Arthropod Community Characteristics In Overlap Period Of Winter And Spring Rape Growth In Cold And Humid High Altitude Region

Rape is a major oil crops in Gansu provice , rape plays an important role in the local agriculture, with the climate warming,in the original production of spring rape, Area continued to increase in winter oilseed rape to make a single spring rape growing areas into a winter and spring rapeseed hybrid zone. Kangle is located in a typical wet zone,with the climate warming, this region formed a new pattern of coexistence of winter and spring rape,arthropod taxa distribution and characteristics of diversity in this region has not been reported,through the annlyzing diversity in winter and spring rape fields by investigation the structure of arthropod community in this region in winter and spring oilseed rape can be gained ,and then the results can provide a theoretical basis and data to support for the winter and spring rape fields of pest control. Major work is as follows:1. Community structureThe investigation was carried out on the different types of arthropod community in the winter and spring rape fields in cold and humid region in high altitude. Shannon-wiener diversity index ,richness index and evenness index were used to analyze the data. The total number of insects showed that arthropod belonged to 11 orders,29families and 39species.The coleoptera,hymenopteara,diptera were primary order,their number accounted of 62.07% for the total number.different rape development period with different arthropod community and the dominant species were fleabeetle,stemweevil,aphis and leaf miner.2. Characteristics of arthropod communityThe composition of the arthropod commumity in winter and spring rape was different in winter and spring rape fields. The richness diversity and evenness changed along with the different growth period of rape. The richness and evenness indexes were all laid high level,the richness index (DMA)changed alternately ,but the diversity index in winter rape is higher than that of spring rape.3. Distribution of major pest in overlap period of the winter and spring rape During the overlap period of winter and spring rape growing fromApril to June,theInvestigation showed: Population of flea beetle in spring rape was more than that in winter rape; Roughly the same amount of aphids occurred in two type fields; The amount of Leafminer occurring early in the winter rape fields was more than that in spring rape fields ,Late its amount was similar; adult stem weevil was similar At first; After the end of April, the amount in Spring rape was significantly higher than winter rape. 4. Pest control strategy in mix area of spring rape and winter rapeThroughout analyzing the data, We believe that the mix planting of winter and spring rapeseed has created extremely favorable conditions for occurrence of pests, Especially for aphids, leafminers continuing damage; winter oilseed rape also provides the nutrition in early spring for the flea beetle, sap beetle, stem weevil, which is beneficial to reproduction and increases difficulties of prevention damage in spring rape. With a result of winter oilseed rape early recover green and mature before June , the pest risk is obviously smaller.in the present situation, it is necessary to emphasis the prediction,monitoring and control of the pest in spring rape field. Reduceing or refusing to grow the winter rape is suggested for the control pest strategy in this new mix area growing two type rape.