South Australian Research and Development Institute, GPO Box 397, Adelaide, SA 5001, Australia.
J Econ Entomol. 2010 Aug;103(4):1347-54. doi: 10.1603/EC09171.
Field surveys of pest insect pest populations in agroecosystems reveal low but significant levels of tolerance to synthetic and biological pesticides but fail to uncover resistance alleles in test crosses. To study the potential of inducible mechanisms to generate tolerance to synthetic pesticides, we performed baseline susceptibility studies in field and laboratory populations of diamondback moth, Plutella xylostella (L.), to commercial formulations of emamectin benzoate. Pesticide exposure in the field caused elevated levels of tolerance, which decreased in field-collected populations after maintaining insects with pesticide-free diet in the laboratory. Because no significant resistance alleles were identified in back-crossed individuals, the observed increase in tolerance was probably not based on preexisting recessive resistance mechanisms in the population. Instead, the genetic analysis after five and 12 generations is compatible with a transient up-regulation of an immune and metabolic status in tolerant insects that can be transmitted to offspring by a maternal effect. Although the epigenetic effects contributed to incremental increases in tolerance in the first five generations, other resistance mechanisms that are transmitted genetically predominate after 12 generations of increased exposure to the pesticide.
在农业生态系统中对害虫种群进行实地调查显示，它们对合成杀虫剂和生物杀虫剂有低但显著的耐受性，但在测试杂交中未能发现抗性等位基因。为了研究诱导机制产生对合成杀虫剂耐受性的潜力，我们对小菜蛾（Plutella xylostella）的田间和实验室种群进行了基线敏感性研究，以评估其对商品化的甲氨基阿维菌素苯甲酸盐制剂的敏感性。田间施药导致了耐受性的显著提高，但在实验室中用无农药饮食饲养昆虫后，田间采集的种群的耐受性降低。由于在回交个体中没有发现显著的抗性等位基因，因此观察到的耐受性增加可能不是基于种群中预先存在的隐性抗性机制。相反，经过五和十二代的遗传分析与耐受昆虫中免疫和代谢状态的瞬时上调一致，这种状态可以通过母体效应传递给后代。尽管表观遗传效应导致在前五代中耐受性的递增增加，但在接触杀虫剂 12 代后，遗传传递的其他抗性机制占主导地位。
