江浙麦区灰飞虱春季种群的发生消长和迁飞动态

Fluctuation and Migration of Spring Population of Small Brown Planthopper(Laodelphax striatellus) on Wheat in Jiangsu and Zhejiang Provinces

对灰飞虱进行越冬调查、田间调查、卵巢解剖、逐时扑灯行为观察、迁飞轨迹和虫源地分析发现:1)灰飞虱以3～5龄若虫越冬,并以4龄为主;2)江苏北部麦田灰飞虱若虫于3月越冬结束,3-4月陆续发育羽化为越冬代成虫,4-5月在麦田繁殖为第1代若虫;3)浙江海宁春季第1代灯诱灰飞虱具有本地迁出和外地迁入两种性质与时期,并可依卵巢发育级别加以区分;4)春夏季浙江海宁灰飞虱可由本地越冬虫源繁衍而来,或由江苏、安徽、浙江、江西、福建等省迁入。无论从越冬寄主小麦向夏寄主水稻扩散转移,或6月初大量外地迁入,杂草充当了极其重要的中间寄主;5)逐时灯诱观察结果表明,迁出期灰飞虱起飞呈晨暮双峰型,迁入期在19:00至次日凌晨5:00,每1h均有上灯,以上半夜居多;6)利用美国NOAA的HYSPLIT轨迹模拟平台对主要迁入期进行数值模拟和虫源地分析,结果表明,2009年5月底至6月初迁入浙江海宁的灰飞虱虫源地来自江苏北部和中部、皖南、浙南、赣东北和闽西北等地区。

The field surveys for overwintering and spring populations of the small brown planthopper ELaodelphax striatellus （Fall6n）, SBPH] on wheat and weeds were performed, and the hourly immigration under the light trap was observed in northern Jiangsu Province and Haining, Zhejiang Provincel The results illustrated that SBPH overwintered as 3rd--Sth instars （mainly as 4th instar） on wheat, weeds and rice stubble from October to the next March. The overwintering nymphs finished their dormancy in March and emerged during March to April. The first generation nymphs were found in wheat during April to May. From the end of May to the mid-June, mass of the macropterous adults of SBPH emigrated in wheat fields, then immigrated into rice fields and weeds after a short or long journey. The emigrated and immigrated population could be distinguished by the status of ovarian development. The hourly collected light trap catches revealed that SBPH did migrate regularly for several hours after taking off at dawn and dusk, even an all night long-distance flight. SBPH collected by the light trap showed a bimodal takeoff peak and they would immigrate at every hour during all night, but mainly before midnight. The source regions of the immigrants were tracked by trajectory analysis using NOAA HYSPLIT model, which proved that the SBPH immigrants might come from the middle and north Jiangsu Province, southern Anhui Province, southern Zhejiang Province, northeastern Jiangxi Province and northwestern Fujian Province.