TY - JOUR A1 - Leonhardt, Sara D. A1 - Schmitt, Thomas A1 - Blüthgen, Nico T1 - Tree Resin Composition, Collection Behavior and Selective Filters Shape Chemical Profiles of Tropical Bees (Apidae: Meliponini) N2 - The diversity of species is striking, but can be far exceeded by the chemical diversity of compounds collected, produced or used by them. Here, we relate the specificity of plant-consumer interactions to chemical diversity applying a comparative network analysis to both levels. Chemical diversity was explored for interactions between tropical stingless bees and plant resins, which bees collect for nest construction and to deter predators and microbes. Resins also function as an environmental source for terpenes that serve as appeasement allomones and protection against predators when accumulated on the bees’ body surfaces. To unravel the origin of the bees’ complex chemical profiles, we investigated resin collection and the processing of resin-derived terpenes. We therefore analyzed chemical networks of tree resins, foraging networks of resin collecting bees, and their acquired chemical networks. We revealed that 113 terpenes in nests of six bee species and 83 on their body surfaces comprised a subset of the 1,117 compounds found in resins from seven tree species. Sesquiterpenes were the most variable class of terpenes. Albeit widely present in tree resins, they were only found on the body surface of some species, but entirely lacking in others. Moreover, whereas the nest profile of Tetragonula melanocephala contained sesquiterpenes, its surface profile did not. Stingless bees showed a generalized collecting behavior among resin sources, and only a hitherto undescribed species-specific ‘‘filtering’’ of resin-derived terpenes can explain the variation in chemical profiles of nests and body surfaces fromdifferent species. The tight relationship between bees and tree resins of a large variety of species elucidates why the bees’ surfaces contain a much higher chemodiversity than other hymenopterans. KW - Stachellose Biene Y1 - 2011 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-69035 ER - TY - JOUR A1 - Drescher, Jochen A1 - Bluethgen, Nico A1 - Schmitt, Thomas A1 - Buehler, Jana A1 - Feldhaar, Heike T1 - Societies Drifting Apart? Behavioural, Genetic and Chemical Differentiation between Supercolonies in the Yellow Crazy Ant Anoplolepis gracilipes N2 - Background: In populations of most social insects, gene flow is maintained through mating between reproductive individuals from different colonies in periodic nuptial flights followed by dispersal of the fertilized foundresses. Some ant species, however, form large polygynous supercolonies, in which mating takes place within the maternal nest (intranidal mating) and fertilized queens disperse within or along the boundary of the supercolony, leading to supercolony growth (colony budding). As a consequence, gene flow is largely confined within supercolonies. Over time, such supercolonies may diverge genetically and, thus, also in recognition cues (cuticular hydrocarbons, CHC’s) by a combination of genetic drift and accumulation of colony-specific, neutral mutations. Methodology/Principal Findings: We tested this hypothesis for six supercolonies of the invasive ant Anoplolepis gracilipes in north-east Borneo. Within supercolonies, workers from different nests tolerated each other, were closely related and showed highly similar CHC profiles. Between supercolonies, aggression ranged from tolerance to mortal encounters and was negatively correlated with relatedness and CHC profile similarity. Supercolonies were genetically and chemically distinct, with mutually aggressive supercolony pairs sharing only 33.1%617.5% (mean 6 SD) of their alleles across six microsatellite loci and 73.8%611.6% of the compounds in their CHC profile. Moreover, the proportion of alleles that differed between supercolony pairs was positively correlated to the proportion of qualitatively different CHC compounds. These qualitatively differing CHC compounds were found across various substance classes including alkanes, alkenes and mono-, di- and trimethyl-branched alkanes. Conclusions: We conclude that positive feedback between genetic, chemical and behavioural traits may further enhance supercolony differentiation through genetic drift and neutral evolution, and may drive colonies towards different evolutionary pathways, possibly including speciation. KW - Ameisen KW - Anoplolepis gracilipes Y1 - 2010 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-68573 ER - TY - JOUR A1 - Menzel, Florian A1 - Blüthgen, Nico A1 - Tolasch, Till A1 - Conrad, Jürgen A1 - Beifuss, Uwe A1 - Beuerle, Till A1 - Schmitt, Thomas T1 - Crematoenones - a novel substance class exhibited by ants functions as appeasement signal JF - Frontiers in Zoology N2 - Background: Parasitic, commensalistic, and mutualistic guests in social insect colonies often circumvent their hosts' nestmate recognition system to be accepted. These tolerance strategies include chemical mimicry and chemical insignificance. While tolerance strategies have been studied intensively in social parasites, little is known about these mechanisms in non-parasitic interactions. Here, we describe a strategy used in a parabiotic association, i.e. two mutualistic ant species that regularly share a common nest although they have overlapping food niches. One of them, Crematogaster modiglianii, produces an array of cuticular compounds which represent a substance class undescribed in nature so far. They occur in high abundances, which suggests an important function in the ant's association with its partner Camponotus rufifemur. Results: We elucidated the structure of one of the main compounds from cuticular extracts using gas chromatography, mass spectrometry, chemical derivatizations and nuclear magnetic resonance spectroscopy (NMR). The compound consists of two fused six-membered rings with two alkyl groups, one of which carries a keto functionality. To our knowledge, this is the first report on the identification of this substance class in nature. We suggest naming the compound crematoenone. In behavioural assays, crematoenones reduced interspecific aggression. Camponotus showed less aggression to allospecific cuticular hydrocarbons when combined with crematoenones. Thus, they function as appeasement substances. However, although the crematoenone composition was highly colony-specific, interspecific recognition was mediated by cuticular hydrocarbons, and not by crematoenones. Conclusions: Crematenones enable Crematogaster to evade Camponotus aggression, and thus reduce potential costs from competition with Camponotus. Hence, they seem to be a key factor in the parabiosis, and help Crematogaster to gain a net benefit from the association and thus maintain a mutualistic association over evolutionary time. To our knowledge, putative appeasement substances have been reported only once so far, and never between non-parasitic species. Since most organisms associated with social insects need to overcome their nestmate recognition system, we hypothesize that appeasement substances might play an important role in the evolution and maintenance of other mutualistic associations as well, by allowing organisms to reduce costs from antagonistic behaviour of other species. KW - cuticular hydrocarbons KW - appeasement substance KW - bees KW - ecology KW - parasitism KW - alkyloctahydronaphthalene KW - usurpation KW - venom KW - pheromone KW - crematogaster KW - parabiotic ants KW - Dufours gland KW - polyergus rufescens KW - formicidae KW - interspecific aggression KW - nestmate recognition cues KW - parabiotic association Y1 - 2013 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-122595 SN - 1742-9994 VL - 10 IS - 32 ER - TY - JOUR A1 - Strube-Bloss, Martin F. A1 - Brown, Austin A1 - Spaethe, Johannes A1 - Schmitt, Thomas A1 - Rössler, Wolfgang T1 - Extracting the Behaviorally Relevant Stimulus: Unique Neural Representation of Farnesol, a Component of the Recruitment Pheromone of Bombus terrestris JF - PLoS One N2 - To trigger innate behavior, sensory neural networks are pre-tuned to extract biologically relevant stimuli. Many male-female or insect-plant interactions depend on this phenomenon. Especially communication among individuals within social groups depends on innate behaviors. One example is the efficient recruitment of nest mates by successful bumblebee foragers. Returning foragers release a recruitment pheromone in the nest while they perform a ‘dance’ behavior to activate unemployed nest mates. A major component of this pheromone is the sesquiterpenoid farnesol. How farnesol is processed and perceived by the olfactory system, has not yet been identified. It is much likely that processing farnesol involves an innate mechanism for the extraction of relevant information to trigger a fast and reliable behavioral response. To test this hypothesis, we used population response analyses of 100 antennal lobe (AL) neurons recorded in alive bumblebee workers under repeated stimulation with four behaviorally different, but chemically related odorants (geraniol, citronellol, citronellal and farnesol). The analysis identified a unique neural representation of the recruitment pheromone component compared to the other odorants that are predominantly emitted by flowers. The farnesol induced population activity in the AL allowed a reliable separation of farnesol from all other chemically related odor stimuli we tested. We conclude that the farnesol induced population activity may reflect a predetermined representation within the AL-neural network allowing efficient and fast extraction of a behaviorally relevant stimulus. Furthermore, the results show that population response analyses of multiple single AL-units may provide a powerful tool to identify distinct representations of behaviorally relevant odors. KW - instinct KW - plant-insect interactions KW - pheromones KW - bumblebees KW - odorants KW - principal component analysis KW - neurons KW - action potentials Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-125875 VL - 10 IS - 9 ER - TY - THES A1 - Schmitt, Thomas T1 - Communication in the hymenoptera : chemistry, ecology and evolution T1 - Kommunikation bei Hymenopteren - Chemie, Ökologie und Evolution N2 - Insects exhibit complex systems of communication with chemical signalling being the most important mode. Although there are many studies on chemical communication in insects, the evolution of chemical signals is not well understood. Due to the conflict of interests between individuals, different selective pressures might act on sender and receiver. In this thesis I investigate different types of communication where either the sender, the receiver or both parties yield benefits. These studies were conducted with one digger wasp species, honeybees, one chrysidid wasp, and three ant species. Senders might benefit by exploiting existing preferences of receivers. Such sensory exploitation might influence the evolution of male signals that are designed to attract females. The sex pheromone of male European beewolves Philanthus triangulum (Hymenoptera, Crabronidae) might have evolved according to the sensory exploitation hypothesis. A three-step scenario is supported by our studies. First, a major component of the honeybee alarm pheromone, (Z)-11-eicosen-1-ol, is also found on the cuticles and in the air surrounding foraging honeybees. Second, it could be shown, that (Z)-11- eicosen-1-ol plays a crucial role as kairomone for prey identification of honeybees by beewolf females. Third, a reanalysis of the beewolf male sex pheromone shows a remarkable similarity of compounds between the pheromone and the honeybee cuticle, besides the co-occurrence of (Z)-11-eisosen-ol. The majority of the cuticular hydrocarbons of honeybees occur also in the headspace of foraging workers. These results strongly support the hypothesis that beewolf males evolved a pheromone that exploits the females’ pre-existing sensory sensitivity. In addition, the male sex pheromone shows a significantly higher similarity among brothers than among non-related individuals, which might enable beewolf females to discriminate against brothers and avoid detrimental effects of breeding. Together with the studies on the possible sensory exploitation this result shows that both, male and female beewolves probably gain more benefits than costs from the pheromone communication and, thus, the communication system as a whole can be regarded as cooperative. To maintain the reproductive division of labour in eusocial colonies, queens have to signal their presence and fecundity. In the ant Camponotus floridanus (Hymenoptera, Formicidae) queens mark their own eggs with a distinctive pattern of cuticular hydrocarbons. Two different hypotheses have been developed. One suggests a form of worker manipulation by the queen. The alternative hypothesis assumes a cooperative signal that provides information on the condition of the queen. The results of our investigation clearly favour the latter hypothesis. Chemical mimicry is a form of non-cooperative communication that benefits predominantly the sender. We provided conclusive evidence that the cockoo wasp, Hedychrum rutilans (Hymenoptera, Chrysididae), the primary brood parasitoid of Philanthus triangulum, evades recognition by beewolf females most probably by chemical mimicry of the odour of its host. Furthermore, the adaptation of the chemical signature in the social ant parasite Protomognathus americanus (Hymenoptera, Formicidae) to its Leptothorax (Hymenoptera, Formicidae) hosts was investigated. Although this parasite is principally adapted to its hosts’ cuticular hydrocarbon profile, there are still pronounced differences between the profiles of parasites and hosts. This might be explained by the trade-off, which the parasites faces when confronted locally with two host species with different cuticular hydrocarbon profiles. Non-cooperative communication in the sense that only receivers benefit was discovered in the exploitation of honeybees volatile cuticular hydrocarbons by beewolf females. By using emitted (Z)-11-eicosen-1-ol as a kairomone, the receiver, the beewolf female, yields the benefits and the sender, the honeybee prey, bears all the costs. The results of these studies contribute to the understanding of the evolution of cooperative and non-cooperative communication with chemical signals taking into account differential benefits for sender and/or receiver. N2 - Insekten weisen ein komplexes System der Kommunikation auf, wobei chemische Signale die wichtigste Rolle spielen. Obwohl viele Studien über chemische Kommunikation an Insekten durchgeführt wurden, ist die Evolution von chemischen Signalen nicht gut verstanden. Aufgrund von Interessenkonflikten wirken unterschiedliche Selektionsdrücke auf Sender und Empfänger. In dieser Dissertation untersuchte ich verschiedene Typen von Kommunikation, bei denen entweder der Sender, der Empfänger oder beide von der Kommunikation profitieren. Als Modellorganismen wurden eine Grabwespenart (Crabronidae), Honigbienen (Apidae), eine Goldwespenart (Chrysididae) und drei Ameisenarten (Formicidae) studiert. Sender können von der Ausnutzung existierender Präferenzen der Empfänger profitieren. Eine solche Ausnutzung kann die Evolution von Männchensignalen beeinflussen, die entwickelt wurden, um Weibchen anzulocken. Solch eine „sensory exploitation“ könnte die Evolution des Sexualpheromons von Männchen des Europäischen Bienenwolfs Philanthus triangulum (Hymenoptera, Crabronidae) beeinflußt haben. Unsere Studien unterstützen das folgende Drei-Stufen-Szenario: Erstens, eine Hauptkomponente aus dem Honigbienenalarmpheromon, das (Z)-11- Eicosen-1-ol, wurde auf der Kutikula und in der Umgebungsluft furagierender Honigbienen nachgewiesen. Zweitens konnte gezeigt werden, daß (Z)-11-Eicosen-1-ol eine wichtige Rolle als Kairomon bei der Identifizierung der Honigbiene als Beute durch Bienenwolfweibchen spielt. Schließlich zeigte eine detaillierte chemische Analyse des Bienenwolfmännchenpheromons, daß außer dem Auftreten von (Z)-11- Eicosen-1-ol weitere bemerkenswerte Übereinstimmungen zwischen dem Pheromon und der Honigbienenkutikula auftreten. Die meisten der kutikulären Substanzen der Honigbiene finden sich auch in der Umgebungsluft furagierender Honigbienen. Diese Ergebnisse bestätigen, daß bei der Evolution des Pheromons der Bienenwolfmännchen bereits existierende sensorische Fähigkeiten der Weibchen eine wichtige Rolle spielten und somit die „sensory exploitation“ Hypothese unterstützt wird. Das Sexualpheromon der Bienenwolfmännchen zeigt außerdem eine signifikant größere Ähnlichkeit zwischen Brüdern im Vergleich zu nicht verwandten Individuen. Dies könnte den Bienenwolfweibchen ermöglichen, bei der Paarung gegen Brüder zu diskriminieren und damit einen nachteiligen Effekt der Inzucht bei Nachkommen zu vermeiden. Dieses Ergebnis zeigt zusammen mit den Studien zur möglichen „sensory exploitation“, daß Männchen und Weibchen wahrscheinlich mehr Nutzen als Kosten aus diesem Kommunikationssystem erzielen und deshalb das System insgesamt als kooperativ betrachtet werden kann. Um die reproduktive Arbeitsteilung in eusozialen Kolonien aufrecht zu erhalten, müssen Königinnen ihre Anwesendheit und Fekundität signalisieren. Bei der Ameisenart Camponotus floridanus (Hymenoptera, Formicidae) markieren die Königinnen ihre eigenen Eier mit einem unverwechselbaren kutikulären Kohlenwasserstoffmuster. Zwei unterschiedliche Hypothesen, die diese Form der Kommunikation erklären, wurden formuliert. Eine Hypothese schlägt eine Manipulation von Arbeiterinnen durch die Königin vor. Eine Alternativhypothese geht von einem kooperativen Signal aus, das Informationen über den Zustand der Königin übermittelt. Die Ergebnisse unserer Untersuchungen stützen eindeutig letztere Hypothese. Chemische Mimikry ist eine Form von nicht-kooperativer Kommunikation, von der ausschließlich der Sender profitiert. Die Goldwespe, Hedychrum rutilans (Hymenoptera, Chrysididae), der wichtigste Brutparasitoid von Philanthus triangulum, entgeht der Entdeckung durch das Bienenwolfweibchen wahrscheinlich durch Imitierung des Geruchs seines Wirtes. Weiterhin wurde die Anpassung der chemischen Signatur des sozialen Ameisenparasiten Protomognathus americanus (Hymenoptera, Formicidae) an seine Leptothorax Wirtsarten untersucht. Obwohl dieser Parasit prinzipiell an das kutikuläre Kohlenwasserstoffprofil seines Wirtes angepaßt ist, gibt es trotzdem ausgeprägt Unterschiede zwischen den Profilen des Parasits und seines Wirtes. Dies könnte durch einen „trade-off“ erklärt werden, dem die Parasiten ausgesetzt sind, wenn sie lokal mit zwei Wirtsarten mit unterschiedlichen kutikulären Kohlenwasserstoffprofilen konfrontiert werden. Nicht-kooperative Kommunikation im Sinne, daß nur der Empfänger profitiert, wurde bei der Ausnutzung der flüchtigen kutikulären Kohlenwasserstoffen der Honigbiene durch seinen Prädator, das Bienenwolfweibchen, gezeigt. Durch die Nutzung von (Z)- 11-Eicosen-1-ol als Kairomon profitiert nur der Empfänger, das Bienenwolfweibchen, wohingegen der Sender, die Honigbiene (Beute), alle Kosten trägt. Die Ergebnisse dieser Studien tragen zu einem besseren Verständnis der Evolution von kooperativer und nicht-kooperativer Kommunikation mit chemischen Signalen unter Berücksichtigung des unterschiedlichen Nutzens für Sender und/oder Empfänger bei. KW - Hautflügler KW - Chemische Kommunikation KW - Pheromone KW - kutikuläre Kohlenwasserstoffe KW - chemische Kommunikation KW - Hymenopteren KW - pheromones KW - cuticular hydrocarbons KW - chemical communication KW - Hymenoptera Y1 - 2004 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-11267 ER - TY - JOUR A1 - Christopher D., Pull A1 - Ugelvig, Line V. A1 - Wiesenhofer, Florian A1 - Anna V., Grasse A1 - Tragust, Simon A1 - Schmitt, Thomas A1 - Brown, Mark JF A1 - Cremer, Sylvia T1 - Destructive disinfection of infected brood prevents systemic disease spread in ant colonies JF - eLIFE N2 - In social groups, infections have the potential to spread rapidly and cause disease outbreaks. Here, we show that in a social insect, the ant Lasius neglectus, the negative consequences of fungal infections (Metarhizium brunneum) can be mitigated by employing an efficient multicomponent behaviour, termed destructive disinfection, which prevents further spread of the disease through the colony. Ants specifically target infected pupae during the pathogens non-contagious incubation period, utilising chemical 'sickness cues' emitted by pupae. They then remove the pupal cocoon, perforate its cuticle and administer antimicrobial poison, which enters the body and prevents pathogen replication from the inside out. Like the immune system of a metazoan body that specifically targets and eliminates infected cells, ants destroy infected brood to stop the pathogen completing its lifecycle, thus protecting the rest of the colony. Hence, in an analogous fashion, the same principles of disease defence apply at different levels of biological organisation. KW - division of labor KW - Fungal cell-walls KW - Leaf cutting ants KW - Metarhizium anisopliae KW - Beauveria bassiana Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-223728 VL - 7 ER - TY - JOUR A1 - Maihoff, Fabienne A1 - Bohlke, Kyte A1 - Brockmann, Axel A1 - Schmitt, Thomas T1 - Increased complexity of worker CHC profiles in Apis dorsata correlates with nesting ecology JF - PLoS ONE N2 - Cuticular hydrocarbons (CHC) are known to serve as discrimination cues and will trigger defence behaviour in a plethora of eusocial insects. However, little is known how about nestmate recognition ability selects for CHC diversification. In this study we investigate differences in CHC composition of four major honey bee species with respect to the differences in their nesting behavior. In contrast to A. mellifera, A. cerana and A. florea, the giant honey bee A. dorsata prefers to build their nests in aggregations with very small spatial distances between nests, which increases the probability of intrusions. Thus, A. dorsata exhibits a particularly challenging nesting behavior which we hypothesize should be accompanied with an improved nestmate recognition system. Comparative analyses of the worker CHC profiles indicate that A. dorsata workers exhibit a unique and more complex CHC profile than the other three honey bee species. This increased complexity is likely based on a developmental process that retains the capability to synthesize methyl-branched hydrocarbons as adults. Furthermore, two sets of behavioral experiments provide evidence that A. dorsata shows an improved nestmate discrimination ability compared to the phylogenetically ancestral A. florea, which is also open-nesting but does not form nest aggregations. The results of our study suggest that ecological traits like nesting in aggregation might be able to drive CHC profile diversification even in closely related insect species. KW - Apis dorsata KW - cuticular hydrocarbons KW - nesting Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-301353 VL - 17 IS - 7 ER - TY - RPRT A1 - Müller, Jörg A1 - Scherer-Lorenzen, Michael A1 - Ammer, Christian A1 - Eisenhauer, Nico A1 - Seidel, Dominik A1 - Schuldt, Bernhard A1 - Biedermann, Peter A1 - Schmitt, Thomas A1 - Künzer, Claudia A1 - Wegmann, Martin A1 - Cesarz, Simone A1 - Peters, Marcell A1 - Feldhaar, Heike A1 - Steffan-Dewenter, Ingolf A1 - Claßen, Alice A1 - Bässler, Claus A1 - von Oheimb, Goddert A1 - Fichtner, Andreas A1 - Thorn, Simon A1 - Weisser, Wolfgang T1 - BETA-FOR: Erhöhung der strukturellen Diversität zwischen Waldbeständen zur Erhöhung der Multidiversität und Multifunktionalität in Produktionswäldern. Antragstext für die DFG Forschungsgruppe FOR 5375 T1 - BETA-FOR: Enhancing the structural diversity between patches for improving multidiversity and multifunctionality in production forests. Proposal for DFG Research Unit FOR 5375 BT - β\(_4\) : Proposal for the 1st phase (2022-2026) of the DFG Research Unit FOR 5375/1 (DFG Forschergruppe FOR 5375/1 – BETA-FOR), Fabrikschleichach, October 2021 N2 - Der in jüngster Zeit beobachtete kontinuierliche Verlust der β-Diversität in Ökosystemen deutet auf homogene Gemeinschaften auf Landschaftsebene hin, was hauptsächlich auf die steigende Landnutzungsintensität zurückgeführt wird. Biologische Vielfalt ist mit zahlreichen Funktionen und der Stabilität von Ökosystemen verknüpft. Es ist daher zu erwarten, dass eine abnehmende β-Diversität auch die Multifunktionalität verringert. Wir kombinieren hier Fachwissen aus der Forstwissenschaft, der Ökologie, der Fernerkundung, der chemischen Ökologie und der Statistik in einem gemeinschaftlichen und experimentellen β-Diversitätsdesign, um einerseits die Auswirkungen der Homogenisierung zu bewerten und andererseits Konzepte zu entwickeln, um negative Auswirkungen durch Homogenisierung in Wäldern rückgängig zu machen. Konkret werden wir uns mit der Frage beschäftigen, ob die Verbesserung der strukturellen β-Komplexität (ESBC) in Wäldern durch Waldbau oder natürliche Störungen die Biodiversität und Multifunktionalität in ehemals homogenen Produktionswäldern erhöhen kann. Unser Ansatz wird mögliche Mechanismen hinter den beobachteten Homogenisierungs-Diversitäts-Beziehungen identifizieren und zeigen, wie sich diese auf die Multifunktionalität auswirken. An elf Standorten in ganz Deutschland haben wir dazu zwei Waldbestände als zwei kleine "Waldlandschaften" ausgewählt. In einem dieser beiden Bestände haben wir ESBC (Enhancement of Structural Beta Complexity)-Behandlungen durchgeführt. Im zweiten, dem Kontrollbestand, werden wir die gleich Anzahl 50x50m Parzellen ohne ESBC einrichten. Auf allen Parzellen werden wir 18 taxonomische Artengruppen aller trophischer Ebenen und 21 Ökosystemfunktionen, einschließlich der wichtigsten Funktionen in Wäldern der gemäßigten Zonen, messen. Der statistische Rahmen wird eine umfassende Analyse der Biodiversität ermöglichen, indem verschiedenen Aspekte (taxonomische, funktionelle und phylogenetische Vielfalt) auf verschiedenen Skalenebenen (α-, β-, γ-Diversität) quantifiziert werden. Um die Gesamtdiversität zu kombinieren, werden wir das Konzept der Multidiversität auf die 18 Taxa anwenden. Wir werden neue Ansätze zur Quantifizierung und Aufteilung der Multifunktionalität auf α- und β-Skalen verwenden und entwickeln. Durch die experimentelle Beschreibung des Zusammenhangs zwischen β-Diversität und Multifunktionalität in einer Reallandschaft wird unsere Forschung einen neuen Weg einschlagen. Darüber hinaus werden wir dazu beitragen, verbesserte Leitlinien für waldbauliche Konzepte und für das Management natürlicher Störungen zu entwickeln, um Homogenisierungseffekte der Vergangenheit umzukehren. N2 - The recently observed consistent loss of β-diversity across ecosystems indicates increasingly homogeneous communities in patches of landscapes, mainly caused by increasing land-use intensity. Biodiversity is related to numerous ecosystem functions and stability. Therefore, decreasing β-diversity is also expected to reduce multifunctionality. To assess the impact of homogenization and to develop guidelines to reverse its potentially negative effects, we combine expertise from forest science, ecology, remote sensing, chemical ecology and statistics in a collaborative and experimental β-diversity approach. Specifically, we will address the question whether the Enhancement of Structural Beta Complexity (ESBC) in forests by silviculture or natural disturbances will increase biodiversity and multifunctionality in formerly homogeneously structured production forests. Our approach will identify potential mechanisms behind observed homogenization-diversity-relationships and show how these translate into effects on multifunctionality. At eleven forest sites throughout Germany, we selected two districts as two types of small ‘forest landscapes’. In one of these two districts, we established ESBC treatments (nine differently treated 50x50 m patches with a focus on canopy cover and deadwood features). In the second, the control district, we will establish nine patches without ESBC. By a comprehensive sampling, we will monitor 18 taxonomic groups and measure 21 ecosystem functions, including key functions in temperate forests, on all patches. The statistical framework will allow a comprehensive biodiversity assessment by quantifying the different aspects of multitrophic biodiversity (taxonomical, functional and phylogenetic diversity) on different levels of biodiversity (α-, β-, γ-diversity). To combine overall diversity, we will apply the concept of multidiversity across the 18 taxa. We will use and develop new approaches for quantification and partitioning of multifunctionality at α- and β- scales. Overall, our study will herald a new research avenue, namely by experimentally describing the link between β-diversity and multifunctionality. Furthermore, we will help to develop guidelines for improved silvicultural concepts and concepts for management of natural disturbances in temperate forests reversing past homogenization effects. KW - Waldökosystem KW - Biodiversität KW - BETA-Multifunktionalität KW - beta-multifunctionality KW - BETA-Diversität KW - beta diversity KW - Forschungsstation Fabrikschleichach Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-290849 ER - TY - JOUR A1 - Diao, Wenwen A1 - Mousset, Mathilde A1 - Horsburgh, Gavin J. A1 - Vermeulen, Cornelis J. A1 - Johannes, Frank A1 - van de Zande, Louis A1 - Ritchie, Michael G. A1 - Schmitt, Thomas A1 - Beukeboom, Leo W. T1 - Quantitative Trait Locus Analysis of Mating Behavior and Male Sex Pheromones in Nasonia Wasps JF - G3: Genes Genomes Genetics N2 - A major focus in speciation genetics is to identify the chromosomal regions and genes that reduce hybridization and gene flow. We investigated the genetic architecture of mating behavior in the parasitoid wasp species pair Nasonia giraulti and Nasonia oneida that exhibit strong prezygotic isolation. Behavioral analysis showed that N. oneida females had consistently higher latency times, and broke off the mating sequence more often in the mounting stage when confronted with N. giraulti males compared with males of their own species. N. oneida males produce a lower quantity of the long-range male sex pheromone (4R,5S)-5-hydroxy-4-decanolide (RS-HDL). Crosses between the two species yielded hybrid males with various pheromone quantities, and these males were used in mating trials with females of either species to measure female mate discrimination rates. A quantitative trait locus (QTL) analysis involving 475 recombinant hybrid males (F2), 2148 reciprocally backcrossed females (F3), and a linkage map of 52 equally spaced neutral single nucleotide polymorphism (SNP) markers plus SNPs in 40 candidate mating behavior genes revealed four QTL for male pheromone amount, depending on partner species. Our results demonstrate that the RS-HDL pheromone plays a role in the mating system of N. giraulti and N. oneida, but also that additional communication cues are involved in mate choice. No QTL were found for female mate discrimination, which points at a polygenic architecture of female choice with strong environmental influences. KW - Nasonia courtship KW - female choice KW - sex pheromone KW - QTL analysis KW - speciation Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-165412 VL - 6 IS - 6 ER - TY - JOUR A1 - Buellesbach, Jan A1 - Diao, Wenwen A1 - Schmitt, Thomas A1 - Beukeboom, Leo W. T1 - Micro‐climate correlations and conserved sexual dimorphism of cuticular hydrocarbons in European populations of the jewel wasp Nasonia vitripennis JF - Ecological Entomology N2 - 1. Protection against desiccation and chemical communication are two fundamental functions of cuticular hydrocarbons (CHCs) in insects. In the parasitoid jewel wasp Nasonia vitripennis (Walker), characterised by a cosmopolitan distribution through largely different environments, CHCs function as universally recognised female sex pheromones. However, CHC uniformity as basis for sexual recognition may conflict with the desiccation protection function, expected to display considerable flexibility through adaptation to different environmental conditions. 2. We compared male and female CHC profiles of N. vitripennis across a wide latitudinal gradient in Europe and correlated their CHC variation with climatic factors associated with desiccation. Additionally, we tested male mate discrimination behaviour between populations to detect potential variations in female sexual attractiveness. 3. Results did not conform to the general expectation that longer, straight‐chain CHCs occur in higher proportions in warmer and drier climates. Instead, unexpected environmental correlations of intermediate chain‐length CHCs (C31) were found exclusively in females, potentially reflecting the different life histories of the sexes in N. vitripennis. 4. Furthermore, we found no indication of population‐specific male mate preference, confirming the stability of female sexual attractiveness, likely conveyed through their CHC profiles. C31 mono‐ and C33 di‐methyl‐branched alkanes were consistently and most strongly associated with sexual dimorphism, suggesting their potential role in encoding the female‐specific sexual signalling function. 5. Our study sheds light on how both adaptive flexibility and conserved sexual attractiveness can potentially be integrated and encoded in CHC profiles of N. vitripennis females across a wide distribution range in Europe. KW - chemical communication KW - climatic factors KW - desiccation resistance KW - sex pheromones KW - sexual dimorphism Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-262770 VL - 47 IS - 1 SP - 38 EP - 51 ER -