Houjun Tian, Lin Shuo, Chen Yong, Chen Yixin, Zhao Jianwei, Gu Xiaojun, Wei Hui
Institute of Plant Protection, Fujian Academy of Agricultural Sciences, Fuzhou, China.
Fujian Key Laboratory for Monitoring and Integrated Management of Crop Pests, Fuzhou, China.
J Econ Entomol. 2018 May 28;111(3):1354-1360. doi: 10.1093/jee/toy022.
The diamondback moth (DBM), Plutella xylostella (L.) (Lepidoptera: Plutellidae), is the main destructive insect pest of brassica vegetables around the world, and has developed resistance to numerous insecticides. Although host plant volatiles are important in pest control, the mechanism of low-level insecticide resistance in P. xylostella due to plant volatiles has not been examined. Here, electroantennograms (EAGs) were used to compare the responses of adult male and female DBMs of a susceptible strain (S-strain) and a derived resistant strain, Fen-R-strain (6.52-fold more resistant than the S-strain), to different concentrations of nine plant volatiles. We found significantly different relative EAG responses between S-strain and Fen-R-strain males to different concentrations of methyl jasmonate, methyl salicylate, and octanal. The relative EAG responses of S-strain and Fen-R-strain females to different concentrations of β-myrcene, methyl jasmonate, methyl salicylate, and allyl isothiocyanate were significantly different. Fen-R-strain females showed lower EAG responses to most of the tested plant volatiles (at concentrations of 1:10) than males, except for allyl isothiocyanate. A larger difference in relative EAG response to α-farnesene and β-myrcene was found between S-strain and Fen-R-strain females than between males of the two strains. A larger difference in relative EAG response to octanal, nonanal, and octan-1-ol was found between S-strain and Fen-R-strain males than between females of the two strains. These results illustrate the relationship between the function of plant volatiles and resistance in an insect pest species, and provide a scientific basis for resistance evolutionary theory in pest management research.
小菜蛾（DBM），即小菜蛾（Plutella xylostella (L.)，鳞翅目：菜蛾科），是全球十字花科蔬菜的主要毁灭性害虫，并且已对多种杀虫剂产生抗性。尽管寄主植物挥发物在害虫防治中很重要，但小菜蛾因植物挥发物产生低水平杀虫剂抗性的机制尚未得到研究。在此，采用触角电位（EAG）技术比较了敏感品系（S品系）和衍生抗性品系Fen-R品系（抗性比S品系高6.52倍）的成年雌雄小菜蛾对9种不同浓度植物挥发物的反应。我们发现，S品系和Fen-R品系雄虫对不同浓度的茉莉酸甲酯、水杨酸甲酯和辛醛的相对EAG反应存在显著差异。S品系和Fen-R品系雌虫对不同浓度的β-月桂烯、茉莉酸甲酯、水杨酸甲酯和异硫氰酸烯丙酯的相对EAG反应也存在显著差异。除异硫氰酸烯丙酯外，Fen-R品系雌虫对大多数测试植物挥发物（浓度为1:10）的EAG反应低于雄虫。S品系和Fen-R品系雌虫对α-法尼烯和β-月桂烯的相对EAG反应差异大于两品系雄虫之间的差异。S品系和Fen-R品系雄虫对辛醛、壬醛和1-辛醇的相对EAG反应差异大于两品系雌虫之间的差异。这些结果阐明了植物挥发物功能与害虫抗性之间的关系，并为害虫管理研究中的抗性进化理论提供了科学依据。
