Search

Lichens are widely acknowledged to be a key component of high latitude ecosystems. However, the time investment needed for full inventories and the lack of taxonomic identification resources for crustose lichen and lichenicolous fungal diversity have hampered efforts to fully gauge the depth of species richness in these ecosystems. Using a combination of classical field inventory and extensive deployment of chemical and molecular analysis, we assessed the diversity of lichens and associated fungi in Glacier Bay National Park, Alaska (USA), a mixed landscape of coastal boreal rainforest and early successional low elevation habitats deglaciated after the Little Ice Age. We collected nearly 5000 specimens and found a total of 947 taxa, including 831 taxa of lichen-forming and 96 taxa of lichenicolous fungi together with 20 taxa of saprotrophic fungi typically included in lichen studies. A total of 98 species (10.3% of those detected) could not be assigned to known species and of those, two genera and 27 species are described here as new to science: Atrophysma cyanomelanos gen. et sp. nov., Bacidina circumpulla, Biatora marmorea, Carneothele sphagnicola gen. et sp. nov., Cirrenalia lichenicola, Corticifraga nephromatis, Fuscidea muskeg, Fuscopannaria dillmaniae, Halecania athallina, Hydropunctaria alaskana, Lambiella aliphatica, Lecania hydrophobica, Lecanora viridipruinosa, Lecidea griseomarginata, L. streveleri, Miriquidica gyrizans, Niesslia peltigerae, Ochrolechia cooperi, Placynthium glaciale, Porpidia seakensis, Rhizocarpon haidense, Sagiolechia phaeospora, Sclerococcum fissurinae, Spilonema maritimum, Thelocarpon immersum, Toensbergia blastidiata and Xenonectriella nephromatis. An additional 71 'known unknown' species are cursorily described. Four new combinations are made: Lepra subvelata (G. K. Merr.) T. Sprib., Ochrolechia minuta (Degel.) T. Sprib., Steineropsis laceratula (Hue) T. Sprib. & Ekman and Toensbergia geminipara (Th. Fr.) T. Sprib. & Resl. T

Lichens are widely acknowledged to be a key component of high latitude ecosystems. However, the time investment needed for full inventories and the lack of taxonomic identification resources for crustose lichen and lichenicolous fungal diversity have hampered efforts to fully gauge the depth of species richness in these ecosystems. Using a combination of classical field inventory and extensive deployment of chemical and molecular analysis, we assessed the diversity of lichens and associated fungi in Glacier Bay National Park, Alaska (USA), a mixed landscape of coastal boreal rainforest and early successional low elevation habitats deglaciated after the Little Ice Age. We collected nearly 5000 specimens and found a total of 947 taxa, including 831 taxa of lichen-forming and 96 taxa of lichenicolous fungi together with 20 taxa of saprotrophic fungi typically included in lichen studies. A total of 98 species (10.3% of those detected) could not be assigned to known species and of those, two genera and 27 species are described here as new to science: Atrophysma cyanomelanos gen. et sp. nov., Bacidina circumpulla, Biatora marmorea, Carneothele sphagnicola gen. et sp. nov., Cirrenalia lichenicola, Corticifraga nephromatis, Fuscidea muskeg, Fuscopannaria dillmaniae, Halecania athallina, Hydropunctaria alaskana, Lambiella aliphatica, Lecania hydrophobica, Lecanora viridipruinosa, Lecidea griseomarginata, L. streveleri, Miriquidica gyrizans, Niesslia peltigerae, Ochrolechia cooperi, Placynthium glaciale, Porpidia seakensis, Rhizocarpon haidense, Sagiolechia phaeospora, Sclerococcum fissurinae, Spilonema maritimum, Thelocarpon immersum, Toensbergia blastidiata and Xenonectriella nephromatis. An additional 71 'known unknown' species are cursorily described. Four new combinations are made: Lepra subvelata (G. K. Merr.) T. Sprib., Ochrolechia minuta (Degel.) T. Sprib., Steineropsis laceratula (Hue) T. Sprib. & Ekman and Toensbergia geminipara (Th. Fr.) T. Sprib. & Resl. T

Lichens are widely acknowledged to be a key component of high latitude ecosystems. However, the time investment needed for full inventories and the lack of taxonomic identification resources for crustose lichen and lichenicolous fungal diversity have hampered efforts to fully gauge the depth of species richness in these ecosystems. Using a combination of classical field inventory and extensive deployment of chemical and molecular analysis, we assessed the diversity of lichens and associated fungi in Glacier Bay National Park, Alaska (USA), a mixed landscape of coastal boreal rainforest and early successional low elevation habitats deglaciated after the Little Ice Age. We collected nearly 5000 specimens and found a total of 947 taxa, including 831 taxa of lichen-forming and 96 taxa of lichenicolous fungi together with 20 taxa of saprotrophic fungi typically included in lichen studies. A total of 98 species (10.3% of those detected) could not be assigned to known species and of those, two genera and 27 species are described here as new to science: Atrophysma cyanomelanos gen. et sp. nov., Bacidina circumpulla, Biatora marmorea, Carneothele sphagnicola gen. et sp. nov., Cirrenalia lichenicola, Corticifraga nephromatis, Fuscidea muskeg, Fuscopannaria dillmaniae, Halecania athallina, Hydropunctaria alaskana, Lambiella aliphatica, Lecania hydrophobica, Lecanora viridipruinosa, Lecidea griseomarginata, L. streveleri, Miriquidica gyrizans, Niesslia peltigerae, Ochrolechia cooperi, Placynthium glaciale, Porpidia seakensis, Rhizocarpon haidense, Sagiolechia phaeospora, Sclerococcum fissurinae, Spilonema maritimum, Thelocarpon immersum, Toensbergia blastidiata and Xenonectriella nephromatis. An additional 71 'known unknown' species are cursorily described. Four new combinations are made: Lepra subvelata (G. K. Merr.) T. Sprib., Ochrolechia minuta (Degel.) T. Sprib., Steineropsis laceratula (Hue) T. Sprib. & Ekman and Toensbergia geminipara (Th. Fr.) T. Sprib. & Resl. T

Lichens are widely acknowledged to be a key component of high latitude ecosystems. However, the time investment needed for full inventories and the lack of taxonomic identification resources for crustose lichen and lichenicolous fungal diversity have hampered efforts to fully gauge the depth of species richness in these ecosystems. Using a combination of classical field inventory and extensive deployment of chemical and molecular analysis, we assessed the diversity of lichens and associated fungi in Glacier Bay National Park, Alaska (USA), a mixed landscape of coastal boreal rainforest and early successional low elevation habitats deglaciated after the Little Ice Age. We collected nearly 5000 specimens and found a total of 947 taxa, including 831 taxa of lichen-forming and 96 taxa of lichenicolous fungi together with 20 taxa of saprotrophic fungi typically included in lichen studies. A total of 98 species (10.3% of those detected) could not be assigned to known species and of those, two genera and 27 species are described here as new to science: Atrophysma cyanomelanos gen. et sp. nov., Bacidina circumpulla, Biatora marmorea, Carneothele sphagnicola gen. et sp. nov., Cirrenalia lichenicola, Corticifraga nephromatis, Fuscidea muskeg, Fuscopannaria dillmaniae, Halecania athallina, Hydropunctaria alaskana, Lambiella aliphatica, Lecania hydrophobica, Lecanora viridipruinosa, Lecidea griseomarginata, L. streveleri, Miriquidica gyrizans, Niesslia peltigerae, Ochrolechia cooperi, Placynthium glaciale, Porpidia seakensis, Rhizocarpon haidense, Sagiolechia phaeospora, Sclerococcum fissurinae, Spilonema maritimum, Thelocarpon immersum, Toensbergia blastidiata and Xenonectriella nephromatis. An additional 71 'known unknown' species are cursorily described. Four new combinations are made: Lepra subvelata (G. K. Merr.) T. Sprib., Ochrolechia minuta (Degel.) T. Sprib., Steineropsis laceratula (Hue) T. Sprib. & Ekman and Toensbergia geminipara (Th. Fr.) T. Sprib. & Resl. T

Lichens are widely acknowledged to be a key component of high latitude ecosystems. However, the time investment needed for full inventories and the lack of taxonomic identification resources for crustose lichen and lichenicolous fungal diversity have hampered efforts to fully gauge the depth of species richness in these ecosystems. Using a combination of classical field inventory and extensive deployment of chemical and molecular analysis, we assessed the diversity of lichens and associated fungi in Glacier Bay National Park, Alaska (USA), a mixed landscape of coastal boreal rainforest and early successional low elevation habitats deglaciated after the Little Ice Age. We collected nearly 5000 specimens and found a total of 947 taxa, including 831 taxa of lichen-forming and 96 taxa of lichenicolous fungi together with 20 taxa of saprotrophic fungi typically included in lichen studies. A total of 98 species (10.3% of those detected) could not be assigned to known species and of those, two genera and 27 species are described here as new to science: Atrophysma cyanomelanos gen. et sp. nov., Bacidina circumpulla, Biatora marmorea, Carneothele sphagnicola gen. et sp. nov., Cirrenalia lichenicola, Corticifraga nephromatis, Fuscidea muskeg, Fuscopannaria dillmaniae, Halecania athallina, Hydropunctaria alaskana, Lambiella aliphatica, Lecania hydrophobica, Lecanora viridipruinosa, Lecidea griseomarginata, L. streveleri, Miriquidica gyrizans, Niesslia peltigerae, Ochrolechia cooperi, Placynthium glaciale, Porpidia seakensis, Rhizocarpon haidense, Sagiolechia phaeospora, Sclerococcum fissurinae, Spilonema maritimum, Thelocarpon immersum, Toensbergia blastidiata and Xenonectriella nephromatis. An additional 71 'known unknown' species are cursorily described. Four new combinations are made: Lepra subvelata (G. K. Merr.) T. Sprib., Ochrolechia minuta (Degel.) T. Sprib., Steineropsis laceratula (Hue) T. Sprib. & Ekman and Toensbergia geminipara (Th. Fr.) T. Sprib. & Resl. Thirty-ei

Lichens are widely acknowledged to be a key component of high latitude ecosystems. However, the time investment needed for full inventories and the lack of taxonomic identification resources for crustose lichen and lichenicolous fungal diversity have hampered efforts to fully gauge the depth of species richness in these ecosystems. Using a combination of classical field inventory and extensive deployment of chemical and molecular analysis, we assessed the diversity of lichens and associated fungi in Glacier Bay National Park, Alaska (USA), a mixed landscape of coastal boreal rainforest and early successional low elevation habitats deglaciated after the Little Ice Age. We collected nearly 5000 specimens and found a total of 947 taxa, including 831 taxa of lichen-forming and 96 taxa of lichenicolous fungi together with 20 taxa of saprotrophic fungi typically included in lichen studies. A total of 98 species (10.3% of those detected) could not be assigned to known species and of those, two genera and 27 species are described here as new to science: Atrophysma cyanomelanos gen. et sp. nov., Bacidina circumpulla, Biatora marmorea, Carneothele sphagnicola gen. et sp. nov., Cirrenalia lichenicola, Corticifraga nephromatis, Fuscidea muskeg, Fuscopannaria dillmaniae, Halecania athallina, Hydropunctaria alaskana, Lambiella aliphatica, Lecania hydrophobica, Lecanora viridipruinosa, Lecidea griseomarginata, L. streveleri, Miriquidica gyrizans, Niesslia peltigerae, Ochrolechia cooperi, Placynthium glaciale, Porpidia seakensis, Rhizocarpon haidense, Sagiolechia phaeospora, Sclerococcum fissurinae, Spilonema maritimum, Thelocarpon immersum, Toensbergia blastidiata and Xenonectriella nephromatis. An additional 71 'known unknown' species are cursorily described. Four new combinations are made: Lepra subvelata (G. K. Merr.) T. Sprib., Ochrolechia minuta (Degel.) T. Sprib., Steineropsis laceratula (Hue) T. Sprib. & Ekman and Toensbergia geminipara (Th. Fr.) T. Sprib. & Resl. T

Data on seed morphology of 132 species from 40 genera of all subfamilies (Ornithogaloideae, Hyacinthoideae, Urgineoideae, Oziroëoideae) of Hyacinthaceae are presented. So far, this is the most extensive study on the seed surface of Hyacinthaceae using scanning electron microscopy (SEM), and we also give insights into the systematic implications of seed surface micromorphology.

Polistine wasps collect nectar for their energetic demand and for the provision of the brood. They are mainly ectothermic during different behavioral tasks. We investigated the body temperature of two species living in differing habitats and climate regions, in order to reveal the environmental influence on their thermoregulatory behavior. The species were Polistes dominula in the temperate climate of Central Europe, and Polistes gallicus in the warm Mediterranean climate of Southern Europe. The wasp’s body temperature was measured during foraging on lovage (Levisticum officinale) and fennel (Foeniculum vulgare) by infrared thermography in the entire ambient temperature range they are usually exposed to (Ta ~ 20–40 °C). The temperature of all body parts increased nearly linearly with ambient temperature, with the thorax as the warmest part. To achieve optimal foraging temperatures, they preferably use solar radiation. An “operative temperature model” enabled the evaluation of the endothermic effort. Polistes dominula foraging on lovage exhibited no endothermic activity. However, while foraging on fennel they had a weak and almost constant endothermic performance of about 1 °C. Polistes gallicus, by contrast, exhibited mostly no or only minor endothermy during foraging. Both wasps avoid a high energetic effort and this way reduce their foraging costs.

Data on seed morphology of 132 species from 40 genera of all subfamilies (Ornithogaloideae, Hyacinthoideae, Urgineoideae, Oziroëoideae) of Hyacinthaceae are presented. So far, this is the most extensive study on the seed surface of Hyacinthaceae using scanning electron microscopy (SEM), and we also give insights into the systematic implications of seed surface micromorphology.

vorgelegt von BA Julia M. Stabentheiner, Universität Innsbruck, Masterarbeit, 2018, (VLID)2673461

Spring frosts, as experienced in Europe in April 2016 and 2017, pose a considerable risk to agricultural production, with the potential to cause significant damages to agricultural yields. Meteorological blocking events (stable high-pressure systems) have been shown to be one of the factors that trigger cold spells in spring. While current knowledge does not allow for drawing conclusions as to any change in future frequency and duration of blocking episodes due to climate change, the combination of their stable occurrence with the biological system under a warming trend can lead to economic damage increases. To evaluate future frost risk for apple producers in south-eastern Styria, we combine a phenological sequential model with highly resolved climate projections for Austria. Our model projects a mean advance of blooming of –1.6 ± 0.9 days per decade, shifting the bloom onset towards early April by the end of the 21st century. Our findings indicate that overall frost risk for apple cultures will remain in a warmer climate and potentially even increase due to a stronger connection between blocking and cold spells in early spring that can be identified from observational data. To prospectively deal with frost risk, measures are needed that either stabilize crop yields or ensure farmers’ income by other means. We identify appropriate adaptation measures and relate their costs to the potential frost risk increase. Even if applied successfully, the costs of these measures in combination with future residual damages represent additional climate change related costs., Fonds zur Förderung der Wissenschaftlichen Forschung W 1256-G15, Version of record

Pollen germination as a crucial process in plant development strongly depends on the accessibility of carbon as energy source. Carbohydrates, however, function not only as a primary energy source, but also as important signaling components. In a comprehensive study, we analyzed various aspects of the impact of 32 different sugars on in vitro germination of Arabidopsis pollen comprising about 150 variations of individual sugars and combinations. Twenty-six structurally different mono-, di- and oligosaccharides, and sugar analogs were initially tested for their ability to support pollen germination. Whereas several di- and oligosaccharides supported pollen germination, hexoses such as glucose, fructose and mannose did not support and even considerably inhibited pollen germination when added to germination-supporting medium. Complementary experiments using glucose analogs with varying functional features, the hexokinase inhibitor mannoheptulose and the glucose-insensitive hexokinase-deficient Arabidopsis mutant gin2-1 suggested that mannose- and glucose-mediated inhibition of sucrose-supported pollen germination depends partially on hexokinase signaling. The results suggest that, in addition to their role as energy source, sugars act as signaling molecules differentially regulating the complex process of pollen germination depending on their structural properties. Thus, a sugar-dependent multilayer regulation of Arabidopsis pollen germination is supported, which makes this approach a valuable experimental system for future studies addressing sugar sensing and signaling.

Pollen germination as a crucial process in plant development strongly depends on the accessibility of carbon as energy source. Carbohydrates, however, function not only as a primary energy source, but also as important signaling components. In a comprehensive study, we analyzed various aspects of the impact of 32 different sugars on in vitro germination of Arabidopsis pollen comprising about 150 variations of individual sugars and combinations. Twenty-six structurally different mono-, di- and oligosaccharides, and sugar analogs were initially tested for their ability to support pollen germination. Whereas several di- and oligosaccharides supported pollen germination, hexoses such as glucose, fructose and mannose did not support and even considerably inhibited pollen germination when added to germination-supporting medium. Complementary experiments using glucose analogs with varying functional features, the hexokinase inhibitor mannoheptulose and the glucose-insensitive hexokinase-deficient Arabidopsis mutant gin2-1 suggested that mannose- and glucose-mediated inhibition of sucrose-supported pollen germination depends partially on hexokinase signaling. The results suggest that, in addition to their role as energy source, sugars act as signaling molecules differentially regulating the complex process of pollen germination depending on their structural properties. Thus, a sugar-dependent multilayer regulation of Arabidopsis pollen germination is supported, which makes this approach a valuable experimental system for future studies addressing sugar sensing and signaling.

Pollen germination as a crucial process in plant development strongly depends on the accessibility of carbon as energy source. Carbohydrates, however, function not only as a primary energy source, but also as important signaling components. In a comprehensive study, we analyzed various aspects of the impact of 32 different sugars on in vitro germination of Arabidopsis pollen comprising about 150 variations of individual sugars and combinations. Twenty-six structurally different mono-, di- and oligosaccharides, and sugar analogs were initially tested for their ability to support pollen germination. Whereas several di- and oligosaccharides supported pollen germination, hexoses such as glucose, fructose and mannose did not support and even considerably inhibited pollen germination when added to germination-supporting medium. Complementary experiments using glucose analogs with varying functional features, the hexokinase inhibitor mannoheptulose and the glucose-insensitive hexokinase-deficient Arabidopsis mutant gin2-1 suggested that mannose- and glucose-mediated inhibition of sucrose-supported pollen germination depends partially on hexokinase signaling. The results suggest that, in addition to their role as energy source, sugars act as signaling molecules differentially regulating the complex process of pollen germination depending on their structural properties. Thus, a sugar-dependent multilayer regulation of Arabidopsis pollen germination is supported, which makes this approach a valuable experimental system for future studies addressing sugar sensing and signaling.

Pollen germination as a crucial process in plant development strongly depends on the accessibility of carbon as energy source. Carbohydrates, however, function not only as a primary energy source, but also as important signaling components. In a comprehensive study, we analyzed various aspects of the impact of 32 different sugars on in vitro germination of Arabidopsis pollen comprising about 150 variations of individual sugars and combinations. Twenty-six structurally different mono-, di- and oligosaccharides, and sugar analogs were initially tested for their ability to support pollen germination. Whereas several di- and oligosaccharides supported pollen germination, hexoses such as glucose, fructose and mannose did not support and even considerably inhibited pollen germination when added to germination-supporting medium. Complementary experiments using glucose analogs with varying functional features, the hexokinase inhibitor mannoheptulose and the glucose-insensitive hexokinase-deficient Arabidopsis mutant gin2-1 suggested that mannose- and glucose-mediated inhibition of sucrose-supported pollen germination depends partially on hexokinase signaling. The results suggest that, in addition to their role as energy source, sugars act as signaling molecules differentially regulating the complex process of pollen germination depending on their structural properties. Thus, a sugar-dependent multilayer regulation of Arabidopsis pollen germination is supported, which makes this approach a valuable experimental system for future studies addressing sugar sensing and signaling.

Pollen germination as a crucial process in plant development strongly depends on the accessibility of carbon as energy source. Carbohydrates, however, function not only as a primary energy source, but also as important signaling components. In a comprehensive study, we analyzed various aspects of the impact of 32 different sugars on in vitro germination of Arabidopsis pollen comprising about 150 variations of individual sugars and combinations. Twenty-six structurally different mono-, di- and oligosaccharides, and sugar analogs were initially tested for their ability to support pollen germination. Whereas several di- and oligosaccharides supported pollen germination, hexoses such as glucose, fructose and mannose did not support and even considerably inhibited pollen germination when added to germination-supporting medium. Complementary experiments using glucose analogs with varying functional features, the hexokinase inhibitor mannoheptulose and the glucose-insensitive hexokinase-deficient Arabidopsis mutant gin2-1 suggested that mannose- and glucose-mediated inhibition of sucrose-supported pollen germination depends partially on hexokinase signaling. The results suggest that, in addition to their role as energy source, sugars act as signaling molecules differentially regulating the complex process of pollen germination depending on their structural properties. Thus, a sugar-dependent multilayer regulation of Arabidopsis pollen germination is supported, which makes this approach a valuable experimental system for future studies addressing sugar sensing and signaling.

Endothermic insects like honeybees and some wasps have to cope with an enormous heat loss during foraging because of their small body size in comparison to endotherms like mammals and birds. The enormous costs of thermoregulation call for optimisation. Honeybees and wasps differ in their critical thermal maximum, which enables the bees to kill the wasps by heat. We here demonstrate the benefits of a combined use of body temperature measurement with infrared thermography, and respiratory measurements of energy turnover (O2 consumption or CO2 production via flow-through respirometry) to answer questions of insect ecophysiological research, and we describe calibrations to receive accurate results. To assess the question of what foraging honeybees optimise, their body temperature was compared with their energy turnover. Honeybees foraging from an artificial flower with unlimited sucrose flow increased body surface temperature and energy turnover with profitability of foraging (sucrose content of the food; 0.5 or 1.5 mol/L). Costs of thermoregulation, however, were rather independent of ambient temperature (13–30 °C). External heat gain by solar radiation was used to increase body temperature. This optimised foraging energetics by increasing suction speed. In determinations of insect respiratory critical thermal limits, the combined use of respiratory measurements and thermography made possible a more conclusive interpretation of respiratory traces.

For over 140 years, lichens have been regarded as a symbiosis between a single fungus, usually an ascomycete, and a photosynthesizing partner. Other fungi have long been known to occur as occasional parasites or endophytes, but the one lichen-one fungus paradigm has seldom been questioned. Here we show that many common lichens are composed of the known ascomycete, the photosynthesizing partner, and, unexpectedly, specific basidiomycete yeasts. These yeasts are embedded in the cortex, and their abundance correlates with previously unexplained variations in phenotype. Basidiomycete lineages maintain close associations with specific lichen species over large geographical distances and have been found on six continents. The structurally important lichen cortex, long treated as a zone of differentiated ascomycete cells, appears to consistently contain two unrelated fungi.

The European paper wasp, Polistes dominulus Christ, is an abundant wasp species in South and Central Europe which dispersed to the north in recent times. Polistes dominulus exhibits an energy-extensive mode of life, spending much time resting at the nest, which should be reflected in adaptations regarding gas exchange and standard metabolism. We analysed the resting metabolism (CO2 emission) of Polistes dominulus workers in the ambient temperature range an individual may be exposed to during a breeding season (T a = 2.4–40.6 °C) via flow through respirometry. Behaviour and endothermic activity were assessed by infrared thermography. With rising T a, CO2 release followed an exponential increase from 27 to 149 and 802 nl g−1 min−1 at T a = 3, 20 and 35 °C, respectively. Measurements of the thermal regime at the nest showed that resting P. dominulus are most of the time in the lower range of their standard metabolic curve. A comparison with a “highly energetic” wasp like Vespula sp. revealed that Polistes dominulus not only optimises behaviour but also reduces metabolism to save energy. The CO2 emission patterns changed with ambient temperature, from discontinuous (≤25 °C) to cyclic (25–36 °C) and continuous gas exchange at higher temperatures. A pronounced break appeared in the data progression regarding cycle frequency and CO2 emission per gas exchange cycle between 15 and 10 °C. This striking change in gas exchange features indicates a physiological adaptation to special respiratory requirements at low temperatures.

The European paper wasp, Polistes dominulus Christ, is an abundant wasp species in South and Central Europe which dispersed to the north in recent times. Polistes dominulus exhibits an energy-extensive mode of life, spending much time resting at the nest, which should be reflected in adaptations regarding gas exchange and standard metabolism. We analysed the resting metabolism (CO2 emission) of Polistes dominulus workers in the ambient temperature range an individual may be exposed to during a breeding season (T a = 2.4–40.6 °C) via flow through respirometry. Behaviour and endothermic activity were assessed by infrared thermography. With rising T a, CO2 release followed an exponential increase from 27 to 149 and 802 nl g−1 min−1 at T a = 3, 20 and 35 °C, respectively. Measurements of the thermal regime at the nest showed that resting P. dominulus are most of the time in the lower range of their standard metabolic curve. A comparison with a “highly energetic” wasp like Vespula sp. revealed that Polistes dominulus not only optimises behaviour but also reduces metabolism to save energy. The CO2 emission patterns changed with ambient temperature, from discontinuous (≤25 °C) to cyclic (25–36 °C) and continuous gas exchange at higher temperatures. A pronounced break appeared in the data progression regarding cycle frequency and CO2 emission per gas exchange cycle between 15 and 10 °C. This striking change in gas exchange features indicates a physiological adaptation to special respiratory requirements at low temperatures.

The analysis of physiological parameters is important to understand the link between plant phenotypes and their genetic bases, and therefore is needed as an important element in the analysis of model and crop plants. The activities of enzymes involved in primary carbohydrate metabolism have been shown to be strongly associated with growth performance, crop yield, and quality, as well as stress responses. A simple, fast, and cost-effective method to determine activities for 13 key enzymes involved in carbohydrate metabolism has been established, mainly based on coupled spectrophotometric kinetic assays. The comparison of extraction buffers and requirement for dialysis of crude protein extracts resulted in a universal protein extraction protocol, suitable for the preparation of protein extracts from different organs of various species. Individual published kinetic activity assays were optimized and adapted for a semi-high-throughput 96-well assay format. These assays proved to be robust and are thus suitable for physiological phenotyping, enabling the characterization and diagnosis of the physiological state. The potential of the determination of distinct enzyme activity signatures as part of a physiological fingerprint was shown for various organs and tissues from three monocot and five dicot model and crop species, including two case studies with external stimuli. Differential and specific enzyme activity signatures are apparent during inflorescence development and upon in vitro cold treatment of young inflorescences in the monocot ryegrass, related to conditions for doubled haploid formation. Likewise, treatment of dicot spring oilseed rape with elevated CO2 concentration resulted in distinct patterns of enzyme activity responses in leaves.

The Western honeybees Apis mellifera carnica and A. m. ligustica are closely related subspecies living in neighbouring regions. Metabolism and the upper lethal thermal limits are crucial physiological traits, adapted in the evolutionary process to environment and climate conditions. We investigated whether samples from these two ecotypes differ in these traits. The standard metabolic rate was higher in the A. m. ligustica population only at a high temperature (T a ~ 40 °C; dVCO2 = 12 nl s−1; P < 0.05), probably due to a higher body temperature (dTthorax = 1.5 °C; P < 0.01). The critical thermal maximum of activity and respiration was similar (difference activity CTmax = 0.8 °C, respiratory CTmax = 1.1 °C). The lethal temperature (LT50, 8h) revealed higher tolerance and survival rates of the Ligustica bees (Carnica 50.3 °C; Ligustica 51.7 °C; P < 0.02). Results reveal the adaptation of the two subspecies to their historic climate conditions, possibly favouring Ligustica in a warming environment.

The Western honeybees Apis mellifera carnica and A. m. ligustica are closely related subspecies living in neighbouring regions. Metabolism and the upper lethal thermal limits are crucial physiological traits, adapted in the evolutionary process to environment and climate conditions. We investigated whether samples from these two ecotypes differ in these traits. The standard metabolic rate was higher in the A. m. ligustica population only at a high temperature (T a ~ 40 °C; dVCO2 = 12 nl s−1; P < 0.05), probably due to a higher body temperature (dTthorax = 1.5 °C; P < 0.01). The critical thermal maximum of activity and respiration was similar (difference activity CTmax = 0.8 °C, respiratory CTmax = 1.1 °C). The lethal temperature (LT50, 8h) revealed higher tolerance and survival rates of the Ligustica bees (Carnica 50.3 °C; Ligustica 51.7 °C; P < 0.02). Results reveal the adaptation of the two subspecies to their historic climate conditions, possibly favouring Ligustica in a warming environment.

We investigated the respiration patterns of wasps (Vespula sp.) in their viable temperature range (2.942.4 C) by measuring CO2 production and locomotor and endothermic activity. Wasps showed cycles of an interburstburst type at low ambient temperatures (Ta < 5 C) or typical discontinuous gas exchange patterns with closed, flutter and open phases. At high Ta of >31 C, CO2 emission became cyclic. With rising Ta they enhanced CO2-emission primarily by an exponential increase in respiration frequency, from 2.6 mHz at 4.7 C to 74 mHz at 39.7 C. In the same range of Ta CO2 release per cycle decreased from 38.9 to 26.4 l g1 cycle1. A comparison of wasps with other insects showed that they are among the insects with a low respiratory frequency at a given resting metabolic rate (RMR), and a relatively flat increase of respiratory frequency with RMR. CO2 emission was always accompanied by abdominal respiration movements in all open phases and in 71.4% of the flutter phases, often accompanied by body movements. Results suggest that resting wasps gain their highly efficient gas exchange to a considerable extent via the length and type of respiration movements.

Helmut Kovac, Anton Stabentheiner, Helmut Käfer, Barbara Oswald

Helmut Kovac, Anton Stabentheiner, Helmut Käfer, Barbara Oswald

Vespine wasps are known for their high endothermic capacity. Endothermic activity is directly linked to respiration. However, knowledge on wasp respiration is sparse and almost nothing is known about their resting metabolism. We investigated the yellowjackets CO2 production in a flow-through respirometer chamber overnight. Endothermic and behavioral activity was observed by real-time infrared thermography. Most resting wasps were ectothermic or only slightly endothermic (thoracic temperature excess against abdomen < 0.6 C). In the investigated temperature range (Ta = 2.942.4 C) mean CO2 production rate of resting wasps increased steeply according to an exponential function, from 5.658 l g1 min1 at 8.3 C to 8.504 l g1 min1 at 20.2 C, 58.686 l g1 min1 at 35.3 C and 102.84 l g1 min1 at 40 C. The wasps respiratory critical thermal maximum (CTmax), marking the upper edge of their viable temperature range, was 45.3 C. The respiratory CTmax did not differ significantly from the activity CTmax of 44.9 C. CTmax values were considerably below that of honeybees (48.9 and 49.0 C for respiration and activity, respectively). This allows honeybees to kill wasps by heat-balling. Comparison with other arthropods showed that vespine wasps are among the insects with the highest mass-specific resting metabolic rate and the steepest increase of metabolism with ambient temperature.

Wespen (Vespula sp., Hymenoptera, Vespidae) sind zu beeindruckenden thermoregulatorischen Leistungen fähig. Trotzdem sind Informationen über ihre Atmung rar, und über ihren Ruhestoffwechsel ist fast nichts bekannt. Wir untersuchten Atmung und Stoffwechsel von ruhenden Wespen, indem wir die CO2 Produktion mittels Durchfluss-Respirometrie über Nacht bestimmten. Um sicherzustellen, dass die Tiere unserer Definition nach „ruhig“ waren, wurden etwaige thermoregulatorische Aktivität sowie das Verhalten mittels IR-Thermographie aufgezeichnet. Die meisten ruhenden Wespen waren ektotherm oder nur schwach endotherm (Temperaturüberschuss Thorax zu Abdomen < 0,6 °C). Bei hohen Temperaturen (> 30 °C) kühlten viele Individuen Kopf und Thorax durch Herauswürgen von Flüssigkeit (Verdunstungskühlung). Im beobachteten Temperaturbereich (Ta = 2,8 bis 42,4 °C) stieg die CO2-Produktion exponentiell (32,6 nl mg-1 s-1 bei 2,8 °C, 437,4 nl mg-1 s-1 bei 25,0 °C, 2312,5 nl mg-1 s-1 bei 42,3 °C) mit der Außentemperatur bis zum Erreichen des kritischen thermischen Maximums bei ~ 45 °C. Vergleiche mit anderen Arthropoden zeigen, dass Wespen unter den Arten mit dem höchsten massenspezifischen Ruheumsatz sind. Bei 20 °C ist ihre CO2 Produktion um 60% höher als die der Honigbiene (Apis mellifera): 300,9 nl mg-1 s-1 vs. 186 nl mg-1 s-1. Nowickia sp., eine Tachinide mit vergleichbarer Masse, hat einen noch niedrigeren Ruhestoffwechsel von nur 38,4 nl mg-1 s-1 oder 13 % des Umsatzes der Wespe. Ein Vergleich mehrerer Arten anhand von Literaturdaten zeigt, dass der Grundumsatz offensichtlich nicht über Taxongrenzen hinaus mit der Körpermasse korreliert. Sogar relativ nahe verwandte Arten wie Honigbiene und Wespe unterscheiden sich im Ruhestoffwechsel beträchtlich., Helmut Käfer, Helmut Kovac & Anton Stabentheiner

Wespen (Vespula sp., Hymenoptera, Vespidae) sind zu beeindruckenden thermoregulatorischen Leistungen fähig. Trotzdem sind Informationen über ihre Atmung rar, und über ihren Ruhestoffwechsel ist fast nichts bekannt. Wir untersuchten Atmung und Stoffwechsel von ruhenden Wespen, indem wir die CO2 Produktion mittels Durchfluss-Respirometrie über Nacht bestimmten. Um sicherzustellen, dass die Tiere unserer Definition nach „ruhig“ waren, wurden etwaige thermoregulatorische Aktivität sowie das Verhalten mittels IR-Thermographie aufgezeichnet. Die meisten ruhenden Wespen waren ektotherm oder nur schwach endotherm (Temperaturüberschuss Thorax zu Abdomen < 0,6 °C). Bei hohen Temperaturen (> 30 °C) kühlten viele Individuen Kopf und Thorax durch Herauswürgen von Flüssigkeit (Verdunstungskühlung). Im beobachteten Temperaturbereich (Ta = 2,8 bis 42,4 °C) stieg die CO2-Produktion exponentiell (32,6 nl mg-1 s-1 bei 2,8 °C, 437,4 nl mg-1 s-1 bei 25,0 °C, 2312,5 nl mg-1 s-1 bei 42,3 °C) mit der Außentemperatur bis zum Erreichen des kritischen thermischen Maximums bei ~ 45 °C. Vergleiche mit anderen Arthropoden zeigen, dass Wespen unter den Arten mit dem höchsten massenspezifischen Ruheumsatz sind. Bei 20 °C ist ihre CO2 Produktion um 60% höher als die der Honigbiene (Apis mellifera): 300,9 nl mg-1 s-1 vs. 186 nl mg-1 s-1. Nowickia sp., eine Tachinide mit vergleichbarer Masse, hat einen noch niedrigeren Ruhestoffwechsel von nur 38,4 nl mg-1 s-1 oder 13 % des Umsatzes der Wespe. Ein Vergleich mehrerer Arten anhand von Literaturdaten zeigt, dass der Grundumsatz offensichtlich nicht über Taxongrenzen hinaus mit der Körpermasse korreliert. Sogar relativ nahe verwandte Arten wie Honigbiene und Wespe unterscheiden sich im Ruhestoffwechsel beträchtlich., Helmut Käfer, Helmut Kovac & Anton Stabentheiner

The ichneumonid wasp Pimpla turionellae (L.) (Hymenoptera) is a specialist parasitoid of lepidopteran pupae, and has to overcome the challenge of reduced chemical and visual cues as pupae are immobile, do not feed and do not emit excrements. Certain hymenopteran species have developed a particular mechanosensory mechanism in order to locate hosts hidden in hollow spaces inside of plant material (Broad & Quicke 2000). Similar to echolocation they use self-produced vibrations, instead of sounds, that are transmitted by the antennae onto the substrate. In analogous way to acoustics, this mechanosensory mechanism is referred to as vibrational sounding (Wäckers & al. 1998). Thermal dependence is well known in acoustical and vibrational communication of arthropods (e.g. Pires & Hoy 1992, Shimizu & Barth 1996) and is likewise presumed to affect mechanosensory host location by vibrational sounding. The species P. turionellae has recently been found to use vibrational sounding successfully in a temperature range from 8 to 28°C, but with less performance of searching behaviour and an adjusted signal production at extreme temperatures (Kroder & al. 2006, & al. 2007b, Samietz & al. 2006). Many insects have evolved strategies to maintain a balance of body temperature by ecto- and endothermic means. Raising and maintaining body temperatures above the ambient environment by endothermic means is particularly known in several hymenopteran species (Heinrich 1993). In the case of a thermally influenced host location mechanism, such means of thermoregulation could be supposed as well in order to maintain performance with changing temperatures. The study elucidates if the wasps are able to regulate their body temperature at suboptimal conditions during vibrational sounding and furthermore examines the role of vibrational sounding in multisensory orientation at different ambient temperatures., Die Schlupfwespe Pimpla turionellae parasitiert versteckte Lepidopterenpuppen und orientiert sie sich bei der Wirtssuche multisensorisch mittels visueller Reize und aktiver Vibrationsortung mit selbst produzierten Schwingungen (Vibrational-Sounding). Die Studie untersucht, inwieweit die Wespen bei Änderung der Umgebungstemperaturen von 8-26°C (1) zwischen der temperatur-sensitiven vibratorischen und der -insensitiven visuellen Orientierung wechseln und (2) gegebenenfalls selbst die Körpertemperatur regulieren können, um die sehr präzise Vibrationsortung bei niedrigen Temperaturen aufrechtzuerhalten. Messungen mit Infrarot-Thermographie zeigen, dass suchende Wespen leicht erhöhte Körpertemperaturen während der vibratorischen Wirtssuche aufweisen, welche auf metabolische Wärmeproduktion zurückzuführen sind. Wahlexperimente unter kontrollierten Temperaturen zeigen zudem, dass die Nutzung der temperatur-sensitiven vibratorischen Reize bei pessimalen Temperaturen abnimmt und die Wespen auf fast ausschließliche visuelle Orientierung wechseln. Folglich wird die Relevanz einzelner Reize bei der multisensorischen Orientierung direkt vom Faktor Temperatur beeinflusst. Solange ein zuverlässiger Reiz vorhanden ist, nimmt dabei auch die Präzision der Lokalisation insgesamt nicht ab.

The ichneumonid wasp Pimpla turionellae (L.) (Hymenoptera) is a specialist parasitoid of lepidopteran pupae, and has to overcome the challenge of reduced chemical and visual cues as pupae are immobile, do not feed and do not emit excrements. Certain hymenopteran species have developed a particular mechanosensory mechanism in order to locate hosts hidden in hollow spaces inside of plant material (Broad & Quicke 2000). Similar to echolocation they use self-produced vibrations, instead of sounds, that are transmitted by the antennae onto the substrate. In analogous way to acoustics, this mechanosensory mechanism is referred to as vibrational sounding (Wäckers & al. 1998). Thermal dependence is well known in acoustical and vibrational communication of arthropods (e.g. Pires & Hoy 1992, Shimizu & Barth 1996) and is likewise presumed to affect mechanosensory host location by vibrational sounding. The species P. turionellae has recently been found to use vibrational sounding successfully in a temperature range from 8 to 28°C, but with less performance of searching behaviour and an adjusted signal production at extreme temperatures (Kroder & al. 2006, & al. 2007b, Samietz & al. 2006). Many insects have evolved strategies to maintain a balance of body temperature by ecto- and endothermic means. Raising and maintaining body temperatures above the ambient environment by endothermic means is particularly known in several hymenopteran species (Heinrich 1993). In the case of a thermally influenced host location mechanism, such means of thermoregulation could be supposed as well in order to maintain performance with changing temperatures. The study elucidates if the wasps are able to regulate their body temperature at suboptimal conditions during vibrational sounding and furthermore examines the role of vibrational sounding in multisensory orientation at different ambient temperatures., Die Schlupfwespe Pimpla turionellae parasitiert versteckte Lepidopterenpuppen und orientiert sie sich bei der Wirtssuche multisensorisch mittels visueller Reize und aktiver Vibrationsortung mit selbst produzierten Schwingungen (Vibrational-Sounding). Die Studie untersucht, inwieweit die Wespen bei Änderung der Umgebungstemperaturen von 8-26°C (1) zwischen der temperatur-sensitiven vibratorischen und der -insensitiven visuellen Orientierung wechseln und (2) gegebenenfalls selbst die Körpertemperatur regulieren können, um die sehr präzise Vibrationsortung bei niedrigen Temperaturen aufrechtzuerhalten. Messungen mit Infrarot-Thermographie zeigen, dass suchende Wespen leicht erhöhte Körpertemperaturen während der vibratorischen Wirtssuche aufweisen, welche auf metabolische Wärmeproduktion zurückzuführen sind. Wahlexperimente unter kontrollierten Temperaturen zeigen zudem, dass die Nutzung der temperatur-sensitiven vibratorischen Reize bei pessimalen Temperaturen abnimmt und die Wespen auf fast ausschließliche visuelle Orientierung wechseln. Folglich wird die Relevanz einzelner Reize bei der multisensorischen Orientierung direkt vom Faktor Temperatur beeinflusst. Solange ein zuverlässiger Reiz vorhanden ist, nimmt dabei auch die Präzision der Lokalisation insgesamt nicht ab.

The ichneumonid wasp Pimpla turionellae (L.) (Hymenoptera) is a specialist parasitoid of lepidopteran pupae, and has to overcome the challenge of reduced chemical and visual cues as pupae are immobile, do not feed and do not emit excrements. Certain hymenopteran species have developed a particular mechanosensory mechanism in order to locate hosts hidden in hollow spaces inside of plant material (Broad & Quicke 2000). Similar to echolocation they use self-produced vibrations, instead of sounds, that are transmitted by the antennae onto the substrate. In analogous way to acoustics, this mechanosensory mechanism is referred to as vibrational sounding (Wäckers & al. 1998). Thermal dependence is well known in acoustical and vibrational communication of arthropods (e.g. Pires & Hoy 1992, Shimizu & Barth 1996) and is likewise presumed to affect mechanosensory host location by vibrational sounding. The species P. turionellae has recently been found to use vibrational sounding successfully in a temperature range from 8 to 28°C, but with less performance of searching behaviour and an adjusted signal production at extreme temperatures (Kroder & al. 2006, & al. 2007b, Samietz & al. 2006). Many insects have evolved strategies to maintain a balance of body temperature by ecto- and endothermic means. Raising and maintaining body temperatures above the ambient environment by endothermic means is particularly known in several hymenopteran species (Heinrich 1993). In the case of a thermally influenced host location mechanism, such means of thermoregulation could be supposed as well in order to maintain performance with changing temperatures. The study elucidates if the wasps are able to regulate their body temperature at suboptimal conditions during vibrational sounding and furthermore examines the role of vibrational sounding in multisensory orientation at different ambient temperatures., Die Schlupfwespe Pimpla turionellae parasitiert versteckte Lepidopterenpuppen und orientiert sie sich bei der Wirtssuche multisensorisch mittels visueller Reize und aktiver Vibrationsortung mit selbst produzierten Schwingungen (Vibrational-Sounding). Die Studie untersucht, inwieweit die Wespen bei Änderung der Umgebungstemperaturen von 8-26°C (1) zwischen der temperatur-sensitiven vibratorischen und der -insensitiven visuellen Orientierung wechseln und (2) gegebenenfalls selbst die Körpertemperatur regulieren können, um die sehr präzise Vibrationsortung bei niedrigen Temperaturen aufrechtzuerhalten. Messungen mit Infrarot-Thermographie zeigen, dass suchende Wespen leicht erhöhte Körpertemperaturen während der vibratorischen Wirtssuche aufweisen, welche auf metabolische Wärmeproduktion zurückzuführen sind. Wahlexperimente unter kontrollierten Temperaturen zeigen zudem, dass die Nutzung der temperatur-sensitiven vibratorischen Reize bei pessimalen Temperaturen abnimmt und die Wespen auf fast ausschließliche visuelle Orientierung wechseln. Folglich wird die Relevanz einzelner Reize bei der multisensorischen Orientierung direkt vom Faktor Temperatur beeinflusst. Solange ein zuverlässiger Reiz vorhanden ist, nimmt dabei auch die Präzision der Lokalisation insgesamt nicht ab.

Over last 130 years the American assh was often used for afforestation of Croatian lowland areas where the native narrow leafed ash (Fraxinus angustifolia Vahl) did not grow well. Due to unequivocal species identification of the American ash F. americana L. or F. pennsylvanica Marshall, pollen samples of concerned specimens were collected. Based on species pollen samples of F. americana and F. pennsylvanica, collected from trees growing at the Royal Botanical Gardens Hamilton in Canada, and on their distinctive morphological features, pollen samples of American ash trees from a plantation Črnovščak in Dugo Selo near Zagreb and from arboricultures in Zagreb were determined as Fraxinus pennsylvanica.

Over last 130 years the American assh was often used for afforestation of Croatian lowland areas where the native narrow leafed ash (Fraxinus angustifolia Vahl) did not grow well. Due to unequivocal species identification of the American ash F. americana L. or F. pennsylvanica Marshall, pollen samples of concerned specimens were collected. Based on species pollen samples of F. americana and F. pennsylvanica, collected from trees growing at the Royal Botanical Gardens Hamilton in Canada, and on their distinctive morphological features, pollen samples of American ash trees from a plantation Črnovščak in Dugo Selo near Zagreb and from arboricultures in Zagreb were determined as Fraxinus pennsylvanica.

Hermaphroditic flowers blooming unseasonably on an oak tree (»the green oak«) of uncertain hybrid origin prompted a detailed investigation into the biology of the flowering, and the morphology of various traits of the tree, which is growing in an urban area near Zadar, northern Dalmatia, Croatia. Hermaphroditic flowers were also detected on one holm oak tree from Weihenstephan, Germany. Since the first oak tree was described as a hybrid between Q. cerris f. austriaca Q. ilex, scanning electron microscope investigations of pollen and hairs on the leaves of three species were made, on: Q. ilex L., Q. cerris L. and the »green oak«. Oak pollen is of elliptical shape and tricolpate. The ornamentation of the pollen grains of Q. cerris and the »green oak« were similar concerning the ornamentation of the exine – warty and rough and with small rounded protrusions – as well as the size of the pollen grain. Q. ilex pollen was much smaller and the surface lacked the small irregularly shaped protrusions typical of the other oaks.Within samples of holm oak pollen, significant difference in the surface structures was observed. Concerning the different types and number of hairs on the leaf surfaces, Q. ilex revealed a much greater number of stellate hairs on the upper leaf side as compared to Q. cerris and the »green oak«. Simple uniseriate hairs and simple unicellular hairs were missing on the leaves of Q. ilex, but were present on both the other oaks. To sum up the results, the »green oak« and Q. cerris reveal some similarities whereas Q. ilex does not.

Hermaphroditic flowers blooming unseasonably on an oak tree (»the green oak«) of uncertain hybrid origin prompted a detailed investigation into the biology of the flowering, and the morphology of various traits of the tree, which is growing in an urban area near Zadar, northern Dalmatia, Croatia. Hermaphroditic flowers were also detected on one holm oak tree from Weihenstephan, Germany. Since the first oak tree was described as a hybrid between Q. cerris f. austriaca Q. ilex, scanning electron microscope investigations of pollen and hairs on the leaves of three species were made, on: Q. ilex L., Q. cerris L. and the »green oak«. Oak pollen is of elliptical shape and tricolpate. The ornamentation of the pollen grains of Q. cerris and the »green oak« were similar concerning the ornamentation of the exine – warty and rough and with small rounded protrusions – as well as the size of the pollen grain. Q. ilex pollen was much smaller and the surface lacked the small irregularly shaped protrusions typical of the other oaks.Within samples of holm oak pollen, significant difference in the surface structures was observed. Concerning the different types and number of hairs on the leaf surfaces, Q. ilex revealed a much greater number of stellate hairs on the upper leaf side as compared to Q. cerris and the »green oak«. Simple uniseriate hairs and simple unicellular hairs were missing on the leaves of Q. ilex, but were present on both the other oaks. To sum up the results, the »green oak« and Q. cerris reveal some similarities whereas Q. ilex does not.