抗药性是害虫防治中的主要障碍，与抗性相关的适合度代价在多种昆虫中存在（包括多杀菌素抗性西花蓟马），但抗性代价的调控机制尚不明确。本项目拟在前期研究的基础上，以多杀菌素敏感和抗性近等基因系西花蓟马为研究对象，开展三方面研究：利用RNA-Seq进行差异基因表达分析，筛选出与生殖发育相关的差异基因；采用RT-PCR结合RACE技术获得Vg、SgAbd-2、Cp19等差异基因的全序列，进行种群间序列和表达谱比对，采用RNAi技术研究候选基因的功能；研究保幼激素、蜕皮激素和胰岛素样多肽信号途径中的转录因子Kr-h1, Br和FOXO的表达谱、功能及RNAi后对Vg合成的影响等。研究结果一方面可以阐明多杀菌素抗性西花蓟马生殖适合度降低的调控机制，明确以西花蓟马为代表的缨翅目昆虫生殖和发育的调控途径；另一方面对明确西花蓟马对多杀菌素的抗性发展规律，挖掘害虫防治新途径，制订有效的抗性治理策略有重要意义。

Insecticide resistance is a major hurdle in pest management. Fitness costs associated with insecticide resistance have been reported in a variety of insects, including spinosad resistant Frankliniella occidentalis. However, it remains unclear how pests regulate the trade-off between resistance and fitness costs. Reproduction and development is one of most hot fields in insect physiological research. Based on our previous research, three aspects will be conducted in this project: 1) Next-generation RNA sequence (RNA-Seq) will be performed to find and identify differentially expressed genes related to reproduction and development in spinosad-susceptible and -resistant near-isogenic lines of F. occidentalis. 2) The full-length of candidate genes, Vg, SgAbd-2, and Cp19 genes for instance, will be cloned by RT-PCR and RACE and allele sequence and expression profile will be compared between susceptible and resistant strains. The functions of each candidate gene will be ivestigated by RNA interference (RNAi) technique. 3) Transcription factors in juvenile hormone (Kr-h1), ecdysone (Br), and insulin-like peptide (FOXO) signaling pathways will be cloned and their expression profiles will be investigated as well. The functions and their effects of transcription factors on Vg synthesis will be conducted by RNAi methods. These results, on the one hand will clarify the regulation mechanisms underlying the reproduction trade-off associated with spinosad resistance in F. occidentalis, and to reveal the pathways regulating reproduction and development in insects of Thysanoptera. On the other hand, these results will be helpful to clarify the resistance development of F. occidentalis to spinosad, to explore candidate targets for designing novel insecticides, and to provide effective control strategies for insecticide resistant pest control.