Acetic Acid-Treated Common Beans Attenuate the Host Plant Preference of Spider Mites

Chemical pesticides are indispensable for protecting crops from pests and supporting a stable food supply; however, their environmental impacts have raised growing concerns. This has driven efforts to develop alternative, lower-impact pesticides and technologies for sustainable agriculture. Vinegar, a natural and eco-friendly option, has been used to protect plants from pests and diseases. Here, we investigated the effects of acetic acid, the main component of vinegar, on host selection by spider mites using a common bean (Phaseolus vulgaris)-two-spotted spider mite (Tetranychus urticae) system. The results indicated that spider mites avoided acetic acid-treated plants, with plant volatiles influencing their preference. Volatile organic compound (VOC) analysis revealed that acetic acid treatment altered VOC composition. Although changes in the levels of compounds such as (E)-2-hexenal and 1-octen-3-one contributed to this shift, individual testing showed that unrealistically high concentrations were required to repel spider mites. This suggests that the effect of acetic acid treatment is not primarily due to the induction of specific VOCs, but rather to an overall alteration of VOC composition. These findings highlight the potential of vinegar as an eco-friendly pest management strategy, although further studies are needed to evaluate its long-term efficacy and impact on crop protection under field conditions.