Journal of Entomological Research

The acaricides tested against European red mite, Panonychus ulmi (Koch) included cyenopyrafen, fenazaquin, etoxazole, spiromesifen, hexythiazox, propargite and a combination of propargite + hexythiazox and compared with horticultural mineral oil (HMO). Cyenopyrafen has been reported to be most toxic acaricide to adults with an LC₅₀ value of 100.35 ppm and a relative toxicity of 74.68, making it the most effective acaricide followed by fenazaquin with LC₅₀ value of 130.22 ppm and a relative toxicity of 57.0. Other acaricides including etoxazole (LC₅₀ 203.25 ppm), spiromesifen (LC₅₀ 205.11 ppm), and hexythiazox (LC₅₀ 529.75 ppm) were comparatively less toxic with relative toxicities of 36.57, 36.20 and 14.03, respectively. On the other hand, propargite and propargite + hexythiazox exhibited lowest toxicity among tested chemicals with LC₅₀ values of 626.47 and 629.65 ppm, and relative toxicities of 11.86 and 11.80, respectively. HMO was least toxic with an LC₅₀ value of 7434.42 ppm. The order of toxicity based on LC₅₀ values was cyenopyrafen followed by fenazaquin, etoxazole, spiromesifen, hexythiazox, propargite, propargite + hexythiazox and HMO. The fiducial limits of the acaricides varied, indicating differences in their range of effectiveness. Cyenopyrafen and fenazaquin were found most potent acaricides.