松褐天牛卵金小蜂种群保持及寄生机制

Callimomoides monochaphagae newly discovered has not so far only been reported at as egg parasitoids on Monochamus alternatus home and abroad which is an important natural enemy of M. alternatus. Because of the strong host specialization characteristics, it can control the pest before the pest causing harm, which appears significant use value and application prospects in biocontrol of M. alternatus. At present, in addition to the applicant's laboratory, there are few studies on this parasitoid. In this study, the biology characteristics will be first investigated, including life history, longevity, developmental threshold temperature, effective accumulated temperature, diapause, alternate hosts and so on. According the study above, the mechanism of its population continuity in the forest will be found out and a stable experimental population will be established for the study of its parasitic mechanism. First, according the scanning electron microscope on the antenna and maxillary palpus, sensilla type and function will be analyzed and compared. The parasitic behavior process will be also recorded and analyzed by macro tracking shooting technique. Remote attract odor and close identification of pheromone to the female parasitoid will be filtered, which will be collected. To test and verify the substances deciding the parasitic behavior of C. monochaphagae, the substances gathered are going to test by EAG and Y tube, the substance about parasitic behavior is precisely to find out which would provide basis for accurate identification of the information compound. All of the studies above can provide the basis reference data for the rational use of C. monochaphagae to ontrol M. alternatus.

松褐天牛卵金小蜂是新近发现、也是迄今为止国内外唯一报道的寄生松褐天牛卵的重要天敌。由于卵寄生蜂寄主专化性强，可将害虫控制在造成危害之前，因此在松褐天牛的生物防治上具有重要的利用价值和应用前景。目前除了申请人所在研究室外，国内外还未开展对此蜂的研究。本项目从松褐天牛卵金小蜂的基本生物学入手，调查其生活史、发育起点温度、有效积温、转主寄主、滞育等情况；搞清其在林间的种群保持机制，进而建立稳定的实验种群以研究它的寄生机制。首先对其触角和下颚须进行扫描电镜分析感器类型和功能；通过微距跟踪摄像分析小蜂对寄主卵的寄生行为过程；再通过选择和非选择试验筛选远距离吸引雌虫的气味源和近距离识别健康卵的信息化合物源，将气味源和信息化合物源粗提后进行EAG和Y管生物测定，进一步验证气味源的准确性，为下一步精确鉴定信息化合物成分奠定基础。以上研究可为合理利用此卵寄生蜂防治松褐天牛提供基础参考数据。

松褐天牛卵金小蜂是迄今为止国内外唯一报道的寄生松褐天牛卵的重要天敌。它在野外对松褐天牛的寄生率最高能达到12.6%，雌雄比接近2:1，寄主专化性较强，因此其在控制松褐天牛防治松材线虫病方面具有一定的潜力，目前国内外对其生物学和生态学研究很少。本项目以解析松褐天牛卵金小蜂的种群保持和寄生机制为目标，研究了松褐天牛卵金小蜂详细的生活史，此蜂在安徽九华山一年可发生完整2代，以老熟幼虫在松褐天牛卵内越冬。确定了松褐天牛卵金小蜂两代的羽化盛期，在生活史上与松褐天牛发育具有跟随效应。完成了松褐天牛金小蜂成虫寿命的测定，补充营养的情况下，雌成虫平均存活11.97±1.87天，雄成虫存活9.52±1.97天。发现了打破小蜂越冬期滞育的条件，即在25℃的温度下，保持长光照（光暗比16：8），37天可解除滞育。测得松褐天牛卵金小蜂蛹期有效积温48.8日度及发育起点温度16.4℃。明确了松褐天牛卵金小蜂感器类型和功能，在松褐天牛卵金小蜂的触角、产卵器、下颚须、上颚须、足和翅膀上共观察到五种感器，触角上着生刺形感器（Ⅰ型、Ⅱ型）、毛形感器、未知类型感器Ⅰ型、锥形感器、坛形感器。产卵器上着生刺形感器Ⅲ型。下颚须和上颚须上均着生刺形感器Ⅰ型。翅膀上着生刺形感器Ⅱ型。其中刺形感器在雌、雄蜂除触角的柄节外均有分布，且基本呈对称排列，推断其具有定位的功能，可以给触角、足、和产卵器提供位置信息。提取了松褐天牛危害后刻槽周边、健康树干、产卵树的叶片、产卵树的树干、空气、健康树叶片、健康树干、有刻槽的活树叶片、产卵刻槽对照、卵浸出物等10种处理的信息化学物质并进行了比较，初步推断出产卵树的叶片挥发物是松褐天牛卵金小蜂雌蜂远距离定位寄主卵栖境化合物，而卵浸出物和产卵刻槽提取物中含有松褐天牛卵金小蜂雌蜂近距离定位松褐天牛卵的挥发性物质。研究结果丰富了松褐天牛卵金小蜂生物生态学的基础资料，为合理利用松褐天牛卵金小蜂来治理松褐天牛奠定了基础。