Some Effects of Alternating Temperatures on the Growth and Metabolism of Cutworm Larvae1

Abstract

The first part of this paper presents the results of experiments in which larvae of Porosagrotis orthogonia Morr. were reared with daily alternations of high and low temperature. It was found that growth was accelerated by these alternations, the highest acceleration being for an eight hour exposure to high temperatures. In the second part of the paper, experiments are discussed in which the metabolism of larvae of Chortragrotis auxiliaries Grt. was measured after varying exposures to high temperatures. Here also it was found that metabolism, as measured by carbon dioxide output, also showed a maximum for an eight hour exposure. Both sets of experiments are discussed in relation to current chemical theories, and a time-temperature-rate surface is developed which shows the general relationship.