Library

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Journal of comparative physiology 186 (2000), S. 193-203 
    ISSN: 1432-1351
    Keywords: Key wordsEristalis tenax ; Pollen ; Taste hairs ; Contact chemoreception ; Proline
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract The labellar gustatory system of the dronefly Eristalis tenax L. (Syrphidae; Diptera) that enables the fly to discriminate between pollen and nectar is investigated, and the triggering of pollen ingestion is examined. In behavioural preference tests, exhaustively extracted pollen of the sunflower Helianthus annuus is consumed in smaller amounts than untreated pollen, indicating that water-soluble substances are important for acceptance. Dry pollen is preferred over moist pollen in which the grains stick together, suggesting that mechanical properties of the pollen also play a role in its sensory assessment. Electrophysiological studies of the labellar taste hairs reveal that aqueous extracts of pollen (2% w/v) stimulate the salt receptor cell, but not the sugar receptor cell. The response of the water receptor cell remains the same as to pure water (or standard electrolyte, 10 mmol · l−1 KCl). Of the 20 amino acids tested, the salt cell is sensitive only to proline in a submillimolar range. Behavioural experiments support the electrophysiological findings. When KCl is applied at concentrations eliciting salt-cell spike frequencies equal to those produced by pollen extract (which is often accepted), the water receptor cell is inhibited and a pronounced rejection behaviour occurs. This rejection of concentrated salt solution in Eristalis is therefore mainly mediated by the inhibition of the water cell.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Journal of comparative physiology 174 (1994), S. 61-64 
    ISSN: 1432-1351
    Keywords: Diopsidae ; Reproductive success ; Sexual selection ; Optical signals ; Eyespan
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Some species of stalk-eyed flies (Diopsidae, Diptera) have a sexual dimorphism of eyespan. For example, Cyrtodiopsis whitei males have much longer eyestalks than females of equal body length. Expression of this trait increases with the bearers' size. The slope of the log-log regression line eyespan versus body length is close to two in males, while in females it is roughly one. Behavioural experiments suggest that male eyespan signals quantitatively a male's strength or attractiveness to a competitor or mate. We used 3 pure strains of C. Whitei, which were distinguished by their different phosphoglucomutase allele outfit. We compared the reproductive success of males of different sizes and found the number of offspring to be directly proportional to body length. Thus eyespan, rising with the square of body length, provides an exaggerated and highly conclusive signal in the advertisement of fitness.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Journal of comparative physiology 178 (1996), S. 477-489 
    ISSN: 1432-1351
    Keywords: Bombus terrestris ; Innate colour preferences ; Colour difference ; Colour saturation Colour vision ; Colour perception
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract The innate preferences of inexperienced bumble bees, Bombus terrestris, for floral colour stimuli were studied using artificial flowers. The artificial flowers provided a colour pattern and consisted of a star-shaped corolla and of central colour patches similar to the “nectar guide” of natural flowers. The innate choice behaviour was assessed in terms of the number of approach flights from some distance towards the artificial flowers and the percentage of approach flights terminating in antennal contact with the floral guide. The colours of the floral guide, the corolla and the background were varied. It was shown that the innate flower colour preference in bumble bees has two components. 1. The frequency of approaches from a distance is correlated with the colour difference between the corolla and the background against which it is presented. If the corolla colour was constant but its background colour varied, the relative attractiveness of the corolla increased with its colour difference to the background. The colour difference assessment underlying this behaviour on a perceptual basis can be attained by means of colour opponent coding, a system well-established in Hymenoptera. 2. The frequency of antennal contacts with the floral guides relative to that of approach flights cannot be accounted for by colour opponent coding alone. Whether the approach flights are interrupted, or whether they end in an antennal contact with the “nectar guide” is strongly dependent on the direction (sign) of the colour difference, not only its magnitude. The choice behaviour requires a unique perceptual dimension, possibly that of colour saturation or that of hue perception comparable to components of colour perception in humans.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Journal of comparative physiology 174 (1994), S. 575-579 
    ISSN: 1432-1351
    Keywords: Proboscis extension ; Eristalis ; Wavelength ; specific behaviour ; Colour preference ; Pollen feeding
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Freshly emerged, inexperienced imagos of the hoverfly Eristalis tenax L. extend their proboscis towards small, yellow colour stimuli, such as anther parts and artificial floral guides. The releasing of this behaviour, which is adapted to pollen feeding, was investigated in behavioural tests using white, UV-reflecting artificial flowers with four small screens illuminated with test stimuli serving as artificial floral guides. The releasing of the innate proboscis extension was tested using monochromatic test lights. Within an intensity range from approx. 5·1011 to approx. 1014 quanta · cm-2· s-1, the flies extended their proboscis only towards green and yellow test lights (approx. 520–600 nm). The inhibition of the innate proboscis extension was tested using mixed light stimuli composed of a yellow monochromatic reference light (560 nm, 1013 quanta·cm-2 -1) and of a monochromatic test light. When the reference light was mixed with ultraviolet or blue test lights, the releasing of the innate proboscis extension was strongly inhibited, whereas admixing green/yellow light slightly promoted it; admixing red light had no effect. The results indicate that the releasing of the innate proboscis extension is mediated by the photoreceptor type R8y. Other receptor types which could cause the inhibition of the proboscis reaction are discussed.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Journal of comparative physiology 177 (1995), S. 1-19 
    ISSN: 1432-1351
    Keywords: Colour preference ; Flower colouration ; Flower visitation ; Visual signals ; Innate behaviour
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Freshly emerged flower visitors exhibit colour preferences prior to individual experience with flowers. The understanding of innate colour preferences in flower visitors requires a detailed analysis, as, on the one hand, colour is a multiple-signal stimulus, and, on the other hand, flower visits include a sequence of behavioural reactions each of which can be driven by a preferential behaviour. Behavioural reactions, such as the distant approach, the close-range orientation, the landing, and the extension of mouthparts can be triggered by colour stimuli. The physiological limitations of spectral sensitivity, the neuro-sensory filters, and the animals' different abilities to make use of visual information such as brightness perception, wavelength-specific behaviour and colour vision shape colour preferences. Besides these receiverbased factors, there are restrictions of flower colouration due to sender-based factors such as the absorption properties of floral pigments and the dual function of flower colours triggering both innate and learned behaviour. Recordings of the spectral reflection of coloured objects, which trigger innate colour preferences, provide an objective measure of the colour stimuli. Weighting the spectral reflection of coloured objects by the spectral composition of the ambient light and the spectral sensitivity of the flower visitors' photoreceptors allows the calculation of the effective stimuli. Perceptual dimensions are known for only a few taxa of flower visitors.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Naturwissenschaften 82 (1995), S. 432-434 
    ISSN: 1432-1904
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Natural Sciences in General
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 7
    Electronic Resource
    Electronic Resource
    Springer
    Naturwissenschaften 82 (1995), S. 432-434 
    ISSN: 1432-1904
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Natural Sciences in General
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 8
    Electronic Resource
    Electronic Resource
    Springer
    Naturwissenschaften 83 (1996), S. 579-580 
    ISSN: 1432-1904
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Natural Sciences in General
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 9
    Electronic Resource
    Electronic Resource
    Springer
    Naturwissenschaften 83 (1996), S. 579-580 
    ISSN: 1432-1904
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Natural Sciences in General
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 10
    Electronic Resource
    Electronic Resource
    Springer
    Cellular and molecular life sciences 49 (1993), S. 1002-1010 
    ISSN: 1420-9071
    Keywords: Colour preferences ; bumblebees ; hoverflies ; floral colour pattern ; flower signals
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract The colour patterns of angiosperm flowers visited by bees and hoverflies were shown to provide a dual signalling system, giving the flower-visitors visual orientation cues for the initial detection of flowers, as well as for learned discrimination. Pollinators show an innate response to interspecifically uniform colour signals, which enable them to detect flowers and to orient towards the site of reward. Interspecifically diverse colour signals provide pollinators with cues for learned discrimination between flowers of different species.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...