我国粘虫研究现状及发展趋势

粘虫Mythimna separata(Walker)是一种典型的季节性远距离迁飞害虫,也是我国及其它亚洲和澳洲国家粮食作物上重大害虫。具有发生范围广、危害世代多、受害作物种类和组织多、产量损失重以及发生危害历史长的特点。我国粘虫的研究进展主要体现在以下四个方面:揭示了粘虫越冬、迁飞及发生危害规律;解析了粘虫迁飞行为发生与调控的环境、生理、遗传、激素与分子机制;创建了以越冬、迁飞规律及生物学习性为基础的粘虫监测预警技术;组建了粘虫区域综合治理技术体系。针对粘虫研究现状及存在的问题,结合现代昆虫学技术的发展,提出了今后粘虫研究的主要方向。     

稻飞虱种群发生的调查与取样技术

稻飞虱是中国和许多国家水稻生产上的主要害虫,属r对策暴发危害类型。其中,褐飞虱和白背飞虱是典型的远距离迁飞性害虫,具有大区域同期"突增"和"突减"的灾变特性;灰飞虱则主要以本地越冬为主,远距离迁飞对种群结构的影响较小,但其传播的病毒病对水稻生产的影响更甚。针对3种稻飞虱的生物学特性,本文发展了稻飞虱田间种群发生与危害等的调查与取样技术,为其种群发生及其监测预警提供技术支撑。     

粘虫生殖与迁飞

解放以来,各有关单位在各级党组织领导下密切协作,对粘虫的发生危害规律进行了广泛研究,采用标记回收、海面捕蛾以及对各地粘虫资料的分析研究,基本上明确了粘虫的越冬和远距离随季节性南北在返迁飞等危害规律。 卵、幼虫、蛹、成虫四个虫期所能忍受的最高最低温度幅度在5—35℃之间,一般要求的适宜相对湿度在50—95％之间,高于或低于这个温湿度范围,生长均不良,甚至可引起死亡。所以从粘虫个体发育特点看,在幼虫期或蛹期遭受不利因子的刺激后,到了成虫期一定要迁飞转移,选择适宜的生活地区来避免冬季严寒与夏季高温高湿等不利因子的袭击。从生殖生物     

粘虫在贵州成功越冬的实证

粘虫Mythimna separata(Walker)是一种典型的季节性远距离迁飞害虫,也是我国及其它亚洲和澳洲国家粮食作物上重大害虫。贵州省地处我国西南部,是二代粘虫的常年发生地,但有关粘虫在贵州的越冬问题未有详细报道。为探明粘虫是否可以在贵州越冬,本文对2日龄蛹过冷却点,耐低温能力进行了测定,并在田间进行了越冬笼罩实验和越冬调查试验。结果表明,粘虫的过冷却点为-14.95℃,结冰点为-9.52℃。低温和暴露时间对粘虫的存活率具有显著影响。在10℃下处理30 d后,其存活率高达96.5%,处理90 d后仅有5%个体存活。但在-5℃下处理0.5 h后的存活率为80.00%,而处理8 h就全部死亡。田间笼罩试验结果发现2日龄蛹的存活率随埋蛹时间延长而降低,但至100 d仍有46.67%个体存活;同时,越冬调查发现少量的蛹和老熟幼虫,包括1头老熟幼虫和29头蛹。这些结果表明,粘虫可以以老熟幼虫和蛹等虫态在贵州低海拔地区成功越冬。     

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。     

湖北省钟祥市粘虫发生规律研究

为了明确粘虫Mythimna separata(Walker)在湖北省钟祥市的发生规律,对小麦玉米轮作田粘虫成虫和幼虫种群的发生动态、粘虫雌蛾卵巢发育进度以及粘虫越冬虫量作了调查,分析了粘虫种群虫源性质。结果表明,钟祥市为1代粘虫多发区,其虫源为外地迁入的越冬代成虫,1代粘虫危害高峰期在4月中下旬,羽化盛期在5月中下旬,羽化后以迁出为主。第2代粘虫发生量很小,羽化后基本全部迁出;在田间未调查到第3代粘虫幼虫,本区发现的第3代成虫可能为由北方南迁的过境种群;第4代粘虫发生量也很小,羽化后全部迁出,不在本区繁殖危害。在田间未调查到准备越冬的粘虫。     

湖北省钟祥市粘虫发生规律研究

为了明确粘虫Mythimna separata(Walker)在湖北省钟祥市的发生规律,对小麦玉米轮作田粘虫成虫和幼虫种群的发生动态、粘虫雌蛾卵巢发育进度以及粘虫越冬虫量作了调查,分析了粘虫种群虫源性质。结果表明,钟祥市为1代粘虫多发区,其虫源为外地迁入的越冬代成虫,1代粘虫危害高峰期在4月中下旬,羽化盛期在5月中下旬,羽化后以迁出为主。第2代粘虫发生量很小,羽化后基本全部迁出;在田间未调查到第3代粘虫幼虫,本区发现的第3代成虫可能为由北方南迁的过境种群;第4代粘虫发生量也很小,羽化后全部迁出,不在本区繁殖危害。在田间未调查到准备越冬的粘虫。     

我国粘虫发生危害新特点及趋势分析

粘虫Mythimna separata是我国玉米、小麦和水稻三大主粮作物上的重大害虫,对我国粮食安全有重大威胁,每年在我国南北往返迁飞危害。近年来,粘虫在我国的发生危害呈现出新的特点,主要体现为:一是受害严重区域发生变化,各世代危害范围扩大;二是主要危害世代发生变化,2代、3代粘虫发生较重;三是主害作物发生变化,玉米成第一大危害作物;四是迁飞规律发生变化,南北往返迁飞格局不变;五是田间种群抗药性明显增强,防治困难程度加重;六是生物学习性发生变异,适应能力增强。针对以上发生危害新特点的形成原因和未来趋势进行了分析与讨论。     

粘虫雌蛾求偶周期和性信息素含量变化规律

粘虫岭thimnaseParata是发生在中国和日本的一种季节性迁飞害虫,由于其远距离迁飞习性,往往造成暴发性的危害。由于粘虫性成熟在迁飞过程中完成,人们研究较多的是有关粘虫迁飞习性与性成熟的关系［”。Johnson提出了卵子发生与飞行综合症（oogenesis－flightsyndrome）假说,认为许多昆虫的迁飞发生在生殖前期,即成虫羽化后到产卵前这段时期‘”。在有关粘虫雌蛾求偶一交配一繁殖一产卵一系列生殖行为研究中,Han等采用了求偶前期（Pre－callingPeriod,PCP）指标,即成虫羽化到释放性信息素这段时间”’。因为当时没有确定粘虫性信…     

农业害虫跨越渤海的迁飞规律与控制策略

迁飞是农业害虫适应环境变化、保障种群繁衍的季节性转移为害策略。受东亚季风气候的影响,农业害虫在中国迁飞致灾问题十分严重。我们自2003年起,在农业昆虫自华北及其以南地区迁入东北地区的必经之地,位于渤海中间的山东省长岛县北隍城岛(38°24′N;120°55′E),系统监测研究了迁飞昆虫的种类组成、群落结构、种群动态、生理生化特征和季节性迁飞规律。研究表明,跨越渤海迁飞的昆虫种类有9目36科120余种,以棉铃虫Helicoverpa armigera (Hübner)、粘虫Mythimna separate (Walker)等鳞翅目害虫为优势种类。多数种类呈现迁飞性昆虫的生理生化特征,春季和夏初种群多数个体卵巢发育成熟、交配基本完成,显示迁飞末期的生殖特征,夏末和秋季种群卵巢尚未发育、交配率低,显示迁飞初期的生殖特点。对迁飞路径的分析表明,迁飞类型可分为以亚洲玉米螟Ostrinianubilalis(Hübner)和绿盲蝽Apolyguslucorum (Meyer-Dür)为代表的单个夜晚为主的近距离迁飞,其迁移距离多在200 km以内;以棉铃虫Helicoverpa armigera (Hübner)和二点委夜蛾Athetis lepigone (M?schler)为代表的1-2个夜晚为主的中距离迁飞,其迁移距离多在500km以内;以及以小地老虎Agrotisypsilon(Rottemberg)和粘虫Mythimna separate (Walker)为代表的多个夜晚的远距离迁飞,其迁移距离多远于500 km。文中基于这些害虫的迁飞生物学特征和迁飞规律,提出了以"阻断成虫迁飞过程"为核心的防控策略。     

Causality, randomness, intelligibility, and the epistemology of the cell

Because the basic unit of biology is the cell, biological knowledge is rooted in the epistemology of the cell, and because life is the salient characteristic of the cell, its epistemology must be centered on its livingness, not its constituent components. The organization and regulation of these components in the pursuit of life constitute the fundamental nature of the cell. Thus, regulation sits at the heart of biological knowledge of the cell and the extraordinary complexity of this regulation conditions the kind of knowledge that can be obtained, in particular, the representation and intelligibility of that knowledge. This paper is essentially split into two parts. The first part discusses the inadequacy of everyday intelligibility and intuition in science and the consequent need for scientific theories to be expressed mathematically without appeal to commonsense categories of understanding, such as causality. Having set the backdrop, the second part addresses biological knowledge. It briefly reviews modern scientific epistemology from a general perspective and then turns to the epistemology of the cell. In analogy with a multi-faceted factory, the cell utilizes a highly parallel distributed control system to maintain its organization and regulate its dynamical operation in the face of both internal and external changes. Hence, scientific knowledge is constituted by the mathematics of stochastic dynamical systems, which model the overall relational structure of the cell and how these structures evolve over time, stochasticity being a consequence of the need to ignore a large number of factors while modeling relatively few in an extremely complex environment.     

Parallelism,parsimony, and the phytogeny of the lemuridae

In spite of the increasing popularity of cladistic methods in studies of primate systematics, few authors have investigated the effects of parallel evolution when such methods are applied to empirical data. To counter the effects of parallelism, cladistic techniques rely on the principle of evolutionary parsimony. When parsimony procedures are used to reconstruct the phylogeny of the Lemuridae, nine highly parsimonious phylogenies can be deduced. Further choice among these competing hypotheses of relationship is determined by the extent to which one embraces the parsimony principle. The phylogeny obtained by the most rigorous adherence to the parsimony principle is one which is wholly consistent with traditional evolutionary classifications of the Lemuridae. Moderate levels of parallelism can lead to the generation of several plausible, alternative phylogenetic hypotheses; less than 25% of the characters analyzed here need have evolved in parallel, yet they are largely responsible for the ambiguity of the nine different lemurid phylogenies. This suggests that phylogeny reconstructions based entirely on cladistic methods do not provide a suitable basis for the construction of classifications for groups such as the order Primates, where the degree of parallelism is likely to be quite high.     

Phylogenetic circumscription of Saccharomyces, Kluyveromyces and other members of the Saccharomycetaceae, and the proposal of the new genera Lachancea, Nakaseomyces, Naumovia, Vanderwaltozyma and Zygotorulaspora

Genera currently assigned to the Saccharomycetaceae have been defined from phenotype, but this classification does not fully correspond with species groupings determined from phylogenetic analysis of gene sequences. The multigene sequence analysis of Kurtzman and Robnett [FEMS Yeast Res. 3 (2003) 417-432] resolved the family Saccharomycetaceae into 11 well-supported clades. In the present study, the taxonomy of the Saccharomyctaceae is evaluated from the perspective of the multigene sequence analysis, which has resulted in reassignment of some species among currently accepted genera, and the proposal of the following five new genera: Lachancea, Nakaseomyces, Naumovia, Vanderwaltozyma and Zygotorulaspora.