| Abstract | 第4-5页 |
| 中文摘要 | 第6-8页 |
| Preface | 第8-17页 |
| Abbreviations | 第17-19页 |
| CHAPTER Ⅰ Literature reviews | 第19-46页 |
| 1.1. Wheat crop (Triticum aestivum L.): | 第19-22页 |
| 1.1.1 Taxonomy of cultivated wheat | 第19-20页 |
| 1.1.2 Domestication of cultivated wheat | 第20-21页 |
| 1.1.3 Production of wheat: | 第21-22页 |
| 1.2 Wheat aphids | 第22-36页 |
| 1.2.1 Taxonomy | 第22-23页 |
| 1.2.2 Life history | 第23-25页 |
| 1.2.3 Economic importance | 第25-27页 |
| 1.2.5 Major species of wheat aphids | 第27-32页 |
| 1.2.6 Management of Aphids | 第32-36页 |
| 1.3 Natural enemies | 第36-38页 |
| 1.3.1 Predators: | 第36-37页 |
| 1.3.2. Parasitoids: | 第37-38页 |
| 1.3.3 Pathogen: | 第38页 |
| 1.4 Imidacloprid insecticide: | 第38-41页 |
| 1.4.1 History | 第38-39页 |
| 1.4.2 Mode of actions: | 第39页 |
| 1.4.3 Importance: | 第39-40页 |
| 1.4.4 Undesirable effects of pesticides: | 第40-41页 |
| 1.5 Competitions among herbivorous: | 第41-42页 |
| 1.5.1 Intraspecific competition | 第42页 |
| 1.5.2 Interspecific competition | 第42页 |
| 1.6 Factors influence competitions among herbivores insect pests | 第42-44页 |
| 1.6.1 Abiotic factors | 第43页 |
| 1.6.2 Biotic factors | 第43-44页 |
| 1.7 Exclusion trials | 第44-46页 |
| CHAPTER Ⅱ: LABORATORY EXPERIMENTS | 第46-64页 |
| 2. Impact of insecticide on intra and interspecific competitions of cereal aphids | 第46-64页 |
| 2.1 Introduction: | 第46-48页 |
| 2.2 Materials and Methods | 第48-51页 |
| 2.2.1 Biological materials | 第48-49页 |
| 2.2.2 Insecticide: | 第49页 |
| 2.2.3 Bioassays | 第49-51页 |
| 2.2.6 Statistical analysis: | 第51页 |
| 2.3 The Results: | 第51-60页 |
| 2.3.1 Insecticide bioassays: | 第51-53页 |
| 2.3.2 Impact of insecticides on intraspecific competition: | 第53-55页 |
| 2.3.3 The impact of insecticides on even interspecific competition: | 第55-57页 |
| 2.3.4 The impact of insecticides on uneven inter-specific competition: | 第57-60页 |
| 2.4 Discussion: | 第60-63页 |
| 2.4.1 Bioassays: | 第60页 |
| 2.4.2 Impact of insecticides on intra-specific competition: | 第60-61页 |
| 2.4.3 Impact of insecticides on even intra/inter-specific competition: | 第61页 |
| 2.4.4 Impact of insecticides on inter-specific competition (uneven): | 第61页 |
| 2.4.5 Impact of insecticide on dominance aphid species (R. padi vs. S. avenae): | 第61-63页 |
| 2.5 Conclusions | 第63-64页 |
| CHAPTER Ⅲ: FIELD EXPERIMENTS | 第64-89页 |
| 3. Sole and combined impact of pesticides, natural enemies on population dynamic andcompetition of cereal aphids in wheat fields of Northern China | 第64-89页 |
| 3.1 Introduction: | 第64-67页 |
| 3.2 Materials and Methods | 第67-70页 |
| 3.2.1 Experimental site | 第67页 |
| 3.2.2 Insects | 第67-68页 |
| 3.2.3 Insecticide | 第68页 |
| 3.2.4 Experimental design and data collection | 第68-70页 |
| 3.2.5 Statistical analyses | 第70页 |
| 3.4 Results | 第70-83页 |
| 3.4.1 Impact of insecticide and natural enemies on aphid population dynamics | 第70-73页 |
| 3.4.2 Impact of insecticide on competition among aphids: | 第73-75页 |
| 3.4.3 Impact of natural enemies on competition among aphids | 第75-79页 |
| 3.4.4 Combined impact of insecticide and natural enemies on competition among aphids | 第79-80页 |
| 3.4.5 Impact of insecticide on population dynamics of natural enemies | 第80-83页 |
| 3.5 Discussion | 第83-88页 |
| 3.5.1 Impact of pesticide on population dynamics and interspecific competition of cereal aphids | 第83-85页 |
| 3.5.2 Impact of natural enemies on population dynamics and interspecific competition of cerealaphids | 第85-86页 |
| 3.5.3 Interaction of pesticide and natural enemies on population dynamics and interspecific competition of cereal aphids | 第86-87页 |
| 3.5.4 Impact of pesticide on population dynamics of natural enemies | 第87-88页 |
| 3.6 Conclusions | 第88-89页 |
| CHAPTER Ⅳ General Conclusions | 第89-92页 |
| Impact of imidacloprid insecticide on intra and interspecific competitions among cereal aphid'sRhopalosiphum padi L. and Sitobion avenae Fab (Hemiptera: Aphididae) | 第89-90页 |
| Sole and combine impact of imidacloprid and natural enemies on competitions among cerealaphids in wheat fields of Northern China | 第90页 |
| Impact of imidacloprid and natural enemies on cereal aphids: Integration or ecosystem servicedisruption? | 第90-92页 |
| List of references | 第92-109页 |
| ACKNOWLEDGEMENTS | 第109-111页 |
| AUTHOR'S RESUME | 第111-113页 |
