<p>Air anions are molecules that have gained one or more additional electrons. While there have been several studies on the application of air anions in various fields such as air pollution, microorganisms, and plants, there has been no reported application to insects. This study explored the effects of air anions on greenhouse pests, <i>Tetranychus urticae</i> and <i>Aphis gossypii</i>, and analyzed their potential as an eco-friendly pest control method. The results showed that air anions exhibited insecticidal and repellent effects on both <i>T. urticae</i> and <i>A. gossypii</i>. Moreover, treatment with air anions for three weeks increased the total phenolic content in kidney beans, and the consumption of these leaves resulted in mortality effects on <i>T. urticae</i>. Additionally, in a greenhouse assay, a three-week air anion treatment on kidney beans resulted in approximately 92.3% control efficacy against <i>T. urticae</i>. In conclusion, air anions negatively impacted <i>T. urticae</i>, suggesting their potential use as an eco-friendly pest control method.</p>