Organic Compounds as a Natural Alternative for Pest Control: How Will Climate Change Affect Their Effectiveness?

Climate change scenarios predict increased temperatures, potentially impacting the development of phytopathogenic fungi and the efficacy of their control. This study evaluated the effects of four natural organic compounds-carvacrol, eugenol, <i>trans</i>-cinnamaldehyde, and 1-heptyn-3-ol-on the growth of <i>Fusarium verticillioides</i> and the survival of <i>Sitophilus zeamais</i> under two temperature regimes (28 °C and 32 °C). Fungal growth was assessed through the lag phase duration and mycelial expansion, while insecticidal activity was determined by mortality of <i>S. zeamais</i>. Carvacrol (1 ppm) produced the most pronounced inhibitory effect on fungal growth, significantly extending the lag phase and reducing mycelial area, with eugenol showing similar effects at selected concentrations. Both compounds maintained or enhanced their antifungal activity at elevated temperatures. Trans-cinnamaldehyde and 1-heptyn-3-ol exhibited moderate or low effects, depending on concentration and temperature. Regarding <i>S. zeamais</i>, 1-heptyn-3-ol achieved complete mortality at all concentrations under both temperature scenarios, whereas carvacrol, eugenol, and <i>trans</i>-cinnamaldehyde showed dose-dependent effects at 28 °C and enhanced efficacy at 32 °C. Overall, these findings highlight the potential of these compounds as sustainable, climate-resilient alternatives for managing fungal pathogens and stored-product pests.