Plant volatile compound methyl benzoate is highly effective against Spodoptera frugiperda and safe to non-target organisms as an eco-friendly botanical-insecticide

• Published in: Ecotoxicology and environmental safety Vol. 245; p. 114101
• Main Authors: Zhao, Rui, Wang, Huan-Huan, Gao, Jie, Zhang, Yong-Jun, Li, Xianchun, Zhou, Jing-Jiang, Liang, Pei, Gao, Xi-Wu, Gu, Shao-Hua
• Format: Journal Article
• Language: English
• Published: Elsevier Inc 15.10.2022; Elsevier
• Subjects: Botanical insecticide; Methyl benzoate; Oviposition deterrence; Repellent; Selectivity; Toxicity; Botanical insecticide; Repellent; Oviposition deterrence; Selectivity; Toxicity; Methyl benzoate
• ISSN: 0147-6513; 1090-2414; 1090-2414
• DOI: 10.1016/j.ecoenv.2022.114101

Recent studies have indicated that the plant volatile methyl benzoate (MB) exhibits significant insecticidal bioactivity against several common insects. However, the potential environmental hazards of MB and its safety to non-target organisms is poorly understood. In the present study, these characteristics were investigated through laboratory experiments and field investigations. The results revealed that MB was highly toxic to the agricultural pest, fall armyworm Spodoptera frugiperda. Compared with the commercial pesticide lambda-cyhalothrin, the toxicities of MB against S. frugiperda larvae and adults were comparable and 3.41 times higher, respectively. Behavioral bioassays showed that the percentage repellency of MB to S. frugiperda larvae was 56.72 %, and MB induced 69.40 % oviposition deterrence rate in S. frugiperda female adults. Furthermore, in terms of median lethal concentration (LC50) and median lethal doses (LD50), MB exhibited non-toxic effects on non-target animals with 3-d LC50 of > 1 % to natural predators (Coccinella septempunctata and Harmonia axyridis), 3-d LD50 of 467.86 µg/bee to the bumblebee Bombus terrestris, 14-d LC50 of 971.09 mg/kg to the earthworm Eisenia fetida, and 4-d LC50 of 47.30 mg/L to the zebrafish Brachydanio rerio. The accumulation of MB in the soil and earthworms was found to be extremely limited. Our comparative study clearly demonstrated that MB is effective as a selective botanical pesticide against S. frugiperda and it is safe to use in the tested environment, with no toxic effects on non-target animals and natural predators. [Display omitted] •Plant volatile compound methyl benzoate (MB) has a significant insecticidal bioactivity against S. frugiperda.•MB has high repellent activity and oviposition-deterring to S. frugiperda larvae and adult.•MB is safe to tested insect predators, pollinating bumblebees, environmental indicators earthworms and zebrafish.•MB has a very limited accumulation in soil and earthworms.