DYE-SENSITIZED HOUSE-FLY TOXICITY PRODUCED AS A FUNCTION OF VARIABLE LIGHT-SOURCES

House fly mortality induced by light after xanthene dye ingestion is dependent upon both light intensity and light source. Three variable light sources were employed in this study including fluorescent light, quartz iodide sunlamp, and the sun, and were compared to the total absence of light. Two dyes, rose bengal and erythrosin B, were tested for toxicity in the absence of light and appear to induce mortality by a similar, but different, mechanism. Six xanthene dyes were investigated for house fly toxicity with three different light sources to determine the relative effectiveness and efficiency of these light sources. The sun was the most effective light source, ca. 3.4 times more effective than fluorescent lights; but when light efficiency is considered, fluorescent lights are nearly 2.5 times more efficient than the sun and 3 times more efficient than the sunlamp. © 1979 Entomological Society of America.