The O, CO, and HO exchange of single flying male bumblebees (Bombus lucorum and B. terrestris) were measured simultaneously. A respiratory quotient RQ=1 was found for all activities investigated (torpor-flight). The dependence of respiratory CO production in flight on body-weight was measured: for a 220-mg male bumblebee it amounts to 24.5 mg CO/h (=56.4 ml O/g·h). The corresponding evaporative water loss amounts to 6 mg HO/h. Males tranferred to a climatic test chamber and conditioned to artificial flower feeders started to fly, after a few days of acclimatization, in typical scent-marked flight-paths. The daily pattern of flight activity was recorded: the mean total time in flight amounts to 244 min, and the corresponding daily flight length is about 17 km. At 20°C and 50% relative humidity (RH) a daily uptake of 180 μl (≙ 220mg) of 50% sugar solution was measured, equal to the mean body weight of the male bumblebees. Since the body weight remains constant on consecutive days a 24-h energy- and water-budget could be calculated. The energy-budget is balanced; the activities observed can be fuelled with the sugar available. About 70% of the energy is used for the 4 h of flight activity. With the daily nectar volume 110 mg of water is ingested; in the oxidation of 110 mg sugar, 66 mg of metabolic water is produced and 40 mg water is dissipated by the evaporative water-loss. Thus, to have a balanced water-budget, 136 mg of water must be voided in 24 h, which equals the total body-water of the bumblebees. Nectar is a nutrient of high water content which not only provides the sugar necessary for activity but also, in most circumstances, an excess of water. The effect of this high water load in limiting daily activity is discussed and compared with the water- and osmoregulation of hummingbirds. The strategy of maximizing energy for a male bumblebee must be one of minimizing water load.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1007/BF00384264 | DOI Listing |
Int J Yoga Therap
December 2024
Patanjali Research Foundation, Haridwar, Uttarakhand, India.
Changes in breathing during pranayama (yoga breathwork) are usually inferred from practice guidelines in traditional texts or contemporary writings. These changes point to understanding the effects of pranayama and indicate applications of pranayama in health. Previously, a pilot study on a single participant suggested that each pranayama changes breathing uniquely.
View Article and Find Full Text PDFZootaxa
September 2024
El Colegio de la frontera Sur (ECOSUR); Departamento Agricultura Sociedad y Ambiente; San Cristóbal de Las Casas; Chiapas; Mexico.
COI-barcode-like sequences appear to show substantially more species diversity among Mesoamerican bumblebees than had been reported previously from morphological studies. Closer examination shows that some of this apparent diversity may be pseudospecies (groups falsely misinterpreted as separate species), often supported by paralogous 'numts' (nuclear copies of mitochondrial sequences). For the well-sampled weisi-complex, we seek to filter out pseudogenes in order to use the orthologous COI-barcode sequences for identifying estimates of evolutionary relationships and likely species' gene coalescents for candidate species.
View Article and Find Full Text PDFAm J Bot
December 2024
Agroécologie, INRAE, Institut Agro, Université Bourgogne, Université Bourgogne Franche-Comté, Dijon, F-21000, France.
Premise: Restoration of seminatural field margins can elevate pollinator activity. However, how they support wild plant gene flow through interactions between pollinators and spatiotemporal gradients in floral resources remains largely unknown.
Methods: Using a farm-scale experiment, we tested how mating outcomes (expected heterozygosity and paternity correlation) of the wild, self-incompatible plant Cyanus segetum transplanted into field margins (sown wildflower or grass-legume strips) were affected by the abundance of different pollinator functional groups (defined by species traits).
Proc Biol Sci
August 2024
Animal Ecology and Tropical Biology, University of Würzburg, Würzburg, Germany.
Global climate change disrupts key ecological processes and biotic interactions. The recent increase in heatwave frequency and severity prompts the evaluation of physiological processes that ensure the maintenance of vital ecosystem services such as pollination. We used experimental heatwaves to determine how high temperatures affect the bumblebees' ability to detect floral scents.
View Article and Find Full Text PDFNew Phytol
November 2024
Department of Environment and Biodiversity, Paris Lodron University of Salzburg, Hellbrunnerstrasse 34, Salzburg, 5020, Austria.
The globally changing climatic condition is increasing the incidences of drought in several parts of the world. This is predicted and already shown to not only impact plant growth and flower development, but also plant-pollinator interactions and the pollination success of entomophilous plants. However, there is a large gap in our understanding of how drought affects the different flowers and pollen transfer among flowers in sexually polymorphic species.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!