小波分析二点委夜蛾发生规律

Wavelet analysis of the occurrence frequency of Proxenus lepigone (Moschler)

二点委夜蛾Proxenus lepigone(Moschler),属鳞翅目夜蛾科,主要分布于日本、朝鲜、俄罗斯和欧洲等地。我国于2005年7月在河北省夏玉米田首次发现。近年来,该虫发生范围不断扩大,为害程度日益加重。2011年二点委夜蛾在我国夏玉米产区严重暴发,虫情涉及6省47市302个区(县),面积近220万hm2。山东省2007年首次在德州市发现该虫为害玉米,2011年全省17个地市普遍为害严重。为更准确地确定该虫的发生代次、每代各虫态发生历期、发生盛期、发生高峰日等信息,适时准确监控发生时期,本文采用symlets小波函数变换滤除高频信息,对山东省多地点二点委夜蛾成虫诱虫数据进行分析,结果显示,二点委夜蛾在山东省一年发生4代,越冬代、1代、2代、3代,始见蛾日在3月底—4月上旬,越冬代成虫发生期在3月底至4月上中旬,1代发生期在4月上旬至6月中下旬,2代发生期在6月中旬至8月上中旬,3代发生期在8月上旬至9月中下旬,越冬代幼虫发生期在9月中旬至10月中下旬,10月下旬左右老熟幼虫做茧越冬。另外,通过调查和室内观察还发现高温环境不利于二点委夜蛾幼虫生长发育,7—8月份高温期,成虫致畸率较高。

Proxenus lepigone （Moschler） （ Lepidoptera： Noctuidae）, a species mainly distributed in Japan, Korea, Russia and Europe, was first discovered in China in a summer maize field in Hebei Province in 2005 July. The range of P. lepigone in China has expanded in recent years, and it is causing progressively more damage. In 2011, an outbreak on the summer corn crop in China involved 302 districts, 6 provinces and 47 cities and covered an area of nearly 2 200 000 hm2. P. lepigone was first found in Shandong Province on maize crops in Dezhou City in 2007, and later in 17 cities in that Province, where it caused serious damage. In order to more accurately determine the occurrence generations, development period, peak period, peak day, and so on,we analyzed trapping data on P. lepigone adults using symlets wavelet transformed filter high frequency information. The results show that P. lepigone has 4 generations a year in Shandong Province; an overwintering generation, first generation, second generation and third generation. The appearance of the first overwintering moths is from the end of March to the middle of April, overwintering generation moths occur from the end of March to the middle of April. The occurrence period of the first generation is from early April to late June, that of second generation from middle June to middle August, the third generation from early August to late September, and overwintering larvae from mid-September to late October; after that the mature larvae overwinter in cocoons. In addition,field and laboratory observations indicate that a high temperature environment is not conducive to P. lepigone larval growth and development. Adult deformity rates are very high in July and August because of high temperature.