Effects of allicin fumigation on the repellency and development of <i>Aphis gossypii</i> (Hemiptera: Aphididae)

Aphis gossypii Glover (Hemiptera: Aphididae) is a significant agricultural pest, and the growing issue of pesticide resistance, in this species, has underscored the urgent need to identify alternative, sustainable insecticides. Allium sativum Linnaeus (Asparagales: Amaryllidaceae) is renowned for its broad-spectrum biological activities, including antibacterial and detoxifying properties. Consequently, it has gained considerable attention in the field of plant protection. This study investigates the repellent effects of allicin on A. gossypii and its impact on the pest's growth and development under fumigation conditions, leveraging the volatile nature of allicin. The findings revealed that fumigation with allicin, diluted 50-fold, exhibited the most pronounced repellent effect on A. gossypii. The repellency rates reached 88% and 86% after 12 and 24 hours of treatment, respectively, while the mortality rates were 46% and 66% for the exact durations. Additionally, allicin significantly influenced the behavioral choices, growth and development, reproductive capacity, and population establishment of A. gossypii. The efficacy of allicin against A. gossypii demonstrated a concentration-dependent effect, with its fumigation activity diminishing as the concentration decreased. These results provide a scientific foundation for the application of allicin in controlling A. gossypii, offer valuable insights for further field trials, and establish a groundwork for utilizing allicin as a fumigant to manage and prevent aphid infestations in agricultural settings.