【作者】 魏永平；

【导师】 张雅林；

【作者基本信息】 西北农林科技大学 ， 农业昆虫与害虫防治， 2011， 博士

【摘要】 对陕西黄土高原优质苹果产区洛川和黄陵苹果园及周边生境的昆虫多样性和植物多样性进行研究,通过对果园生境的系统调查研究了黄土高原苹果园昆虫群落的组成和结构特征;调查分析了不同生境果园的植物多样性,根据重要值明确了果园野生植物优势种;利用生多样性研究方法评价了野生植物、农作物对果园昆虫群落的影响;运用昆虫群落生态学方法探讨了利用野生植物进行生境调节果园中主要害虫和天敌种群之间的竞争关系,为果园杂草的科学管理和利用植物进行生境调节和害虫生态治理理提供了理论依据。1.黄土高原优质苹果产区果园昆虫物种丰富。在苹果园调查共发现昆虫219种,隶属于12目85科。其中,害虫7目48科118种;天敌昆虫和蜘蛛类9目27科72种;中性昆虫3目13科29种。害虫种类占调查总数的53.88%,天敌昆虫占到32.88%,中性昆虫占到13.24%。中华草蛉、丽草蛉、大草蛉、异色瓢虫、多异瓢虫、七星瓢虫为该地区果园天敌优势种群。2.黄土高原苹果园植物种类多,不同生境植物优势种存在差异。果园野生植物种类丰富,共有33科69属84种,其中21科49属63种存在于果园树下,21种存在于果园内的生境岛屿;菊科植物种类最多,有20种,占调查种类的23.81%,其次为禾本科、藜科、豆科;沟壑坡地果园植物种类最多,为35种,其次为沟谷地形果园,有26种;抱茎苦荬菜、狗尾草、丝毛飞廉、灰绿藜、刺儿菜、田旋花重要值分别为0.36、0.22、0.22、0.18、0.17、0.14,为该地区果园植物优势种。3.黄土高原果园地形及耕作方式对果园天敌昆虫群落有影响。保留天然杂草的果园昆虫多样性丰富,天敌种类达到58种,昆虫种类益害比为1:23,而清耕园益害比为1∶46;黄土高原沟壑底部沟谷地形果园天敌昆虫多样性丰富,瓢虫、草蛉、捕食性蜘蛛、食虫蝽四个类群多样性指数分别为1.9987、1.9484、2.4282、1.4429;塬面清耕果园四个类群的多样性指数最低。4.果园杂草影响昆虫群落的个体数量和丰富度,部分优势种对天敌昆虫有增助作用。反枝苋覆盖的生境诱集昆虫种类最多,为75种,其次为三叶鬼针草;诱集天敌昆虫最多的杂草为刺儿菜;刺苋、碱蓬、灰绿藜、藜对昆虫的诱集能力很低;在果园保留刺儿菜和田旋花有助于提高果园天敌昆虫群落的多样性,多样性指数分别为1.0735和0.8799;紫花苜蓿+狗尾草与苹果园的天敌昆虫群落相似度最高,相似性度指数达到0.853。其次为反枝苋和刺苋;抱茎苦荬菜与苹果园天敌昆虫的相似度最低,相似性指数为0.463。5.周边生境不同类型对果园昆虫群落的影响作用不同。周边杂草生境昆虫种类最多,多样性指数高,其次为甘蓝地;紫花苜蓿与果园天敌昆虫群落相似性系数最高,为0.835,其次为天然杂草地,相似系数达到0.813;油菜田可以提高相邻果园天敌昆虫的多样性,在苹果生长的幼果期有助于控制害虫,建议在果园周边生境种植油菜。6.有选择利用优势种杂草进行生境调节有助于果园害虫的控制。人工种草果园天敌昆虫瓢虫、草蛉、捕食性蜘蛛等功能团的多样性指数均大于清耕园,其中种草果园瓢虫类的多样性指数(2.1697)最高,其次为捕食性蜘蛛类。保留刺儿菜、田旋花、反枝苋等杂草的果园,捕食性天敌及寄生性天敌的丰度高于清耕园;七星瓢虫对绣线菊蚜和苹果瘤蚜在空间上生态位重叠值为0.9365和0.8902,中华草蛉对绣线菊蚜和苹果瘤蚜在空间上生态位重叠值为0.9142和0.8715,两种天敌对主要害虫绣线菊蚜和苹果瘤蚜的跟随作用很强。在时间维度上,瓢虫类与绣线菊蚜重叠值最大,说明瓢虫与绣线菊蚜在时间上具有同步性,并对绣线菊蚜有随作用。在时空二维上,绣线菊蚜生态位宽度最大,瓢虫类比草蛉类占据较大的空间生态位,瓢虫、草蛉与绣线菊蚜的重叠值最大,控制作用明显。建议黄土高原果园保留刺儿菜、田旋花、反枝苋等杂草,对提高果园天敌昆虫多样性和害虫的生态治理有帮助。更多还原

【Abstract】 This paper deals with the insect diversity and the related plants community in apple orchards and their surroundings in Luochuan and Huangling Counties in the Loess Plateau, the well-known high quality apple-growing region of China. The insect diversities in apple orchards with different composition of plant community are investigated, and the dominant wild plant species are determined according to the species importance values (IV). The effects of wild plants and crops on the insect diversity and populations are evaluated by using biodiversity research methods; the adjusting function of wild plants to the competition relationship between dominant pests and their natural enemies are studied with the view to providing information for scientific management, biotope improvement and pest ecological control in apple orchards. The main results are presented below.1. The insect diversity is rich in the high quality apple-growing orchards in Loess Plateau. There are 219 insect species, belong to 85 families of 12 orders, were found occurring there, among which pests amount to 118 species belonging to 48 classes of seven order, natural enemy insects and arachnids amount to 72 species belonging to 27 classes of nine orders, and neutral insects amount to 29 species of 13 classes. The pests, natural enemy insects and neutral insects amount to 53.88%, 32.88% and 13.24% to the total species, respectively. Chrysopa sinica,Chrysopa formosa,Chrysopa septempunc,Harmonia axyridis,Hippodamia variegata and Coccinella sepbempunctata are the dominant species in the orchards of this region.2. The diversity of plants in apple orchards in the Loess Plateau is rich, and the dominant species in different biotopes are different. The wild plants diversity is rich in these orchards, including 84 species belonging to 69 genera of 33 families, among which 63 species belonging to 49 genera of 21 families occur under apple trees and 21 species occur in island habitats of orchards; the diversity of Asteraceae is the highest, amounting to 23.81% of the total species, and the diversities of Poaceae, Chenopodiaceace and Fabaceae are decreasing in sequence. Orchards located on slopes of valleys have the richest diversity of plants (35 species), and those in the bottom of valleys are the next (26 species). Ixeris sonchifolia, Setaria viridis (L.) , Carduus crispus L. Chenopodium glaucum, Cephalanoplos segetum and Convolvulus arvensis L. are the dominant species in the orchards, and their importance values (IV) are 0.36, 0.22, 0.22, 0.18, 0.17 and 0.14, respectively.3. Terrain and cultivating forms affect the diversity and populations of natural enemy insects in the orchards in the Loess Plateau. The insect diversity in orchards with weeds kept is richer than those with weeds cleared away, which include 58 species and the ratio of beneficial insects and pest is 1:23; while in those with weeds cleared away the ratio of beneficial insects and pest is 1:46. The biodiversity of insects of orchards located at the bottoms of valleys in the Loess Plateau is the highest, and in these orchards the diversity indices of lady bugs, lacewings, preying arachnids and preying true bugs are 1.9987, 1.9484, 2.4282 and 1.4429, respectively. In comparison, the diversity indices of the aforementioned four groups in the orchards located on the top of plateau are all among the lowest.4. Weeds affect the population and richness index of insects in orchards and some dominant species of weeds are beneficial to natural enemy insects. The species number of insects hosted in habitats with Amaranthus retroflexus is the most, including 75 species, and the next is that in habitats with Bidens pilosa. The species number of natural enemy insects hosted in habitats with Cephalanoplos segetum is the most, and attracting ability of habitats with Amaranthus spinosus,Suaeda glauca,Chenopodium glaucum is relatively low. It is beneficial to protect the diversity of natural enemy insects by keeping Cephalanoplos segetum and Convolvulus arvensis L. in orchards, and their diversity indices are 1.0735 and 0.8799, respectively. The Cs of natural enemy insects between the apple orchards and fields artificially planted with Medicago sativa L. Alfalfa and Setaria viridis (L.) together is the highest (Cs = 0.853), and then the Cs of natural enemy insects between the apple orchards and fields with wild Amaranthus retroflexus and Amaranthus spinosus L., the Cs of natural enemy insects between the apple orchards and fields with Ixeris sonchifolia is the lowest (Cs = 0.463)5. Effects of habitats with different type of surroundings on the diversity and population of insects are different. The diversity of insects in habitats with weeds around orchards is the highest, and the next is that in habitats with Cabbage; the Cs of natural enemy insects between the apple orchards and fields planted with Alfalfa is highest (Cs = 0.835), and the next is that between the apple orchards and fields with natural weeds (Cs = 0.813). Rape fields around orchards are beneficial to improving the biodiversity of natural enemy insects and also helpful to pest control in the young fruit-growing period in orchards.6. It is helpful to control pests in orchards by select and utilize dominant weed species to adjust the habitat of orchards. The diversity indices of natural enemies such as lady bugs, lace wings and preying arachnids in orchards with artificially planted weeds are all higher than that of cleared orchards, of which the diversity index of lady bugs is the highest (2.169), and the next is that of preying arachnids. The richness indices of preying natural enemies in orchards with weeds such as Cephalanoplos segetum、Convolvulus arvensis L.、Amaranthus retroflexus kept are all higher than that of cleared orchards. The Qij of Coccinella sepbempunctata toAphis citricolaand Myzus malisutus amount to 0.9365 and 0.8902, respectively; and the Qij of Chrysopa sinica to Aphis citricola and Myzus malisutus amount to 0.9142 and 0.8715, respectively. The following effects of the above two natural enemy insects are both remarkable. The Qij of lady bugs toAphis citricola is the highest in time dimension, which implies lady bugs andAphis citricolaare synchronic and lady bugs have following effect on Aphis citricola. In time and spatial dimensions, the niche breadth of Aphis citricola is the highest, and that of lady bugs is higher than that of lacewings; the overlap value between lady bugs, lacewings and Aphis citricola is the highest, which shows that the two natural enemies have evident control effect to Aphis citricola. It is concluded that keeping weeds, e.g. Cephalanoplos segetum and Convolvulus arvensis L. and Amaranthus retroflexus ect., are beneficial to improve the diversity of natural enemies insect and to control the pests in apple orchards of the Loess Plateau.更多还原