Anisole is an environmentally friendly fumigant for postharvest pest control

Authors: Yang, Xiangbing; Liu, Yong Biao

Submitted to: Journal of Stored Products Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/9/2021
Publication Date: 6/16/2021
Publication URL: https://handle.nal.usda.gov/10113/7416636
Citation: Yang, X., Liu, Y.-B. 2021. Anisole is an environmentally friendly fumigant for postharvest pest control. Journal of Stored Products Research. 93. Article 101842. https://doi.org/10.1016/j.jspr.2021.101842.
DOI: https://doi.org/10.1016/j.jspr.2021.101842

Interpretive Summary: Plant essential oils are generally regarded as safe (GRAS) compounds and, therefore, good candidates as environmentally friendly pesticides. Many plant essential oils have been demonstrated to be insecticidal. However, very few of them have been demonstrated to be effective as fumigants because of their very low volatility. Anisole is a plant essential oil with relatively smaller molecule size and higher volatility, and is insecticidal. We tested anisole as a fumigant against adults of rice weevil, granary weevil, and confused flour beetle at 25C and against larvae and adults of western flower thrips at 2C. Complete control of all four insect species was achieved in fumigations with anisole at different concentrations of 100 to 600 microliter/liter in 6 to 24 hours. Anisole fumigation was also effective against rice weevil adults in stored corn, indicating that it can penetrate stored corn. The results of this study suggest that anisole has potential as a fumigant for postharvest pest control on fresh and stored products.

Technical Abstract: Many plant essential oils have been found to be insecticidal but not many were as effective as currently used fumigants. We evaluated anisole as a potential fumigant for controlling four insect pests including adults of three stored product pests (granary weevil, rice weevil, and confused flour beetle at 25°C), and a fresh produce product pest (western flower thrips (WFT) at 2°C) in small-scale laboratory tests. Anisole fumigations were effective against all four pests. At a dose of 100 ul/L, anisole fumigation completely controlled granary weevil and rice weevil in 24 and 16 h, respectively. At a dose of 150 ul/L, complete control of the two pests was achieved in 16 and 8 h, respectively. Confused flour beetle was completely controlled in 16 and 8 h with anisole fumigations at 400 ul/L and 600 ul/L respectively. Complete control of WFT was achieved in 8 and 6 h fumigations with anisole at doses of 150 ul/L and 300 ul/L, respectively. The median lethal time (LT50) of anisole fumigation at 50 ul/L were 0.6 and 0.5 h for granary weevil and rice weevil, respectively. LT50 for confused flour beetle at 600 ul/L was 2.9 h. In a 16 h confirmatory test in a mini silo, anisole fumigation achieved 100% control of rice weevil at different depth of stored corn. This study demonstrated that anisole fumigation has good efficacy against insects and, therefore, has potential as an environmentally friendly, alternative fumigant for postharvest pest control.