Essential oils are being increasingly utilised as a biorational element in integrated pest management regimes. Whereas there has been much research on the effects of these oils on mortality and behaviour of pestiferous molluscs, insects and nematodes, there has (to the present authors’ knowledge) been no research into their effects on the mortality and behaviour of beneficial nematodes. We address this lacuna by conducting laboratory assays on the behaviour (thrashing assays) and mortality of 13 essential oils plus controls of Tween and water on the malacophagous nematode Phasmarhabditis hermaphrodita and two species of entomopathogenic nematodes, namely: Steinernema feltiae and Heterorhabditis bacteriophora. Mortality results showed an “all or nothing” response with only three oils—pine oil, peppermint and lemongrass—displaying intermediate mortalities. Also, toxicity of essential oils was conserved across phylogenetically quite distinct beneficial nematode species with oil toxicity largely being repeated across the three beneficial nematodes. Thrashing assays confirmed the toxic effects of certain oils. We recommend that the effects of essential oils be tested on beneficial organisms in ecosystems before choices are made over which oils should be used. The present paper highlights some oils which are not toxic to beneficial nematodes but may affect their behaviour. Research should focus on these oils as part of a biorational control programme for pestiferous molluscs and insects.

中文翻译：

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精油对to虫和昆虫病原线虫的毒性

香精油被越来越多地用作有害生物综合治理制度中的生物合理成分。尽管已经对这些油对食用软体动物，昆虫和线虫的死亡率和行为的影响进行了很多研究，但（就本作者的知识而言）尚未对其对有益线虫的死亡率和行为的影响进行研究。我们通过对13种精油的行为（th激分析）和死亡率以及吐温和水的对照进行实验室测定来解决这一缺陷，该方法包括在乳头状线虫性寄生线虫和两种致病性线虫中，即：Steinernema feeliae和Heterorhabditis细菌。。死亡率结果表明，只有三种油（松油，薄荷和柠檬草）有“全有或全无”的反应，显示出中等死亡率。同样，精油的毒性在系统发育上完全不同的有益线虫物种中得以保留，而油毒性在三种有益线虫中被大大重复。脱粒试验证实了某些油的毒性作用。我们建议在选择使用哪种精油之前，先对生态系统中有益生物进行精油效果测试。本文重点介绍了一些对有益线虫无毒但可能影响其行为的油。研究应将这些油作为对虫类软体动物和昆虫的生物合理控制计划的一部分。