共查询到19条相似文献，搜索用时 31 毫秒
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由于蜉蝣成虫翅基结构变形大,起始状态难以确定,其原始脉相及其起源过程仍未有清楚呈现.不过,少数中国大型蜉蝣稚虫翅芽的基部却保留着一些原始线索,如中国古丝蜉Siphluriscus chinensis、长茎蜉Ephemera pictipennis和戴氏短丝蜉Siphlonurus davidi.总体上,它们表明:蜉蝣翅脉中的亚前缘脉弓(Subcostal brace)可能起源于亚前缘脉前支(ScA);径脉(Radius,R)与中脉(Media,M)在基部就完全合并,后中脉(Media Posterior,MP)最先离开它们的主干,然后是基部合并在一起的径分脉(Radial Section,Rs)和前中脉(Media Anterior,MA);肘脉(Cubitus,Cu)完全独立;臀脉(Anal,A)的气管起源于肘脉中的气管.在蜉蝣翅中,所有纵脉都有独立的翅基骨片但它们都不能活动,而是与纵脉完全愈合在一起,特别是在径脉(R)与中脉(M)的基部形成一个较大的骨板,所有这些骨片与骨板又因翅基的骨化和硬化而连接成块,因而蜉蝣翅不具有折叠的结构基础.从系统发育的角度看,蜉蝣目内不同的演化支系具有不同的脉相,它缘于各纵脉在翅基的位置不同,如亚前缘脉弓(ScA)与翅前缘的距离以及肘脉(Cu)与中脉(M)的距离.而对于有翅昆虫的三大支而言,蜉蝣似乎与新翅类较接近,因为它们的翅基都具有3块腋片且径脉(R)与中脉(M)在基部合并,而蜻蜓翅基不具腋片且中脉(M)与肘脉(Cu)合并,似乎与蜉蝣的关系较远,故从翅基结构与脉相来看,\"古翅类\"(=蜉蝣目+蜻蜓目)应该不是单系群. 相似文献
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"古翅类"系统发育关系研究进展(昆虫纲,有翅类) 总被引：4，自引：2，他引：4
古翅类的系统发育问题是六足总纲中有争议的热点问题之一。对现存古翅类(孵蝣目 蜻蜒目)与新翅类之间的系统发育关系有3种主要观点：古翅类(＝蜉蝣目 蜻蜒目) 新翅类,蜉蝣目 (蜻蜒目 新翅类),蜻蜒目 (蜉蝣目 新翅类)。第1种观点得到化石、形态和部分基因证据支持,第2种观点得到较多形态特征支持,支持第3种观点的证据较少。这一问题的解决有赖于更多昆虫种类、化石以及分子证据的发现和研究。 相似文献
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脉翅目(Neuroptera)草蛉科(Chrysopidae)作为一类重要天敌资源,在我国各地非常丰富,大量的标本有待鉴定。本文主要记述2新属及其所属种类,模式标本均保存于北京农业大学昆虫标本室。 相似文献
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记述采自中国香港的蜉蝣目扁蜉科2新种。根据稚虫和成虫的形态特征,详细描述了中国新纪录属康扁蜉属Compsoneuria 1新种：大埔浯康扁蜉Compsoneuria taipokauensis sp．nov．。该新种的成虫标本由稚虫在实验室内饲养而成。根据稚虫形态特征,详细描述了高翔蜉属1新种：箭鬃高翔蜉Epeorus sagittatus sp．nov．。 相似文献
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中国内蒙古中侏罗世脉翅目昆虫化石—新科(英文) 总被引：1，自引：0，他引：1
任东 《Entomologia Sinica》2002,(4)
建立脉翅目昆虫化石新科———Grammolingiidaefamnov .,并描述该科化石 3新属 6新种 :Grammolingiaboigen .nov .ofsp .nov .,Litholingiarhoragen .nov .ofsp .nov .,Litholingiaeumorphagen .nov .ofsp .nov .,Litholing iapolychotomagen .nov .ofsp .nov .,Leptolingiajurassicagen .nov .ofsp .nov .,Leptolingiatianyiensisgen .nov .etsp .nov ..给出了新科的属级检索表 ,描述的所有模式标本均采自于内蒙古自治区宁城县中侏罗世九龙山组地层中。标本分别保存在义县博物馆和首都师范大学生物系。本次发现再次表明目前关于脉翅目昆虫的认识仍然十分贫乏。 相似文献
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同翅类昆虫的雄性生殖系统及精子发生(昆虫纲:半翅目) 总被引：2，自引：1，他引：2
本文比较了同翅类昆虫雄性生殖系统的结构、减数分裂期间染色体的行为和精子尾部的超微结构。研究表明蜡蝉总科和异翅类的精巢具有被膜,而蝉总科、叶蝉总科、沫蝉总科、角蝉总科、木虱总科、蚜总科、粉虱总科和蚧总科的精巢均不具有被膜。也可以根据精巢小叶的形状将精巢分为三类,蝉总科、叶蝉总科、沫蝉总科、角蝉总科、蚜总科和粉虱总科的精巢小叶为球形,蜡蝉总科、木虱总科和蚧总科的精巢小叶为管状,而异翅类的精巢小叶为片层状。减数分裂可以被分为5类:①蝉型(Cicadoidtype);②蜡蝉型(Fulgoroidtype);③木虱型(Psyloidtype);④蚜型(Aphidoidtype);⑤粉虱型(Aleyrodoidtype)和⑥蚧型(Coccoidtype),至少具有四个类群的减数分裂前期I具有弥散期,它们是:木虱总科、蜡蝉总科、蚧总科和异翅类。除粉虱总科和蚧总科的精子尾部退化以外,其余种类的精子鞭毛均具有典型的9 9 2轴丝结构。 相似文献
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我国侏罗纪脉翅目化石一新属一新种(脉翅目:蚁蛉总科) 总被引：7，自引：1，他引：7
描述脉翅目化石一新属一新种,精细华蛉Siniphes delicatus gen.et sp.nov.,标本采自辽宁省北票市晚侏罗世义县组地层中。讨论了华蛉属的科级分类问题。新属可归于蚁蛉总科,但科级位置不能确定。模式标本保存在首都师范大学生物系。 相似文献
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Although there is mounting evidence that passive mechanical dynamics of insect wings play an integral role in insect flight, our understanding of the structural details underlying insect wing flexibility remains incomplete. Here, we use comparative morphological and mechanical techniques to illuminate the function and diversity of two mechanisms within Odonata wings presumed to affect dynamic wing deformations: flexible resilin vein‐joints and cuticular spikes. Mechanical tests show that joints with more resilin have lower rotational stiffness and deform more in response to a load applied to an intact wing. Morphological studies of 12 species of Odonata reveal that resilin joints and cuticular spikes are widespread taxonomically, yet both traits display a striking degree of morphological and functional diversity that follows taxonomically distinct patterns. Interestingly, damselfly wings (suborder Zygoptera) are mainly characterized by vein‐joints that are double‐sided (containing resilin both dorsally and ventrally), whereas dragonfly wings (suborder Epiprocta) are largely characterized by single‐sided vein‐joints (containing resilin either ventrally or dorsally, but not both). The functional significance and diversity of resilin joints and cuticular spikes could yield insight into the evolutionary relationship between form and function of wings, as well as revealing basic principles of insect wing mechanical design. J. Morphol., 2011. © 2011 Wiley‐Liss, Inc. 相似文献
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The limb proportions of the extinct flying pterosaurs were clearly distinct from their living counterparts, birds and bats. Within pterosaurs, however, we show that further differences in limb proportions exist between the two main groups: the clade of short-tailed Pterodactyloidea and the paraphyletic clades of long-tailed rhamphorhynchoids. The hindlimb to forelimb ratios of rhamphorhynchoid pterosaurs are similar to that seen in bats, whereas those of pterodactyloids are much higher. Such a clear difference in limb ratios indicates that the extent of the wing membrane in rhamphorhynchoids and pterodactyloids may also have differed; this is borne out by simple ternary analyses. Further, analyses also indicate that the limbs of Sordes pilosus, a well-preserved small taxon used as key evidence for inferring the extent and shape of the wing membrane in all pterosaurs, are not typical even of its closest relatives, other rhamphorhynchoids. Thus, a bat-like extensive hindlimb flight membrane, integrated with the feet and tail may be applicable only to a small subset of pterosaur diversity. The range of flight morphologies seen in these extinct reptiles may prove much broader than previously thought. 相似文献
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James H. Marden 《Evolution; international journal of organic evolution》2013,67(7):2150-2153
Benner, Knecht, and Engel have replied to my critique of their interpretation of a Carboniferous trace fossil produced by an insect at the edge of water. Here I respond by pointing out that their reiterated scenario still requires mutually exclusive paths of motion and I show that their assertions of methodological shortcomings are tangential and lack merit. Overall, this discussion provides an opportunity to examine in greater detail competing hypothesis about behaviors and taxonomic identity of the trace maker, and relevance thereof to competing theories regarding early events in the evolution of pterygote insects. 相似文献
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S.J. McCauley 《水生昆虫》2013,35(3-4):195-204
Morphology is an important determinant of flight performance and can shape species’ dispersal behaviour. This study contrasted the morphology of flight-related structures in dragonfly species with different dispersal behaviours to gain insights into the relationship between morphology and dispersal behaviour. Specifically, wing size, wing shape and thorax size were compared in three co-occurring species from different clades within the genus Libellula (Odonata: Anisoptera: Libellulidae) to assess how these morphological traits are related to differences in dispersal behaviour and to how broadly their larvae occur across a habitat gradient. Two species had broad larval habitat distributions as well as high rates and distances of dispersal. These two species had relatively larger wings and thoraces than the third species, which was found only in permanent lakes and had limited dispersal. The hind-wings of more dispersive species also had lower aspect ratios and a relatively wider basal portion of the wing than the less dispersive species. Broad hind-wings may facilitate the use of gliding flight and reduce the energetic costs of dispersal. Determining the morphological traits associated with alternative dispersal behaviours may be a useful tool to assess the differential dispersal capacities of species or populations. 相似文献
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Eugenio Rico 《水生昆虫》2013,35(3):133-139
A revision of the Limnius perrisi subspecies group in the Iberian Peninsula is presented. Limnius perrisi subcarinatus (Sharp, 1872) is a new synonym of Limnius perrisi carinatus (Pérez-Arcas, 1865). Morphological variability related to some elytral interstriae corresponds to a geographical gradation. Limnius perrisi is restricted to the headwaters of highslope streams with low levels of dissolved minerals. 相似文献
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Insect head shapes are remarkably variable, but the influences of these changes on biomechanical performance are unclear. Among ‘basal’ winged insects, such as dragonflies, mayflies, earwigs and stoneflies, some of the most prominent anatomical changes are the general mouthpart orientation, eye size and the connection of the endoskeleton to the head. Here, we assess these variations as well as differing ridge and sclerite configurations using modern engineering methods including multibody dynamics modelling and finite element analysis in order to quantify and compare the influence of anatomical changes on strain in particular head regions and the whole head. We show that a range of peculiar structures such as the genal/subgenal, epistomal and circumocular areas are consistently highly loaded in all species, despite drastically differing morphologies in species with forward‐projecting (prognathous) and downward‐projecting (orthognathous) mouthparts. Sensitivity analyses show that the presence of eyes has a negligible influence on head capsule strain if a circumocular ridge is present. In contrast, the connection of the dorsal endoskeletal arms to the head capsule especially affects overall head loading in species with downward‐projecting mouthparts. Analysis of the relative strains between species for each head region reveals that concerted changes in head substructures such as the subgenal area, the endoskeleton and the epistomal area lead to a consistent relative loading for the whole head capsule and vulnerable structures such as the eyes. It appears that biting‐chewing loads are managed by a system of strengthening ridges on the head capsule irrespective of the general mouthpart and head orientation. Concerted changes in ridge and endoskeleton configuration might allow for more radical anatomical changes such as the general mouthpart orientation, which could be an explanation for the variability of this trait among insects. In an evolutionary context, many‐to‐one mapping of strain patterns onto a relatively similar overall head loading indeed could have fostered the dynamic diversification processes seen in insects. 相似文献
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Measurement on Camber Deformation of Wings of Free-flying Dragonflies and Beating-flying Dragonflies
Deqiang Song Lijiang Zeng . State Key Laboratory of Precision Measurement Technology Instruments Tsinghua University Beijing P.R. China . Gilman Dr. University of California San Diego CA USA 《仿生工程学报（英文版）》2004,1(1):41-45
1 IntroductionNumerouskinematicparameters,includingwing beatfrequency ,wingorientation ,andbothspan andchord wisedeformation ,arerelevanttotheaerodynam icanalysisofinsectflight[1,2 ] .Althoughnearlyalltherecentstudiesofinsectflightaerodynamics[3,4 ] haveidentifiedthatthemechanismsrequireflowseparationattheleadingedge ,andcamberisnotexpectedtohaveanysignificantinfluenceonthemagnitudeoftheforcecoefficient,someinsects ,suchasdragonfliesandbut terflies,frequently glideusinglowanglesofattack ,lead… 相似文献
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采用PCR产物直接测序法,获得了蜻科6属9种蜻蜓的线粒体细胞色素b（Cyt b）核苷酸序列（长度576 bp）。A＋T平均含量较高,为69．2％。氨基酸密码子第三位点的A＋T平均含量最高（86．5％）。变异位点数为216个（约占37．5％）,简约信息位点148个,数据显示这几种蜻蜓之间DNA序列变异丰富。用一种豆娘Megalestes maai作外群构建系统发育树表明：蜻科为单系群,灰蜻属较进化,黄蜻属相对较古老一些。这6属的起源关系为：黄蜻属和赤蜻属→宽腹蜻属→椎腹蜻属和红蜻属→灰蜻属。 相似文献