RESPONSE OF AEDES AEGYPTI (L.) TO GRADED LIGHT STIMULI

Abstract

Female adults of Aedes aegypti, starved in the dark in a stable, saturated environment at a constant temperature of 23 °C for 3.5 days after emergence, were subjected to a graded stimulus of increasing light intensity. Mosquitoes responded to increasing intensity of light when the humidity in the experimental environment was reduced below the dew point to a level that was favorable for flight. Response–time curves for groups of simultaneously stimulated individuals indicated that the influence of light varied with the time allowed for adaptation to the change in hygrothermal environment. A relation was established between quantal measurements of the response and the 'time × intensity' factor of the light stimulus in series of experiments at 24, 28, and 34 °C in 80% relative humidity. Log transformation of this relation indicated that response was subject to temporal summation of subthreshold increments of intensity when the hygrothermal environment was favorable for sustained flight. Rate of take-off increased with postemergence age in starving adult females.