【作者】 黄绍哲；

【导师】 罗礼智；

【作者基本信息】 中国农业科学院 ， 农业昆虫与害虫防治， 2010， 博士

【摘要】 草地螟, Loxostege sticticalis Linnaeus (鳞翅目:螟蛾科)是我国北方农牧业生产的一种重大害虫。在长期适应北纬36°-53°的狭长地带的干旱和寒冷气候带中形成的迁飞和滞育两种重要的生活史对策,是草地螟能够在这些地区生存并且其种群动态经常发生变化的主要原因之一。因此,研究揭示草地螟种群的时空动态规律,无论是对于促进草地螟相关研究邻域的发展,还是对于改善和提高草地螟的预测预报和防治技术水平,减少草地螟造成的灾害损失,均具有十分重要的理论和实践意义。本文在认真总结分析了我国草地螟的发生危害特征、国内外已有研究进展的同时,针对国内外对草地螟种群时空动态规律研究比较薄弱的现状,采用种群生态学方法及原理,并结合地理统计分析方法和地理信息系统(GIS)的应用,对我国1953-2008年草地螟种群的时间动态特征、大发生种群的空间分布特征及影响因素,我国与俄罗斯及蒙古国草地螟大发生的虫源关系等开展较全面和系统的研究,取得了一些原创性结果,主要的为:明确了我国草地螟种群动态具有周期性大发生的特点,大发生类型属于周期性勃发式,且草地螟的大发生特征与研究尺度或涉及的范围紧密相关。对全国草地螟幼虫种群、内蒙自治区幼虫种群和农区幼虫种群,以及河北康保县一代幼虫种群和农区一代幼虫种群,河北康保县草地螟成虫种群进行自相关分析和相空间轨迹分析的结果表明:在1953-2008年间,全国和内蒙自治区尺度上草地螟的大发生均表现出周期性的特点,即1953-1959,、1978-1984和1996-2008三个大发生周期,其大发生类型均属于周期性勃发式大发生,而在1996-2008大发生周期内则呈现出了持续性勃发式大发生和周期性的特征;在康保县范围内,草地螟种群的时间种群动态规律则相对比较复杂,仅农区一代幼虫种群表现出周期性勃发式大发生的特点,而草地螟幼虫种群和成虫种群则无明显的自相关性。这些结果表明,草地螟种群时空动态规律与涉及的范围或研究的尺度紧密相关。因此,无论是对草地螟种群动态规律的研究、还是对草地螟预测预报和监控工作的开展均应尽可能从大尺度着手。在研究明确了环境温湿度是影响我国草地螟种群动态规律的主要环境因子的同时,研究比较了华北和东北地区草地螟的种群动态规律,明确了华北地区越冬种群是东北地区草地螟大发生的主要虫源之一。在研究明确了成虫盛发期的环境温湿度可以显著影响成虫种群和次代幼虫种群空间分布格局的基础上,确定了在成虫盛发期湿度大于44%,环境温度在19°C-25°C的区域内,幼虫的大发生显著高于其他区域。所得的研究结果还表明,由于华北和东北地区地理及环境条件的差异,特别是一代幼虫大发生期间的7月上中旬环境温度的影响,华北地区一、二代幼虫均可以滞育形成次年的越冬虫源,而东北地区仅在二代幼虫大发生年才有数量较多的越冬虫源。另外,华北地区草地螟越冬代成虫,在适当的环境条件下,在盛发期主导的西南气流携带下,可迁往东北地区,形成东北地区发生危害的主要虫源。在研究揭示了中国、俄罗斯亚洲部分和蒙古国的草地螟大发生具有高度同步性的同时,研究明确了在这三国相邻的草地螟区域内,存在着有利于越冬代和一代草地螟成虫从俄罗斯东西伯利亚地区和蒙古国东部地区向我国华北和东北地区迁入的高空气流,而大量一代成虫从俄罗斯东西伯利亚地区和蒙古国东部地区的迁入是我国2008年二代幼虫大发生的主要原因。应用相位分析对我国、俄罗斯及蒙古草地螟大发生历史进行分析的结果表明,在1978～1984年期间,中国和蒙古,中国和俄罗斯远东地区,中国和俄罗斯东、西西伯利亚地区的草地螟同步大发生年份分别为4,3,1和5年,在1985～1995年间草地螟处于同步低发期的年份分别为9,11,9和8年,而在1996～2008年的草地螟同步发生年份分别为2,4,8,11年,表明这些区域内的草地螟种群具有密切的关系;对草地螟越冬代和一代成虫盛发期间中国海拉尔,俄罗斯赤塔,蒙古乔巴山三地草地螟迁飞高度(850hPa)的高空风向分析表明,这些区域内的高空盛行西北风,有利于草地螟成虫从俄罗斯东西伯利亚地区和蒙古国东北向我国的华北和东北地区迁入;对2008年这三个国家的一代草地螟成虫盛发期的风场和迁飞轨迹进行分析的结果表明,2008年我国二代幼虫大发生的虫源系来自俄罗斯东西伯利亚地区和蒙古国东部地区,以及中俄和中蒙边境地区一代草地螟成虫。因此,我国草地螟大发生虫源与俄罗斯西伯利亚地区和蒙古国的有密切的联系。这些首次获得的结果为改善和提高草地螟的监测、预报和防治水平提供了重要的科学依据。研究明确了我国草地螟大发生成虫种群,越冬幼虫在大尺度空间范围内具有聚集分布的特点,且存在着明显的空间各向异性。运用地理统计方法,对我国草地螟大发生成虫种群和越冬幼虫的半方差函数进行结构分析,并基于半方差函数模型拟合,对各变量的空间分布进行克立格估计,结果表明:我国草地螟大发生成虫种群和由其产生的越冬幼虫均呈聚集分布,且具有明显的空间各向异性,半方差函数的变程分别为153.18～407.37公里,137.64～293.04公里,主变程方向分别为63.2°和65.5°,而其块金系数分别为0.11和0.45。二者的主要聚集方向集中在西南至东北方向上,且大发生期的成虫种群的聚集程度和最大相关范围亦明显高于越冬幼虫。而越冬幼虫的空间分布与前人的研究结果一致,但是次要越冬区的基数有明显的上升趋势。这些结果表明,草地螟在我国主要发生区范围内呈明显的聚集分布,主要的聚集方向为西南至东北方向,而由于成虫具有较强的迁飞能力,因此在空间分布上表现出更大的聚集范围。本文的主要创新点:1)应用自相关分析和相空间轨迹分析方法,首次确定了我国草地螟种群55年时间序列动态规律并具有周期性大发生规律的同时,进一步明确了我国草地螟大发生种群动态规律与涉及的尺度紧密相关:涉及的范围越广,成虫和幼虫的自相关关系均越密切;2)在研究明确了我国草地螟的发生危害程度主要受环境温湿条件影响的基础上,首次分析比较了我国华北和东北两大主要草地螟发生危害区的草地螟种群动态规律及虫源关系:华北地区的越冬代成虫羽化后可以随着气流迁飞到东北地区,因此华北地区也是东北地区的主要虫源地之一。3)通过对中国,俄罗斯和蒙古国的草地螟大发生同步性,三国相邻区域的高空气流条件,以及2008年我国一代成虫和二代幼虫大发生的虫源的科学分析,确定了俄罗斯的亚洲部分以及蒙古国的草地螟也是我国草地螟大发生的主要虫源。4)运用地理统计学方法对我国草地螟大发生成虫和越冬幼虫的空间分布格局进行了结构分析,首次明确了我国草地螟具有聚集分布的特点,且成虫的聚集程度高于越冬幼虫,而二者的聚集方向均为西南至东北方向。更多还原

【Abstract】 The beet webworm, Loxostege sticticalis Linneaus (Lepidoptera: Pyralidae) is one of the most destructive pests of crops and fodder plants in northern China. It survived maily in a long belt zone between 36°N-53°N and the population dynamic offen changed dramatically due to the two important life history strategies obtained by L. sticticalis: migration and diapause, adapted to the dry and cold climate in this area. Thus, understanding of the spatiotemporal dynamics was of great importance in improving the forcasting and control of beet webworm outbreaks. As the spatiotemporal dynamic were poorly understood, systematic studies were conducted to the population dynamics of beet webworm in China during 1953-2008, spatial distribution of outbreak population and affecting factors, and outbreak source relationship between China, Russian and Mongolia, using population ecology and geostatistic methods and geographic information system. The major progresses obtained were summarized as follows:Beet webworm outbreak in China was characterized with periodicity, and the outbreaks were classified as periodic eruption, while the outbreak characters were colosely related to spatial scale investigated. Basing autocorrelation and phase trajectory analysis of larvae population in national, Inner Mongolia, farming area in Inner Mongolia, Kangbao county of Hebei province, and farming area in Kangbao county of Hebei province, and adult population in Kangbao county of Hebei province, results showed that beet webworm outbreaks at national and Inner Mongolia scale were characterized with periodicity during 1953-2008, and outbreaks were classified as periodic eruption, including three outbreak periods 1953-1959, 1978-1984, 1996-2008. Beet webworm population dynamic at county level became more complicated, larvae population in farming area of Kangbao county of Hebei province were characterized with periodicity and classified as periodic eruption, while no significant autocorrelation were found in larvae population and adult population at Kangbao county of Hebei province. These results indicated that spatialtemporal population dynamic of beet webworm were closely related to spatial scales investigated, thus, discussion on spatialtemporal population dynamic of beet webworm and its monitoring and forecasting application should carried out at macro scale. Spatial population dynamics of beet webworm in China were greatly affected by environmental temperature and relative humidity, and overwintering population at northern China was one of the major sources of beet webworm outbreak at northeastern China.Environmental temperature and relative humidity could greatly affect the spatial distribution of adult population and consequent larvae population, serious outbreak of larvae happened in areas with temperature ranged 19°C-25°C and relative humidity higher than 44% during adult outbreak. The first and second generation larval population can overwintered as diapause larvae in northern China, while only the second generation larvae can overwintered as diapause larvae in northeastern China, and this was mainly because of environment variation, especially the temperature during 1 July to 20 July, serious outbreak period of the first generation larvae. Overwintering generation adults would migrate into northeastern areas and cause consequent serious outbreaks, when unfavorable environmental conditions and favorable southwest air flow happened.Beet weebworm outbreaks in China, Asia part of Russia and Mongolia were highly synchronized and wind direction by migration hight of beet webworm in the neighbouring areas favored the adults of overwintering and 1st generation migrated from eastern Siberia of Russia and eastern Mongolia into northern and northeastern China, and 1st generation adult population migrated from eastern Siberia of Russia and eastern Mongolia were responsible for the serious outbreaks of 2nd generation larvae in China in 2008. Phase analysis showed that the synchornized outbreak years between China and Mongolia, China and Far East, China and western and eastern Siberia of Russia were 4, 1, 3 and 5 years from 1978 to 1984, and 2, 4, 8 and 11 years from 1996 to 2008 by phase analysis, while synchronized nonoutbreak years between China and Mongolia, China and Far East, China and western and eastern Siberia of Russia were 9, 11, 9 and 8 years, indicating that migration taken by adult L. sticticalis were the possible cause for the synchronized outbreaks in these areas. Furthermore, the analysis of wind system by the height where the migration of adult L. sticticalis usually occur showed that possibility of northwestern wind in Haila’er (China), Chita (Russia) and Choybalsan (Mongolia) was high, which favored the adults migrate successfully from these areas to northern and northeastern China during its reproductive seasons. Finally, the larvae of the second generation infested an area of 11 million hectares at extremely high density in Northern China, although the crop damaged by the first generation larvae with low density was only 700 thousand hectares in 2008. Results of wind field and trajectory analysis showed that the source of the first-generation adults, which caused severe outbreak of second generation larvae, was tracked back to eastern Siberia of Russia, eastern Mongolia, and the boundary regions of China-Russia and China-Mongolia. All these results suggested that the outbreak source of L. sticticalis in northern China were closely related to outbreak populations in Siberia of Russia and Mongolia, via long distance windborne migration of L. sticticalis with the help of frequent northwestern wind. The results firstly reported here will greatly improve the mornitoring, forcasting and control of beet webworm population.Adult population and overwintering larvae populations of beet webworm in China belonged to the aggregated distribution, and evident spatial anisotropy were detected. Geostatistical analysis was applied to adult population and overwintering larvae population, results showed that they were charaterized with aggregated distribution and spatial anisotropy were detected. The rages of the semivariograms were 153.18-407.37 kilometers and 137.64-293.04 kilometers respectively, and the direction of major range were 63.2°, 65.5°respectively, and the nugget coefficient were 0.11, 0.45, showing that the aggregated intensity and maximum correlated range of adult population were higher than that of overwintering larvae population. Kriging prediction map also showed that the spatial distribution of overwintering larvae was similar to former reports, but the density in secondary overwintering area grew markedly. These results indicated that beet webworm populations were spatially aggregated and the main aggregation directions were southwest to northeast, and the aggregation range of adults were higher than larvae, mainly due to higher migration mobality.The major innovative discoveries in this disertation were as follows:1) Longterm population dynamic patterns of beet webworm in China were analyzed with autocorrelation and phase trajectory, results showed that population dynamic pattern were characterized with periodicity during the past 55 years, and the population dynamic pattern were found to be closely related to the spatial scale investigated. The autocorrelation level increased as the spatial scale expanded.2) As the outbreak level of beet webworm in China were proved to be closely related to the environmental temperature and relative humidity in this study, the spatial population dynamic pattern of beet webworm population in northern and northeastern China were firstly studied. Results showed that the overwintering generation adults in northern China can migrate into northeastern China with the help of favorable air flow, thus the overwintering population in northern China served as an important source area to beet webworm outbreaks in northeastern China.3) Basing on phase analysis, wind direction condition analysis and outbreak souce analysis of 1st generation adusts and 2nd generation larvae of beet webworm in China in 2008, outbreak population at Asian part of Russia and Mongolia were proved to be one of the major source areas responsible for beet webworm outbreak in China.4) Basing on geostatistical analysis of beet webowrm adults and overwintering larvae populations, the spatial distribution pattern of beet webowrm population in China was firstly proved to be aggregation, and the aggregation intensity of adults were higher than that of overwintering larvae, both their main aggregation directions were southwest to northeast.更多还原