Data set on Insecticidal Activity of Lantana Camara Extract oil on Controlling Maize grain weevils

Currently farmers are faced by serious post-harvest problems from weevils especially in storage of grains. When grain is attacked by weevils, they become less marketable and this causes economic loss to the producers and quality loss to the consumers. As a result of these problems, many farmers prefer to sell most of their crop immediately after harvesting to avoid making losses from the infestation of the weevils. Maize has ability to be stored for long period for latter consumption or to look for good price. However, it suffer major economic loss caused by grain infesting insects because of cumulative effects of feeding, breeding, transmission of toxic and saprophytic fungi and associated changes in the micro-ecological conditions in the grain bulk, which hasten the deterioration process in the grain. Various control methods are available for use in storage systems in numerous and diverse with their environmental factors for the post-harvest system. Insect pests have been prevented principally by synthetic insecticides chemicals such as DDT, Malataine and others. However, this continued and wide spread use of synthetic insecticides chemicals has given rise to the development of resistance, pest resurgence, lethal effects on non-target organisms, toxic residues, worker safety. The chemicals contaminate stored food commodity, leaving behind harmful residue in health, causes cancer. The use of botanical extract crude oil and powder is suitable for grain protection from infested insects. It would be increase demand and experience in the use of these eco-friendly natural products, which could replace synthetic chemicals for management stored grain protection from weevils including the development of non-chemical technologies which may eliminate the use of insecticides and have economic and health benefits for applicators, consumers and the environment.
The operational parameters for repellency and mortality of weevils are effect of extract oil concentration (0% (w/w), 2% (w/w), 3% (w/w), 5% (w/w), 7% (w/w), and 10% (w/w), exposed time (1-5 days), and type of extract solvents (methanol, ethanol and ethyl acetate) were investigated. Repellency effect was also conducted at 6, 12 and 24 h at different concentration oil. Gas Chromatography-Mass spectrometry (GC-MS) and Fourier transform infrared spectroscopy (FT-IR) was used to identify the chemical composition and Functional group of solvent extracted oil respectively. The number of weevil’s death increases significantly as exposed time increases. The extracted oil by the three-solvent fraction had direct repellent and toxic effect to the weevil. From all treatment applied, extracted by methanol fraction had showed highest percentage mortality (74%). The lowest mortality rate was observed in ethyl acetate fraction oil (26%), at 2% (w/w) concentration. The effect of lantana Camara leaf powder and extracted oil on repellency and mortality was showed directly proportional to concentration dosage.

当前农户正面临严峻的采后象鼻虫（weevils）虫害问题，尤以谷物储存阶段为甚。谷物遭受象鼻虫侵染后，商品价值大幅降低，这不仅给生产者带来经济损失，也损害了消费者所购谷物的品质。受此影响，许多农户倾向于在收获后立即售出大部分作物，以规避象鼻虫侵染造成的损失。玉米虽可长期储存以备后续食用或待价而沽，但却极易受到储粮昆虫的侵害：昆虫取食、繁殖、传播有毒及腐生真菌，加之粮堆内微生态环境发生改变，多重因素叠加加速了谷物的劣变进程，由此造成重大经济损失。储粮系统中可用的防治手段多样，且各有其适配的采后系统环境条件。长期以来，人们主要通过合成杀虫剂（如滴滴涕（DDT）、马拉硫磷（Malataine）等）来防控储粮害虫。然而，此类合成杀虫剂的长期广泛使用引发了诸多问题：害虫抗药性发展、害虫再猖獗、对非靶标生物的致死效应、有毒残留以及施药人员的安全隐患。这类化学药剂会污染储粮食品，残留有害成分，危害人体健康甚至诱发癌症。采用植物提取物粗提油与粉剂来保护谷物免受昆虫侵染，是更为适宜的方案。当前这类环保天然产品的应用需求与实践经验正逐步提升，有望替代合成化学药剂，用于储粮象鼻虫的防控；同时，开发无需使用杀虫剂的非化学防治技术，可为施药者、消费者及环境带来经济与健康效益。
本研究针对象鼻虫的驱避活性与致死率相关操作参数展开了调查，考察因素包括提取物油浓度（0%（w/w）、2%（w/w）、3%（w/w）、5%（w/w）、7%（w/w）及10%（w/w））、暴露时长（1-5天）以及提取物溶剂类型（甲醇（methanol）、乙醇（ethanol）与乙酸乙酯（ethyl acetate））。此外，还在6h、12h与24h的不同时间节点，针对不同浓度的提取物油开展了驱避效果测试。采用气相色谱-质谱联用仪（Gas Chromatography-Mass spectrometry, GC-MS）与傅里叶变换红外光谱仪（Fourier transform infrared spectroscopy, FT-IR），分别鉴定了溶剂提取油的化学成分与官能团。研究发现，象鼻虫的死亡数量随暴露时长的增加显著上升。三种溶剂分级提取得到的油样对象鼻虫均具有直接驱避与毒杀作用。在所有处理组中，甲醇分级提取的油样展现出最高的致死率（74%）；而在2%（w/w）浓度下，乙酸乙酯分级提取的油样致死率最低（26%）。马缨丹（Lantana Camara）叶粉与提取物油的驱避活性及致死率效应，均与施用浓度呈正相关。