A METHOD FOR RAPID MEASUREMENT OF HEAT OR COLD RESISTANCE OF SMALL INSECTS

1. We describe a new technique for rapidly measuring the heat or cold resistance of many small insects. We heat (or cool) insects in a temperature-controlled column and measure the temperature at which they are knocked down. 2. An artificial selection experiment on heat resistance demonstrates that knock-down temperatures respond rapidly to selection. After only four generations of selection, the experimental and control lines differed significantly in both knock-down temperature and physiological heat tolerance, as measured by per cent survival of a heat shock. 3. Potential applications (acclimation, ageing, selection) and technical problems (body size, humidity, statistical considerations) are evaluated.