Insecticidal and Acaricidal Activity of Essential Oils Rich in (E)-Nerolidol from Melaleuca leucadendra Occurring in the State of Pernambuco (Brazil) and Effects on Two Important Agricultural Pests

Essential oils from the leaves, stems, flowers and fruits of Melaleuca leucadendra growing in the state of Pernambuco, Brazil, were analyzed using gas chromatography-mass spectrometry (GC-MS). The effects of the oils and their major constituent were evaluated on the agricultural pests Tetranychus urticae and Plutella xylostella in different stages of development. The analysis revealed a M. leucadendra chemotype rich in (E)-nerolidol (81.78 ± 0.90 to 95.78 ± 1.20%). P. xylostella was more susceptible to the oils and major constituent than T. urticae. The fruit oil was 1.5-fold more toxic than the leaf oil to T. urticae eggs. (E)-Nerolidol was 5.5-fold and 4.5-fold more toxic to T. urticae adults than the leaf and fruit oils, respectively. Azamax® used as the positive control was more efficient than the oils and (E)-nerolidol against T. urticae. However, the oils and (E)-nerolidol were more toxic to P. xylostella than Azamax®.

本研究采用气相色谱-质谱联用法（gas chromatography-mass spectrometry, GC-MS），对产自巴西伯南布哥州的白千层（Melaleuca leucadendra）的叶、茎、花及果实所提取的精油进行了成分分析，并评估了该类精油及其主要成分对不同发育阶段的农业害虫二斑叶螨（Tetranychus urticae）与小菜蛾（Plutella xylostella）的生物活性。分析结果表明，该白千层为富含(E)-橙花叔醇的化学型，其含量区间为81.78 ± 0.90%至95.78 ± 1.20%。小菜蛾（P. xylostella）对该精油及其主要成分的敏感性高于二斑叶螨（T. urticae）：相较于叶部精油，果实精油对二斑叶螨卵的毒力高出1.5倍；(E)-橙花叔醇对二斑叶螨成螨的毒力分别为叶部精油与果实精油的5.5倍和4.5倍。作为阳性对照的阿杂麦（Azamax®）对二斑叶螨的防治效果优于该精油及(E)-橙花叔醇，但针对小菜蛾时，该精油及(E)-橙花叔醇的毒力则高于阿杂麦（Azamax®）。