Comparison and analysis on the sources of brown planthoppers, Nilaparvata lugens, and weather conditions in the three outbreak years in Anqing
Author of the article:
Author's Workplace：
Key Words：brown planthopper, Nilaparvata lugens, outbreak, source of insect, weather, analysis
Abstract：The sources of brown planthoppers (BPH) Nilaparvata lugens (Stal) and weather conditions in outbreak years in 1997, 2005 and 2006 in Anqing were compared and analysed. In 1997, a larger number of BPH immigrated earlier, 1 228～8 698 BPH were catched in a light trap by July 26. The temperature was 0.2～1.3℃ lower than the average temperature over the years (as a CK) from July to August, that was suited for the outbreak of BPH in singleharvest rice field. Although more BPH immigrated again, the temperature was lower for 1℃ than CK in September, inhibited the outbreak of BPH in late rice field. In 2005, the earlier immigration of BPH was less than 1997, .Single light trap catches of BPH were 200～3 334by July 26. The temperature was 0.4～0.8℃ lower than CK from the middle ten days of July to August, but 1.8～2.2℃ higher than CK from September to the middle ten days of October. So, during the whole rice developmental season, the temperature was suited for the BPH outbreak. At the same time, the typhoones occured more frequently in this summer and autumn, more and more BPH immigrated with the strong wind and storm, 5 BPH peaks were recorded in light trap (more than 1 000 BPHper light trap) from August 16 to September 25. In 2006, enormous earlier immigrations of BPH were seen before the end of June, that were 6.4 times and 2.1 times more than the immigrated population at the same time of 1997 and 2005. 1 595～7 181 BPH were catched in a light trap by July 26. Although the temperature was 1.0～2.0℃ higher than the CK from July to August ,the microclimate of the field of singleharvest rice suited for the outbreak of BPH. During the late August andearly September, huge late immigration occurred. And the temperature was 1.5～3.0℃ higher than CK from the last tendays of September to October., that caused the continued outbreak in the fields of singleharvst rice and late rice.