资源昆虫论文需要文献

蜻蜓是自然界最优秀的飞行者之一，我为大家整理的关于蜻蜓的科技论文，希望你们喜欢。 关于蜻蜓的科技论文篇一 洛阳地区蜻蜓目昆虫资源概述 摘要： 为了解洛阳地区蜻蜓目昆虫多样性状况，作者2010～2013年在洛阳地区所辖9县2区，进行了多次针对蜻蜓的采集调查，获得了较全面的标本数据，共采获蜻蜓目昆虫标本700余号。本研究记述了分布于洛阳地区的蜻蜓，共计6总科、15科、37属、57种。通过对洛阳地区蜻蜓目昆虫的资源调查研究，列出了洛阳蜻蜓名录，并对洛阳分布的蜻蜓属(种)数量进行了分析探讨。 关键词： 蜻蜓目;分布;洛阳 中图分类号：(261)文献标识号：A文章编号：1001-4942(2014)05-0109-04 蜻蜓目昆虫是一类比较古老的昆虫类群，其幼虫(稚虫)水生，成虫陆生，对环境变化十分敏感，尤其是水质的变化，对水质的污染程度具有指示性[1]。其成虫是农、林业的天敌昆虫，还是一类药用昆虫。我国蜻蜓种类约有650余种[2，3]，约占世界蜻蜓总数的10%。据王治国(2007)[4]《河南蜻蜓志》一书记述，河南蜻蜓目昆虫计6总科、15科、96种，而洛阳地区具有独特的地貌，气候和生态环境比较复杂，蜻蜓目昆虫资源十分丰富，但过去一直没有系统进行调查研究，目前这方面的资料十分匮乏。本文在前人研究的基础上，通过几年来标本的采集、调查、研究后，对洛阳地区蜻蜓目昆虫资源进行了较为详细的归类和分析，对洛阳地区的生物多样性保护、资源调查、开展相关研究等提供参考依据。 1洛阳地区自然地理概况 洛阳位于河南省西部、亚欧大陆桥东段，横跨黄河中游两岸，四季分明，年平均气温℃，年降水量546 mm，平均相对湿度66%，平均无霜期225天。洛阳东邻郑州，西接三门峡，北跨黄河与焦作接壤，南与平顶山、南阳相连。东西长约179 km，南北宽约168 km;地处秦岭山脉东段，地势西高东低，境内山川丘陵交错，其中山区、丘陵、平原占。此外，洛阳地区跨黄河、长江两大水系，主要流域面积为黄河水系，洛河、伊河为主干河流，二者在偃师境内交汇称为伊洛河，而汇入黄河，南部老灌河、白河、汝河自北西向南东汇入长江;地处中纬度内陆地区，远离海洋，故而属暖温带大陆性季风气候区。 2洛阳地区的蜻蜓资源 经调查、研究、鉴定得知，目前洛阳地区蜻蜓目昆虫共计57种，分别隶属于2亚目6总科15科37属，名录如下： 差翅亚目Anisoptera 大蜓总科 Cordulegasteroidea 大蜓科 Cordulegasteridae 圆臀大蜓属 Anotogaster Selys，1854 (1)双斑圆臀大蜓 Anotogaster kuchenbeiseri Foerster 分布：栾川、嵩县。 大蜓属 Cordulegaster Leach，1815 (2)晋大蜓 Cordulegaster jinensis Zhu et Han 分布：栾川、嵩县、洛宁、新安。 裂唇蜓科 Chlorogomphidae 华裂唇蜓属 Sinorogomphus Carle，1995 (3)侗乡华裂唇蜓 Sinorogomphus tunti Needham 分布：栾川、孟津、吉利、嵩县。 蜓总科 Aeschnoidea 蜓科 Aeschnidae 伟蜓属 Anax Leach，1815 (4)黑纹伟蜓 Anax nigrafasciatus Oguma 分布：孟津、吉利、偃师、新安。 (5)马大头[碧伟蜓]Anax parthenope julius Brauer 分布：孟津、吉利、偃师、栾川。 头蜓属 Cephalaeschna Selys，1883 (6)淡绿头蜓 Cephalaeschna patrorum Needham 分布：洛宁、栾川、嵩县、汝阳。 普蜓属 Planaeschna McLachlan，1895 (7)米普蜓 Planaeschna milnei Selys 分布：洛宁、栾川。 春蜓科 Gomphidae 亚春蜓属 Asiagomphus Asahina，1985 (8)和平亚春蜓Asiagomphus pacificus Chao 分布：栾川。 异春蜓属 Anisogomphus Selys，1854 (9)马奇异春蜓Anisogomphus maacki Selys 分布：洛宁、栾川、嵩县。 戴春蜓属 Davidius Selys，1878 (10)平截戴春蜓Davidius truncus Chao 分布：栾川。 环尾春蜓属 Lamelligomphus Fraser，1922 (11)环纹环尾春蜓Lamelligomphus ringens Needham 分布：洛宁、栾川、嵩县。 小叶春蜓属 Gomphidia Selys，1854 (12)联纹小叶春蜓Gomphidia confluens Selys 分布：孟津、吉利、偃师。 蜻总科 Libelluloidea 伪蜻科 Corduliidae 金光伪蜻属 Somatochlora Selys，1871 (13)绿金光伪蜻Somatochlora dido Needham 分布：洛宁、栾川、嵩县、汝阳。 大蜻科 Macromiidae 弓蜻属Macromia Rambur，1842 (14)摩氏弓蜻Macromia moorei moorei Selys 分布：栾川、汝阳。 蜻科 Libellulidae 蜻属 Libellula Linnaeus，1758 (15)基斑蜻Libellula depressa Linnaeus 分布：洛宁、栾川、嵩县。 宽腹蜻属 Lyriothemis Brauer，1868 (16)闪绿宽腹蜻Lyriothemis pachgastra Selys 分布：栾川。 灰蜻属 Orthetrum Newman，1833 (17)白尾灰蜻Orthetrum albistylum speciosum Uhler 分布：全地区广布。 (18)褐肩灰蜻Orthetrum japonicum internum McLachlan 分布：孟津、吉利、偃师、汝阳。 (19)线痣灰蜻Orthetrum lineostigma Selys 分布：洛宁、新安。 (20)狭腹灰蜻Orthetrum sabina Drury 分布：孟津、吉利。 (21)异色灰蜻Orthetrum triangulare melania Selys 分布：洛宁、栾川、嵩县、新安。 (22)青灰蜻Orthetrum triangulare triangulare Selys 分布：孟津、吉利、栾川、嵩县、伊川。 红蜻属 Crocothemis Braure，1868 (23)红蜻Crocothemis servilia Drury 分布：全地区广布。 多纹蜻属 Deielia Kirby，1889 (24)异色多纹蜻Deielia phaon Selys 分布：孟津、吉利、栾川。 赤蜻属 Sympetrum Newman，1833 (25)大赤蜻Sympetrum baccha Selys 分布：洛宁、栾川。 (26)半黄赤蜻Sympetrum croceolum Selys 分布：栾川。 (27)夏赤蜻Sympetrum darwinianum Selys 分布：栾川、嵩县。 (28)眉斑赤蜻Sympetrum eroticum eroticum Selys 分布：洛宁、栾川。 (29)旭光赤蜻Sympetrum hypomelas Selys 分布：栾川。 (30)黄腿赤蜻Sympetrum imitens Selys 分布：孟津、吉利、新安、宜阳。 (31)褐顶赤蜻Sympetrum infuscatum Selys 分布：栾川。 (32)小黄赤蜻Sympetrum kunckeli Selys 分布：洛宁、栾川、嵩县。 (33)小赤蜻Sympetrum parvulum Bartenef 分布：洛宁、栾川、嵩县。 (34)秋赤蜻Sympetrum frequens Selys 分布：洛宁、栾川、嵩县、宜阳。 玉带蜻属 Pseudothemis Kirby，1889 (35)玉带蜻Pseudothemis zonata Burmeister 分布：全地区广布。 褐蜻属 Trithemis Brauer，1868 (36)晓褐蜻Trithemis aurora Burmeister 分布：栾川。 黄蜻属 Pantala Hagen，1861 (37)黄蜻Pantala flavesens Fabricius 分布：全地区广布。 均翅亚目(束翅亚目)Zygoptera 色�总科 Calopterygoidea 丽�科 Amphiptergidae 大丽�属 Philoganaa Kirby，1890 (38)粗壮大丽�Philoganaa robusta Navas 分布：栾川。 色�科 Calopterygidae 色�属 Calopteryx Leach，1815 (39)黑色�Calopteryx atratum Selys 分布：栾川、嵩县。 眉色�属 Matrona Selys，1853 (40)晕翅眉色�Matrona basilaris Selys 分布：洛宁、栾川、嵩县、宜阳、新安。 (41)褐翅眉色�Matrona basilaris nigipectus Selys 分布：洛宁、栾川、嵩县。 绿色�属 Mnais Selys，1853 (42)绿色�Mnais andersoni tenuis Oguma 分布：洛宁、栾川、嵩县、宜阳、新安、孟津。 闪色�属 Calipaea Selys，1859 (43)紫闪色�Calipaea consimilis McLachlan 分布：栾川。 溪�科 Euphaeidae 尾溪�属 Bayadera Selys，1853 (44)巨齿尾溪�Bayadera medanopteryx Ris 分布：洛宁、栾川、嵩县。 �总科 Coenagrionoidea �科 Coenagrionidae 黄�属 Ceriagrion Selys，1876 (45)长尾黄�Ceriagrion falla Ris 分布：洛宁、栾川、嵩县。 瘦�属 Ischnura Charpentier，1840 (46)青纹瘦�Ischnura senegalenensis Rambur 分布：栾川。 (47)二色瘦�Ischnura lobata Needham 分布：栾川、嵩县。 扇�科 Platycnemididae 长腹扇�属 Coeliccia Kirby，1890 (48)四斑长腹扇�Coeliccia didyma Selys 分布：栾川、孟津、偃师。 (49)六斑长腹扇�Coeliccia sexmaculatus Wang 分布：栾川、嵩县。 华扇�属 Sinocnemis Wilson & Zhou，2000 (50)河南华扇�Sinocnemis henanese Wang 分布：栾川、嵩县。 扇�属 Platycnemis Charpentier，1840 (51)白扇�Platycnemis foliacea foliacea Selys 分布：全地区广布。 (52)粉扇�Platycnemis phyllopoda Djakonov 分布：洛宁、栾川。 山�科 Megapodagriidae 藏山�属 Mesopodagrion McLachlan，1896 (53)藏山�Mesopodagrion tibetanum McLachlan 分布：洛宁、栾川。 齿山�属 Rhipidolest Ris，1912 (54)二星齿山�Rhipidolest nectans Needham 分布：栾川。 丝�总科 Lestinoidea 丝�科 Lestidae 丝�属 Lestes Leach，1815 (55)蕾尾丝�Lestes nodalis Selys 分布：栾川。 综�科 Chlorolestidae 绿综�属 Megalestes Selys，1862 (56)褐腹绿综�Megalestes chengi Chao 分布：栾川。 (57)褐尾绿综�Megalestes distans Needham 分布：栾川、嵩县。 3 洛阳地区蜻蜓属种的数量分析 地位以及与全省所具有的各属、种之间相比有着明显的差异。差翅亚目在洛阳地区所含属、种的数量分别是22属37种，均翅亚目为15属20种，与全省范围内蜻蜓目属、种的比较来看，洛阳地区差翅亚目的属种数量占全省比例分别为和，而均翅亚目所占比例分别为和，总体来看，洛阳地区蜻蜓目昆虫占全省属、种的比例分别是和。由表1可以看出，差翅亚目的大蜓科、裂唇蜓科、蜓科、蜻科，均翅亚目的丽�科、色�科、溪�科、扇�科、山�科、综�科，无论从属的数量上，还是从种的数量上来看，在洛阳地区蜻蜓目昆虫的分布上所占的地位十分明显和重要，说明洛阳地区十分适合蜻蜓目昆虫的生存。由于洛阳地区跨黄河、长江两大水系，区内河流众多，有“四面环山，六水并流，八关通邑，十省通衢”之称，且区内山川丘陵交错，地形复杂多样，植被类型更是多样化，区域性较强，故在蜻蜓的分布上也表现出了丰富的多样性和明显的差异性，尤其是洛阳地区的西部和南部，雨水比较充沛，使得这些地区的蜻蜓数量和种类所占比例也比较高，蜻蜓资源也十分丰富，同时也说明，洛阳地区的水质还是比较好的。 参考文献： [1]黄小清，蔡笃程.水生昆虫在水质监测与评价中的应用[J].华南热带农业大学学报，2006，12(2)：72-75. 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Formosan Entomol.，2006，26(2)：187-195.山 东 农 业 科 学2014，46(5)：113～114，117Shandong Agricultural Sciences 关于蜻蜓的科技论文篇二 浅谈蜻蜓眼式玻璃珠的工艺型式与审美体验 摘 要：蜻蜓眼式玻璃珠系统地反映了中国琉璃珠的鼎盛时期，见证了中西文化全方位的交流过程，展示了人类文明的历史进程、地域特色、信仰方式、文化背景、科技发展以及审美趣味，是人类物质文明与精神文明的结晶。 关键词：蜻蜓眼式玻璃珠;审美;工艺 中图分类号：J524 文献标识码：A 文章编号：1005-5312(2013)03-0174-01 一、概述 蜻蜓眼式玻璃珠，是指以眼睛图案作为装饰的玻璃珠。在珠体上嵌入一种或数种不同于母体颜色，形成一层或多层类似眼睛的效果，或在珠体上造出凸出表面的眼睛形状，形成“鼓眼”，与蜻蜓的复眼十分相似。西方学界称之为“眼式珠”或“复合眼式珠”，安家瑶称它为“镶嵌玻璃珠”，这种珠子的制造方法多样，并非“镶嵌”一种方法，然而以其形式命名的“蜻蜓眼式玻璃珠”却更为形象和全面。 二、造型分类 蜻蜓眼式玻璃珠均为手工制造，所以会带有随意性，同时也具有唯一性，也就是说我们很难找到两件相同的珠子。如果完全依据其外观，我们发现难以对其进行准确的分类。国外学者曾经提出通过其上“眼珠”制造工艺的不同来对蜻蜓眼式玻璃珠进行分类的方法。我国出土蜻蜓眼式玻璃珠，根据其“眼珠”造型的不同所反映的制造工艺，可分为九种造型。 A型：层状眼珠。早期的层状眼珠，是在珠体上多次滴不同颜色的玻璃料，由下至上渐次减小，再加以修整而成。更为常见的做法是，按照上述方法单独制作眼珠，趁母体尚未凝固时嵌入，加以打磨修整而成。 Aa型：“瞳孔”位于眼眶正中，又称为同心圆纹眼珠。在中国出土的蜻蜓眼式玻璃珠中，年代最早。 Ab型：“瞳孔”位于一侧，即离心圆纹眼珠。整体形成“斜视”的效果，给珠体平添活泼的氛围。 B型：圆斑状眼珠。艾森称之为“简易点状眼珠”，是制作最简单的一种类型，将不同于母体颜色的玻璃料滴在母体上，或将玻璃料滴加工成适当形状后嵌入未凝固的母体，略加修整即可制成。“眼”整体仅为一种颜色的玻璃料。 Ba型：平齐圆斑状眼珠。将加工好的玻璃料滴(即眼珠)嵌入母体，然后修整齐平。 Bb型：突出圆斑状。眼珠，保持滴上的玻璃料凸出于母体的状态，有时甚至通过修整突出强调。推测制造工艺应是：“先制成一带穿孔的圆形内胎，内胎先经烧制，然后在胎的外部再加涂白色的料，白色料之外再涂各种彩色料，以组成各种纹饰。 C型：嵌环眼珠。将不同于母体颜色的玻璃料制成细条，嵌入母体，近环形，成为“眼眶”，环内的母体颜色形成眼珠的效果。嵌入的料环略呈弯月形，眼珠整体给人一种“斜视”的印象，嵌入的料环已脱落，时代为战国。 D型：角锥状眼珠。将母体制成带有多个角锥的不规则形态或在圆形母体上嵌入单独制作的角锥，这种装饰手法要和其他方式组合运用，角锥状眼珠最为突出。 E型：套圈眼珠。一个大圆圈中套若干小圆圈，艾森描述为“小眼分组置于特定颜色(通常是棕色)的区域”，小圆圈的数量似有定规，通常为六个或七个，其中一个位于中心，其余环绕置于周围，在港台收藏界常被称为“六星纹”和“七星纹”。 F型：镶嵌玻璃料卷眼珠。是在母体上滴大滴的玻璃料，在周围镶嵌不同颜色玻璃料条裹成的卷，形成眼眶的同时，又具有睫毛的效果，艾森简称为“镶嵌料卷”。 H型：几何线间隔眼珠。用连珠点纹形成圆、椭圆、三角等形状，将珠体表面的眼珠分隔开来，形成若干独立的小单元。 I型：组合型眼珠，即复合眼珠。采取多种装饰手法于一体。上述八型蜻蜓眼式玻璃珠中很多装饰手法都不是单一的，分型的依据是主要的装饰手法。 三、工艺特征与装饰纹饰 蜻蜓眼式玻璃珠集中出现在春秋战国时期，其造型、色彩及制作工艺均具有多样性。从质地上讲，有陶胎与玻璃胎两种，玻璃胎又分为透明与半透明。从造型上看，有方、圆、管状形，亦有相对内敛、平滑、整体的表现方式，亦有造型夸张、强调眼球凸出的效果。 蜻蜓眼式玻璃珠的纹饰丰富多彩，以眼形纹为装饰，最初是从埃及或西亚经印度传入中国的。融入中国文化后，蜻蜓眼式玻璃珠最初的宗教象征意义渐渐消失，在纹饰上也出现了更多中国式样的图案。比如：对称图案或点线连接，还有称为“珍珠地”或“连珠纹”的纹饰都是当时中国流行的样式。典型纹样是大眼里套贴小眼的复眼星纹珠，根据小眼数目被分成三星纹、五星纹、六星纹、七星纹等，甚至有十二星纹。此外，春秋时出现的被称作泼墨纹的珠子，尤其具有水墨大写意的雏形，其纹饰妙绝、配色讲究，有勾魂摄魄的惊人美感。 四、美学特性与审美感受 黑格尔认为，艺术形式不是随意创造出来的，相反，它们产生于一定的社会和历史状态的具体规定性之中。正如蜻蜓式玻璃珠注定只会产生于中西文化有所交流的大背景下，也只能产生在先人们熟练掌握玻璃制作技术的情况下。而人类对抽象的几何形图案有一种天然的爱好和一种天赋的感觉，也正是因为这种感觉，先人们才首先选择眼形纹构成琉璃珠的装饰图案。 审美就是感受、领悟客观事物或现象所呈现的美;是先人们将社会实践中与客观事物或现象，以历史为背景所建构的一种特殊表现性关系。西方的艺术创造是入木三分的细腻肌肉块状和骨骼关节灵活的直观再现。东方艺术则是充分利用外在条件的包裹意象影射着人体内在的那种气质和想象。“蜻蜓眼”作为琉璃艺术的代表，是人类审美表现关系专注于对象生动可感的表现性形式，是合规律性与目的性的统一，它们与先人首先形成了意志实践关系和理智认知关系。 五、民族创新性与图腾崇拜 战国早期以后，楚地成为中国蜻蜓眼式玻璃珠最为流行的地区，仿制的蜻蜓眼式珠，与此是密不可分的。这些模仿蜻蜓眼式玻璃珠的标本，材质之多样，形式之丰富，不见于西方古代世界，应当是本土制造的。它们的存在表明，蜻蜓眼式玻璃珠传入之后，得到了本土文化的强烈共鸣。 楚人有强烈的的艺术创造意识，从来不满足于单纯的模仿，楚国利用已经掌握的玻璃工艺仿制了大量的蜻蜓眼式玻璃珠，在仿制过程中，极富创造力的楚人由于自己审美习惯，把自己偏爱的传统纹样也添加一点进去，蜻蜓眼式玻璃珠上醒目的菱形纹就是楚人偏爱的一种纹样。从玻璃珠的发展来看，玻璃珠上的纹饰越来越富于变化，越来越丰富。单纯的蜻蜓眼纹装饰发展到多种纹饰组合的绚丽繁复的复合纹饰，使玻璃珠更加精美、典雅，充分体现出楚人审美情趣。 蜻蜓眼式玻璃珠具有多方面社会功能。由于其外形极具观赏性，不仅有精美的装饰艺术特性，更多的是贵族们把能够佩戴它作为身份的象征。其眼形纹饰也有明显的宗教信仰含义。佛教徒对琉璃极其重视，把它视为七宝之一。在魏晋南北朝时期，汉译的印度佛经亦有记载。“骨之精气凝为瞳孔。筋之精气凝为黑眼珠。气之精气凝为白眼仁。”眼睛乃“心之符也”。可见眼球凝聚了不可替代的原始神秘力量，人们相信眼球的魔力，并且认为眼球越多魔力越大。 六、结语 蜻蜓眼式玻璃珠最早在公元前二千纪在地中海沿岸出现，进入中国的时间不晚于春秋晚期。蜻蜓眼式玻璃珠系统地反映了中国琉璃珠的鼎盛时期，见证了中西文化全方位的交流过程，为科学研究中国古玻璃艺术提供了契机。 参考文献： [1]王敏.琉璃[J].上海工艺美术，1998，(03). [2]蒋玄怡.古代的琉璃[J].文物，1959，(06). [3]朱狄.艺术的起源[M].北京：中国社会科学出版社，1982. [4]潘谷西.段文杰.中国美术全集・琉璃[M].北京：人民美术出版社，2006，第三册. [5]李会.蜻蜓眼式玻璃珠的初步研究.《四川大学》2004年硕士论文. 看了关于蜻蜓的科技论文的人还看 1. 关于科技论文的范文 2. 关于科技论文2000字 3. 关于光的科技论文 4. 关于手机的科技论文 5. 关于科技的议论文作文

参考文献：[1]彩万志等.普通昆虫学.中国农业大学出版社, 2011.[2]张巍巍. 昆虫家谱.重庆大学出版社,2014.[3]任东. 昆虫口器多样性及其演历史, 2004.

研究昆虫控制的文章Athenix and Monsanto Announce Collaboration on Research for Insect ControlRESEARCH TRIANGLE PARK, . and ST. LOUIS, June 20 /PRNewswire-FirstCall/ -- Athenix Corp. and Monsanto Company today announced they have entered into a three-year research collaboration for insect control on a key class of insects that affects a number of Monsanto's major crops of interest. Financial terms of the agreement were not disclosed. "We are pleased to work with the market leader in crop genetics to bring our technical capabilities to commercialization," said Mike Koziel, chief executive officer for Athenix. "Working with Monsanto to discover novel genes for controlling insect pests increases options for farmers and allows Athenix to demonstrate the power of its integrated discovery platforms for new biotech traits," said Nick Duck, vice president of research at Athenix. Athenix will apply its expertise in microbial screening and genomics to facilitate gene discovery intended to help protect crops such as cotton, soybeans and corn against a common class of insects known as Hemipterans. Hemipteran insects include Lygus, a pest of cotton, and stinkbug, a pest of soybean. "This collaboration will work to offer an essential benefit to our farmer customers by providing insect protection in crops such as corn, cotton and soybeans against the piercing and sucking insects. Insect tolerant crops allow growers to spray less pesticide, making their operations more efficient and at the same time stewarding the environment," said Robert T. Fraley, ., Monsanto executive vice president and chief technology officer. "We're excited to collaborate with Athenix to help broaden grower's options for insect control." About Athenix: Athenix is a leading biotechnology company that develops novel products and technologies for agricultural and industrial applications, including biofuels and bioconversions. Athenix has established an outstanding intellectual property portfolio and market access ability around enhanced plants, microbes, genes, enzymes, and processes with emphasis on two major markets: 1) novel agricultural traits for growers such as insect resistance, nematode resistance, herbicide tolerance, and their use for the crop production industry; and 2) the discovery of genes and proteins for use in the sustainable chemical industry with a focus on biofuels like ethanol and other natural control of locusts New weapons for old enemiesDuring the 1988 desert locust plague, swarms crossed the Atlantic from Mauritania to the Caribbean, flying 5 000 kilometres in 10 were stumped because migrating swarms normally come down to rest every night. But locusts can’t swim, so how could it be? It turned out that the swarms were coming down at sea – on any ships they could find, but also in the water itself. The first ones in all drowned but their corpses made rafts for the other ones to rest on. Since the dawn of agriculture more than 10 000 years ago mankind has had to deal with a resourceful and fearless enemy, Schistocerca gregaria, the desert locust. Normally loners, every so often these natives of the deserts from West Africa to India turn into vast, voracious swarms that leave hunger and poverty behind them wherever they go. Throughout history, farmers and governments have made attempts to repel the bands and swarms of locusts by collecting insects, creating noise, making smoke and burying and burning the insects. But all of this had little effect. With swarms sometimes extending for hundreds of kilometres, and containing billions of individuals, they conquered by sheer force of numbers. Health concernsIt has long puzzled humans where these animals came from and where they survived. Only in the mid-20th century was it realized that the light brown solitary desert-dwelling insect was the same species as the red and yellow locusts of the plagues. Only when its biology was understood and chemical pesticides and aerial spraying became available a few decades ago, could efforts be made to control the insect. But large-scale pesticide use also raised real concerns for human health and the environment. On the seventh-floor Emergency Centre for Locust Operations (ECLO) at FAO Headquarters in Rome, Keith Cressman, FAO's locust forecaster, checks current environmental conditions and locust population data from the three computer screens on his desk. The last big locust upsurge ended early in 2005 and the current alert level is green or calm. The experts at FAO’s ECLO are readying to fight the next round in the age-old battle against locusts – wherever and whenever that may be. “The next time,” says Cressman, “we’ll fight with new tools”. New bio-control agents Recent advances in biological control research, coupled with improved surveillance and intelligence, could make a big difference when the next round in the battle is fought. Such products could make it possible to sharply reduce the amount of chemical pesticides used. One promising avenue is research currently under way at the International Centre for Insect Physiology and Ecology (ICIPE) in Nairobi. An ICIPE team headed by a Zanzibar-born chemical ecologist, Ahmed Hassanali, has identified and synthesized a specific locust pheromone, or chemical signal, that can be used against young locusts with devastating , or PAN for short, normally governs swarming behaviour in adult males who also use it to warn other males to leave them in peace while they mate. But, Hassanali found it has startlingly different results on juvenile wingless locusts, known as hoppers. Hopper bandsJust as adult locusts form swarms, hoppers will, given the right conditions, stop behaving as individuals and line up in marauding bands up to 5 kilometres wide. They are only slightly less voracious than adults, who eat their own weight of food every day. In three separate field trials – the most recent in Sudan last year – Hassanali’s team showed that even minute doses of PAN could stop hopper bands dead in their tracks and make them break caused the insects to resume solitary behaviour. Confused and disoriented, some lost their appetite altogether, while others turned cannibal and ate one other. Any survivors were easy prey for predators. What makes PAN particularly attractive is that the dose needed is only a fraction – typically less than 10 millilitres per hectare – of the quantities of chemical or biological pesticides. This translates into substantially lower costs – 50 cents per hectare as opposed to US$12 for chemical pesticides and $15-20 for other bio-control is clearly a major consideration in the countries in the front line – many of them among the world’s poorest. Green Muscle A different, but also highly effective biological approach is Green Muscle ®, a bio-pesticide developed by the International Institute for Tropical Agriculture’s biological control centre in Cotonou, Benin, and manufactured in South Africa. Green Muscle ® contains spores of the naturally occurring fungus Metarhizium anisopliae var. acridum, which germinate on the skin of locusts and penetrate through their exoskeletons. The fungus then destroys the locust's tissues from the inside. This is definitely not good news for locusts, but the fungus has no effect on other life forms. A product similar to Green Muscle ® is already successfully used in Australia, but the latter's introduction in Africa and Asia is being slowed by several factors. These include a need for further large-scale trials, official approval of the product in several countries, and a relatively short shelf-life in its normal ready-to-spray liquid form. One drawback is that it takes days to kill the locusts. It is also relatively expensive and large-scale production would need to be organized. A solution would be to store the product in powder form and dilute it just before use. Hassanali’s team has also shown that, if used in combination with a small amount of PAN, only a quarter of the normal dose of Green Muscle ® is Growth RegulatorsAlso being readied for the modern locust fighter’s armoury is a class of products known as Insect Growth Regulators, or IGRs, which influence the ability of hoppers to moult and grow properly. They have no direct toxic effects on vertebrates. IGRs are effective for several weeks after application and can be used in so-called barrier treatments. In this method only narrow swathes of the product are applied, perpendicular to the direction of the marching hopper bands. Only 10 percent of the amount used in blanket treatment is needed. After marching over one or two barriers the hoppers absorb enough product to die while moulting. As with PAN and Green Muscle ®, however, IGRs need to be aimed at locusts at an early stage in their lives, before they take to the air. That, in turn, requires an advanced level of surveillance and intelligence-gathering to make sure that any locust concentrations are nipped in the bud. eLocust2Although back at ECLO Keith Cressman has satellites, computers and mathematical models at his disposal, the weak link in the chain has been the time it takes to get good information from the mobile ground teams whose job it is to keep tabs on locust populations have to work in some of the world’s remotest, hottest and sometimes (for environmental and security reasons) most hostile places. A week or more might go by before a report from, say, the central Sahara, reached Cressman’s desk. By that time the locusts – “They don’t need visas,” he says – would quite likely have moved to another country or continent altogether. This will soon change however. Field teams are now being issued with special hand-held devices to record vital locust and environmental data and relay them back to their own headquarters and on to Rome in real time. Developed by the French Space Agency CNES, the eLocust2 device is able to bounce the information off communications satellites and have the data arrive in the National Locust Control Centre in the affected country a few minutes later, from where they are passed on to Cressman for analysis. In case of unusually heavy hopper concentrations, immediate action can be taken to make sure that the locusts never grow old enough to swarm. Back to the fieldWriting in Science magazine, locust expert Martin Enserink gave the following graphic description of a locust population gone out of control:“On a beautiful November morning (in Morocco) it’s clear, even from afar, that something’s terribly wrong with the trees around this tiny village. They are covered with a pinkish-red gloss, as if their leaves were changing colour... "As you get closer, the hue becomes a wriggling mass; a giant cap of insects on every tree, devouring the tiny leaves. Get closer still and you’ll hear a soft drizzle: the steady stream of locust droppings falling to the ground.” Such nightmare visions, and locust plagues with them, may one day be a thing of the past.

呵呵。这个提问太哪个了。不好回答。