Color and Light Intensity Preferences of Four Species of Alate Cereal Aphids

Color and light intensity preferences of 4 species of alate cereal aphids, the English grain aphid, Macrosiphum avenae (Fab.); oat bird-cherry aphid, Rhopalosiphum padi (L.); corn leaf aphid, R. maidis (Fitch); greenbug, Schizaphis graminum (Rondani); were tested under controlled conditions. No significant differences in color response were found between post-teneral (flight-active) and flight-exhausted alates of any species. Macrosiphum avenae, R. maidis, and S. graminum showed a distinct preference for yellow; R. padi usually preferred green. Alates of all species preferred high light intensities to low within the range tested (350-3500 ft-c). Preferred colors (yellow and green) were more important than light intensity in attracting the alates. All species chose yellow light over daylight of equal or greater intensity; all chose green light over equal or greater intensity. Nonpreferred colors (red and blue) were usually inferior to the total visible spectrum of greater intensity in attracting aphids. Confinement under yellow light significantly increased survival, reproduction, and rate of development whereas confinement under green, red, and blue lights resulted in decreased survival (50-80% mortality), reproduction, and rate of development of all species. Attempts to condition responses of cereal aphids to color, by rearing or confining them under various colors, were unsuccessful