test their taxonomic status by integrating morphological and molecular data. We generated partial sequences of the mitochondrial, protein-coding gene cytochrome c oxidase subunit I (COI), the nuclear, internal transcribed spacer (ITS2) region, and the D2 region of thenuclear 28S rRNA gene. COI and ITS2 sequences were obtained for most included taxa. The variability of the COI sequences showed great differences between the studied species groups, exhibiting an interspecific range from 0.29% to 12.5% between ingroup taxa. Closely related taxa of the aureus complex (e.g. M. quercetorum and M. legionensis) presented identical COI sequences. The obtained ITS2 sequences showed low intraspecific variability, and only a few taxa presented more than one genotype. Species status and delimitation were discussed for all taxa in the light of available morphological and molecular character information. Using the obtained sequence data for COI and 28S we inferred the phylogenetic relationships of the included taxa, using parsimony analysis. Separate analysis of the COI sequences identified four, quite well supportedclades within Merodon, the desuturinus, albifrons, nigritarsis and aureus groups. Combined analysis of the COI and 28S genes produced a topology similar to the COI topology.Ministry of Science and Environmental Protection of Serbia (Grant Number 143037), the Provincial Secretariat for Science and Technological Development (Maintenance of biodiversity–“Hot spots” on the Balkan and Iberian Peninsula), the Spanish Ministerio de Medio Ambiente (MMA-040/2002), the Spanish Ministerio de Educación y Ciencia (CGL2005-0713/BOS and grant number AP2003-3998) and Generalitat Valenciana (ACOMP06/063)

Integrative Taxonomy and the Operationalization of Evolutionary Independence

There is growing agreement among taxonomists that species are independently evolving lineages. The central notion of this conception, evolutionary independence, is commonly operationalized by taxonomists in multiple, diverging ways. This leads to a problem of operationalization-dependency in species classification, as species delimitation is not only dependent on the properties of the investigated groups, but also on how taxonomists choose to operationalize evolutionary independence. The question then is how the operationalization-dependency of species delimitation is compatible with its objectivity and reliability. In response to this problem, various taxonomists have proposed to integrate multiple operationalizations of evolutionary independence for delimiting species. This paper first distinguishes between a standard and a sophisticated integrative approach to taxonomy, and argues that it is unclear how either of these can support the reliability and objectivity of species delimitation. It then draws a parallel between the measurement of physical quantities and species delimitation to argue that species delimitation can be considered objective and reliable if we understand the sophisticated integrative approach as assessing the coherence between the idealized models of multiple operationalizations of evolutionary independence

Towards an Integrative Taxonomy of Social-Emotional Competences

Social-emotional competences are critical for positive development and significantly predict educational and occupational attainment, health, and well-being. There is however a lack of consensus about the number of core competences, and how these are defined and operationalized. This divergence in approach challenges future research as well as the scientific usefulness of the construct. In an effort to create an integrative framework, this focused review evaluates different approaches of conceptualizing and assessing social-emotional competences. Building on shared conceptions, an integrative taxonomy “DOMASEC” is introduced, specifying core domains and manifestations of social-emotional competences that bridge across frameworks focusing on social and emotional learning, personality traits (such as the Big Five) and self-determination theory. Core domains include intrapersonal, interpersonal and task-oriented competencies, differentiating between affective, cognitive, and behavioral manifestations of competences across these domains. It is argued that the integrative taxonomy facilitates the conceptual specification of key constructs, that it helps to better organize the multitude of terms and definitions used, and to guide the conceptualization and operationalization of social-emotional competences and their various facets

Integrative Taxonomy for Continental-Scale Terrestrial Insect Observations

Although 21st century ecology uses unprecedented technology at the largest spatio-temporal scales in history, the data remain reliant on sound taxonomic practices that derive from 18th century science. The importance of accurate species identifications has been assessed repeatedly and in instances where inappropriate assignments have been made there have been costly consequences. The National Ecological Observatory Network (NEON) will use a standardized system based upon an integrative taxonomic foundation to conduct observations of the focal terrestrial insect taxa, ground beetles and mosquitoes, at the continental scale for a 30 year monitoring program. The use of molecular data for continental-scale, multi-decadal research conducted by a geographically widely distributed set of researchers has not been evaluated until this point. The current paper addresses the development of a reference library for verifying species identifications at NEON and the key ways in which this resource will enhance a variety of user communities

Integrative Taxonomy, a New Tool for Fisheries Conservation

Species delimitation is becoming increasingly objective and integrative. Sequence capture approaches allow collection of 1000s of loci for 100s of individuals. New approaches address the computational challenges of large datasets and offer potential for genome-wide sampling of variation at different evolutionary scales. These new approaches also allow integration of genetic and non-genetic data in a unified framework. Despite these advances, few studies have attempted to combine genetic and morphological data for delimiting species. Hakes (Merluccius spp.) are an ideal group for an empirical test of the power and applicability of these new methods because they are morphologically conserved and have distributional patterns ideal for studying a broad range of evolutionary questions. They also are of economic and conservation concern so the results of this phylogenetic study can be directly applied to fisheries management. Hakes are demersal fishes that inhabit the continental shelf and slope of the Atlantic, Pacific, and around New Zealand and there are 16 putative species. Hakes can be difficult to identify due to their conservative external morphology and high level of intraspecific variation, resulting in serious identification problems. Many species of hakes are sympatric and there is moderate ecological overlap. Unresolved alpha taxonomy and the lack of diagnostic characters have led to mixed-species in landings data, making management and conservation difficult. This study uses a broad taxonomic and geographic sampling combined with new morphological and genetic characters to clarify the taxonomy, systematics and the global biogeography and diversification of hake species

Cautioning the move from morphology to molecules in the taxonomy of Metazoa: Comments on Lawley et al. (PeerJ 2021;9, e11954) and a plea for considered integration

This paper serves as a commentary on a recently published paper by Lawley et al. (PeerJ 2021;9, e11954). We caution the adoption of practices in the taxonomy of Scyphozoa by Lawley et al. on the basis that they may lead to taxonomic splits and parallel taxonomies in the face of a concerted push towards integrative taxonomy

Species delimitation in the Andean grasshopper genus <i>Orotettix</i> Ronderos & Carbonell (Orthoptera: Melanoplinae): an integrative approach combining morphological, molecular and biogeographical data

The reciprocal illumination nature of integrative taxonomy through hypothesis testing, corroboration and revision is a powerful tool for species delimitation as more than one source has to support the hypothesis of a new species. In this study, we applied an integrative taxonomy approach combining molecular and morphological data sets with distributional patterns to examine the level of differentiation between and within the grasshopper Orotettix species. Orotettix was described based on five valid species distributed in the Andes of Peru. In our study, initially a molecular-based hypothesis was postulated and tested against morphological data and geographical patterns of distribution. Results from molecular and morphological analyses showed agreement among the species delimitation in Orotettix, and were also consistent with the geographical distribution. The analyses allowed us to delimit five new species for the genus (O. lunatus sp. nov., O.astreptos sp. nov., O. colcaensis sp. nov., O.paucartambensis sp. nov. and O.dichrous sp. nov.) from the Eastern and Western Cordilleras of Peru. We also provide critical knowledge on the phylogenetic relationships and distribution of the genus and conduct a revision of Orotettix.Facultad de Ciencias Naturales y MuseoCentro de Estudios Parasitológicos y de Vectore