Some Observations on the Hunger-cycle of the Tsetse-fliesGlossina swynnertoniandG. pallidipes(Diptera) in the Field

Abstract

The mean hunger-cycles ofG. swynnertoniandG. pallidipeshave been studied in the field by marking tsetses with cut proboscidae, which have been released and subsequently recaptured.The length of time that hungry flies are able to survive before dying from starvation varies with the season, probably according to the amounts of reserve fats and atmospheric humidity.The mean hunger-cycle also varies with the season and correlates significantly with the evaporation rate or other measurements of humidity. The variation of temperature experienced in these experiments was not sufficient to have any appreciable effect on the hunger-cycle.G. pallidipes, a thicket haunting fly and larger thanG. swynnertoni, a thorn bush species, frequently than the latter under moist conditions, but frequently under adverse conditions.Smaller individuals probably feed more frequently than larger individuals.