【作者】 沈慧梅；

【导师】 翟保平；

【作者基本信息】 南京农业大学 ， 农业昆虫与害虫防治， 2010， 博士

【摘要】 褐飞虱(BPH) Nilaparvata lugens (Stal)和白背飞虱(WBPH) Sogatella furcifera (Horvath)是整个东南亚地区水稻种植史上最重要的害虫,具有远距离迁飞习性。自本世纪以来,再次在东南亚地区暴发成灾,造成水稻严重减产。2005年,褐飞虱在我国特大发生,之后几年,我国不断遭受两种飞虱带来的损失,2007年全国稻飞虱又一次大发生,尤其在云南等西部省份,白背飞虱的发生程度更是史无前例。随后的2008年、2009年云南省稻飞虱发生态势依旧严峻：2009年滇南前期迁入虫量不仅数量上超越2007年,在时间上更比往年提前一个月,打破历史记录。2008年春,我国南方遭遇了百年不遇的冰雪灾害,两种迁飞性飞虱在我国的越冬范围明显缩小,越冬北界南移至19°N以南地区,可同年3月底,北部湾与雷州半岛迎来第一个稻飞虱迁入高峰,灯下虫量过千,随后的4月上旬北部湾地区一些站点连续多日单日单灯虫量超过3万头。纵观20世纪60年代以来东南亚所有地区关于稻飞虱的成灾记录,发现泰国、越南、柬埔寨等国家褐飞虱的大发生年份上与褐飞虱在我国发生的情况在时空上呈现某种一致性,两者之间虫源有无直接联系是我们关心的问题。稻飞虱难以治理的主要原因在于其迁飞特性,因我国地处温带,每年主要虫源来自境外中南半岛,在国内无法进行越冬虫源的监测和控制,所以无法预测中南半岛春季迁出虫源的发生量和致害性变化,进而也就无法实施全年周期性综合治理。要控制稻飞虱的暴发危害,关键需把稻飞虱的“虫情侦察范围”扩展到国门之外,找准确切的虫源地,对其实施源头治理和区域性综合治理,这样才能有效遏制其暴发势头,降低后期损失。本论文2-4章通过对云南、广西、福建3个省份2007年以来稻飞虱早期迁入过程进行分析,基本摸清了三个省份早期稻飞虱虫源的境外分布范围。第5-6章分析了2009年泰国中部褐飞虱的几种迁飞路径,并结合历史气象资料对中南半岛最近几年稻飞虱的发生情况做分析总结,探索了中南半岛褐飞虱与白背飞虱在不同国家地区间往返迁飞的路径模式。主要研究结果如下：1.国内初始虫源分析结果(1)2009年云南4-5月份前期迁入飞虱虫源主要来自缅甸,部分虫源自老挝与越南,极少数虫源来自印度东部因帕尔地区。低温屏障、风场切变以及垂直气流扰动是造成飞虱集中降落的最主要气象因子。缅甸虫源区偏西气流频繁、冬春稻种植面积增加而导致的虫源基数增加是造成2009年云南白背飞虱大量迁入的根本原因。(2)云南江城2007年与2009年主要迁入种群的虫源地不同。2007年主迁峰出现在5月中旬,主要虫源来自缅甸南部、泰国北部、老挝北部的金三角地区；2009年主迁峰出现在4月份,主要虫源区集中在缅甸中东部,有少数虫源来自印度的因帕尔地区。2008年迁入峰次少,轨迹落点也集中在缅甸中北部。(3)因为地理位置以及气流走向的时空差异,滇西南江城与滇东南西畴两站点迁入的稻飞虱虫源地范围不同。江城的虫源主要由西南气流以及偏西气流携带而至,虫源地范围广阔,整个缅甸、泰国北部以及老挝北部均可提供虫源。相比之下,西畴的迁入虫源主要依靠东南气流运载,虫源地范围小,集中分布在越南北部红河三角洲地区以及靠近我国的边境山区。(4)越南中部与海南岛是2008年钦州4月份稻飞虱迁入种群的直接虫源地。不同时段,不同高度迁入的种群虫源地范围稍有差异,但24h轨迹落点主要集中在越南中部,部分来源于海南岛。4月9日-11日虫源地集中在越南中部、泰国东北部；4月15日-21日的迁入过程受0801号台风“浣熊”外围风圈影响,虫源轨迹散乱,12h落点显示来源于海南岛,24h、35h轨迹则显示来自越南中部。钦州4月份稻飞虱6次大规模的迁入时段与出现高温中心的时段相吻合,早期大气温度的升高对稻飞虱迁入过程有促进作用。(5)2007年与2010年5至6月福建省提前出现的稻飞虱迁入种群虫源地相似,主要来自国内的广东、海南地区,与菲律宾没有虫源交流。低空急流与持续降水的配合是导致稻飞虱集中降落的直接原因。2007年与2010年5-6月份灯下峰日期间,85011Pa高空均对应强大的西南低空急流。而西太平洋副高比往年偏西、偏强,且北跳推迟,使得华南地面准静止锋形成,雨季延长；两广、海南早期田间二代稻飞虱虫源基数增加是这两年福建稻飞虱迁入量增加的最根本原因。主要表现在2007年,2010年两广、海南地区早期一代成虫迁入量大,进而造成两广、海南地区田间二代虫量增加,为后期迁出积累了足够的虫源。2007年与2010年福建省主迁入的稻飞虱虫源主要来自国内的两广、海南地区,与境外虫源鲜有直接交流；虫源地基数增加与持续降雨是其大量降虫的最主要原因。2.泰国中部地区褐飞虱的迁飞路径探讨泰国中部褐飞虱虫源与我国不存在直接交流。(1)3-5月份,泰国上空西南气流频率增加,但因受赤道幅合气流控制,风速普遍小于5m/s,因此中部迁出虫源只能迁入到本国东北部以及老挝中南部地区,无法进入我国；(2)7-8月份,泰国上空偏西的低空急流频繁,迁出种群可以借助高速气流进入中南半岛东部的老挝、越南、柬埔寨等国,还是无法到达我国。(3)11月份,泰国上空以东风、东北风为主,柬埔寨、老挝南部以及越南的种群可以顺风迁入泰国；(4)泰国中部850hpa等压面全年盛行风向以东风、南风、西风为主,在稻飞虱迁飞季节,只有西南风盛行的4-5月份有迁入我国的可能,但因为距离太远,褐飞虱自主飞行能力较弱,此期间低空急流的出现频次很小,故直接迁入我国的概率很低,与我国稻飞虱无直接虫源交流。3.稻飞虱在中南半岛不同地区的迁飞路径根据云南、广西、福建、泰国最近几年稻飞虱早期初始虫源分析结果,结合多年气象风场频率统计,将每年春季可以迁飞进入我国的稻飞虱虫源区进行了划分,结果如下：(1)缅甸是云南白背飞虱初迁入种群的最主要的虫源地,金三角地区位居第二。江城与西畴虫源地范围不同,江城虫源主要来自西南方向,而西畴虫源地范围偏东南。(2)越南中部地区是广西北部湾早期迁入种群的直接虫源地。(3)越南北部红河三角洲地区在每年的5月中、下旬,才成为我国广西、云南的主要虫源地,并由此带来华南地区的主迁峰,与国内虫源衔接。(4)泰国中部地区的虫源与我国没有直接交流,但是与老挝、越南、柬埔寨三个国家间存在直接交流。且泰国中部每年7-8月份随低空急流迁出的褐飞虱种群可以进入越南、老挝定殖为害,其后代第二年春季再进入我国广西,从而实现年际间的虫源交流循环的可能。更多还原

【Abstract】 Rice planthoppper, including brown planthopper (BPH), Nilaparvata lugens (Stal), and white-backed planthopper (WBPH), Sogatella furcifera (Horvath), were major harmful rice pests in Southeast and East Asia, and can migrated long distance, In the past5years, problems from both two species of planthopper have intensified in several countries again, such as China, Thailand, and Vietnam, which cause the huge loss on rice production,In2005, outbreaks of BPH occurrence again in China and other countries of Indochina Peninsula, and the threat cause by BPH continued in the following years, In2007, another worst year on record, severe damage extended in southwest of China specially Yunnan province. In addition, there is mass immigration of WBPH in South Yunnan in2009, not only the light-catches numbers much more than2007, and the main immigration peak time was one month earlier than2007. We want to know Where the WBPH immigrants come from and what reason cause the mass landing in2007&2009.South China suffered the snowing and freezing Disaster in spring,2008, and the north limits of over-winter by WBPH and BPH were in19°, but immigration peak of WBPH appeared in Gulf Qin Zhou (to the south of21.94°N) and Lei Zhou Peninsula (to the south of23.43°N) in lat Mar,2008. And another huge immigration peak was been recorded in Qinzhou Gulf in9to11April,2008.Since1960’s, the records of BPH outbreaks in China and Indochina Peninsula indicated that the time of BPH outbreak appeared simultaneous and temporal delay. We want known if the BPH populations have exchange with the populations of mainland in China.The migration behavior of BPH and WBPH is the key factor that limited the effective management all over the Asia. China lies in temperate area, the over-winter area of BPH and WBPH is little, all infestations at high latitudes because of the immigrants from Indochina Peninsula. The initial source area of WBPH and BPH immigrated into China was remain unclear. After immigration of BPH and WBPH into China in early spring, accurate migration route of BPH and WBPH between rice production areas in China still need to be studied. The oversea source area of WBPH and BPH in China were examined in this paper, including the early migration in Yunnan in2009&2007(chapter2), Qinzhou in2008(chapter3), Fujian in2007&2010(chapter4). In addition, the migration route of WBPH and BPH were been drawn between Indochina Peninsula and South of China.The major findings are as follows:1. the initial resource area of WBPH and BPH in China1) The source areas of early immigration of WBPH from April to May2009in5research spots of Yunnan were studied through the daily light-trap catches, field surveys, immigration trajectory simulation and meteorological background analysis. The results showed:(1) The main source areas of the early immigration of WBPH in2009were located in Myanmar, and the secondary source area was at the Laos and "Vietnam, only a few came from Imphal of India.(2) The ceiling of the threshold temperature of flying WBPH in atmosphere and the wind shear associated with heavy precipitation were the main impact factors for the concentrated landing of WBPH.(3) The high frequency of westerly and the great increasing of rice planting area in the source areas of Myanmar were the principal reasons, which caused the mass immigration of WBPH to Yunnan.2) There are different initial source of WBPH in Jiangcheng between2007and2009. In2007, the largest immigrants’peak appeared in May, and the main source area located in South Myanmar and Golden Triangle. The major immigrants peaks take place in April and came from central Myanmar and north Myanmar in2009. There are small peaks on lamp in2008.3) There are different initial source of WBPH between Jiangcheng and Xichou, in past3years. Jiangcheng lie in southwest of Yunnan province, and mass immigrants were come from Myanmar and Golden Triangle. However, Xichou lie in southeast of Yunnan, and the main source area located in North of Vietnam.4) The central region of Vietnam offered the main numbers of WBPH to Qinzhou, Guangxi Zhuang Autonomous Region on April2008. The12h endpoints of backwards were located in Hainan Island. Only a few endpoints of24h and35h were come from Northeast and north of Thailand. In addition, High temperature was an affected factor for the concentrated landing of WBPH in April2008in Qinzhou.5) Guangdong and Hainan were the main source area of RPH immigration peaks occurred from mid May to June2007and2010, in Fujian province.(1)The mass immigrations have little significant correlation with the original source areas of WBPH. in the Indochina Peninsula, but were triggered by the continuous rainfall and the outbreaking population of the2nd generation RPH in southern China. The earlier mass immigration population of WBPH occurred from mid May to early June of2007and2010had exhibited the similar source area:mostly from Guangdong, and Hainan province, had no trajectory from the southeast, Philippines.(2) The co-occurrence of low-level jet and continuous rainfall directly caused the concentration of the airborne migrants and the mass immigration of WBPH. During the appearance of major immigrants on May to June2007and2010, there were strong southwest low-level jets at850hPa simultaneously. Meanwhile, the West Pacific subtropical high was stronger than normal and extended towards west, and the northern jump of its ridge postponed, that caused the formation of a stationary front in south China and brought the sustained rainfall.(3) The increasing of the population of the2nd generation rice planthoppers in Guangdong, Guangxi and Hainan during mid May to early June in2007and2010was the underlying reason for mass immigration in Fujian province, which was bred by the early-immigration of the1st generation in those source areas in April to early May.2. The study on migration route of BPH in central of Thailand in2009There are no exchange of BPH population between the central Thailand and mainland of China. In March and April, Thailand were controlled by subtropical high-pressure, the wind speed cannot exceed5m/s at850hPa, which have no use to assistant the insect long-migration. In Jun and July, with increasing frequency of low-level jet, the e migrated distance increasing, in July and August. West airflow control the whose Thailand, the emigration population only to south of Laos and central of Vietnam with west airflows. Thus, the generation of the immigrants migrated to South of China next year.3. migration route of BPH and WBPH in Indochina PeninsulaAccording the results of the first five chapters, incorporated the31years statistics data (1979-2009) on airflow directions at850hPa in Indochina Peninsula, we obtain the following conclusions:(1) Myanmar is the most important source area of WBPH immigrated to northwest of Yunnan, and the Golden Triangle region in second place. After mid May, planthopper immigrants occurred in southeast Yunnan were provided by the North Vietnam.(2) The central region of Vietnam is the main source area of Guangxi Zhuang Autonomous Region in March and April.(3) The Red River Delta provided emigration population to main China, such as Yunnan and Guangxi, only in late May.(4) The possibility exists an annual cycle of BPH population between Thailand and China. BPH from Thailand have gene exchange with the ones from Laos, Vietnam and Cambodia, by eastwards airflow in spring and westwards airflow in winter each year. Indirect exchanges of BPH population were occurrences that BPH from Thailand immigrated to Laos, Vietnam during Jun to August each year, and then whose offspring migrated to China in spring in the next year.更多还原