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 chemical ecology 15 (1989), S. 183-208 
    ISSN: 1573-1561
    Keywords: Ips paraconfusus ; Coleoptera ; Scolytidae ; bark beetles ; olfaction ; orientation ; counterturning ; chemotaxis ; taxis ; pheromones ; tropotaxis ; schemakinesis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The position of beetles were marked at 1-sec intervals after they were released in still air 16–18 cm from point sources of pheromone. Characteristics of the tracks were quantified and compared to those that might be produced by counterturning schemakinesis, tropotaxis, klinotaxis, zigzagging, look-and-leap, or steepest-ascent schemakinesis mechanisms. The beetles' movements were highly irregular, but they turned almost continually and never fixed on a heading near 0° (=straight towards the source). Turn angle sizes increased slightly with absolute size of heading but had the opposite sign, thus compensating slightly for heading. Their distribution was centered about 0° and was unimodal. Heading decreased gradually as the source was neared, but the decrease became steeper within 1–5 cm of the source. Histograms showed that the maximum headings between occurrences when the beetle was headed directly towards the source (0°) were centered around 0° and most of them were less than 90°. However, maximum headings between 90° and 180° were not uncommon. Turn radius decreased as the source was neared. The counterturning mechanism was the most consistent with these observations. An analysis of rate of change of concentration with respect to heading and distance to the source further demonstrated that the counterturning mechanism could explain the form of the decrease in heading as the source was neared, if the major cue used to initiate counterturns was a decrease in the rate of increase of concentration. The tropotaxis could not recreate the form of the decrease, under any form of stimulus processing.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    ISSN: 1573-1561
    Keywords: Olfaction ; ipsenol ; ipsdienol ; cis-verbenol ; chemotaxis ; perception ; discrimination ; neural models ; logit models ; stimulus-response models ; Ips paraconfusus ; Coleoptera ; Scolytidae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The male-produced aggregation pheromone inIps paraconfusus is composed of three compounds. Female bark beetles were exposed to combinations of these compounds, presented as point sources in an enclosed, circular arena. By itself,cis-verbenol (cV) had no effect on the number of beetles that reached the source. Either ipsenol (Ip) alone or ipsdienol (Id) alone strongly increased the number that reached the source, with Id producing a dose-response curve with a much steeper slope. cV moved the onset of the response to Id to higher doses of Id, but the response rose more rapidly after onset than when cV was absent. Overall, cV inhibited the effect of Id except at the highest dose. cV affected the onset of the response to Ip little or none, but strongly increased the slope of the response, synergizing the effect of Ip. The responses to combinations of Id and Ip were related to the log of a linear combination of their doses. The results are consistent with a model where Id and Ip act at a single site of action, but with different potencies, while cV appears to modify the effects of Id and Ip, rather than affecting the site of action directly.
    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 chemical ecology 15 (1989), S. 1147-1159 
    ISSN: 1573-1561
    Keywords: Ips paraconfusus ; bark beetles ; Coleoptera ; Scolytidae ; olfaction ; orientation ; anemotaxis ; pheromones
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Synthetic pheromone was released from a dispenser stretched across the width of a wind tunnel. Beetles in pheromone-free wind wandered in all directions and did not appear to orient to the wind. A dosage series showed that pheromone decreased the walking rate and deviations from the upwind direction, and it increased the turning rate. The tracks were composed of relatively straight or gently curving sections interspersed with more infrequent, larger course adjustments. Although pheromone clearly affected the average heading of beetles within a treatment, any given individual exposed to pheromone did not necessarily head directly upwind or maintain a fixed absolute angle with respect to the wind direction. The response appeared to be an inaccurate anemotaxis, rather than an anemomenotaxis.
    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 chemical ecology 15 (1989), S. 3-24 
    ISSN: 1573-1561
    Keywords: Ips paraconfusus ; Coleoptera ; Scolytidae ; bark beetles ; taxis ; chemotaxis ; orientation ; olfaction ; pheromones
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Gas-liquid chromatography of the air within the arena developed for this assay showed that a concentration gradient was established within 1–2 min of applying the pheromone (ipsenol, ipsdienol,cis-verbenol), and that this gradient was nearly constant for 20–95 min after application. The concentration fell rapidly and approximately exponentially between the source and the center of the arena. Turning rate and the number of beetles that reached the source increased, and heading with respect to the source decreased, in the presence of pheromone. Responses of beetles that did and did not reach the source were significantly different, but within each group there were no significant differences among dosages. Turning rate and heading varied little with distance from the source, while walking rate decreased as distance from the release point of the beetles increased. We hypothesize that dosage exerts its major effect on source location by altering the probability that a beetle will enter into orientation behavior and that beetles orienting to sources have similar behaviors even when orienting to a wide range of dosages.
    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...