ナノエマルジョン化したニンニク油の主成分は標的外生物にやさしく貯蔵豆を守る ー害虫を殺す一方で植物の発育や天敵羽化数を向上ー

2026-07-29 九州大学

＜関連情報＞

• https://www.kyushu-u.ac.jp/ja/researches/view/1530
• https://www.sciencedirect.com/science/article/pii/S0147651326007037

貯蔵豆害虫に対するジアリルジスルフィドおよびカルボンナノエマルジョンの毒性増強と、その寄生蜂および種子の生存率に対する非標的効果 Enhanced toxicity of diallyl disulfide and carvone nanoemulsions against a stored bean pest and their nontarget effects on its parasitoid and seed viability

Urvashi Sahu, Eman Ahmed Mohamed Helmy, Midori Tuda
Ecotoxicology and Environmental Safety  Available online 16 June 2026
DOI:https://doi.org/10.1016/j.ecoenv.2026.120374

Highlights

• Stable diallyl disulfide and carvone nanoemulsion (NE) produced by ultrasonication.
• NEs had higher fumigant toxicity against Callosobruchus chinensis than bulk form.
• Binary mixture NEs exhibited additive effects, suggesting multi-target action.
• Parasitoid was more tolerant to diallyl disulfide, supporting biocontrol compatibility.
• NEs of diallyl disulfide and 2:1 mixture with carvone facilitated bean root growth.

Abstract

Botanical essential oils and their volatile constituents are increasingly recognized as environmentally safer alternatives to synthetic insecticides for managing stored-product pests. The adzuki bean beetle, Callosobruchus chinensis, is a cosmopolitan pest that causes substantial postharvest losses in legumes. In this study, nanoemulsions (NEs) of diallyl disulfide (a garlic-derived organosulfur compound), (R)-carvone (a spearmint-derived monoterpenoid), and their binary mixtures (1:1 and 2:1) were formulated using ultrasonication. The nanoemulsions consisted of spherical droplets (54–62 nm) and moderately high zeta potentials (−9.6 to −16.9 mV). Among treatments, diallyl disulfide NE exhibited the highest fumigant toxicity to C. chinensis, with an LC₅₀ of 0.79 µL active compound/L air at 24 h. Nanoemulsification enhanced efficacy by 30.5% for diallyl disulfide and 8.19% for carvone. Binary mixtures showed additive toxicity. Male beetles were generally more susceptible than females, except at a low concentration of the 1:1 mixture. At the 24 h LC₅₀ estimated for the host beetle, diallyl disulfide NE and the 2:1 mixture were less toxic (<50% mortality) to the parasitoid Anisopteromalus calandrae adults. These treatments, particularly the 2:1 mixture, increased root length and seedling vigor index, with no measurable phytochemical residues on bean surfaces. Exposure of host larvae to diallyl disulfide NE increased total host mortality and parasitoid emergence. Overall, diallyl disulfide NE, alone or in a 2:1 mixture with carvone, showed strong potential as a plant-based fumigant against C. chinensis, with comparatively low adverse effects on the parasitoid longevity, positive diallyl disulfide NE effects on parasitism, and neutral or positive effects on seedling growth.