PHOTO-INHIBITION OF DIAPAUSE IN FIELD POPULATIONS OF AEDES-ATROPALPUS DIPTERA, CULICIDAE

A one-h light pulse, which occurred between 7 and 9 h after the beginning of a short-day scotophase, inhibited diapause in a laboratory colony of the mosquito Aedes atropalpus. Tests were conducted to see if induction of diapause in the field is also inhibited by nighttime light pulsing. It was determined that the natural light intensities at which A. atropalpus experiences the start of the scotophase occur shortly before sunset. Therefore, a one h pulse of light, at 8 h post sunset, was used to simulate the conditions which inhibited diapause in the laboratory. This prevented induction of diapause both in field cages and at a natural breeding site for,4. atropalpus. The observation, made during this study, that the natural scotophase for A. atropalpus ends at much lower light intensities than those at which it begins is discussed. © 1979 Entomological Society of America.