【作者】 陈明；

【导师】 任继周；

【作者基本信息】 兰州大学 ， 草业科学， 2008， 博士

【摘要】 本研究从可持续农业和可持续的害虫调控要求出发,着眼于甘肃棉花生产和害虫发生与治理的现状,采用系统调查的研究手段,综合应用群落生态学和种群生态学的原理和方法,通过连续2年的深入系统研究,对间作豆科牧草(紫花苜蓿、沙打旺、毛苕子和箭筈豌豆)棉田和不同模式间作苜蓿棉田节肢动物群落的结构特征、时序动态、天敌群落组成及动态规律、棉蚜与主要天敌消长动态等进行了研究,探讨了利用棉田间作苜蓿控制棉蚜的生态防治效果。主要研究结果如下:1.棉田内间作豆科牧草可以增加棉田节肢动物群落的物种数,间作紫花苜蓿、沙打旺、毛苕子、箭筈豌豆棉田和单种棉田的节肢动物物种数分别为81、76、75、72和68种。棉田内间作豆科牧草还可提高棉田节肢动物群落的益害比,间作紫花苜蓿、毛苕子、沙打旺、箭筈豆棉田和单种棉田的节肢动物群落的益害比分别为0.0734、0.0625、0.0608、0.0531和0.0259。2.间作豆科牧草棉田节肢动物群落的均匀度、丰富度、多样性指数大于单种棉田,均匀度对多样性的影响大于物种丰富度对多样性的影响,而优势集中性和优势度指数小于单种棉田。间作豆科牧草棉田节肢动物群落的主要物种是:棉蚜、棉叶蝉、敦煌叶螨、盲蝽类、棉蓟马、多异瓢虫、蜘蛛类、褐斑和瓢虫、小花蝽、草蛉类等。蜘蛛类、暗色姬蝽、食蚜蝇类、多异瓢虫、草蛉类和棉蚜的生态位宽度分别为0.7814-0.8563、0.6398-0.8689、0.5973-0.7642、0.5969-0.7132、0.5531-0.6163和0.2428-0.3405。在供试的4种豆科牧草中,间作紫花苜蓿棉田节肢动物群落的个体数(N)、物种数(S)、物种丰富度(R)、优势度(d)、优势集中性(C)、均匀度(J)、多样性指数(H)显著地优于其他3种牧草间作棉田。3.间作苜蓿带棉田的4个处理中,捕食性天敌群落的物种丰富度、优势度指数及多样性指数均高于单种棉田,尤以每隔1膜间作75cm宽苜蓿带棉田的相关特征指数为最高。捕食性天敌种群以小花蝽、星豹蛛、多异瓢虫、十一星瓢虫、三突花蛛、短翅细腹食蚜蝇、七星瓢虫和草间小黑蛛的生态位宽度较大。瓢虫类、蜘蛛类、草蛉类和花蝽类的相对丰盛度分别为:0.2059-0.3035、0.2229-0.2495、0.1524-0.1958和0.1199-0.1825。4.每隔1膜间作75cm、50cm宽苜蓿带,每隔2膜、3膜间作50cm宽苜蓿带棉田的百株捕食性天敌个体数,分别是单种棉田的249%、205%、164%和135%。与单种棉田相比,间作苜蓿棉田内的瓢虫、蜘蛛、草蛉种群数量有大幅度的增长,每隔1膜间作75cm宽苜蓿带处理区分别增长了318.0%、120.9%和79.6%;每隔1膜间作50cm宽苜蓿带处理区分别增长了204.7%、103.3%和70.6%。特别是在6月25日和7月25日的两次刈割苜蓿后,捕食性天敌群落数量增长十分明显。5.在整个调查期间(5月15日至8月18日),单种棉田平均棉蚜种群数量分别是每隔1膜、2膜、3膜间作50cm宽苜蓿带棉田和每隔1膜间作75cm宽苜蓿带棉田的554%、421%、3295和781%。在棉蚜种群增长初期刈割苜蓿(6月25日)后10天,单种棉田平均棉蚜种群数量分别是每隔1膜、2膜、3膜间作50cm宽苜蓿带棉田和每隔1膜间作75cm宽苜蓿带棉田的542%、407%、332%和896%。第二次刈割苜蓿(7月25日)后5天,单种棉田平均棉蚜数量分别是每隔1膜、2膜、3膜间作50cm宽苜蓿带棉田和每隔1膜间作75cm宽苜蓿带棉田的3 591%、1 849%、814%和5 070%。间作苜蓿带棉田中,天敌对棉蚜种群增长的控制效应十分显著。6.通过棉花产量测定,每隔1膜间作50cm宽苜蓿带棉田的皮棉产量为5461.80 kg/hm~2、每隔1膜间作75cm宽苜蓿带棉田为5298.75 kg/hm~2、每隔2膜间作50cm宽苜蓿带棉田为5017.95 kg/hm~2、单种棉田(防治)为4853.10kg/hm~2、每隔3膜间作50cm宽苜蓿带棉田为4719.15 kg/hm~2、单种棉田(不防治)为4173.15 kg/hm~2。更多还原

【Abstract】 The cotton aphid,Aphis gossypii Glover(Homoptera:Aphididae),is a major pest of cotton (Gossypium hirsutum L.)in China and many other countries,especially in the seedling stage of cotton.High cotton aphid densities cause a negative impact on cotton yield and result in serious economic losses.In this study,the community structure,temporal dynamics,dominant natural enemies composition and dynamics of arthropod,increasing and decreasing tendency of cotton aphid and their predacious natural enemies were examined on cotton inter-planted legumes (Medicago sativa L.,Astragalus adsurgens Pall.,Vicia villosa Roth,and V.sativa L.)and different cotton-alfalfa intercropping systems from 2004 to 2005 at Dunhuang,western Gansu Province.The main results are summarized as the follows:1.The species numbers of arthropod community were increased in the fields of cotton inter-planted legumes.The species reached 81,76,75,72 and 68 in cotton-alfalfa,cotton-erect milk vetch,cotton-hairy vetch,cotton-fodder vetch intercropping fields and cotton field,respectively.The ratio of natural enemy and pest was enhanced in cotton inter-planted legumes,it reached 0.0734, 0.0625,0.0608,0.0531 and 0.0259 in cotton-alfalfa,cotton-hairy vetch,cotton-erect milk vetch, cotton-fodder vetch intercrop fields and cotton field,respectively.2.Evenness,abundance and diversity index of arthropod community in cotton inter-planted legumes were higher than that of in cotton field,and superiority concentricity and dominance index of arthropod community in cotton inter-planted legumes were lower than that of in cotton field.The evenness had a great influence over the diversity,and the species abundance had a slight influence over the diversity.The dominant species and groups were A.gossypii,Empoasca biguttula, Tetranychus dunhuangensis,leaf bugs,Thrips sp.,Adonia variegate,Spiders,Synharmonia conglobata,Orius minutus and lacewings.Niche width of spiders,Nobis palifer,syrphus flies,A. variegate,lacewings and A.gossypii were 0.7814-0.8563,0.6398-0.8689,0.5973-0.7642, 0.5969-0.7132,0.5531-0.6163 and 0.2428-0.3405,respectively.Individual number(N),species number(S),species abundance(R),dominance index(d),superiority concentricity(C),evenness(J) and diversity index(H)of arthropod community in cotton-alfalfa interplant field were higher than that of in cotton inter-planted other legumes. 3.Species abundance,dominance and diversity index of predacious natural enemy community in cotton-alfalfa interplant fields were higher than that of in cotton field,especially in the treatment of 120cm-wide cotton inter-planted 75cm-wide alfalfa Population niche width of O.minutus, Pardosa astrigera,A.variegate,Coccinella undecimpunctata,Misumenops tricuspidatus, Sphaerophoria scripta,Coccinella septempunctata and Erigonidium graminicola was higher within predacious natural enemy communities.Relative abundance of ladybirds,spiders,lacewings and flower bugs was 0.2059-0.3035,0.2229-0.2495,0.1524-0.1958 and 0.1199-0.1825,respectively in cotton-alfalfa interplant fields.4.Individual number of predators in cotton-alfalfa interplant fields(75cm-wide alfalfa belt every 120cm-wide cotton belt,50cm-wide alfalfa belt every 120cm-wide cotton belt,50cm-wide alfalfa belt every 2×120cm-wide cotton belt and 50cm-wide alfalfa belt every 3×120cm-wide cotton belt)were 249%,205%,164%and 135%of that in the cotton field,respectively.Population density of ladybirds,spiders and lacewings in cotton-alfalfa interplant fields showed a considerable increase over the cotton field.Population density of ladybirds,spiders and lacewings in cotton-alfalfa interplant field(75cm-wide alfalfa belt every 120cm-wide cotton belt)showed an increase of 318.0%,120.9%and 79.6%,and in cotton-alfalfa interplant field(50cm-wide alfalfa belt every 120cm-wide cotton belt)showed an increase of 204.7%,103.3%and 70.6%over the cotton field,respectively.In particular,population density of predators increased rapidly after cutting alfalfa twice on June 25 and July 25.5.Cotton aphis density in the cotton field was 554%,421%,329%and 781%of that in cotton-alfalfa interplant fields(50cm-wide alfalfa belt every 120cm-wide cotton belt,50cm-wide alfalfa belt every 2×120cm-wide cotton belt,50cm-wide alfalfa belt every 3×120cm-wide cotton belt and 75cm-wide alfalfa belt every 120cm-wide cotton belt)during the whole examined period, 542%,407%,332%and 896%after 10 days in the first cutting alfalfa(June 25),and 3 591%,1 849%,814%and 5 070%after 5 days in the second cutting alfalfa(July 25).The population density of cotton aphis was significantly controlled by predators in cotton-alfalfa interplant fields.It was very effective to force the predators from the alfalfa strips into the nearby cotton field to control cotton aphid.6.By measuring the output of ginned cotton,the output was 5461.80 kg/hm~2 in cotton-alfalfa interplant field(50cm-wide alfalfa belt every 120cm-wide cotton belt),5298.75 kg/hm~2 in cotton-alfalfa interplant field(75cm-wide alfalfa belt every 120cm-wide cotton belt),5017.95 kg/hm~2 in cotton-alfalfa interplant field(50cm-wide alfalfa belt every 2×120cm-wide cotton belt), 4853.10 kg/hm~2 in cotton field(controlled),4719.15 kg/hm~2 in cotton-alfalfa interplant field (50cm-wide alfalfa belt every 3×120cm-wide cotton belt),and 4173.15 kg/hm~2 in cotton field (no-controlled),respectively.更多还原