丽翼蛉昆虫的化石介绍及其防御策略分析

丽翼蛉科是脉翅目昆虫中的一个绝灭科，迄今为止正式发表9属12种，仅在我国、蒙古国、俄罗斯的侏罗统地层及黎巴嫩的白垩统地层中被发现。本文介绍了丽翼蛉科成虫的特征、分类研究状况，以及多样的翅斑类型，并分析了丽翼蛉化石标本展示的色彩防御策略，如混隐色、瞬彩、警戒色和拟态等。     

中生代脉翅目昆虫的叶状拟态

拟态是一种生物模拟另一种生物或环境中的其它物体从而使自身获得好处的现象,是昆虫在进化过程中特化出的一种极为重要和有效的防御策略。脉翅目昆虫是一类完全变态性昆虫,在其超过2.7亿年的演化历史中,出现了形态多样的翅斑。美翼蛉属Bellinympha Wang,Ren,Liu,Shih&Engel,2010是脉翅目溪蛉科丽翼蛉亚科的一个绝灭属,发现于中国内蒙古道虎沟地区中侏罗世九龙山组地层。该属的发现代表了迄今报道的最古老的叶状拟态现象,也是唯一报道的昆虫模拟裸子植物或蕨类植物叶片。本文简要概述了脉翅目昆虫研究概况,总结了中生代脉翅目翅斑的多样性,对美翼蛉属进行了描述,并对其叶状拟态及其生物学意义进行了探讨。     

Ancient pinnate leaf mimesis in Mesozoic lacewings

拟态是一种生物模拟另一种生物或环境中的其它物体从而使自身获得好处的现象,是昆虫在进化过程中特化出的一种极为重要和有效的防御策略.脉翅目昆虫是一类完全变态性昆虫,在其超过2.7亿年的演化历史中,出现了形态多样的翅斑.美翼蛉属Bellinympha Wang,Ren,Liu,Shih&Engel,2010是脉翅目溪蛉科丽翼蛉亚科的一个绝灭属,发现于中国内蒙古道虎沟地区中侏罗世九龙山组地层.该属的发现代表了迄今报道的最古老的叶状拟态现象,也是唯一报道的昆虫模拟裸子植物或蕨类植物叶片.本文简要概述了脉翅目昆虫研究概况,总结了中生代脉翅目翅斑的多样性,对美翼蛉属进行了描述,并对其叶状拟态及其生物学意义进行了探讨.     

丽草蛉

正丽草蛉(Chrysopa formosa),脉翅目草蛉科昆虫,成虫体长约10 mm,鲜绿色,触角细长丝状,复眼有金色闪光,翅透明,翅脉大部分绿色,少数黑色。常飞翔于草木间,肉食性,尤其喜欢捕食蚜虫,且常在蚜虫较多的植物上产卵。群产,产卵前,雌虫分泌长丝,卵产于长丝顶部,每卵一丝,使各卵相互分离,以防孵出的幼虫自相残杀。幼虫     

“中生代的蝴蝶”——脉翅目丽蛉类昆虫

丽蛉类昆虫是脉翅目昆虫在中生代特有的一类绝灭昆虫,被誉为"中生代的蝴蝶",其体型巨大、脉序复杂,部分身体特征高度特化,与现代脉翅目昆虫表现出明显的差异,而其在脉翅目演化中的地位也是一直难以确定。同时,由于化石保存的局限性,该类昆虫多是依靠不完整的结构进行分类,缺少系统的总结和修订,也为该类群的深入研究带来了很大的困难。本文对中生代丽蛉类昆虫进行了总结,统计了至今全世界所发现的所有丽蛉类昆虫名录,概述了其研究历史,地质年代及地理分布,系统发育研究进展,功能形态学研究及生态学特性等问题,并提出了研究该类群有待解决的问题及研究展望。     

中生代线蛉科化石(昆虫纲,脉翅目)

线蛉科是脉翅目中的一个灭绝科,仅发现于中国中侏罗统和蒙古晚侏罗统地层中。线蛉科昆虫脉序独特,为其分类地位的确定以及整个脉翅目翅脉演化的研究提供了重要的线索;此外,线蛉科昆虫前后翅上均具有条带状的斑纹,初步推测这种斑纹在其生存繁衍过程中发挥了积极作用,也可能是导致其灭绝的最直接因素之一。目前线蛉科已发表3属9种,本文对其进行了简要的回顾,并编制了线蛉科化石种检索表,对当时的古环境特征进行了简单推测,初步探讨了翅斑在其生存和灭绝中的作用。     

溪蛉科研究进展

溪蛉是脉翅目中比较稀少的一个类群,可以作为天敌资源和研究昆虫演化的"活化石"材料,但历史上溪蛉科在脉翅目中的系统地位一直是个颇具争议难以解决的问题。本文综述了溪蛉科国内外分类研究简史,探讨了溪蛉科的地理分布,以及溪蛉科生物学、化石等其他方面的研究进展。最后提出了溪蛉科分类研究中亟须解决的几个问题并呼吁应该加强对其应用价值的研究。     

叶色草蛉头部斑纹的变化

<正> 叶色草岭Chrysopa phyllochroma Wesmael是冀中平原主要蛉种之一。叶色草蛉和丽草蛉形态相似。共同的特征是头部斑纹9个,头顶、触角下、颊和唇基两侧各一对,触角间1个;触角第一节绿色,第二节黑色。叶色草蛉与丽草蛉的体色和体长均差不多,仅从体形大小和色泽上尚难以区分。 叶色草蛉前翅前缘横脉列绿色,只近亚前缘脉一端黑色;丽草蛉前翅前缘横脉列黑色,是两者主要鉴别特征。     

FOSSIL GRAMMOLINGIIDAE FROM THE MESOZOIC (INSECTA,NEUROPTERA)

线蛉科是脉翅目中的一个灭绝科,仅发现于中国中侏罗统和蒙古晚侏罗统地层中.线蛉科昆虫脉序独特,为其分类地位的确定以及整个脉翅目翅脉演化的研究提供了重要的线索;此外,线蛉科昆虫前后翅上均具有条带状的斑纹,初步推测这种斑纹在其生存繁衍过程中发挥了积极作用,也可能是导致其灭绝的最直接因素之一.目前线蛉科已发表3属9种,本文对其进行了简要的回顾,并编制了线蛉科化石种检索表,对当时的古环境特征进行了简单推测,初步探讨了翅斑在其生存和灭绝中的作用.     

云南省粉蛉两新种记述（脉翅目：粉蛉科）

记述云南省脉翅目粉岭科2新种：奇斑曲粉岭Coniocom psa spectabilis Liu et yang,sp.nov和丫重粉蛉Semidalis ypsilon Liu et Yang,sp.nov。。模式标本均保存在中国农业大学昆虫标本馆。     

The oldest giant lacewings (Neuroptera: Kalligrammatidae) from the Lower Jurassic of Germany

We describe the oldest Kalligrammatidae, two distantly related species of different subfamilies from the Lower Jurassic (lower Toarcian) of Germany: Liassopsychops curvatus Bode, 1953, sit. nov. (Liassopsychopinae n. subfam.) and Ophtalmogramma klopschari n. gen. n. sp. (Kallihemerobiinae). They lived in warm and relatively dry conditions. Subfamily Liassopsychopinae includes the Jurassic genera Liassopsychops and Huiyingogramma, sit. nov., which bear forewings characterized by Sc and RA not fused distally; MP, CuA, CuP, and A1 dichotomously branched; and a well-developed central eye-spot. The forewing of Ophtalmogramma n. gen. is most similar to that of Apochrysogramma Yang et al., 2011. The diversity of early Toarcian kalligrammatids indicates a late Triassic–earliest Jurassic origin of the family. A modified classification of the central eye-spots is proposed based on the presence/absence of four main components, i.e., the central pigmented disc (A), swellings (B), ocules (C), and outer rings (D). The function of the swellings is unclear, but they may have served as pheromone containers.     

The evolutionary convergence of mid-Mesozoic lacewings and Cenozoic butterflies

Mid-Mesozoic kalligrammatid lacewings (Neuroptera) entered the fossil record 165 million years ago (Ma) and disappeared 45 Ma later. Extant papilionoid butterflies (Lepidoptera) probably originated 80–70 Ma, long after kalligrammatids became extinct. Although poor preservation of kalligrammatid fossils previously prevented their detailed morphological and ecological characterization, we examine new, well-preserved, kalligrammatid fossils from Middle Jurassic and Early Cretaceous sites in northeastern China to unravel a surprising array of similar morphological and ecological features in these two, unrelated clades. We used polarized light and epifluorescence photography, SEM imaging, energy dispersive spectrometry and time-of-flight secondary ion mass spectrometry to examine kalligrammatid fossils and their environment. We mapped the evolution of specific traits onto a kalligrammatid phylogeny and discovered that these extinct lacewings convergently evolved wing eyespots that possibly contained melanin, and wing scales, elongate tubular proboscides, similar feeding styles, and seed–plant associations, similar to butterflies. Long-proboscid kalligrammatid lacewings lived in ecosystems with gymnosperm–insect relationships and likely accessed bennettitalean pollination drops and pollen. This system later was replaced by mid-Cretaceous angiosperms and their insect pollinators.     

Cross-Sectional Shape of Collapsible Tubes

In order to quantify the collapse phenomenon in veins, this paper presents a mathematical analysis of the cross-sectional shape of a flexible tube as its internal pressure varies. Quantitative results are presented in terms of the physical parameters of the tube, such as wall thickness and Young's modulus. It is assumed that the tube is thin walled, that no stretching occurs, that the cross-sectional shape is elliptical when the transmural pressure is zero, and that the longitudinal prestress is zero. The equations were solved on a digital computer which displayed the cross-sectional shapes on an oscilloscope, which were then photographed. A selection of these photographs is presented. Curves are shown which give the cross-sectional area and compliance as functions of transmural pressure. Other curves are shown which are useful for interpolation, and for use in the experimental determination of the physical parameters which may otherwise be difficult or impossible to measure accurately.     

Preliminary Classification of Viruses Based on Quantitative Comparisons of Viral Nucleic Acids

It is proposed that classifications used in science are of two main types; those which are designed to solve practical problems and which are based on conventions, and those which are designed to solve theoretical problems, based on theories, and in which the classes are tested by experiment. An attempt has been made to construct a preliminary classification of viruses which is of the second type. It is based on the theories of molecular biology, with the use of computer-based comparisons of the molecular weights and base ratios of viral nucleic acids to assign the viruses to clusters which show a high degree of correlation with groupings based on nucleic acid hybridization, serological cross-reactions, and phenotypic properties.     

Compound eyes of insects and crustaceans: Some examples that show there is still a lot of work left to be done

Similarities and differences between the 2 main kinds of compound eye (apposition and superposition) are briefly explained before several promising topics for research on compound eyes are being introduced. Research on the embryology and molecular control of the development of the insect clear‐zone eye with superposition optics is one of the suggestions, because almost all of the developmental work on insect eyes in the past has focused on eyes with apposition optics. Age‐ and habitat‐related ultrastructural studies of the retinal organization are another suggestion and the deer cad Lipoptena cervi, which has an aerial phase during which it is winged followed by a several months long parasitic phase during which it is wingless, is mentioned as a candidate species. Sexual dimorphism expressing itself in many species as a difference in eye structure and function provides another promising field for compound eye researchers and so is a focus on compound eye miniaturization in very small insects, especially those that are aquatic and belong to species, in which clear‐zone eyes are diagnostic or are tiny insects that are not aquatic, but belong to taxa like the Diptera for instance, in which open rather than closed rhabdoms are the rule. Structures like interommatidial hairs and glands as well as corneal microridges are yet another field that could yield interesting results and in the past has received insufficient consideration. Finally, the dearth of information on distance vision and depth perception is mentioned and a plea is made to examine the photic environment inside the foam shelters of spittle bugs, chrysales of pupae and other structures shielding insects and crustaceans.     

Phylogenetic position of the Strepsiptera: Review of molecular and morphological evidence

Molecular evidence of the monophyly of the Halteria (Strepsiptera + Diptera) is reviewed. The majority of morphological characters, which have classically been used to establish a Strepsiptera + Coleoptera sister group, are rejected, because they are based on erroneous interpretations of strepsipteran morphology. The scorings of 31 morphological characters, which directly relate to the phylogenetic position of Strepsiptera, are provided, and their distribution and optimization on the molecular + morphological tree is discussed. Of these, 13 characters specifically support the placement of Strepsiptera within the Mecopterida; seven of which are based on the optimization of inapplicable or missing data, and six of which are based on states that can be scored for Strepsiptera. Only a single character (posteromotorism) suggests a sister group relationship with the Coleoptera. The morphological and molecular data are largely congruent, and suggest that the Strepsiptera are sister group to the Diptera.     

How affinity influences tolerance in an idiotypic network

Idiotypic network models give one possible justification for the appearance of tolerance for a certain category of cells while maintaining immunization for the others. In this paper, we provide new evidence that the manner in which affinity is defined in an idiotypic network model imposes a definite topology on the connectivity of the potential idiotypic network that can emerge. The resulting topology is responsible for very different qualitative behaviour of the network. We show that using a 2D shape-space model with affinity based on complementary regions, a cluster-free topology results that clearly divides the space into distinct zones; if antigens fall into a zone in which there are no available antibodies to bind to, they are tolerated. On the other hand, if they fall into a zone in which there are highly concentrated antibodies available for binding, then they will be eliminated. On the contrary, using a 2D shape space with an affinity function based on cell similarity, a highly clustered topology emerges in which there is no separation of the space into isolated tolerant and non-tolerant zones. Using a bit-string shape space, both similar and complementary affinity measures also result in highly clustered networks. In the networks whose topologies exhibit high clustering, the tolerant and intolerant zones are so intertwined that the networks either reject all antigen or tolerate all antigen. We show that the distribution and topology of the antibody network defined by the complete set of nodes and links-an autonomous feature of the system-therefore selects which antigens are tolerated and which are eliminated.     

A review of criticisms of phylogenetic nomenclature: is taxonomic freedom the fundamental issue?

The proposal to implement a phylogenetic nomenclatural system governed by the PhyloCode), in which taxon names are defined by explicit reference to common descent, has met with strong criticism from some proponents of phylogenetic taxonomy (taxonomy based on the principle of common descent in which only clades and species are recognized). We examine these criticisms and find that some of the perceived problems with phylogenetic nomenclature are based on misconceptions, some are equally true of the current rank-based nomenclatural system, and some will be eliminated by implementation of the PhyloCode. Most of the criticisms are related to an overriding concern that, because the meanings of names are associated with phylogenetic pattern which is subject to change, the adoption of phylogenetic nomenclature will lead to increased instability in the content of taxa. This concern is associated with the fact that, despite the widespread adoption of the view that taxa are historical entities that are conceptualized based on ancestry, many taxonomists also conceptualize taxa based on their content. As a result, critics of phylogenetic nomenclature have argued that taxonomists should be free to emend the content of taxa without constraints imposed by nomenclatural decisions. However, in phylogenetic nomenclature the contents of taxa are determined, not by the taxonomist, but by the combination of the phylogenetic definition of the name and a phylogenetic hypothesis. Because the contents of taxa, once their names are defined, can no longer be freely modified by taxonomists, phylogenetic nomenclature is perceived as limiting taxonomic freedom. We argue that the form of taxonomic freedom inherent to phylogenetic nomenclature is appropriate to phylogenetic taxonomy in which taxa are considered historical entities that are discovered through phylogenetic analysis and are not human constructs.     

Persistence,extinction, and critical patch number for island populations

Sufficient conditions are derived for persistence and extinction of a population inhabiting several islands. Discrete reaction-diffusion population models are analyzed which describe growth and diffusion of a population on a group of islands or a patch environment. A critical patch number is defined as the number of islands below which the population goes extinct on that group of islands. It is shown that population persistence on one island leads to population persistence for the entire archipelago. Both single-species and multi-species models are discussed.     

Effect of slotted wing tips on yawing moment characteristics

The aerodynamic yawing moment characteristics of bird wings with slotted tips are dealt with. Emphasis is placed on the effect of sweep which the separated feathers constituting the wing tips show and which can reach significant values. Reference is made to basic aerodynamic characteristics of wings with sweep which yields a stabilizing yawing moment significantly larger than that of unswept wings. Then, the yawing moment characteristics are determined for a wing, the features of which are considered as representative of bird wings with sweep in their slotted tips. A sophisticated aerodynamic procedure is used for obtaining results of high precision. It is shown that the sweep in the slotted wing tips yields a stabilizing yawing moment of significant magnitude, considerably increasing with the lift coefficient. To make the significance of wing tip sweep for the ability to generate yawing moments more perspicuous, a wing modification the slotted tips of which are unswept is considered for comparison. It turns out that this wing shows yawing moments which are substantially smaller. A physical insight into the effect of slotted wing tip sweep on the aerodynamic yawing moment characteristics is provided by showing the underlying mechanism. From the results presented in this paper it follows that the sweep in slotted wing tips provides a substantial contribution to the aerodynamic yawing moment and, thus, to yaw stability. It may be concluded that this is an essential reason why there is sweep in the slotted tips of bird wings.