The increased interest in the harmful effects of most chemical pesticides on the ecosystem has continually served as an impetus to search for safer and eco-friendly pesticides from plant origin. In this study, the termiticidal potentials of extract mixtures of Azadirachta indica (A. Juss.), Nicotiana tabacum (L.), and Jatropha curcas (L.) against Macrotermes subhyalinus (Rambur, 1842) infesting Triplochiton scleroxylon (K. Schum) wood blocks were investigated in the field (open and under shade) and laboratory conditions. Weight loss in wood blocks, level of wood damage, and termite mortality were used as indices of wood protection potential of the botanical mixtures. The level of repellent ability of the extracts mixture was also determined. For the laboratory bioassays, ten termites (worker/soldier) were used per treatment and each treatment was replicated thrice. Profile of components of the three mixtures was also obtained using head space–solid-phase micro-extraction, gas chromatography–mass spectrophotometry (HS-SPME, GC-MS) analysis. Extracts of A. indica plus N. tabacum achieved 100% mortality of worker within 4 h while those of N. tabacum plus J. curcas and A. indica plus N. tabacum plus J. curcas achieved 100% mortality of termites at 6 h post-treatment. Also, extract of A. indica plus N. tabacum and A. indica plus N. tabacum plus J. curcas evoked 100% mortality of soldier termites at 6 h. Termites exposed to N. tabacum plus J. curcas for 1, 2, 3, and 4 h were the most repelled at 73, 87, 73, and 73%, respectively. The extract of J. curcas plus A. indica plus N. tabacum offered the highest protection against termite damage in the open field (6.17%). The botanicals were ineffective under shade. Insecticidal compounds like (S)-3-(1-Methyl-2-pyrrolidinyl) pyridine; Methyl ester, Hexadecanoic acid; (Z, Z)-9, 12-Octadecadienoic acid; Anthracene; 2-Hydroxy-Cyclopentadecanone; and n-Hexadecanoic acid were found in the extracts. These results suggest that the botanical mixtures could confer some protection against termites. Also, the knowledge about the components and varied level of potency under different conditions may be vital in developing biorationals against M. subhyalinus.

中文翻译：

---

三种植物杀白蚁剂作为木材保护剂对抗地下白蚁的协同作用，Macrotermes subhyalinus (Rambur, 1842)

对大多数化学杀虫剂对生态系统的有害影响的兴趣日益增加，这一直推动着从植物来源寻找更安全、更环保的杀虫剂。在这项研究中，Azadirachta indica (A. Juss.)、Nicotiana tabacum (L.) 和 Jatropha curcas (L.) 的提取物混合物对 Macrotermes subhyalinus (Rambur, 1842) 侵染 Triplochiton scleoxylon (K. Schum) 的杀白蚁潜力在野外（露天和阴凉处）和实验室条件下对木块进行了调查。木块的重量损失、木材损坏程度和白蚁死亡率被用作植物混合物木材保护潜力的指标。还测定了提取物混合物的驱避能力水平。对于实验室生物测定，每个处理使用十只白蚁（工人/士兵），每个处理重复三次。还使用顶空-固相微萃取、气相色谱-质谱（HS-SPME、GC-MS）分析获得了三种混合物的组分分布图。A. indica 加 N. tabacum 的提取物在 4 小时内实现了 100% 的白蚁死亡率，而 N. tabacum 加麻疯树和 A. indica 加 N. tabacum 加麻疯树的提取物在 6 小时后实现了 100% 白蚁死亡率-治疗。此外，A. indica 加 N. tabacum 和 A. indica 加 N. tabacum 加 J. curcas 的提取物在 6 小时时引起士兵白蚁的 100% 死亡率。暴露于普通烟草和麻疯病 1、2、3 和 4 小时的白蚁的驱除率分别为 73%、87%、73% 和 73%。J. curcas 加 A. indica 加 N. 的提取物。烟草在开阔地提供了最高的白蚁危害保护 (6.17%)。植物药在阴凉处无效。杀虫化合物，如 (S)-3-(1-Methyl-2-pyrrolidinyl) 吡啶；甲酯，十六烷酸；(Z, Z)-9, 12-十八碳二烯酸；蒽；2-羟基-环十五酮；和正十六烷酸在提取物中被发现。这些结果表明植物混合物可以提供一些针对白蚁的保护。此外，关于不同条件下成分和不同效力水平的知识对于开发针对 M. subhyalinus 的生物理性至关重要。蒽；2-羟基-环十五酮；和正十六烷酸在提取物中被发现。这些结果表明植物混合物可以提供一些针对白蚁的保护。此外，关于不同条件下成分和不同效力水平的知识对于开发针对 M. subhyalinus 的生物理性至关重要。蒽；2-羟基-环十五酮；和正十六烷酸在提取物中被发现。这些结果表明植物混合物可以提供一些针对白蚁的保护。此外，关于不同条件下成分和不同效力水平的知识对于开发针对 M. subhyalinus 的生物理性至关重要。