Department of Zoology, Unit of Applied Entomology, University of Madras, Chennai, Tamil Nadu, India.
Department of Ecotoxicology, Ross Lifescience Ltd., Bhosari, Pune, Maharastra, India.
PLoS One. 2022 Aug 19;17(8):e0270084. doi: 10.1371/journal.pone.0270084. eCollection 2022.
Tribolium castaneum is one of the major pests of stored grains which causes extensive damages. To control this insect pest many synthetic chemical pesticides are used. However, continuous usage of synthetic fumigants causes pest resurgence, toxic residues, genetic resistance in pests, environmental contamination and health hazards etc., To avert these problems, essential oils are used as bio-fumigants to control the stored pests. They could act as best alternatives to synthetic fumigant in closed environment. Hence, the present study aimed to evaluate the pesticidal activity of Callistemon citrinus oil against Tribolium castaneum. GC-MS analysis of C. citrinus essential oil (EO) showed 10 compounds; among them, the major constituent was eucalyptol (1, 8-cineole) at 40.44%. The lethal concentration (LC50) values were 37.05 μL/L (adults) and 144.31 μL/L (larvae) at 24 and 48 hrs respectively. Exposure to C. citrinus EO significantly reduced the beetle fecundity, ovicidal activity, egg hatchability, larvae survival and emergence of adult. The effect of EO on enzymatic activity of T. castaneum adults was examined using Acetylcholinesterase, α-Carboxylesterase, β-Carboxylesterase, Glutathione-S-Transferase, Acid and Alkaline phosphatase assays. The results indicated that the activity of detoxification enzymes drastically varied when compared with control. This EO had toxicant effects on all stages of the life of T. castaneum.
赤桉油对谷蠹的杀虫活性评价。赤桉油（EO）的 GC-MS 分析显示 10 种化合物；其中，主要成分为桉叶油醇（1,8-桉树脑），含量为 40.44%。在 24 和 48 小时时，成虫的致死浓度（LC50）值分别为 37.05 μL/L 和 144.31 μL/L，幼虫的致死浓度（LC50）值分别为 37.05 μL/L 和 144.31 μL/L。暴露于赤桉油 EO 显著降低了甲虫的繁殖力、杀卵活性、卵孵化率、幼虫存活率和成虫的出现率。利用乙酰胆碱酯酶、α-羧酸酯酶、β-羧酸酯酶、谷胱甘肽 S-转移酶、酸性磷酸酶和碱性磷酸酶测定法，研究了 EO 对赤桉油成虫酶活性的影响。结果表明，与对照相比，解毒酶的活性有明显的变化。这种 EO 对赤拟谷盗的各个生活阶段都有有毒作用。
