重大外来入侵害虫——美国白蛾生物防治技术研究

美国白蛾Hyphantria cunea(Drury)是重大外来入侵害虫,对我国林业和园林绿化造成重大危害,尤其是近年来美国白蛾传入北京,严重威胁着我国“绿色奥运”的顺利举办和首都园林绿化及生态环境安全。根据美国白蛾多发生在居民区、乡镇和城市的特点,作者开展对环境安全的生物防治技术研究。汲取前苏联等国家从美国白蛾的原产地引进天敌进行生物防治没有成功的经验和教训,立足调查和寻找我国本土天敌。经过21年的努力,发现和筛选出白蛾周氏啮小蜂Chouioia cunea Yang(新属新种)这种寄生美国白蛾的特优天敌;研究这种小蜂的行为学、生态学、生物学、解剖学及人工大量繁殖、放蜂防治技术;筛选出人工大量繁殖小蜂的替代寄主,解决小蜂的大量繁殖的瓶颈问题;通过放蜂防治试验,取得良好的防治效果。同时,筛选出防治美国白蛾的高毒力HcNPV病毒毒株,研制出美国白蛾人工饲料,利用人工饲料大量饲养美国白蛾幼虫,然后接种扩增病毒,成功解决HcNPV病毒大量扩增生产和常年生产的技术难题,做到病毒的规模化生产和常年生产,保证大面积生产防治的需要和病毒质量。研究出利用天敌昆虫和病原微生物综合应用的防治模式:在美国白蛾幼虫期喷洒HcNPV病毒,蛹期释放白蛾周氏啮小蜂,达到既控制当代美国白蛾的危害,又有效抑制其下代的种群数量,取得长期的持续控制美国白蛾的防治效果。上海市、大连市、烟台市和青岛市利用该项技术已经完全控制美国白蛾,特别是上海市利用本项生物防治技术防治后,已经连续6年没有再发现美国白蛾。由于该项生物防治技术利用的是自然界原有的控制害虫的生态因子,因而对环境安全,做到既消灭害虫,又保证生态环境和人畜的安全,也保护生物多样性。该项研究成果也为北京采用“绿色”防治技术有效控制美国白蛾提供重要的科技支撑和技术保障。

Researches on techniques for biocontrol of the fall webworm,Hyphantria cunea,a severe invasive insect pest to China

The fall webworm, Hyphantria cunea (Drury) (Lepidoptera: Arctiidae) is a severe invasive pest and has caused significant damages to forests and ornamental trees in China since its first finding in 1979. Particularly it has spread aseantriato Beijing in recent year and threats the successful conducting of “the Green Olympics” in Beijing in 2008. From the fail lessons of classical biological control by introductions of parasitoids from USA and Canada carried out during the period of 1952～1965, we have focused on looking for the China native parasitoids for biological control of the pest. By effort of successive studies for 21 years, an effective pupa parasitoid in the pest pupa, Chouioia cunea Yang (gen. & sp. nov.)(Hymenoptera: Eulophidae), was found and selected as a biological control agent. The biology, behavior, ecology, female reproductive system anatomy and mass rearing of the parasitoid have subsequently been studied. Meanwhile, the researches on releasing technique and substitute hosts for mass rearing the parasitoid have been carried out. The excellent control results were gotten by releasing it in many areas. In the same time a strain of nuclear polyhedron virus of the fall webworm (HcNPV) in the pest larva with high toxicity was discovered and selected. A superior artificial diet was developed for mass rearing fall webworm larvae first, and a large number of the pest larvae were reared with the diet, then inoculating HcNPV for mass producing the virus. In this way the quality and quantity of HcNPV have been guaranteed for biological control of the pest larvae. An integrative biological control technique has been developed, i.e. spraying HcNPV in larva stage and releasing the parasitoid, C. cunea in the pupa stage of the fall webworm respectively. By applying the technique to control two generations of the fall webworm successively an effective and sustainable control results could be reached, and the fall webworm has been suppressed for six years in Shanghai, Dalian, Yantai and Qingdao cities. The biocontrol technique is safe for environment, attaining excellent control result without having influence on environment and biodiversity because the biocontrol agents are original ecological factors in forest ecosystems. It has been used in Beijing for control of the fall webworm to ensure that the goal of “the Green Olympics” be realized in 2008.