关键词: 圆形分布法, 蝇类, 季节消长

Abstract: Objective To find out peak day and peak periods of the seasonal change in numbers of flies, so as to work out a scientific plan for controlling and preventing the flies. Methods The circular distribution method was used to analyze the data collected from years of 2003-2004 in Shaoxing urban areas to monitor change in numbers of flies. Results It was showed that in Shaoxing urban areas, the peak day of seasonal change of flies was August 4^th during the years of 2003-2004; but it was August 11^th in 2003, July 29^th in 2004. The peak period of seasonal change of flies was from June 8^th to September 30^th during the years of 2003-2004, however, in the single year, it was from June 17^th to October 5^th in 2003, from June 1st to September 26th in 2004. Conclusion The change in numbers of flies has an obvious seasonal feature during the years of 2003-2004 in Shaoxing urban areas.