华北三代粘虫大发生虫源的形成

【目的】我国3代粘虫的种群构成还少有研究,华北3代粘虫的虫源问题也不清楚。为此,需厘清3代粘虫发生区的风场动态和迁出种群的去向,为明确各地的虫源关系提供依据。【方法】根据国家气象局的高空气象记录,分析高空风场;利用HYSPLIT平台模拟华北粘虫夏季迁出种群的迁飞轨迹和落点分布。【结果】在夏季风盛行的背景下,3代粘虫主要来自于与其发生区相邻的偏南地区(约占45%),如鲁东、苏皖鄂、浙北、赣北、湘北等;另一个主要来源是西北区(包括晋陕甘宁,约占10%)和华北北部(内蒙古及以北区域,约占7%);在某些年份,西南地区也会提供约6%的虫源。另外,还有约30%的虫源来自于发生区域内的相邻地方,属于当地前代滞留虫源的近距离迁飞;而东北区对华北3代粘虫的虫源构成则只有极微的贡献(约0.2%)。从山西和陕西起飞的1代成虫则主要是北迁,有将近30%的个体迁入了华北3代粘虫发生区,约23%迁入内蒙古及以北地区,还有约4%迁入西北的甘肃宁夏、约5%迁入东北区,另有27.5%的个体近距离迁飞落在本省境内。晋陕种群南向迁飞的比率不大,只有大约10%的个体迁入3代粘虫发生区的南邻区域。【结论】华北3代粘虫的暴发属于小概率事件,如此大范围的潜在虫源和如此局部的发生区,以及复杂的天气系统给我国华北地区3代粘虫的预测预警工作造成了极大的困难,需要研究部门与推广部门通力合作,做更多的实证研究和个例分析,逐渐深化对3代粘虫暴发机制的认识。     

东北迁飞场对粘虫的Pied piper效应

【目的】我国2代粘虫的回迁过程和3代粘虫的种群构成还少有研究,东北与华北3代粘虫的虫源问题也不清楚。为此,需厘清2代粘虫发生区的风场动态和迁出种群的去向,明确东北粘虫夏季迁出种群与华北3代粘虫的虫源关系。【方法】根据国家气象信息中心的高空气象记录,统计东北和华北地区夏季各方位风向的频次和平均出现频率,利用HYSPLIT平台模拟东北粘虫夏季迁出种群的迁飞轨迹和落点分布。【结果】东北和华北地区7、8月的风向均以西南、南风为主且因气旋频繁过境而风向多变,不利于东北粘虫夏季种群回迁进入华北农作区;而对其迁出种群的轨迹模拟结果也表明,东北粘虫夏季种群能够进入华北的可能性极低:它们或迁入更北的无法生存的山区,或未能成功跨海而死亡,抑或迁入朝鲜半岛成为当地的虫源(同样无法越冬),还有一部分滞留东北地区继续为害一代后因气候原因死亡,而只有在极少数风向风速条件适宜的情况下才有可能进入河北。【结论】东北地区的夏季风场不利于东北粘虫的回迁,华北3代粘虫的种群构成与东北夏季种群几无关系,东北迁飞场表现出显著的Pied piper效应。     

东北二代粘虫大发生机制:1978年个例分析

【目的】迁入我国东北地区的粘虫繁殖一代后,新羽化的成虫将外迁他地,但某些年份因某种特殊的天气过程而滞留当地,形成当地的2代种群并造成严重危害,如1978年。阐明种群滞留的关键因子和大发生种群的形成机制,是实现东北2代粘虫准确预测和及时防治的前提。【方法】根据东北三省的虫情资料,利用NCEP/NCAR再分析资料和WRF模式输出的大气背景场,对1978年东北地区粘虫蛾盛期的种群动态和迁飞过程进行逐日分析。【结果】(1)因副热带高压稳定偏北导致发蛾峰期东北地区盛行西南风,东北2代粘虫蛾无法向南回迁至关内华北地区,而是向北迁飞;(2)当年黑龙江2代粘虫大发生,其虫源是由当地1代羽化后在当地的存留或迁出成虫蛾又折返黑龙江以及辽宁与吉林两省2代成虫的迁入造成;(3)蛾峰期黑龙江上空气旋的频繁活动、强对流天气的持续出现以及丰富的降水是造成当地虫源滞留和迁入虫源降落与滞留的原因。【结论】东北1代粘虫蛾迁出期的西南大风和大范围强降水使大量迁出种群和过境种群集中滞留在三江平原而形成大发生种群,造成东北2代粘虫1978年在黑龙江的暴发。     

我国粘虫发生概况:60年回顾

本文总结了我国1950—2013年粘虫Mythimna separata(Walker)发生、防治和损失概况,揭示了60余年中我国粘虫种群数量动态的演化规律。(1)南方地区越冬代种群发生年代间有波动,江淮1代发生区为害减轻,东北、华北、黄淮、西北和西南等2、3代发生区发生加重。(2)2代粘虫为发生最为广泛的1代,1995年以来粘虫主要危害作物已由小麦变为玉米。(3)寄主作物种植面积对种群数量总体变动起重要作用,气候条件影响年度间和区域间的种群波动和变化,农田生境影响小区域的发生危害程度。     

高空测报灯监测粘虫区域性发生动态规律探索

【目的】为探索粘虫Mythimna separata Walker成虫种群监测的有效工具。【方法】2014年在全国17个省(市、区)设立了19个高空测报灯观测点,通过各地全年系统监测逐日蛾量。【结果】掌握了粘虫全年南北往返迁飞的种群发生动态,总结出了粘虫全年发生代次(时间)、发生区域和发生数量。【结论】高空测报灯诱测数据反映了粘虫各代次发生时间规律,反映了粘虫种群数量变动规律,体现出区域间种群数量相关性,种群数量变动关系密切的因子有待探讨。此方法为做好其他迁飞性害虫的监测提供了可借鉴的手段和方法。     

三代粘虫成虫迁飞的雷达观测与分析

【目的】明确2015年吉林省3代粘虫Mythimna separata(Walker)成虫的迁飞动态,揭示3代粘虫成虫自东北向南迁出的动向及成功迁出的概率,为粘虫的预测预报及综合治理提供科学依据。【方法】基于扫描昆虫雷达观测,采用田间饲育、诱蛾器监测、轨迹模拟及天气背景学分析等研究方法,分析3代粘虫成虫迁飞动态及迁出概率。【结果】(1)3代粘虫蛾可交尾及产卵,卵亦可孵化,但幼虫发育迟缓。(2)3代粘虫蛾数量相比于一代增长了10.3倍,成虫卵巢发育级别集中于1级,大多未交尾,处于从本地迁出的状态。(3)迁出期的风向以南风、西南风、东南风为主,不利于粘虫回迁至南方的越冬区域。(4)共有3 d的调查日观测到了粘虫聚集成层的迁飞现象。轨迹分析显示,极大比率的粘虫种群最终去向集中于观测点公主岭以北的区域或者朝鲜境内。【结论】3代粘虫受制于秋季风场无法成功回迁,成为了Pied-piper效应的牺牲者,无法为2016年春季粘虫的发生提供有效虫源。     

粘虫迁飞的种群动态监测与夜间扑灯节律研究

【目的】明确北京北部山区粘虫Mythimna separata(Walker)的种群动态和扑灯规律,探索粘虫的早期监测预警技术。【方法】2011年,在北京延庆利用时控开关控制探照灯诱虫器对粘虫的种群动态进行监测,并对整夜诱虫数量自动分时段取样。获得逐日种群动态数据和相关的生物学参数,使用Grads分析粘虫数量与空中风场的关系。【结果】全年诱集粘虫蛾9 699头,单日诱蛾最高1 366头。全年诱蛾可分为3个世代,各个世代种群均由多个高峰组成,并非陆续增加。性比分析发现雌虫数量显著多于雄虫。分时段数据显示粘虫整夜的扑灯节律可分为迁入型、迁出型或本地繁殖型、过境型和迁入迁出混合型。风场分析表明,诱虫高峰与空中风场偏南气流的频率与持续时间高度一致。【结论】北京延庆全年发生粘虫3个世代,二代幼虫造成的危害最大。一代和二代诱蛾数与空中是否存在偏南气流密切相关。雌虫可能具有更强的迁飞能力。对粘虫扑灯节律数据深入分析,可为迁飞种群是否在本地降落繁殖提供参考依据。     

粘虫的秋季回迁:2012-2013年大发生年个例分析

【目的】考察粘虫Mythimna separata (Walker)秋季回迁过程,阐释粘虫在我国东部地区迁飞的周年循环,分析粘虫大发生的原因,提取粘虫暴发的预警参数。【方法】利用欧洲中期天气预报中心(ECMWF)的气象数据,分析9月份我国925hPa高度的迁飞场,用NOAAHYSPLIT平台模拟长岛2010-2013年间过境3代粘虫的回迁过程。【结果】9月份华北低空通常存在一个中心位于鲁西的冷高压,高压西侧的南向风和北侧的西向风导致秋季迁飞场环境不利于北方粘虫的秋季回迁而形成明显的Pied Piper效应。但在2011和2012年9月,冷高压中心明显偏西,我国东部北向风频次大大增加;轨迹分析表明,过境长岛的秋季回迁粘虫分别有20%(2011年)和5%(2012年)的迁飞日能回到30°N以南;北方粘虫成功回迁到越冬区的比率提高,为2012-2013年粘虫的暴发提供了相应的虫源基数。【结论】华北秋季的迁飞场以北向风和西向风为主而不利于粘虫的秋季回迁,只在9月冷高压偏西的年份,大陆东部盛行偏北风,粘虫成功回迁到南方越冬区的成功率较高,为翌年粘虫大发生种群的形成奠定虫源基础。因此,秋季高压中心的位置可作为翌年粘虫大发生的早期预警指标。     

东北二代粘虫大发生机制:1980年个例分析

【目的】1980年东北地区1代粘虫在黑龙江大发生,1代成虫羽化盛期也诱到大量的粘虫蛾,但2代粘虫在黑龙江省却并没有大发生,而在吉林省大发生。那么,黑龙江1代成虫迁往何处?吉林省2代粘虫大发生虫源又来自何方?本文通过解析1980年东北粘虫1代成虫的迁入迁出动态和大发生种群的形成过程,为粘虫间歇性猖獗的预测和治理提供依据。【方法】基于WRF模式输出的高分辨率大气背景场,通过轨迹分析和天气学背景分析,阐释1980年东北粘虫1代蛾盛期的发生过程和迁飞动态及其大发生种群的形成机制。【结果】1980年吉林省1代粘虫蛾盛期受东北气旋降水的影响,1代成虫无法成功外迁而滞留,加之从黑龙江迁出的粘虫蛾南迁过程中亦遇雨而迫降吉林,最终导致当年吉林2代粘虫的暴发。此外,由于副热带高压位置偏南,高压中心7月第6候南移到东北平原而盛行偏北气流,辽宁省有一定比例的南迁粘虫蛾能跨海进入山东、河北。【结论】无法成功外迁而滞留(包括迁出后由于轨迹回旋或天气迫降等最终仍在东北境内降落)是东北2代粘虫暴发的根本原因。     

东亚地区低层大气环流季节性变化与粘虫远距离迁飞

我国位于盛行的东亚季风区域内,季节变化明显。粘虫(Mythimna separata Walker)远距离北迁南回,与东亚地区低层大气环流季节性变化有着密切的关系。因此根据诱蛾资料和气象观测记录,着重对我国粘虫的迁飞方向、迁飞高度、迁飞界限、起飞降落条件以及虫源基地等问题进行分析,绘制我国粘虫迁飞路径图,是十分必要的。     

On the origin of the Hirudinea and the demise of the Oligochaeta

The phylogenetic relationships of the Clitellata were investigated with a data set of published and new complete 18S rRNA gene sequences of 51 species representing 41 families. Sequences were aligned on the basis of a secondary structure model and analysed with maximum parsimony and maximum likelihood. In contrast to the latter method, parsimony did not recover the monophyly of Clitellata. However, a close scrutiny of the data suggested a spurious attraction between some polychaetes and clitellates. As a rule, molecular trees are closely aligned with morphology-based phylogenies. Acanthobdellida and Euhirudinea were reconciled in their traditional Hirudinea clade and were included in the Oligochaeta with the Branchiobdellida via the Lumbriculidae as a possible link between the two assemblages. While the 18S gene yielded a meaningful historical signal for determining relationships within clitellates, the exact position of Hirudinea and Branchiobdellida within oligochaetes remained unresolved. The lack of phylogenetic signal is interpreted as evidence for a rapid radiation of these taxa. The placement of Clitellata within the Polychaeta remained unresolved. The biological reality of polytomies within annelids is suggested and supports the hypothesis of an extremely ancient radiation of polychaetes and emergence of clitellates.     

On the ontogeny of the haptor and the evolution of the Monogenea

Data on the ontogeny of the posterior haptor of monogeneans were obtained from more than 150 publications and summarised. These data were plotted into diagrams showing evolutionary capacity levels based on the theory of a progressive evolution of marginal hooks, anchors and other attachment components of the posterior haptor in the Monogenea (Malmberg, 1986). 5 + 5 unhinged marginal hooks are assumed to be the most primitive monogenean haptoral condition. Thus the diagrams were founded on a 5 + 5 unhinged marginal hook evolutionary capacity level, and the evolutionary capacity levels of anchors and other haptoral attachement components were arranged according to haptoral ontogenetical sequences. In the final plotting diagram data on hosts, type of spermatozoa, oncomiracidial ciliation, sensilla pattern and protonephridial systems were also included. In this way a number of correlations were revealed. Thus, for example, the number of 5 + 5 marginal hooks correlates with the most primitive monogenean type of spermatozoon and with few sensillae, many ciliated cells and a simple protonephridial system in the oncomiracidium. On the basis of the reviewed data it is concluded that the ancient monogeneans with 5 + 5 unhinged marginal hooks were divided into two main lines, one retaining unhinged marginal hooks and the other evolving hinged marginal hooks. Both main lines have recent representatives at different marginal hook evolutionary capacity levels, i.e. monogeneans retaining a haptor with only marginal hooks. For the main line with hinged marginal hooks the name Articulon-choinea n. subclass is proposed. Members with 8 + 8 hinged marginal hooks only are here called Proanchorea n. superord. Monogeneans with unhinged marginal hooks only are here called Ananchorea n. superord. and three new families are erected for its recent members: Anonchohapteridae n. fam., Acolpentronidae n. fam. and Anacanthoridae n. fam. (with 7 + 7, 8 + 8 and 9 + 9 unhinged marginal hooks, respectively). Except for the families of Articulonchoinea (e.g. Acanthocotylidae, Gyrodactylidae, Tetraonchoididae) Bychowsky's (1957) division of the Monogenea into the Oligonchoinea and Polyonchoinea fits the proposed scheme, i.e. monogeneans with unhinged marginal hooks form one old group, the Oligonchoinea, which have 5 + 5 unhinged marginal hooks, and the other group form the Polyonchoinea, which (with the exception of the Hexabothriidae) has a greater number (7 + 7, 8 + 8 or 9 + 9) of unhinged marginal hooks. It is proposed that both these names, Oligonchoinea (sensu mihi) and Polyonchoinea (sensu mihi), will be retained on one side and Articulonchoinea placed on the other side, which reflects the early monogenean evolution. Except for the members of Ananchorea [Polyonchoinea], all members of the Oligonchoinea and Polyonchoinea have anchors, which imply that they are further evolved, i.e. have passed the 5 + 5 marginal hook evolutionary capacity level (Malmberg, 1986). There are two main types of anchors in the Monogenea: haptoral anchors, with anlages appearing in the haptor, and peduncular anchors, with anlages in the peduncle. There are two types of haptoral anchors: peripheral haptoral anchors, ontogenetically the oldest, and central haptoral anchors. Peduncular anchors, in turn, are ontogenetically younger than peripheral haptoral anchors. There may be two pairs of peduncular anchors: medial peduncular anchors, ontogentically the oldest, and lateral peduncular anchors. Only peduncular (not haptoral) anchors have anchor bars. Monogeneans with haptoral anchors are here called Mediohaptanchorea n. superord. and Laterohaptanchorea n. superord. or haptanchoreans. All oligonchoineans and the oldest polyonchoineans are haptanchoreans. Certain members of Calceostomatidae [Polyonchoinea] are the only monogeneans with both (peripheral) haptoral and peduncular anchors (one pair). These monogeneans are here called Mixanchorea n. superord. Polyonchoineans with peduncular anchors and unhinged marginal hooks are here called the Pedunculanchorea n. superord. The most primitive pedunculanchoreans have only one pair of peduncular anchors with an anchor bar, while the most advanced have both medial and lateral peduncular anchors; each pair having an anchor bar. Certain families of the Articulonchoinea, the Anchorea n. superord., also have peduncular anchors (parallel evolution): only one family, the Sundanonchidae n. fam., has both medial and lateral peduncular anchors, each anchor pair with an anchor bar. Evolutionary lines from different monogenean evolutionary capacity levels are discussed and a new system of classification for the Monogenea is proposed.In agreeing to publish this article, I recognise that its contents are controversial and contrary to generally accepted views on monogenean systematics and evolution. I have anticipated a reaction to the article by inviting senior workers in the field to comment upon it: their views will be reported in a future issue of this journal. EditorIn agreeing to publish this article, I recognise that its contents are controversial and contrary to generally accepted views on monogenean systematics and evolution. I have anticipated a reaction to the article by inviting senior workers in the field to comment upon it: their views will be reported in a future issue of this journal. Editor