FORAGING PRESSURE AND ITS ANNUAL VARIATION A METHOD OF EVALUATION USING ARTIFICIAL FOOD SOURCES
J. A. NUNEZ
The foraging drive for nectar of a population of honeybees at different times of day was estimated by counting numbers of bees foraging, or trying to forage, on an artificial source in which the supply of nectar was constant, unaffected by weather or other factors. In winter and spring, foraging pressure remained uniform from one IS-day period to another so long as the temperature was above the threshold for flight. Moderately low temperatures increased foraging pressure, presumably by decreasing the rate of natural nectar secretion. Still lower temperatures decreased it by decreasing flight activity. In summer and autumn foraging pressure fell sharply at the beginning of the main nectar flow, and rose sharply at the end of it.