Grasshopper populations and weather: the effects of insolation on Chorthippus brunneus

Authors

  • MICHAEL BEGON

    Corresponding author
    1. Department of Zoology, University of Liverpool
      Dr M. Begon, Department of Zoology, University of Liverpool, P.O. Box 147, Liverpool L69 3BX.
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Dr M. Begon, Department of Zoology, University of Liverpool, P.O. Box 147, Liverpool L69 3BX.

Abstract

ABSTRACT.

  • 1In nature, the internal body temperature of Chorthippus brunneus Thunberg is found to be raised substantially under the influence of direct insolation.
  • 2In the laboratory, similarly raised body temperatures, resulting from the radiant heat of a light bulb, lead to a 5.6-fold increase in the rate of development, and a similar or even higher increase in the rate of adult maturation. The rate of egg-production is even more greatly affected, being negligible in the absence of a radiant-heat source.
  • 3These physiological results provide an explanation for the frequently found correlation between grasshopper abundance and hot and/or dry weather.
  • 4The results are also discussed in terms of the problems they pose for the derivation of a physiological time-scale for basking insects, and the evolutionary forces and constraints that might give rise to them.

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