Alternating temperatures resulted in higher intrinsic rates of increase (rm) than constant temperatures within the range of temperature favourable for growth and reproduction of the pea aphid. This difference was due to slightly faster development and earlier attainment of maximum fecundity at alternating temperatures.
Preliminary mathematical models relating rm to constant and alternating temperatures are derived. These are:
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for constant temperatures and
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for alternating temperatures of 5°, 10°, and 15° amplitudes respectively. Average deviation between empirical and computed values is 2%. The efficacy of these models is restricted to temperatures favourable for development and reproduction of the pea aphid.