Pesticide resistance in spider mites drives the development of acaricides with novel mode of action, which could benefit from RNAi as a screening tool in search of new molecular targets. RNAi via oral delivery of dsRNA has been frequently reported in spider mites, but injection of dsRNA is rarely reported. We compare here the efficiency of oral delivery versus injection of dsRNA in female adult mites. When comparing silencing efficiency, oral delivery of dsRNAs silenced 40.6 ± 8.9% of CPR, 63.8 ± 6.9% of CHMP2A, and 37.7 ± 5.7% of CHMP3 genes. Similar silencing efficiencies were found for injection (48.6 ± 3.7% of CPR, 70.2 ± 4.1% of CHMP2A, 59.8 ± 2.2% of CHMP3), but with much lower quantities of dsRNAs. Oral delivery of dsRNA failed to silence the expression of the CHMP4B gene, but this could be accomplished by injection of dsRNA (23.1 ± 1.0%). When scoring the phenotypic effects of silencing, both oral delivery and injection of CHMP2A- and CHMP3-dsRNA influenced the locomotion speed of mites significantly. For CPR, silencing could only be accomplished by dsRNA injection, not by feeding. CPR silencing significantly impacted the toxicity of a typical acaricide, pyridaben, as the susceptibility of mites raised 2.75-fold. Last, injection of Eya-dsRNA in adults produced transgenerational phenotypic effects on 3.59% of offspring, as quantified by an observed deviation in eye development, while oral delivery of Eya-dsRNA did not. In conclusion, injection of dsRNA is superior to oral delivery in silencing the expression of the selected genes in this study and could be considered the method of choice to study gene function in reverse genetic approaches.

叶螨的农药抗性推动了具有新型作用方式的杀螨剂的开发，这可能会受益于 RNAi 作为寻找新分子靶标的筛选工具。在叶螨中经常报道通过口服 dsRNA 进行 RNAi，但很少报道注射 dsRNA。我们在这里比较了雌性成年螨的口服给药与注射 dsRNA 的效率。在比较沉默效率时，dsRNA 的口服给药沉默了 40.6 ± 8.9% 的CPR、63.8 ± 6.9% 的CHMP2A和 37.7 ± 5.7% 的CHMP3基因。类似的沉默效率，发现注射（48.6±3.7％的CPR，70.2±4.1％CHMP2A，59.8±2.2％CHMP3)，但 dsRNA 的数量要少得多。dsRNA 的口服给药未能使CHMP4B基因的表达沉默，但这可以通过注射 dsRNA (23.1 ± 1.0%) 来实现。在对沉默的表型效应进行评分时，口服给药和注射CHMP2A-和CHMP3- dsRNA 都显着影响了螨虫的运动速度。对于CPR，沉默只能通过注射 dsRNA 来完成，而不能通过喂食来完成。CPR沉默显着影响了典型的杀螨剂哒螨灵的毒性，因为螨虫的易感性增加了 2.75 倍。最后，注射Eya成人中的 -dsRNA 对 3.59% 的后代产生跨代表型影响，通过观察到的眼睛发育偏差进行量化，而Eya -dsRNA 的口服给药则没有。总之，在本研究中，注射 dsRNA 在沉默所选基因的表达方面优于口服给药，可以被认为是在反向遗传方法中研究基因功能的首选方法。