@article{WallaceLeonhardt2015,
  author    = {Wallace, Helen Margaret and Leonhardt, Sara Diana},
  title     = {Do Hybrid Trees Inherit Invasive Characteristics? Fruits of Corymbia torelliana X C. citriodora Hybrids and Potential for Seed Dispersal by Bees},
  series = {PLoS One},
  volume    = {10},
  journal   = {PLoS One},
  number    = {9},
  doi       = {10.1371/journal.pone.0138868},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-141777},
  pages     = {e0138868},
  year      = {2015},
  abstract  = {Tree invasions have substantial impacts on biodiversity and ecosystem functioning, and trees that are dispersed by animals are more likely to become invasive. In addition, hybridisation between plants is well documented as a source of new weeds, as hybrids gain new characteristics that allow them to become invasive. Corymbia torelliana is an invasive tree with an unusual animal dispersal mechanism: seed dispersal by stingless bees, that hybridizes readily with other species. We examined hybrids between C. torelliana and C. citriodora subsp. citriodora to determine whether hybrids have inherited the seed dispersal characteristics of C. torelliana that allow bee dispersal. Some hybrid fruits displayed the characteristic hollowness, resin production and resin chemistry associated with seed dispersal by bees. However, we did not observe bees foraging on any hybrid fruits until they had been damaged. We conclude that C. torelliana and C. citriodora subsp. citriodora hybrids can inherit some fruit characters that are associated with dispersal by bees, but we did not find a hybrid with the complete set of characters that would enable bee dispersal. However, around 20,000 hybrids have been planted in Australia, and ongoing monitoring is necessary to identify any hybrids that may become invasive.},
  language  = {en}
}
@article{SchneiderTautzGruenewaldetal.2012,
  author    = {Schneider, Christof W. and Tautz, J{\"u}rgen and Gr{\"u}newald, Bernd and Fuchs, Stefan},
  title     = {RFID Tracking of Sublethal Effects of Two Neonicotinoid Insecticides on the Foraging Behavior of Apis mellifera},
  series = {PLoS One},
  volume    = {7},
  journal   = {PLoS One},
  number    = {1},
  doi       = {10.1371/journal.pone.0030023},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-131753},
  pages     = {e30023},
  year      = {2012},
  abstract  = {The development of insecticides requires valid risk assessment procedures to avoid causing harm to beneficial insects and especially to pollinators such as the honeybee Apis mellifera. In addition to testing according to current guidelines designed to detect bee mortality, tests are needed to determine possible sublethal effects interfering with the animal's vitality and behavioral performance. Several methods have been used to detect sublethal effects of different insecticides under laboratory conditions using olfactory conditioning. Furthermore, studies have been conducted on the influence insecticides have on foraging activity and homing ability which require time-consuming visual observation. We tested an experimental design using the radiofrequency identification (RFID) method to monitor the influence of sublethal doses of insecticides on individual honeybee foragers on an automated basis. With electronic readers positioned at the hive entrance and at an artificial food source, we obtained quantifiable data on honeybee foraging behavior. This enabled us to efficiently retrieve detailed information on flight parameters. We compared several groups of bees, fed simultaneously with different dosages of a tested substance. With this experimental approach we monitored the acute effects of sublethal doses of the neonicotinoids imidacloprid (0.15-6 ng/bee) and clothianidin (0.05-2 ng/bee) under field-like circumstances. At field-relevant doses for nectar and pollen no adverse effects were observed for either substance. Both substances led to a significant reduction of foraging activity and to longer foraging flights at doses of >= 0.5 ng/bee (clothianidin) and >= 1.5 ng/bee (imidacloprid) during the first three hours after treatment. This study demonstrates that the RFID-method is an effective way to record short-term alterations in foraging activity after insecticides have been administered once, orally, to individual bees. We contribute further information on the understanding of how honeybees are affected by sublethal doses of insecticides.},
  language  = {en}
}
@phdthesis{Sauer2000,
  author    = {Sauer, Christina},
  title     = {Charakterisierung intrazellul{\"a}rer, bakterieller Endosymbionten im Mitteldarm von Ameisen der Gattung Camponotus},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-1940},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2000},
  abstract  = {In der vorliegenden Dissertation wurden verschiedene Themenbereiche bearbeitet, die zur Charakterisierung der intrazellul{\"a}ren, bakteriellen Endosymbionten im Mitteldarm von Ameisen der Gattung Camponotus beitrugen. Es wurden phylogenetische Untersuchungen mit Hilfe der 16S rDNA-Sequenzen der Symbionten und der Sequenzen der Cytochrom-Oxidase-Untereinheit I (COI-Sequenzen) ihrer Wirte durchgef{\"u}hrt, die zur n{\"a}heren Kl{\"a}rung der Fragen zu {\"U}bertragungsweg und Stellung der Camponotus-Endosymbionten verhalfen. Untersuchungen an dreizehn verschiedenen Camponotus-Arten brachten folgende Ergebnisse. Die intrazellul{\"a}ren Bakterien der Ameisen geh{\"o}ren zur g-Subklasse der Proteobakterien. Innerhalb des 16S-Stammbaumes der Symbionten kann man drei Untergruppen unterscheiden, in denen die einzelnen Arten enger miteinander verwandt sind. Bei den n{\"a}chstverwandten Bakteriennachbarn der Camponotus-Endosymbionten handelt es sich um die ebenfalls symbiontisch lebenden Bakterien der Gattungen Wigglesworthia und Buchnera. Die Ameisen-Symbionten besitzen in ihren rrs-Genen intervenierende DNA-Sequenzen (IVS), die stabile Sekund{\"a}rstrukturen ausbilden k{\"o}nnen. Ihre 16S-Gene sind nicht strangaufw{\"a}rts von den 23S-Genen lokalisiert. Durch diese genetische Besonderheit {\"a}hneln die Camponotus-Symbionten den Buchnera-Symbionten, deren rRNA-Gene auf zwei Transkriptionseinheiten verteilt sind. Innerhalb des Stammbaumes der untersuchten Wirtsameisen existieren ebenfalls drei Untergruppen, deren einzelne Arten enger miteinander verwandt sind. Die direkte Gegen{\"u}berstellung des Symbionten-Stammbaumes mit dem der Ameisen zeigt ein weitgehend gleiches Verzweigungsmuster. Beide Dendrogramme zeigen signifikante {\"U}bereinstimmungen bez{\"u}glich ihrer taxonomischen Beziehungen und legen eine kongruente Entwicklung von Symbionten und Wirten, die nur durch einen vertikalen {\"U}bertragungsweg erzeugt werden kann, nahe. Einzige Ausnahme bildete hierbei der C. castaneus-Symbiont, bei dem ein horizontaler Transfer von Symbionten nicht g{\"a}nzlich ausgeschlossen werden kann. Die im Rahmen dieser Dissertation durchgef{\"u}hrten phylogenetischen Untersuchungen erm{\"o}glichten die Benennung einer neuen Symbiontengattung innerhalb der gamma-Subgruppe der Proteobakterien: "Candidatus Blochmannia spp." Histologische Studien der Endosymbiose mit Hilfe von licht- und elektronenmikroskopischen Methoden sollten Fragen zur Symbiontenlokalisation innerhalb adulter Individuen beantworten und die Ergebnisse zum {\"U}bertragungsweg der intrazellul{\"a}ren Bakterien festigen. Die Endosymbionten sind in den Mitteldarmepithelien von Arbeiterinnen, K{\"o}niginnen und M{\"a}nnchen in Myzetozytenzellen lokalisiert, die in das Mitteldarmepithel interkalieren. Diese spezialisierten Zellen besitzen kaum Vesikel und tragen keinen Mikrovillisaum. In den Oozyten der Ovarien von K{\"o}niginnen und Arbeiterinnen wurden ebenfalls große Symbiontenmengen gefunden. Die Spermatheka der K{\"o}niginnen und die Geschlechtsorgane der M{\"a}nnchen waren symbiontenfrei. Die Abwesenheit von Symbionten innerhalb dieser beiden Organe zeigt, dass eine Bakterieninfektion der weiblichen Tiere nicht durch die M{\"a}nnchen stattfindet, sondern wie schon in den phylogenetischen Untersuchungen postuliert, ein rein maternaler {\"U}bertragungsweg der Symbionten vorliegt. Die Detektion der Bakterien in Eiern und Larven der Ameisen mittels In situ-Hybridisierungen trugen zur Aufkl{\"a}rung des Weges der Endosymbionten w{\"a}hrend der Embryogenese bei. W{\"a}hrend sich im abgelegten Ei ein Ring aus Symbionten bildete, kam es in den Larvenstadien 1 bis 3 zur Auswanderung der Bakterien in Meso- bzw. Ektoderm. Im gr{\"o}ßten untersuchten Larvenstadium 4, das kurz vor der Verpuppung stand, konnten die Symbionten ausschließlich in den Myzetozyten des Mitteldarmes detektiert werden. Die Behandlung der Ameisen mit Antibiotika erm{\"o}glichte es, symbiontenfreie Ameisen zu erzeugen, die {\"u}ber einen l{\"a}ngeren Zeitraum weiterlebten, ohne ihre Symbionten zu regenerieren. Im Rahmen dieser Arbeit gelang es erstmals, die intrazellul{\"a}ren Bakterien intakt aus dem sie umgebenden Mitteldarmgewebe zu isolieren. Somit konnten gereinigte Symbionten f{\"u}r Kultivierungs- und Infektionsversuche verwendet werden. Diese Versuche die mit Hilfe von Bakterienn{\"a}hrmedien und Insektenzelllinien durchgef{\"u}hrt wurden, zeigten jedoch sehr deutlich, dass es nicht m{\"o}glich ist, die Camponotus-Symbionten außerhalb ihrer Wirte zu kultivieren.},
  subject      = {Rossameise},
  language  = {de}
}
@article{MaihoffFriessHoissetal.2023,
  author    = {Maihoff, Fabienne and Friess, Nicolas and Hoiss, Bernhard and Schmid-Egger, Christian and Kerner, Janika and Neumayer, Johann and Hopfenm{\"u}ller, Sebastian and B{\"a}ssler, Claus and M{\"u}ller, J{\"o}rg and Classen, Alice},
  title     = {Smaller, more diverse and on the way to the top: Rapid community shifts of montane wild bees within an extraordinary hot decade},
  series = {Diversity and Distributions},
  volume    = {29},
  journal   = {Diversity and Distributions},
  number    = {2},
  doi       = {10.1111/ddi.13658},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-312126},
  pages     = {272-288},
  year      = {2023},
  abstract  = {Aim Global warming is assumed to restructure mountain insect communities in space and time. Theory and observations along climate gradients predict that insect abundance and richness, especially of small-bodied species, will increase with increasing temperature. However, the specific responses of single species to rising temperatures, such as spatial range shifts, also alter communities, calling for intensive monitoring of real-world communities over time. Location German Alps and pre-alpine forests in south-east Germany. Methods We empirically examined the temporal and spatial change in wild bee communities and its drivers along two largely well-protected elevational gradients (alpine grassland vs. pre-alpine forest), each sampled twice within the last decade. Results We detected clear abundance-based upward shifts in bee communities, particularly in cold-adapted bumble bee species, demonstrating the speed with which mobile organisms can respond to climatic changes. Mean annual temperature was identified as the main driver of species richness in both regions. Accordingly, and in large overlap with expectations under climate warming, we detected an increase in bee richness and abundance, and an increase in small-bodied species in low- and mid-elevations along the grassland gradient. Community responses in the pre-alpine forest gradient were only partly consistent with community responses in alpine grasslands. Main Conclusion In well-protected temperate mountain regions, small-bodied bees may initially profit from warming temperatures, by getting more abundant and diverse. Less severe warming, and differences in habitat openness along the forested gradient, however, might moderate species responses. Our study further highlights the utility of standardized abundance data for revealing rapid changes in bee communities over only one decade.},
  language  = {en}
}
@article{CastilloWurdackPaulietal.2022,
  author    = {Castillo, Ruth and Wurdack, Mareike and Pauli, Thomas and Keller, Alexander and Feldhaar, Heike and Polidori, Carlo and Niehuis, Oliver and Schmitt, Thomas},
  title     = {Evidence for a chemical arms race between cuckoo wasps of the genus Hedychrum and their distantly related host apoid wasps},
  series = {BMC Ecology and Evolution},
  volume    = {22},
  journal   = {BMC Ecology and Evolution},
  number    = {1},
  doi       = {10.1186/s12862-022-02093-8},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-301289},
  year      = {2022},
  abstract  = {Background Brood parasites can exert strong selection pressure on their hosts. Many brood parasites escape their detection by mimicking sensory cues of their hosts. However, there is little evidence whether or not the hosts are able to escape the parasites' mimicry by changing these cues. We addressed this question by analyzing cuticular hydrocarbon (CHC) profiles of Cerceris and Philanthus wasps and their brood parasites, cuckoo wasps mimicking the CHC profiles of their hosts. Some of these hosts use hydrocarbons to preserve their prey against fungal infestation and thus, they cannot significantly change their CHC composition in response to chemical mimicry by Hedychrum brood parasites. Results We found that the CHC overlap between brood parasites and their hosts was lower in case of host wasps not preserving their prey than in case of prey-preserving host wasps, whose CHC evolution is constrained. Furthermore, the CHC profiles in non-preserving host wasps is more strongly diversified in females than in males, thus in the sex that is chemically mimicked by brood parasites. Conclusion Our results provide evidence for a chemical arms race between those hosts that are liberated from stabilizing selection on their chemical template and their parasites.},
  language  = {en}
}