Natural odors (bananas, mangos) were preferred by most flies, whereas artificial flavors induced a more differentiated behavior. (Current Biology Vol. 18, September 23, 2008)
These studies confirm what researchers in the field of Chemical Ecology have observed with other organisms: that the behavior of animals, as well as plant responses to biotic or abiotic stress, are less regulated by an individual signal, but rather by a complex composition and amount of particular volatile compounds.
In their experiments the scientists used different varieties of vinegar flies that had already been characterized neurophysiologically: Canton-S, Oregon-R-C, Oregon R-S, Berlin-K, and wild-type Berlin. Electroantennographic measurements conducted before the actual behavioral experiments showed that all fly varieties showed an identical physiological response to five different chemical stimuli. Also, the vitality and mobility of the animals was similar. Nevertheless, the behavior, measured in periods of 24 hours, was different depending on fly variety and food (odor) supply: some varieties responded fast, others very slow. Equivalent behavioral studies on three additional fly varieties that had only recently been included in the strain collection (Dalby-HL, Helsingborg-E, and Helsingborg-F), proved especially interesting: these varieties turned out to be particularly selective and displayed slower and less strong responses to fruity smells, and especially to single odor components. "These flies, which have only until recently been living in nature, are very likely to show the original phenotype of Drosophila melanogaster behavior: they respond - as other insect species also do - very selectively to host signals and do not just rely on one single odor that is stimulating their antennae. Moreover, the insects' behavior is not only regulated positively by attractive odors, but also negatively by deterring volatile signals, for instance emitted by fruits that are not on the animals' menu," says Bill Hansson, director of the Department of Evolutionary Neuroethology at the Max Planck Institute for Chemical Ecology in Jena.
D. melanogaster varieties that have been bred in laboratories for years, especially Canton-S and both Oregon-R-C and R-S, were not as selective in the experiments as the newly collected Swedish Helsingborg flies were. This may be the result of genetic differences between varieties that evolved in different geographical locations, or the consequence of artificial selection of the flies - in the course of breeding them in the labs of geneticists and neurobiologists. The experiments further showed that the different behaviors of the eight Drosophila varieties cannot be diagnosed just as impaired olfactory mechanisms linked to particular genetic flaws, for instance caused by the absence or the mutation of a specific odor receptor. The behaviors are rather the result of adaptations of evolving Drosophila melanogaster ecotypes to different habitats and living conditions, and therefore to different odor compositions.
Insect traps that use chemical attractants or pheromones to lure insects are becoming more and more important in modern agriculture. With the help of these traps, insect pests can be controlled, e.g. in vineyards and orchards. The traps are also used to monitor pest infestation levels in crop fields. The results of this study increases our understanding of insect odor-directed behavior, and will help to improve such insect traps and to develop more efficient ones.
Original article: Agnieszka Ruebenbauer, Fredrik Schlyter, Bill S. Hansson, Christer Löfstedt, Mattias C. Larsson: Genetic Variability and Robustness of Host Odor Preference in Drosophila melanogaster. Current Biology 18 (2008), 1438-1443.
Dr. Jan-Wolfhard Kellmann | Max-Planck-Institut
Water forms 'spine of hydration' around DNA, group finds
26.05.2017 | Cornell University
How herpesviruses win the footrace against the immune system
26.05.2017 | Helmholtz-Zentrum für Infektionsforschung
Staphylococcus aureus is a feared pathogen (MRSA, multi-resistant S. aureus) due to frequent resistances against many antibiotics, especially in hospital infections. Researchers at the Paul-Ehrlich-Institut have identified immunological processes that prevent a successful immune response directed against the pathogenic agent. The delivery of bacterial proteins with RNA adjuvant or messenger RNA (mRNA) into immune cells allows the re-direction of the immune response towards an active defense against S. aureus. This could be of significant importance for the development of an effective vaccine. PLOS Pathogens has published these research results online on 25 May 2017.
Staphylococcus aureus (S. aureus) is a bacterium that colonizes by far more than half of the skin and the mucosa of adults, usually without causing infections....
Physicists from the University of Würzburg are capable of generating identical looking single light particles at the push of a button. Two new studies now demonstrate the potential this method holds.
The quantum computer has fuelled the imagination of scientists for decades: It is based on fundamentally different phenomena than a conventional computer....
An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.
We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...
Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.
Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...
An Australian-Chinese research team has created the world's thinnest hologram, paving the way towards the integration of 3D holography into everyday...
24.05.2017 | Event News
23.05.2017 | Event News
22.05.2017 | Event News
26.05.2017 | Life Sciences
26.05.2017 | Life Sciences
26.05.2017 | Physics and Astronomy