The Study On Occurrence And Detriment Regularity Of Small Brown Planthopper In Shandong

The small brown planthopper Laodelphax striatellus (Fallen)(SBPH) is one of the important agricultural pests. It can cause serious losses in agriculture by transmissing virus and long-distance migration. Shandong province is located in the lower reaches of Yellow River, and it is the major grain producing areas of wheat, corn, at the same time, there are large areas of high quality japonica in Shandong province. Gramineous crop is the main host plant of SBPH. Thus, studying the occurrence and detriment regularity of SBPH in Shandong will have important practical significance for improving the early warning capabilities to it.In order to indentify the SBPH occurrence regularity in the field in the first half year in Shandong province, this studied respectively investigated the SBPH population dynamic in the field from March to June in2011, the survey locations included Ningjin, Shanghe, Dongguang, Laoling, Lingxian, Jining and Tancheng in Shandong province. The paper studied the light-trap regularity of SBPH through the light-trap data in2010and2011in Ningjin, and we analysised the data of2011as a case. The virus carried rate of SBPH in the field and light-trap cathes were tested, and we found out the general situation of the virus carried rate of SBPH in Shandong province.The main research results were as follows:1. The populations dynamic of SBPH in the fieldWe studied the population dynamic of SBPH in field through systematic investigation in Shandong province, and used statistical analysis software (SAS Institute, USA,1996) to compare the differences of each month and each survey point. The results showed that:the overwinter base of SBPH in the winter wheat field of the rice-wheat rotation field in Tancheng was the highest in the all survey points. There were significant differences on the number of SBPH of each month in the wheat field between the rice-wheat rotation field in Jining and the no rice-wheat rotation field and in Tancheng, and the number of SBPH in rice-wheat rotation field was significantly higher than that in no rice-wheat rotation field. The results of SBPH in the field in Ningjin, Lingxian, Shanghe, Dongguang, Laoling in each month didn’t attain control index, so we didn’t need to take preventive measures but should to closely focus on the population dynamics of SBPH. The number of in March and May in Tancheng and the number of SBPH in May in Jining in the rice-wheat rotation field both attained control index, and the number of SBPH in no rice-wheat rotation field in the above two points did not reach the control index, so we should focus on the control of SBPH in the rice-wheat rotation field.2. The biological characteristics of SBPH in light-trap cathesThe appearance period of SBPH in the light-trap cathes mainly concentrated in early June to the end of June, but the results of white black planthopper (WBPH) and black planthopper (BPH) had great changes along with the different year. The peak time of light-trap catches of SBPH were fouced at18:00-19:00pm on super peak and peak of light-trap catches day, and they belonged to the local properties. The peak time of light-trap catches of WBPH were fouced at5:00-6:00am on super peak of light-trap catches day, it was significantly higher than that on other days, and they were migratory population. There were no significant differences in each hour between peak day and general day of light-trap catches. Light-trap catches of SBPH were mainly emigration population in earlier stage, and they were immigration at in later stage from5June to15June in2011, in NingJin.3. The carried virus rate detection of SBPH in the field and light-trap cathes in Shandong provinceThe SBPH in wheat field mainly carried RBSDV in Shandong province, and they would carry RSV only after the seedling transplanted. The rate of SBHP carried RBSDV was the highest in the test of each month in Jining. As a whole, the SBPH in the field mainly carried RBSDV virus from March to June in Shandong. There were obvious difference on the carried virus rate of SBPH between the field and light-trap cathes in June, in Ningjin and the surrounding area. So we could take the difference of the rate carried virus as a reference to judge population properties. The probability of SBPH carried both RBSDV and RSV was extremely low, and a further study to the reason will be helpful for preventing the harm caused by the virus disease which spreaded by SBPH.