The Experts below are selected from a list of 315 Experts worldwide ranked by ideXlab platform

Stanislav N. Gorb - One of the best experts on this subject based on the ideXlab platform.

  • Influence of ambient humidity on the attachment ability of ladybird beetles (Coccinella septempunctata).
    Beilstein journal of nanotechnology, 2016
    Co-Authors: Lars Heepe, Jonas O. Wolff, Stanislav N. Gorb
    Abstract:

    Many insects possess adhesive foot pads, which enable them to scale smooth vertical surfaces. The function of these organs may be highly affected by environmental conditions. Ladybird beetles (Coccinellidae) possess dense tarsal soles of tenent setae, supplemented with an adhesive fluid. We studied the attachment ability of the seven-spotted ladybird beetle (Coccinella septempunctata) at different humidities by horizontal traction experiments. We found that both low (15%) and high (99%) relative humidities lead to a decrease of attachment ability. The significantly highest attachment forces were revealed at 60% humidity. This relationship was found both in female and male beetles, despite of a deviating structure of adhesive setae and a significant difference in forces between sexes. These findings demonstrate that not only dry adhesive setae are affected by ambient humidity, but also setae that stick due to the capillarity of an oily secretion.

  • evidence for a material gradient in the adhesive tarsal setae of the ladybird beetle Coccinella septempunctata
    Nature Communications, 2013
    Co-Authors: Henrik Peisker, Jan Michels, Stanislav N. Gorb
    Abstract:

    Many insects cling to surfaces by means of specific bristles on the tips of their legs. Peisker et al. show that in the beetle Coccinella septempunctata the composition and stiffness of these bristles vary dramatically along their length, likely allowing for a better grip to uneven surfaces.

  • Evidence for a material gradient in the adhesive tarsal setae of the ladybird beetle Coccinella septempunctata
    Nature Communications, 2013
    Co-Authors: Henrik Peisker, Jan Michels, Stanislav N. Gorb
    Abstract:

    For an insect to be able to efficiently attach to surfaces, the adhesive pads on the distal parts of its legs must establish large contact areas. In case of hairy adhesive pads this requires flexibility of the contact-forming bristles, called adhesive tarsal setae. However, too flexible setae would have a low mechanical stability resulting in a decreased attachment ability of the pads. Here we show that the adhesive tarsal setae of the ladybird beetle Coccinella septempunctata feature pronounced gradients in the material composition and properties along their length. The Young’s modulus ranges from 1.2 MPa at the tips, where we found the incorporation of high proportions of the elastic protein resilin, to 6.8 GPa at the bases of the setae. These gradients likely represent an evolutionary optimization, which increases the performance of the adhesive system by enabling effective adaptation to rough surfaces while simultaneously preventing lateral collapse of the setae. Many insects cling to surfaces by means of specific bristles on the tips of their legs. Peisker et al. show that in the beetle Coccinella septempunctata the composition and stiffness of these bristles vary dramatically along their length, likely allowing for a better grip to uneven surfaces.

Henrik Peisker - One of the best experts on this subject based on the ideXlab platform.

  • evidence for a material gradient in the adhesive tarsal setae of the ladybird beetle Coccinella septempunctata
    Nature Communications, 2013
    Co-Authors: Henrik Peisker, Jan Michels, Stanislav N. Gorb
    Abstract:

    Many insects cling to surfaces by means of specific bristles on the tips of their legs. Peisker et al. show that in the beetle Coccinella septempunctata the composition and stiffness of these bristles vary dramatically along their length, likely allowing for a better grip to uneven surfaces.

  • Evidence for a material gradient in the adhesive tarsal setae of the ladybird beetle Coccinella septempunctata
    Nature Communications, 2013
    Co-Authors: Henrik Peisker, Jan Michels, Stanislav N. Gorb
    Abstract:

    For an insect to be able to efficiently attach to surfaces, the adhesive pads on the distal parts of its legs must establish large contact areas. In case of hairy adhesive pads this requires flexibility of the contact-forming bristles, called adhesive tarsal setae. However, too flexible setae would have a low mechanical stability resulting in a decreased attachment ability of the pads. Here we show that the adhesive tarsal setae of the ladybird beetle Coccinella septempunctata feature pronounced gradients in the material composition and properties along their length. The Young’s modulus ranges from 1.2 MPa at the tips, where we found the incorporation of high proportions of the elastic protein resilin, to 6.8 GPa at the bases of the setae. These gradients likely represent an evolutionary optimization, which increases the performance of the adhesive system by enabling effective adaptation to rough surfaces while simultaneously preventing lateral collapse of the setae. Many insects cling to surfaces by means of specific bristles on the tips of their legs. Peisker et al. show that in the beetle Coccinella septempunctata the composition and stiffness of these bristles vary dramatically along their length, likely allowing for a better grip to uneven surfaces.

Jan Michels - One of the best experts on this subject based on the ideXlab platform.

  • evidence for a material gradient in the adhesive tarsal setae of the ladybird beetle Coccinella septempunctata
    Nature Communications, 2013
    Co-Authors: Henrik Peisker, Jan Michels, Stanislav N. Gorb
    Abstract:

    Many insects cling to surfaces by means of specific bristles on the tips of their legs. Peisker et al. show that in the beetle Coccinella septempunctata the composition and stiffness of these bristles vary dramatically along their length, likely allowing for a better grip to uneven surfaces.

  • Evidence for a material gradient in the adhesive tarsal setae of the ladybird beetle Coccinella septempunctata
    Nature Communications, 2013
    Co-Authors: Henrik Peisker, Jan Michels, Stanislav N. Gorb
    Abstract:

    For an insect to be able to efficiently attach to surfaces, the adhesive pads on the distal parts of its legs must establish large contact areas. In case of hairy adhesive pads this requires flexibility of the contact-forming bristles, called adhesive tarsal setae. However, too flexible setae would have a low mechanical stability resulting in a decreased attachment ability of the pads. Here we show that the adhesive tarsal setae of the ladybird beetle Coccinella septempunctata feature pronounced gradients in the material composition and properties along their length. The Young’s modulus ranges from 1.2 MPa at the tips, where we found the incorporation of high proportions of the elastic protein resilin, to 6.8 GPa at the bases of the setae. These gradients likely represent an evolutionary optimization, which increases the performance of the adhesive system by enabling effective adaptation to rough surfaces while simultaneously preventing lateral collapse of the setae. Many insects cling to surfaces by means of specific bristles on the tips of their legs. Peisker et al. show that in the beetle Coccinella septempunctata the composition and stiffness of these bristles vary dramatically along their length, likely allowing for a better grip to uneven surfaces.

R. V. Flanders - One of the best experts on this subject based on the ideXlab platform.

  • Gene Flow in Populations of the Seven-Spotted Lady Beetle, Coccinella septempunctata
    Journal of Heredity, 1992
    Co-Authors: Elliot S. Krafsur, J. J. Obrycki, R. V. Flanders
    Abstract:

    Polyacrylamide gel electrophoresis was used to reveal gene diversity in exotic North American Coccinella septempunctata populations. This lady beetle recently spread across the northern Nearctic. Sixteen of 28 putative loci were polymorphic; average gene diversity for all loci was 0.1598 ± 0.041. Gene frequencies were estimated at eight polymorphic loci in natural North American beetles from Arkansas, Delaware, lowa, Kansas, New York, Oregon, and Michigan. Also studied were F2 beetles from four laboratory colonies that originated in Eurasia, along with field-collected beetles from France, Greece, and Sicily. Gene diversity among the Nearctic beetles was as great as that among the Palearctic beetles. Analysis of variance by Wright\u27s method showed that only 29% of the variance in gene frequencies was between USDA cultures, Palearctic, and Nearctic beetles; 71% of the genetic variance was shared by beetles within the 21 subpopulations. No evidence of bottlenecks of drift was detected among the Nearctic subpopulations, and gene flow was essentially unrestricted

Richard Harrington - One of the best experts on this subject based on the ideXlab platform.

  • A model describing the population dynamics of Sitobion avenae and Coccinella septempunctata
    Ecological Modelling, 1997
    Co-Authors: D.j. Skirvin, Joe N. Perry, Richard Harrington
    Abstract:

    Abstract A model that described the summer population dynamics of the cereal aphid Sitobion avenae (Carter et al., 1982) was modified and extended to include the population dynamics of the aphidophagous predator Coccinella septempunctata . New equations were formulated to describe the dependence of aphid development and reproduction on temperature. The predation interaction between the aphid and coccinellid was formulated with a modified form of the temperature-mediated functional response equation proposed by Mack et al. (1981) and Mack and Smilowitz (1982). The output obtained from the model provided a reasonably good fit to field data. Recommendations for further research are made based on these results and on a sensitivity analysis reported elsewhere (Skirvin et al., 1996).