云南派姬小蜂对其寄主及寄主植物相关化学线索的行为反应

与寄主植物和寄主相关的化学线索在寄生蜂的寄主搜寻过程中起着重要作用。云南派姬小蜂Pediobius yunnanensis是松树钻蛀性害虫——微红梢斑螟Dioryctria rubella的蛹寄生蜂，为了探究该寄生蜂对其寄主和寄主植物相关化学线索的行为反应，本研究进行了一系列试验。利用Y形嗅觉仪，测定了该寄生蜂对不同处理的油松球果（含蛹球果、含空蛹壳的球果、幼虫为害的球果和健康球果）和松枝（含蛹松枝、幼虫为害的松枝、含蛹球果的系统枝、含蛹松枝的系统枝和健康松枝）以及幼虫虫粪（3龄幼虫虫粪、含蛹球果内的幼虫虫粪）挥发物的趋性行为；在开放场中，测定了老熟幼虫爬行痕迹对该寄生蜂搜索行为的影响；利用双选择试验，在培养皿中测定了该寄生蜂对微红梢斑螟茧或蛹浸提液的行为反应。结果显示，在嗅觉试验中，含蛹球果、含有空蛹壳的球果挥发物对寄生蜂有极显著的引诱作用，而幼虫为害的球果和健康球果对寄生蜂的行为无明显影响；该寄生蜂对含蛹松枝挥发物表现出明显的正趋性反应，而对幼虫为害的松枝、含蛹球果的系统枝、含蛹松枝的系统枝以及健康松枝则无趋性反应；寄生蜂对含蛹球果中的幼虫虫粪挥发物表现出偏爱性，而对3龄幼虫虫粪无明显反应；在开放场中，老熟幼虫的爬行痕迹对寄生蜂的搜索行为无显著影响；在培养皿中，微红梢斑螟茧的甲醇、二氯甲烷或正己烷浸提液以及蛹的二氯甲烷或正己烷浸提液，不仅能强烈地吸引该寄生蜂，还能明显延长其停留时间。该结果为揭示云南派姬小蜂寄主搜寻行为的化学调控机制以及微红梢斑螟的生物防治提供理论依据。

The Behavioral Responses of Pediobius Yunnanensis to the Chemical Cues Related to Its Host and Host Plant

The chemical cues related to host plants and hosts play an important role in the host searching of parasitoids. The wasp Pediobius yunnanensis is the pupal parasitoid of pine borer, Dioryctria rubella. In the present study, a series of experiments were conducted to explore the behavioral responses of female parasitoids to the chemical cues related to its host and host plant. Using a Y-shaped olfactometer, the orientation behaviors of female parasitoids were investigated with regard to the volatiles from different treatments of pine cones (pupa-containing cone, cone containing empty puparium left after emergence, larva-damaged cone, and healthy cone), pine branches (pupa-containing branch, larva-damaged branch, the system branch of either pupa-containing cone or pupa-containing branch, and healthy branch), and larva frass (3^rd instar larva frass, the larva frass in the pupa-containing cone). In an open arena, the effect of walking trails of mature larvae on the searching behaviors of female parasitoids was evaluated. The behavioral responses of the females to the extract of cocoon or pupa of D. rubella were examined by dual-choice test in Petri dish. The results showed that the cones containing either pupa or empty puparium were highly attractive to the females in olfactometer bioassays, while no significant effects of either larva-damaged cone or healthy cone on the behaviors of this parasitoid were observed. The females displayed significantly positive responses to the pupa-containing branch, but not to the larva-damaged branch, the system branch of either pupa-containing cone or pupa-containing branch, and healthy branch. The parasitoids showed a preference for the volatiles of the frass inside the pupa-containing cone, but not for the third instar larva frass. The walking trails of the mature larva had no significant effects on the searching behaviors of the females in the open arena bioassay. In the Petri dish test, the cocoon extract of either methanol, dichloromethane or n-hexane, and the pupa extract of dichloromethane or n-hexane not only strongly attracted the female parasitoids, but also significantly prolonged its residence time. The results are expected to provide theoretical basis for revealing the chemical regulation mechanism for the host searching behaviors of this parasitoid and the biological control of D. rubella.