枸杞瘿螨的携播机制研究

The Wolfberry is a unique medicinal plant with vegetative and reproductive growth at the same time, edible for more than 60 pests. The wolfberry Eriophyes, Aceria pallida Keifer, is one of the major pests prevailing in every growing area. A. pallida, with tiny size, inhabiting in galls, with annual multiple and overlapped generations, rich in propagation coefficient, is extremely difficult to be controlled and becoming the key and difficult points in current growing areas because of the dispersal rules are unclear. How does A. pallida disperse in fields is still currently a research gap. Preliminary study found that for the first time, early stage of the galls are yellow-green, and then color changes into purple close to the wolfberry petals. Phoresy, which is always called "free ride", in which one animal actively seeks out and attaches to another animal for transport, happens during the period of color changes. It is found that not only pests carry the mites, natural enemies may also be involved, presumably the result of coevolution, designed to attract other insects to visit and took the opportunity to carry Eriophyes. In this project, gall mites and their symbiotic arthropods are used as research materials, parting around before and after discoloration, carring out comparative morphology, behavioral ecology and chemical ecology research to reveal the coevolution relationship of phoretic gall mite and its carriers, making clear who are the real carriers of the Wolfberry Eriophyes in fields, provide a theoretical basis for Integrated Pest Management (IPM).

枸杞是营养生长与生殖生长同时进行的特殊药用植物，营养丰富，有60多种害虫为害，其中枸杞瘿螨在全国各产区普遍严重发生，因其个体微小，年发生世代多，世代重叠，繁殖系数大，在虫瘿内隐蔽为害，传播发生规律不清，防治难度极大，是生产防治的重点和难点，也是目前研究的空白点。前期研究首次发现，枸杞瘿螨的虫瘿前期为黄绿色，后期变为近似枸杞花瓣的紫色，变色期间具携播（phoresy）（即一种动物搭载于其它动物进行传播的"搭顺风车"现象）行为，不仅害虫参与携播，天敌也可能参与携播过程，推测为协同进化的结果，旨在吸引其它昆虫访问并借机携播瘿螨。本课题以枸杞瘿螨及其共栖节肢动物为研究材料，围绕虫瘿变色前后瘿螨的分型现象进行形态学、行为学和化学通讯等方面的研究，揭示枸杞瘿螨与其携播者之间的协同进化关系，明晰枸杞群落中枸杞瘿螨的携播者种类及其与枸杞瘿螨携播型之间的耦合关系，为整合各种技术综合防治枸杞害虫提供理论依据。

本研究首次发现植食性螨类（枸杞瘿螨）具有典型的季节性携带传播行为，纠正了文献资料记载的枸杞瘿螨在寄主植物上越冬的错误认识，证实枸杞瘿螨以携播方式攀附藏匿于枸杞木虱成虫胸腹腔内进行越冬，于早春随枸杞木虱到达寄主植物嫩芽并脱载，在嫩叶上形成虫瘿。枸杞瘿螨越冬场所不明，防治失当，是导致其早春大量爆发且难以防治的根本原因。枸杞瘿螨携播行为可在低温短光周期条件下诱导，25℃长光周期环境下可随时脱载。生长季节，枸杞瘿螨主要通过主动爬行的方式在枸杞植株内进行迁移扩散，在植株间主要利用风进行传播扩散。枸杞瘿螨于早春枸杞发芽3天后即可脱载，且74%瘿螨可在一周内完成脱载，防治枸杞瘿螨的关键是在脱载前防治其携播寄主枸杞木虱。在枸杞发芽前喷施仿生胶或阿维菌素防治枸杞木虱可有效防治越冬枸杞瘿螨。本研究揭示了枸杞瘿螨冬季携带越冬的机制，为科学防治枸杞瘿螨提供了依据，在学术和生产实践上均具有一定的价值。