巴州地区设施蔬菜斑潜蝇的危害及绿色防控

为有效防治蔬菜斑潜蝇的危害,对巴州地区危害设施蔬菜的斑潜蝇进行了调查和防控。结果表明:危害巴州地区设施蔬菜的斑潜蝇主要有5种,分别是美洲斑潜蝇L.sativae Blanchard、南美斑潜蝇L.huidobrensis(Blanchard)、豌豆斑潜蝇L.congesta(Becker)、番茄斑潜蝇L.bryoniae(kaltenbach)和葱斑潜蝇L.chinensis(Kato)。在通过外部形态特征及田间危害状判断斑潜蝇种类的基础上,采取农业防治、物理防治、生态调控、生物防治和环境友好型农药化学防治等绿色防控措施,可有效降低其对设施蔬菜生产的危害。     

我国斑潜蝇的发生与防治研究进展

斑潜蝇(Liriomyza)是一类主要危害蔬菜和花卉的重要害虫,其形体小,形态易混淆,在各发生地均造成严重为害.从斑潜蝇的为害症状、形态构造、电泳法等方面进行种类鉴别,总结了其寄主植物范围及其选择性和为害状况.斑潜蝇在各地的生物学特性存在差异,空间分布型为聚集型,基本上符合负二项分布.环境因素对斑潜蝇影响较大,天敌防治斑潜蝇具有良好的效果.采用综合防治技术,对适合斑潜蝇的农业防治、化学防治、物理防治和生物防治方面作了详细论述并分析了防治误区,把自然控制和综合防治相结合.总结了危害蔬菜、花卉的几种斑潜蝇的研究进展,以供广大植物保护工作者和农民参考.     

我国斑潜蝇的发生与防治研究进展

斑潜蝇(Liriomyzn)是一类主要危害蔬菜和花卉的重要害虫，其形体小，形态易混淆，在各发生地均造成严重为害．从斑潜蝇的为害症状、形态构造、电泳法等方面进行种类鉴别，总结了其寄主植物范围及其选择性和为害状况．斑潜蝇在各地的生物学特性存在差异，空间分布型为聚集型，基本上符合负二项分布．环境因素对斑潜蝇影响较大，天敌防治斑潜蝇具有良好的效果．采用综合防治技术，对适合斑潜蝇的农业防治、化学防治、物理防治和生物防治方面作了详细论述并分析了防治误区，把自然控制和综合防治相结合．总结了危害蔬菜、花卉的几种斑潜蝇的研究进展，以供广大植物保护工作者和农民参考．     

官渡区蚕豆斑潜蝇发生规律及综合防治试验示范

1995年南美斑潜蝇(以下简称蚕豆斑潜蝇)在官渡区发现，0．08hm^2蚕豆遭受不同程度危害，平均损失率达30％；1998年蚕豆斑潜蝇在官渡区发生面积达100％。为此，笔者对官渡区蚕豆斑潜蝇的发生规律、防治方法进行了研究，在此基础上提出了蚕豆斑潜蝇的综合防治技术。     

美洲斑潜蝇的发生特点及防治

美洲斑潜蝇是1995年传入北票市的世界性检疫害虫,也是毁灭性害虫,在北票市已造成局部危害,并正在传播蔓延,已对北票市的蔬菜生产构成了严重威胁。为了控制美洲斑潜蝇的危害,我们对其发生特点及防治技术进行了观察、试验。     

蔬菜上主要斑潜蝇的形态特征及危害症状区别

斑潜蝇是农业生产上的重要害虫,严重危害蔬菜,也危害大田农作物。阐述了周口市发生的主要斑潜蝇的形态特征、发生时期和危害症状的区别,以便因地制宜地制订综合防治措施,科学进行大田防治。     

温室栽培小菊对美洲斑潜蝇的综合防治

通过阐述美洲斑潜蝇的生物学习性,结合前人对美洲斑潜蝇的系统研究结果,仔细观察了关洲斑潜蝇在温室条件下的生活习性和发生危害情况,有针对性地提出了一些综合防治美洲斑潜蝇的有效方法,为以后的病虫害防治工作奠定了基础。     

南美斑潜蝇的发生危害与综合防治

对南美斑潜蝇的生物学特性、分布及危害情况进行了简要介绍,提出了几项综合防治措施。     

保护地蔬菜主要虫害综合防治

<正>黄瓜是霍林郭勒市温室蔬菜栽培的主要作物之一,效益较高。但由于温室湿度大,所以病虫危害比较严重。虫害中尤以美洲斑潜蝇、白粉虱、蚜虫最为严重,是重点防治对象,被菜农称为日光温室的"三大害虫"。通过几年来对黄瓜"三大害虫"生活习性以及发生规律观察和探索,逐步掌握了霍林郭勒地区温室黄瓜"三大害虫"的综合防治技术。一、虫害发生情况1.美洲斑潜蝇美洲斑潜蝇寄生广泛,危害作物多,其危害蔬菜     

美洲斑潜蝇对无土栽培哈密瓜的危害及防治初报

美洲斑潜蝇是全国植物检疫对象,其幼虫生活方式隐蔽,繁殖力强,寄生范围广,危害重,难防治。美洲斑潜蝇于1997年8月中旬传入哈密并发生危害,一般危害蔬菜和花卉。1999年,美洲斑潜蝇在哈密地区无土栽培的哈密瓜上严重发生,发生面积达33.33 hm2,株被害率为89.%～100%,叶被害率为41.7%～93.5%,虫情指数为8.8%～39.3%,减产15%～25%,若不及时防治将会提早拉秧,造成绝收,对哈密地区无土栽培哈密瓜生产构成了极大威胁。为了控制此虫的危害,我们进行了调查及防治。现将美洲斑潜蝇在无土栽培哈密瓜上的危害及防治初报如下。     

穴盘规格和苗龄对塑料大棚菜豆性状及产量的影响

本试验以菜豆品种先行者为试材,采用32孔、50孔两种规格穴盘,设置10、15、20、25 d等4个苗龄段,通过研究不同穴盘规格和苗龄对菜豆性状及产量的影响,筛选出适合菜豆育苗的穴盘规格和适宜的苗龄。结果表明：穴盘育苗的营养面积增大,菜豆产量随之增加,25 d苗龄条件下,32孔穴盘的前期产量和总产量均显著高于50孔穴盘;随着苗龄的增长,菜豆的前期产量和总产量呈增加趋势,其中25 d苗龄的产量显著高于其他苗龄。综合上述各项指标,菜豆育苗阶段,10 d苗龄可选用32孔、50孔穴盘,15 d以上秧苗选用32孔穴盘为宜。     

不同基因型小麦苗期耐低氮性评价及筛选

氮素作为重要的营养元素,限制着小麦的生长发育和经济产量,筛选和培育耐低氮小麦品种是提高氮素利用率、降低生产成本的有效途径。以118份不同基因型小麦为材料,在低氮(0.1 mmol·L^-1)和正常氮(5 mmol·L^-1)条件下苗期水培,测定根干重、茎叶干重、根冠比、植株干重、最大根长、初生根数和二级初生根数等相关指标,采用模糊隶属函数法、主成分分析以及聚类分析法综合评价小麦品种的耐低氮性。结果表明,在低氮胁迫下小麦幼苗的根干重、根冠比和初生根数目显著提高,茎叶干重、植株干重和最大根长不同程度的降低,7个苗期性状指标在两个氮水平下均存在显著性差异。主成分分析提取3个主成分,贡献率分别为 43.575%、22.904%和17.873%,累积贡献率达 84.351%。以耐低氮性综合评价D值进行聚类分析,将118份小麦品种划分为强耐低氮型、耐低氮型、中间型、较敏感型和敏感型5类。筛选出3份耐低氮型小麦（齐大195、金丰7183和天民198）和2份强耐低氮型小麦（山农0917和鲁麦8号）。不同小麦品种的耐低氮机制不同,研究结果为小麦耐低氮品种的选育提供理论依据和材料基础。     

一串红N、P、K、Ca、Mg、Fe缺素症状研究

以‘展望红’为材料,研究N、P、K、Ca、Mg、Fe缺乏对其生长发育的影响,并总结缺素症状,研究结果表明:N缺乏时植株矮小,叶发黄;P缺乏时叶色暗绿,且影响开花;K缺乏时基部叶枯黄,并易落叶;缺Fe症状较为明显,但能正常开花;Ca、Mg未表现出缺素症状,且各项指标要优于全素处理;N、P显著影响一串红的生长发育,K对开花品质的影响较大。     

Segregation of form, color, movement, and depth: anatomy, physiology, and perception

Anatomical and physiological observations in monkeys indicate that the primate visual system consists of several separate and independent subdivisions that analyze different aspects of the same retinal image: cells in cortical visual areas 1 and 2 and higher visual areas are segregated into three interdigitating subdivisions that differ in their selectivity for color, stereopsis, movement, and orientation. The pathways selective for form and color seem to be derived mainly from the parvocellular geniculate subdivisions, the depth- and movement-selective components from the magnocellular. At lower levels, in the retina and in the geniculate, cells in these two subdivisions differ in their color selectivity, contrast sensitivity, temporal properties, and spatial resolution. These major differences in the properties of cells at lower levels in each of the subdivisions led to the prediction that different visual functions, such as color, depth, movement, and form perception, should exhibit corresponding differences. Human perceptual experiments are remarkably consistent with these predictions. Moreover, perceptual experiments can be designed to ask which subdivisions of the system are responsible for particular visual abilities, such as figure/ground discrimination or perception of depth from perspective or relative movement--functions that might be difficult to deduce from single-cell response properties.     

ICP-OES法同时测定果蔬中铅、砷、镉、铬、铜、锡含量

果蔬样品经混酸消化后,控制一定的酸度,定容后应用等离子体发射光谱法(ICP-OES)对果蔬中铅、砷、镉、铬、铜、锡六种有害重金属进行测定,研究了分析测定条件,方法简单快速。测定结果表明,五种元素的加标平均回收率在91.0%~107%之间。其RSD均小于3.5%。按该方法进行处理及测定铅、砷、镉、铬、铜、锡,在选择的测定条件下最低检出限分别为0.0006 mg/kg、0.0003 mg/kg、0.00003 mg/kg、0.00005 mg/kg、0.00003 mg/kg、0.0006 mg/kg。     

Space, stars, c60, and soot

Although carbon has been subjected to far more study than all other elements put together, the buckminsterfullerene hollow-cage structure, recently proposed to account for the exceptional stability of the C(60) cluster, has shed a totally new and revealing light on several important aspects of carbon's chemical and physical properties that were quite unsuspected and others that were not previously well understood. Most significant is the discovery that C(60) appears to form spontaneously, and this has particularly important implications for particle formation in combustion and in space as well as for the chemistry of polyaromatic compounds. The intriguing revelation that 12 pentagonal "defects" convert a planar hexagonal array of any size into a quasi-icosahedral cage explains why some intrinsically planar materials form quasi-crystalline particles, as appears to occur in the case of soot. Although the novel structural proposal has still to be unequivocally confirmed, this article pays particular attention to the way in which it provides convincing explanations of puzzling observations in several fields, so lending credence to the structure proposed for C(60).     

Strategic command, control, communications, and intelligence

Command, control, communications, and intelligence (C(3)l) for nuclear forces are essential elements in the deterrence of nuclear war. The present C(3)l) system has vulnerabilities associated with its reliability, survivability, and endurance under attack, thereby weakening deterrence by increasing the ambiguity in our capabilities. Development of a reliable and enduring C(3)l) system would reduce this ambiguity. Its reliable, positive control of nuclear forces would give the national leadership more time to assess situations, ensure discriminate retaliation, and improve our ability to manage crises in general. These capabilities could help to stop a war rapidly should one start. A reliable and enduring C(3)1) system will be needed for a long time to come, even if a freeze on strategic nuclear forces is accomplished or other arms control successes achieved. Indeed, C(3)l) may be the best source today of confidence-building measures to reduce tensions and the threat of nuclear catastrophe.