School of Life Sciences, Henan University, Jin Ming Avenue, Kaifeng, Henan, China.
J Econ Entomol. 2020 Jun 6;113(3):1307-1314. doi: 10.1093/jee/toaa009.
Chinese pear psylla (Cacopsylla chinensis Yang et Li) is a serious orchard pest that causes declines in fruit quality through feeding damage and the spread of pathogens. The rapid development of chemical pesticide resistance has become a severe problem in controlling pear psylla. Thus, the development of natural pesticides to replace conventional chemical pesticides is urgently needed. Here, we found that the essential oil of peppermint (Mentha haplocalyx Briq. [Lamiales: Labiatae]) is an ideal agent for controlling pear psylla based on experiments in the laboratory and the field. The major constituents of peppermint essential oil were found including menthol (49.73%), menthone (30.52%), α-pinene (3.60%), and α-terpineol (3.81%). This oil and chemicals in it performed serious contact toxicity against the winter-form adults and nymphs of pear psylla, yielding LD50 values of 2.54, 10.71, 2.77, 5.85, and 12.58 μg/adult and 1.91, 9.56, 2.18, 4.98, and 12.07 μg/nymph, respectively. Furthermore, the essential oil strongly repelled the adults of pear psylla with 78% repellence at the highest concentration tested in a Y-tube olfactometer in the laboratory. The combined effect of the two factors made peppermint essential oil a natural pesticide, which achieved a maximum reduction of round to 80.9% in winter-form adult population and round to 67.0% in nymph population at the concentration of 4.0 ml/L in the field. Additionally, it had no effect on the natural enemies of pear psylla in the field. Therefore, peppermint essential oil has potential as an alternative to chemical pesticides for pest control in integrated pest management programs in pear orchards.
中国梨木虱（Cacopsylla chinensis Yang et Li）是一种严重的果园害虫，它通过取食危害和传播病原体导致果实品质下降。化学农药抗性的快速发展已成为防治梨木虱的严重问题。因此，迫切需要开发天然农药来替代常规化学农药。在这里，我们发现薄荷精油（Mentha haplocalyx Briq. [Lamiales: Labiatae]）是一种理想的控制梨木虱的药剂，这是基于实验室和田间试验得出的结论。薄荷精油的主要成分包括薄荷醇（49.73%）、薄荷酮（30.52%）、α-蒎烯（3.60%）和α-萜品醇（3.81%）。这种油和其中的化学物质对梨木虱的冬型成虫和若虫表现出严重的接触毒性，LD50 值分别为 2.54、10.71、2.77、5.85 和 12.58 μg/成虫和 1.91、9.56、2.18、4.98 和 12.07 μg/若虫。此外，在实验室 Y 型嗅觉仪中，最高浓度下，薄荷精油强烈排斥梨木虱成虫，排斥率为 78%。这两个因素的综合作用使薄荷精油成为一种天然农药，在田间浓度为 4.0 ml/L 时，对冬型成虫种群的最大减虫率达到 80.9%，对若虫种群的最大减虫率达到 67.0%。此外，它对梨木虱的天敌在田间没有影响。因此，薄荷精油有可能替代化学农药，用于梨树病虫害综合治理计划中的害虫防治。
