24 results match your criteria: "BEEgroup & Chair of Biochemistry; University of Würzburg; Biocenter; Würzburg[Affiliation]"
PLoS One
November 2015
University of Würzburg, BEEgroup, Biozentrum, Würzburg, Germany.
Patterns of behavior within societies have long been visualized and interpreted using maps. Mapping the occurrence of sleep across individuals within a society could offer clues as to functional aspects of sleep. In spite of this, a detailed spatial analysis of sleep has never been conducted on an invertebrate society.
View Article and Find Full Text PDFCommun Integr Biol
November 2013
BEEgroup and Chair of Biochemistry; Biocenter; Julius-Maximilians-University; Würzburg, Germany.
In the first decade of the 20th century, a horse named Hans drew worldwide attention in Berlin as the first and most famous "speaking" and thinking animal. Hans solved calculations by tapping numbers or letters with his hoof in order to answer questions. Later on, it turned out that the horse was able to give the correct answer by reading the microscopic signals in the face of the questioning person.
View Article and Find Full Text PDFPLoS One
March 2014
BEEgroup, Biocentre, University of Würzburg, Würzburg, Germany.
The development of all honey bee castes proceeds through three different life stages all of which encounter microbial infections to a various extent. We have examined the immune strength of honey bees across all developmental stages with emphasis on the temporal expression of cellular and humoral immune responses upon artificial challenge with viable Escherichia coli bacteria. We employed a broad array of methods to investigate defence strategies of infected individuals: (a) fate of bacteria in the haemocoel; (b) nodule formation and (c) induction of antimicrobial peptides (AMPs).
View Article and Find Full Text PDFFront Psychol
April 2013
BEEgroup, Biocentre, Julius-Maximilians-University Würzburg, Germany.
The ability to perceive the number of objects has been known to exist in vertebrates for a few decades, but recent behavioral investigations have demonstrated that several invertebrate species can also be placed on the continuum of numerical abilities shared with birds, mammals, and reptiles. In this review article, we present the main experimental studies that have examined the ability of insects to use numerical information. These studies have made use of a wide range of methodologies, and for this reason it is striking that a common finding is the inability of the tested animals to discriminate numerical quantities greater than four.
View Article and Find Full Text PDFCommun Integr Biol
January 2012
BEEgroup and Chair of Biochemistry, Biocenter, Julius-Maximilians-University, Würzburg, Germany.
Precise recognition of small object numbers without counting is a widespread phenomenon. It is well documented for humans and for a series of non-human vertebrates. Recently this has been confirmed for an invertebrate, the honeybee.
View Article and Find Full Text PDFJ Exp Biol
April 2012
BEEgroup, Biocentre, University of Würzburg, Am Hubland, D-97074 Würzburg, Germany.
Drones are haploid male individuals whose major social function in honey bee colonies is to produce sperm and mate with a queen. In spite of their limited tasks, the vitality of drones is of utmost importance for the next generation. The immune competence of drones - as compared to worker bees - is largely unexplored.
View Article and Find Full Text PDFArch Virol
April 2012
BEEgroup, Biocentre, University of Würzburg, Am Hubland, 97074, Würzburg, Germany.
We have studied the responses of honey bees at different life stages (Apis mellifera) to controlled infection with acute bee paralysis virus and have identified the haemolymph of infected larvae and adult worker bees as the compartment where massive propagation of ABPV occurs. Insects respond with a broad spectrum of induced innate immune reactions to bacterial infections, whereas defence mechanisms based on RNA interference play a major role in antiviral immunity. In this study, we have determined that honey bee larvae and adult workers do not produce a humoral immune reaction upon artificial infection with ABPV, in contrast to control individuals challenged with Escherichia coli.
View Article and Find Full Text PDFJ Insect Physiol
February 2012
BEEGroup, Biozentrum Universität Würzburg, Am Hubland, D-97074 Würzburg, Germany.
In modern managed agro-ecosystems, the supply of adequate food from blooming crops is limited to brief periods. During periods of pollen deficiencies, bees are forced to forage on alternative crops, such as maize. However, pollen of maize is believed to be a minor food source for bees as it is thought to be lacking in proteins and essential amino acids.
View Article and Find Full Text PDFHuman inborn numerical competence means our ability to recognize object numbers precisely under circumstances which do not allow sequential counting. This archaic process has been called "subitizing," from the Latin "subito" = suddenly, immediately, indicating that the objects in question are presented to test persons only for a fraction of a second in order to prevent counting. In contrast, however, sequential counting, an outstanding cultural achievement of mankind, means to count "1, 2, 3, 4, 5, 6, 7, 8…" without a limit.
View Article and Find Full Text PDFInsect Biochem Mol Biol
December 2011
BEEgroup, Biozentrum, University of Würzburg, Am Hubland, 97074 Würzburg, Germany.
Honeybee populations are severely threatened by parasites and diseases. Recent outbreaks of Colony Collapse Disorder (CCD) has caused loss of more than 35% of bee colonies in the USA, and this is thought to at least in part be due to parasites and/or disease. Interestingly, the honeybee possesses of a limited set of immune genes compared to other insects.
View Article and Find Full Text PDFPLoS One
October 2011
BEEgroup, Biocentre, Würzburg University, Würzburg, Germany.
Honeybee foragers frequently fly several kilometres to and from vital resources, and communicate those locations to their nest mates by a symbolic dance language. Research has shown that they achieve this feat by memorizing landmarks and the skyline panorama, using the sun and polarized skylight as compasses and by integrating their outbound flight paths. In order to investigate the capacity of the honeybees' homing abilities, we artificially displaced foragers to novel release spots at various distances up to 13 km in the four cardinal directions.
View Article and Find Full Text PDFPrecise recognition of small numbers of objects without counting is an archaic, inborn ability of humans. Since almost 140 years it is known that we can recognize precisely only up to four objects if sequential counting is prevented. Vertebrates and invertebrates such as honeybees can recognize and remember three and up to four objects, respectively.
View Article and Find Full Text PDFArch Insect Biochem Physiol
December 2008
BEEgroup, Biocenter, University of Würzburg, Würzburg, Germany.
We have employed the proteomic approach in combination with mass spectrometry to study the immune response of honey bee workers at different developmental stages. Analysis of the hemolymph proteins of noninfected, mock-infected and immune-challenged individuals by polyacrylamide gel electrophoresis showed differences in the protein profiles. We present evidence that in vitro reared honey bee larvae respond with a prominent humoral reaction to aseptic and septic injury as documented by the transient synthesis of the three antimicrobial peptides (AMPs) hymenoptaecin, defensin1, and abaecin.
View Article and Find Full Text PDFZoology (Jena)
December 2008
BEEgroup, Department of Zoology II, Behavioral Physiology and Sociobiology, Biocenter, Julius-Maximilians-University, D-97074 Würzburg, Germany.
Honeybees actively regulate their brood temperature by heating between 33 and 36 degrees C if ambient temperatures are lower. Heat is generated by vibrating the flight muscles. Heating rapidly depletes the worker's internal energy; therefore heating performance is limited by the honey that is ingested before the heating process.
View Article and Find Full Text PDFJ Insect Physiol
February 2008
BEEgroup, Biozentrum Universität Würzburg, Am Hubland, Wuerzburg, Germany.
Hemocytes and the (prophenol-) phenoloxidase system constitute the immediate innate immune system in insects. These components of insect immunity are present at any post-embryonic life stage without previous infection. Differences between individuals and species in these immune parameters can reflect differences in infection risk, life expectancy, and biological function.
View Article and Find Full Text PDFJ Exp Biol
October 2007
BEEgroup, Biozentrum, Universitaet Würzburg, Am Hubland, D-97074 Würzburg, Germany.
This study investigates how the colour, shape and location of patterns could be memorized within a time frame. Bees were trained to visit two Y-mazes, one of which presented yellow vertical (rewarded) versus horizontal (non-rewarded) gratings at one site in the morning, while another presented blue horizontal (rewarded) versus vertical (non-rewarded) gratings at another site in the afternoon. The bees could perform well in the learning tests and various transfer tests, in which (i) all contextual cues from the learning test were present; (ii) the colour cues of the visual patterns were removed, but the location cue, the orientation of the visual patterns and the temporal cue still existed; (iii) the location cue was removed, but other contextual cues, i.
View Article and Find Full Text PDFNaturwissenschaften
September 2007
BEEgroup, Zoologie II, Biozentrum, University of Würzburg, Am Hubland, 97074, Würzburg, Germany.
The eusocial bumblebees exhibit pronounced size variation among workers of the same colony. Differently sized workers engage in different tasks (alloethism); large individuals are found to have a higher probability to leave the colony and search for food, whereas small workers tend to stay inside the nest and attend to nest duties. We investigated the effect of size variation on morphology and physiology of the peripheral olfactory system and the behavioral response thresholds to odors in workers of Bombus terrestris.
View Article and Find Full Text PDFJ Chem Ecol
March 2006
Beegroup Würzburg, Department of Behavioral Physiology and Sociobiology, University of Würzburg, Germany.
The major component of the mandibular gland secretion of queen honeybees (Apis mellifera L.), 9-ODA ((2E)-9-oxodecenoic acid), has been known for more than 40 yr to function as a long-range sex pheromone, attracting drones at congregation areas and drone flyways. Tests of other mandibular gland components failed to demonstrate attraction.
View Article and Find Full Text PDFJ Exp Biol
March 2006
Beegroup, Biozentrum, Department of Behavioral Physiology and Sociobiology, University of Würzburg, Germany.
In humans, visual search tasks are commonly used to address the question of how visual attention is allocated in a specific task and how individuals search for a specific object (;target') among other objects (;distractors') that vary in number and complexity. Here, we apply the methodology of visual search experiments to honeybees, which we trained to choose a coloured disc (target) among a varying number of differently coloured discs (distractors). We measured accuracy and decision time as a function of distractor number and colour.
View Article and Find Full Text PDFNaturwissenschaften
July 2004
Beegroup, Biozentrum, Universität Würzburg, 97074 Würzburg, Germany.
Geometrical investigations of honeycombs and speculations on how honeybees measure and construct the hexagons and rhombi of their cells are centuries old. Here we show that honeybees neither have to measure nor construct the highly regular structures of a honeycomb, and that the observed pattern of combs can be parsimoniously explained by wax flowing in liquid equilibrium. The structure of the combs of honeybees results from wax as a thermoplastic building medium, which softens and hardens as a result of increasing and decreasing temperatures.
View Article and Find Full Text PDFPLoS Biol
July 2004
Beegroup Würzburg, Lehrstuhl für Verhaltensphysiologie und Soziobiologie, Würzburg, Germany.
Proc Natl Acad Sci U S A
June 2004
Beegroup, Biozentrum der Universität Würzburg, Am Hubland, D-97074 Würzburg, Germany.
In many species of social Hymenoptera, unmated workers can lay eggs that will produce males by parthenogenesis. Nevertheless, in queenright honey bee colonies (Apis mellifera), worker reproduction is low. One possible mechanism for this difference is worker policing, the removal of worker-laid eggs by other workers.
View Article and Find Full Text PDFJ Exp Biol
December 2003
Beegroup Würzburg, Lehrstuhl für Verhaltensphysiologie und Soziobiologie, Universität Am Hubland, D-97074 Würzburg, Germany.
Honeybee colonies maintain brood nest temperatures of 33-36 degrees C. We investigated brood nest thermoregulation at the level of individual worker behaviour and the transfer of heat from workers to the brood. Worker bees contribute to the regulation of brood nest temperature by producing heat while sitting motionless on the caps of brood cells.
View Article and Find Full Text PDFNaturwissenschaften
September 2003
Beegroup, Lehrstuhl für Zoologie II, Verhaltensphysiologie und Soziobiologie, Theodor-Boveri-Institut für Biowissenschaften, Universität Würzburg, Am Hubland, 97074 Würzburg, Germany.
In social insects, much progress has been made in identifying variations in the cuticular signatures of sexes, castes, kin and reproductive status. In contrast to this, we still do not know how the receivers perceive these recognition cues. This study was designed to investigate whether honeybees use contact-chemosensory or olfactory sensilla to perceive wax components.
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