引进天敌双代盲蝽茧蜂与本地寄生蜂的种间竞争关系

Green plant bug Apolygus lucorum (Heteroptera: Miridae) is an important insect pest, and it outbreaks on multiple crops, recently. Field investigation showed that there are only two parasitoids of green plant bug Peristenus relictus and P. spretus (Hymenoptera: Braconidae), and their natural parasitic rates were very low in the field in China. Peristenus digoneutis (Hymenoptera: Braconidae) is an effective parasitoid of Lygus spp.in Europe. It had been introduced and released into USA and Canada, and successfully control the population of the tarnished plant bug Lygus lineolaris (Heteroptera: Miridae). Based on an acquired import license of P. digoneutis from State Quality Inspection Administration , Peristenus digoneutis had been introduced by our research group. After rearing and studying in the quarantine laboratory, we found that P. digoneutis could complete life cycle on A. lucorum and revealed a high parasitic rate. However, it is essential that learning the risk of interspecific competition and population replacement between P. digoneutis and native parasitoids before mass rearing and release of P. digoneutis for controlling A. lucorum in the field. Therefore, the project mainly discussed around (1) potential host range of P. digoneutis and native parasitoids in China, (2) intrinsic competition for nutrient among immature parasitoids, and (3) extrinsic competition for host resources among free-living adults searching and host discrimination between P. digoneutis and native parasitoids. These studies aim to understand that interspecific competition between P. digoneutis and native parasitoids, and evaluate the host specifity and environmental security of P. digoneutis. This will give a scientific foundation to use the parasitoid for controlling A.lucorum in China.

绿盲蝽是我国近年来在多种作物上暴发的重要害虫。调查发现，国内绿盲蝽寄生性天敌仅有遗常室茧蜂和红颈常室茧蜂，且自然寄生率极低。双代盲蝽茧蜂是欧洲本地盲蝽的重要寄生蜂，被美国和加拿大引进释放后，成功控制牧草盲蝽的暴发。本项目组在获取引进许可证的基础上，引进了双代盲蝽茧蜂，在检疫隔离实验室饲养与研究后，发现其可在绿盲蝽上完成生活史，并具有极高的寄生率。然而，该寄生蜂与本地寄生蜂的竞争替代风险是其大量繁殖与释放前必须探明的问题。鉴于此，本项目重点探讨：1) 引进天敌双代盲蝽茧蜂和本地寄生蜂在中国潜在寄主范围；2）双代盲蝽茧蜂与本地寄生蜂幼虫在寄主体内的营养竞争；3)双代盲蝽茧蜂与本地寄生蜂成虫对寄主资源排斥性竞争及对寄主标记的识别能力。以期揭示双代盲蝽茧蜂与本地寄生蜂的种间竞争关系，明确双代盲蝽茧蜂寄主专一性和安全性，为利用该寄生蜂控制绿盲蝽的发生奠定科学基础。

以引进盲蝽寄生蜂双代盲蝽茧蜂和2种本地寄生蜂遗常室茧蜂和红颈常室茧蜂为研究对象，探讨引进天敌与本地寄生蜂的竞争替代风险。取得的主要研究结果如下：（1）对3种寄生蜂进行寄主范围安全性评估，表明引进天敌双代盲蝽茧蜂对靶标害虫的寄主专一性强，并对绿盲蝽具有显著的偏好，可作为控制绿盲蝽的有效天敌；（2）3种寄生蜂对单头寄主的非选择性的多寄生研究表明，在寄主体内本地天敌具有较强的营养竞争能力，引进天敌不会对本地天敌形成种间替代；（3）此外3种寄生蜂对寄主资源排斥竞争表明说明，在较短的寄生时间内，本地天敌和引进天敌子代种群比例差异不显著，但随着寄生时间的增加，本地天敌的竞争优势更加显著，寄生蜂幼虫的发育速度起着关键的作用；（4）通过对3种寄生蜂寄主标记的识别能力研究，结果表明双代盲蝽茧蜂偏好选择已被红颈常室茧蜂寄生过的绿盲蝽，遗常室茧蜂偏好选择已被双代盲蝽茧蜂寄生过的绿盲蝽。说明双代盲蝽茧蜂和遗常室茧蜂同样具有识别被它种寄生蜂寄生过寄主的能力。