【作者】 汪晓光；

【导师】 魏永平；

【作者基本信息】 西北农林科技大学 ， 农业昆虫与害虫防治， 2007， 硕士

【摘要】 作者于2005年—2006年在陕西省黄陵县对当地苹果园不同生境类型及天敌昆虫群落进行了研究,通过对果园不同植被上的昆虫种类和数量进行调查与统计,筛选对天敌昆虫有诱集作用的植物种类。通过天敌群落的多样性指数分析,明确果园生境植被类型在天敌昆虫躲避药害及其他不利条件,增强种群抗逆性和种群重建恢复能力中的作用,合理布局天敌的适生环境,把保护天敌和利用天敌结合起来,力求更好地发挥天敌昆虫对害虫的控制作用。主要研究结果如下:1.对果园内生境岛屿及其周边生境上的多种杂草和作物进行调查,根据该生物在当地的适生范围和对天敌的诱集效果,初步筛选出紫花苜蓿+狗尾草、反枝苋、三叶鬼针草、白茅+落地稗等对天敌具有较强诱集效果的杂草组合。其中紫花苜蓿的诱集力是最好的,对多种天敌有诱集效果;反枝苋对食虫蝽类有比较强的诱集作用;三叶鬼针草对草蛉类天敌诱集作用是最强的;白茅+落地稗组合对蜘蛛类天敌诱集效果最强。存在一些对害虫具有较大诱集的作物,黄花菜诱集大量的棉蚜,大豆诱集豆象甲和条蜂缘蝽。2.生草园天敌的多样性指数远高于清耕园天敌多样性指数,果园种草有利于天敌的聚集和发展。套种农作物有利于天敌种群多样性指数的增长。果园周边生境中,以小苜蓿为主的天然草地对天敌的诱集效果是最好的。3.果园与周边生境中的天敌多样性指数存在动态变化:果园受到较强的人为干扰,天敌会迁入周边的生境,等到干扰平复后再回迁果园;农作物收割,在其上的天敌会迁入周围果园,增加果园天敌的多样性,夏季作物的收获有多种,更大量的天敌迁入果园。4.果园中的紫花苜蓿+狗尾草和小苜蓿+泥胡菜上的天敌群落相似性指数值高达0.853,两者合理套种,可以增大对天敌的容纳力和保护效果。果园套种作物以豆类对天敌的诱集效果最好,以葱的诱集效果最差。5.对不同调查样地来说,7个调查地点各天敌功能团多样性指数大致是五交地、寇河>赵家塬、果业基地>南峁、侯庄>土桥,从生境特点来看多样性指数大小顺序正好是由较少干扰的原生生境向普遍干扰的改造生境而不断降低。6.果园中的主要害虫有山楂叶螨、苹果黄蚜、苹果瘤蚜,金纹细蛾,桃小食心虫、梨小食心虫。其中苹果黄蚜、苹果瘤蚜在6月份大发生,在7、8月山楂叶螨发生量大。果园主要天敌种类有中华草蛉、丽草蛉和大草蛉。瓢虫的主要优势种是七星瓢虫和龟纹瓢虫,蜘蛛类的优势种是草间小黑蛛。生态位重叠值表示七星瓢虫和中华草蛉对果园害虫的跟随和捕食作用都比较强。在果园9月份。寄生类天敌对主要害虫的跟随和寄生都比较高,达到了0.8以上。更多还原

【Abstract】 This research investigates the insect species and the occurrences in the vegetation of apple orchard in Huangling, Shaanxi, and then selects the certain kind of weeds and crops to be the inducing species. Via analyzing the diversity index of the community of natural enemies, it finds out the function of different habitat for insect to avoid the adverse condition and enhances its ability to resistance and regeneration of insect population. The main conclusion shows below:1. In the investigation of habitats of around or inside orchard, in terms of living habitat of natural enemies, this research concludes that there are some of the ruderals can be proper inducing species for the natural enemies, such as: alfalfa, Setaria viridis、Amaranthus retroflexus、Bidens pilosa、Imperata cylindrical+Echinochloa crusgalli etc. Bidens pilosa shows the strongest abilities to induce lacewings, so does Imperata cylindrical+Echinochloa crusgalli to spiders. And some other kind of weeds have the functions to aphid,soybean can induce a lot of Riptortus linearis and Cowpea weevil etc.2. The index of diversity in the orchards which grows much weed is more than the orchards which have been furrowed, seeding the weeds to the orchard benefit the natural enemies’development. Mixed growing is good for increase the index of natural enemies. Alfalfa will lead a good aggregating effect for the natural enemies.3. There are dynamics showed on the diversity index between orchard and its surrounding habitat: if orchard is disturbed by human activities, natural enemies will move into the around habitat, then go back when the disturbance stopped. For example, human activities such as the harvest, will disturb the community structures of the natural enemies.4. The comparability index of natural enemies in orchard to the weeds such asMedicago sativa+Setaria viridis and Medicago minimach+Hemistepta lyrata, can approximately be 0.853, and rational mixed grows can enlarge the capacity of natural enemies and protection effect. For mixed grows, the best mixed type can be legume, the worst can be shallot.5. To the extent of habitat character, the diversity index from more to less can right be from the less chaos orchard to the ordinary chaos orchard in the sample pool of 7 different trial plot: Wujiaodi, Kouhe, Zhaojiayuan, Guoyejidi, Nanmao, Houzhuang and Tuqiao, etc.6. The main pest in the apple orchard includes Tetranychus viennensis、Aphispomi DeGeer、Myzus malisutus,Lithocolletis ringoniella,Carposina niponensis、Grapholitha molesta .The Aphispomi DeGeer、Myzus malisutus break out in June, and Tetranychus viennensis breaks out during July to August. The main natural enemies include Chrysopa sinica、C.formosa and C.septempunc. The predominant species of Ladybugs can be Coccinella septempunctata and Propylaea Japonica, and the Erigonidium graminicolum to spiders. The value of Niche overlap shows the strong effect of following and preying on Coccinella septempunctata and Chrysopa sinica. During September, parasiting natural enemies show high parasite rate which more than 0.8 for the main pest.更多还原