Plant Protection Department, Faculty of Agriculture, Sohag University, Sohag, Egypt.
Asia Pacific Resources International Holdings Ltd, Riau Andalan Pulp and Paper, Pangkalan Kerinci, Riau, Indonesia.
Pest Manag Sci. 2021 Jul;77(7):3500-3507. doi: 10.1002/ps.6403. Epub 2021 Apr 25.
The rice weevil, Sitophilus oryzae (L., 1763) (Coleoptera: Curculionidae), is a stored grain/seed pest of several crops. Botanicals represent an option to manage this pest, especially those with high toxicity determined by its structure and physicochemical properties and low residue left behind on treated grains/seeds. Enantiomers are bioactive molecules in organic processes. The aim of this study was to evaluate the insecticidal activity of two enantiomeric forms of the monoterpenes citronellal, limonene, linalool, menthone and α-pinene against S. oryzae adults through contact, fumigant and repellent assays.
All results were compared with absolute acetone as the negative control and those from contact assays also with malathion as the positive control. (S)-(-)-linalool was the most toxic by contact to S. oryzae and (S)-(-)-menthone through fumigation, while the two enantiomeric forms of menthone and α-pinene were the best repellents.
The high toxicity of only one of the two monoterpene enantiomers showed the importance of form and percentage of enantiomer in the commercial product, which affect the success of the product to controlling S. oryzae. © 2021 Society of Chemical Industry.
米象（ Sitophilus oryzae （L.，1763））（鞘翅目：象甲科）是几种作物的储粮/种子害虫。植物性药剂是一种防治这种害虫的选择，尤其是那些结构和理化性质决定其高毒性、在处理过的谷物/种子上残留量低的药剂。对映异构体是有机过程中的生物活性分子。本研究的目的是通过接触、熏蒸和驱避试验评估两种单萜柠烯、柠檬烯、芳樟醇、薄荷酮和α-蒎烯对米象成虫的杀虫活性。
所有结果均与绝对丙酮（作为阴性对照）进行比较，接触试验结果还与马拉硫磷（作为阳性对照）进行比较。（S）-（-）-芳樟醇通过接触对米象的毒性最大，（S）-（-）-薄荷酮通过熏蒸的毒性最大，而薄荷酮和α-蒎烯的两种对映异构体则是最好的驱避剂。
仅两种单萜对映异构体中的一种具有高毒性，这表明了商业产品中对映体的形式和百分比的重要性，这会影响产品防治米象的成功。 © 2021 化学工业协会。
