@article{LeonhardtSchmittBluethgen2011, author = {Leonhardt, Sara D. and Schmitt, Thomas and Bl{\"u}thgen, Nico}, title = {Tree Resin Composition, Collection Behavior and Selective Filters Shape Chemical Profiles of Tropical Bees (Apidae: Meliponini)}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-69035}, year = {2011}, abstract = {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.}, subject = {Stachellose Biene}, language = {en} } @article{MenzelBluethgenTolaschetal.2013, author = {Menzel, Florian and Bl{\"u}thgen, Nico and Tolasch, Till and Conrad, J{\"u}rgen and Beifuss, Uwe and Beuerle, Till and Schmitt, Thomas}, title = {Crematoenones - a novel substance class exhibited by ants functions as appeasement signal}, series = {Frontiers in Zoology}, volume = {10}, journal = {Frontiers in Zoology}, number = {32}, issn = {1742-9994}, doi = {10.1186/1742-9994-10-32}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-122595}, year = {2013}, abstract = {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.}, language = {en} } @article{GamezViruesPerovićGossneretal.2015, author = {G{\´a}mez-Viru{\´e}s, Sagrario and Perović, David J. and Gossner, Martin M. and B{\"o}rschig, Carmen and Bl{\"u}thgen, Nico and de Jong, Heike and Simons, Nadja K. and Klein, Alexandra-Maria and Krauss, Jochen and Maier, Gwen and Scherber, Christoph and Steckel, Juliane and Rothenw{\"o}hrer, Christoph and Steffan-Dewenter, Ingolf and Weiner, Christiane N. and Weisser, Wolfgang and Werner, Michael and Tscharntke, Teja and Westphal, Catrin}, title = {Landscape simplification filters species traits and drives biotic homogenization}, series = {Nature Communications}, volume = {6}, journal = {Nature Communications}, number = {8568}, doi = {10.1038/ncomms9568}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-141925}, year = {2015}, abstract = {Biodiversity loss can affect the viability of ecosystems by decreasing the ability of communities to respond to environmental change and disturbances. Agricultural intensification is a major driver of biodiversity loss and has multiple components operating at different spatial scales: from in-field management intensity to landscape-scale simplification. Here we show that landscape-level effects dominate functional community composition and can even buffer the effects of in-field management intensification on functional homogenization, and that animal communities in real-world managed landscapes show a unified response (across orders and guilds) to both landscape-scale simplification and in-field intensification. Adults and larvae with specialized feeding habits, species with shorter activity periods and relatively small body sizes are selected against in simplified landscapes with intense in-field management. Our results demonstrate that the diversity of land cover types at the landscape scale is critical for maintaining communities, which are functionally diverse, even in landscapes where in-field management intensity is high.}, language = {en} } @article{KaluzaWallaceKelleretal.2017, author = {Kaluza, Benjamin F. and Wallace, Helen and Keller, Alexander and Heard, Tim A. and Jeffers, Bradley and Drescher, Nora and Bl{\"u}thgen, Nico and Leonhardt, Sara D.}, title = {Generalist social bees maximize diversity intake in plant species-rich and resource-abundant environments}, series = {Ecosphere}, volume = {8}, journal = {Ecosphere}, number = {3}, doi = {10.1002/ecs2.1758}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-171155}, pages = {e01758}, year = {2017}, abstract = {Numerous studies revealed a positive relationship between biodiversity and ecosystem functioning, suggesting that biodiverse environments may not only enhance ecosystem processes, but also benefit individual ecosystem members by, for example, providing a higher diversity of resources. Whether and how the number of available resources affects resource collection and subsequently consumers (e.g., through impacting functions associated with resources) have, however, been little investigated, although a better understanding of this relationship may help explain why the abundance and richness of many animal species typically decline with decreasing plant (resource) diversity. Using a social bee species as model (Tetragonula carbonaria), we investigated how plant species richness—recorded for study sites located in different habitats—and associated resource abundance affected the diversity and functionality (here defined as nutritional content and antimicrobial activity) of resources (i.e., pollen, nectar, and resin) collected by a generalist herbivorous consumer. The diversity of both pollen and resin collected strongly increased with increasing plant/tree species richness, while resource abundance was only positively correlated with resin diversity. These findings suggest that bees maximize resource diversity intake in (resource) diverse habitats. Collecting more diverse resources did, however, not increase their functionality, which appeared to be primarily driven by the surrounding (plant) source community in our study. In generalist herbivores, maximizing resource diversity intake may therefore primarily secure collection of sufficient amounts of resources across the entire foraging season, but it also ensures that the allocated resources meet all functional needs. Decreasing available resource diversity may thus impact consumers primarily by reduced resource abundance, but also by reduced resource functionality, particularly when resources of high functionality (e.g., from specific plant species) become scarce.}, language = {en} } @article{SeiboldHothornGossneretal.2021, author = {Seibold, Sebastian and Hothorn, Torsten and Gossner, Martin M. and Simons, Nadja K. and Bl{\"u}thgen, Nico and M{\"u}ller, J{\"o}rg and Ambarl{\i}, Didem and Ammer, Christian and Bauhus, J{\"u}rgen and Fischer, Markus and Habel, Jan C. and Penone, Caterina and Schall, Peter and Schulze, Ernst-Detlef and Weisser, Wolfgang W.}, title = {Insights from regional and short-term biodiversity monitoring datasets are valuable: a reply to Daskalova et al. 2021}, series = {Insect Conservation and Diversity}, volume = {14}, journal = {Insect Conservation and Diversity}, number = {1}, doi = {10.1111/icad.12467}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-228309}, pages = {144 -- 148}, year = {2021}, abstract = {Reports of major losses in insect biodiversity have stimulated an increasing interest in temporal population changes. Existing datasets are often limited to a small number of study sites, few points in time, a narrow range of land-use intensities and only some taxonomic groups, or they lack standardised sampling. While new monitoring programs have been initiated, they still cover rather short time periods. Daskalova et al. 2021 (Insect Conservation and Diversity, 14, 1-18) argue that temporal trends of insect populations derived from short time series are biased towards extreme trends, while their own analysis of an assembly of shorter- and longer-term time series does not support an overall insect decline. With respect to the results of Seibold et al. 2019 (Nature, 574, 671-674) based on a 10-year multi-site time series, they claim that the analysis suffers from not accounting for temporal pseudoreplication. Here, we explain why the criticism of missing statistical rigour in the analysis of Seibold et al. (2019) is not warranted. Models that include 'year' as random effect, as suggested by Daskalova et al. (2021), fail to detect non-linear trends and assume that consecutive years are independent samples which is questionable for insect time-series data. We agree with Daskalova et al. (2021) that the assembly and analysis of larger datasets is urgently needed, but it will take time until such datasets are available. Thus, short-term datasets are highly valuable, should be extended and analysed continually to provide a more detailed understanding of insect population changes under the influence of global change, and to trigger immediate conservation actions.}, language = {en} }