鸡皮刺螨体表疏水性机制及对杀虫药液渗入的阻止作用

During the evolution, many organisms (such as lotus, gecko, house fly) surviving in the environment containing a lot of contaminants, have surfaces with hydrophobicity. The micro-structures medicate its surface hydrophobicity enabling their resistance to contaminants. Dermanyssus gallinae is a blood sucking mite widely existing in poultry farms with a serious effect on the poultry industry. There are a lot of contaminants in the surviving environment of Dermanyssus gallinae. Previous studies showed that the surface of Dermanyssus gallinae had hydrophobicity and the insecticide solution had poor efficacy of against mites. To figure out the mechanism of hydrophobicity of the surface of Dermanyssus gallinae and the inhibition of penetration of insecticide solution by it, the following studies will be conducted. 1) The surface micro-structures of Dermanyssus gallinae will be observed with scanning electron microscope and atomic force microscope; the composition of surface of Dermanyssus gallinae will be determined by GC-MS. 2) The change of hydrophobicity will be observed after its micro-structures are destroyed to figure out the mediation of micro-structures on the hydrophobicity. 3) Determination of the change of insecticide (carbaryl) and fluorescer（rhodamine B）concentration penetrated into the mites after its micro-structures are destroyed or the hydrophilicity of insecticide solution is increased to figure out the inhibition of micro-structures on the penetration of insecticide. These studies will figure out the mechanism of hydrophobicity of surface of Dermanyssus gallinae and the inhibition of penetration of insecticide solution by hydrophobicity mediated by surface micro-structure of Dermanyssus gallinae. It will also provide new idea and new theory for development of novel formulation of insecticides and new model for development of bionic materials with hydrophobicity.

在长期适应生存环境过程中，很多生物体（如荷叶、壁虎、家蝇）形成了由微结构介导的高疏水性体表，以减少环境中污染物的吸附。鸡皮刺螨是养鸡业中危害最为严重的外寄生虫，所在环境中有大量生物和非生物污染物，其体表有高疏水性，水性杀虫药液的对其杀灭效果差。为了揭示皮刺螨体表疏水性机制及对杀虫药液渗入的阻止作用，拟开展以下研究：1）用SEM和AFM观测螨体表微结构特征，用GC-MS检测螨体表组份，揭示体表疏水性的物质和结构基础；2）破坏体表微结构对体表疏水性（用体表与水的接触角评价）的影响，阐明微结构对疏水性的介导作用；3）破坏体表微结构、提高药液亲水性对杀虫药液（西维因+罗丹明B）渗入皮刺螨体内的影响，揭示体表微结构介导的疏水性对杀虫药液渗入的阻止作用。本研究将揭示鸡皮刺螨体表微结构特征、疏水性机制以及对杀虫药液渗入的阻止作用，可为防治药液的研制提供新思路，为疏水性、防渗仿生材料的研制提供新参照模型。

鸡皮刺螨是养鸡业中危害最为严重的外寄生虫，其体表可能存在疏水性，是导致水性杀虫药液的对其杀灭效果差的原因。为了揭示皮刺螨体表疏水性机制及对杀虫药液渗入的阻止作用，本项目开展了以下研究：1）观测螨体表微结构特征，解析螨体表组份，揭示体表疏水性的物质和结构基础；2）破坏体表微结构对体表疏水性（用体表与水的接触角评价）的影响，阐明微结构对疏水性的介导作用；3）破坏体表微结构、提高药液亲水性对杀虫药液渗入皮刺螨体内的影响，揭示体表微结构介导的疏水性对杀虫药液渗入的阻止作用。结果表明，鸡皮刺螨与水的接触角>900，显示其体表存在疏水性；其疏水性由体表微结构（褶皱）和化学组分（主要为正构烷烃和脂肪酸）共同介导；鸡皮刺螨体表的疏水性会阻止药物渗入其体内；破坏鸡皮刺螨体表的微结构和化学组分，可提高药液的渗入作用；往药液中添加表面活性剂，看提高药液的杀螨作用。本研究揭示了鸡皮刺螨体表的疏水性机制和以水为基质的药液防控鸡皮刺螨疗效差的原因，为鸡皮刺螨新型防控药剂的研发提供了新的思路。