Using beeswax as wrapping matrix, two types of release-controlled TM (thiamethoxam)/BK(beeswax-kaolin) microcapsules were prepared by adsorbing TM on kaolin and then encapsulated with beeswax, or directly wrapping TM with beeswax. The structure and morphology of the TM/BK microcapsules were characterized. The effects of different preparation methods, the particle size, pH conditions and different additives on the release property of the TM/BK microcapsules were investigated in water and soil column to compare the advantages of the two approaches. Finally, the insecticidal effect of the TM/BK microcapsules against sugarcane borer and rice planthopper was tested. The results show that the TM/BK microcapsules have a better sustained-release in both water and soil, and the release rate is different under different pH conditions. In addition, the releasing time of the TM/BK microcapsules can be modified by different preparation methods and combination of different additives. In the field applications, the insecticidal activity of the TM/BK microcapsules was better than that of non-sustained control group. Especially in the rice field test, 45 days after the application, the control group lost the activity against rice planthopper because of drug loss, whereas the TM/BK microcapsule group still retained about 90% of the insecticidal activity. The results suggest that the microcapsules have better agricultural application for insect control.

中文翻译：

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蜂蜡中噻虫嗪的控释微胶囊及其在野外的应用。

使用蜂蜡作为包裹基质，通过将TM吸附在高岭土上，然后用蜂蜡包封，或直接用蜂蜡包裹TM，来制备两种类型的控释TM（噻虫嗪）/ BK（蜂蜡高岭土）微胶囊。表征了TM / BK微胶囊的结构和形态。在水和土壤柱中研究了不同制备方法，粒径，pH条件和不同添加剂对TM / BK微胶囊释放性能的影响，以比较两种方法的优势。最后，测试了TM / BK微胶囊对甘蔗bore和稻飞虱的杀虫效果。结果表明，TM / BK微胶囊在水和土壤中均具有较好的缓释性能，且在不同pH条件下的释放速率不同。此外，TM / BK微胶囊的释放时间可以通过不同的制备方法和不同的添加剂组合来改变。在野外应用中，TM / BK微胶囊的杀虫活性要优于非维持对照组。特别是在水稻田间试验中，施用后45天，对照组由于失去药物而失去了对稻飞虱的活性，而TM / BK微胶囊组仍保留了约90％的杀虫活性。结果表明，微胶囊在昆虫防治中具有更好的农业应用。TM / BK微胶囊的杀虫活性优于未维持的对照组。特别是在水稻田间试验中，施用后45天，对照组由于失去药物而失去了对稻飞虱的活性，而TM / BK微胶囊组仍保留了约90％的杀虫活性。结果表明，微胶囊在昆虫防治中具有较好的农业应用。TM / BK微胶囊的杀虫活性优于未维持的对照组。特别是在水稻田间试验中，施用后45天，对照组由于失去药物而失去了对稻飞虱的活性，而TM / BK微胶囊组仍保留了约90％的杀虫活性。结果表明，微胶囊在昆虫防治中具有更好的农业应用。