Direct vs. inclusive fitness in the evolution of aphid cornicle length

By comparing the relative sizes of anatomical structures among phenotypes, selective pressures that shape species' morphologies can be evaluated. Aphids emit droplets containing an alarm pheromone/defensive secretion from unique anatomical structures called cornicles, upon being attacked. As aphids live in colonies of high relatedness, it is uncertain whether direct or inclusive fitness benefits have chiefly promoted cornicle evolution. Morphological measurements for apterous parthenogen, alate parthenogen, female sexual and male sexual morphs of 43 species (21 genera, one subfamily) were assessed to distinguish between the hypotheses that: (1) cornicles evolved for mechanical defence against natural enemies (direct fitness); (2) cornicles evolved for alarm signalling (inclusive fitness); or (3) cornicle length has been largely constrained by flight aerodynamics. Our results generally support the inclusive fitness hypothesis; cornicle length decreases as the relative number and relatedness of offspring decreases. As cornicle length is greatest in apterous parthenogenetic morphs, inclusive fitness benefits of protecting highly related kin may have been a key factor selecting for cornicles, and increased cornicle length, in aphids.     

Cornicle length in Macrosiphini aphids: a comparison of ecological traits

Abstract 1. Aphids often emit cornicle droplets when attacked by predators. While the function of cornicle droplets has long been debated (i.e. mechanical protection vs. chemical signalling), it is not understood why aphid species have cornicles of different lengths.
2. It was hypothesised that aphids living in more scattered colonies have longer cornicles to scent-mark predators with cornicle droplets containing alarm pheromone, so that clone-mates are provided with advanced warning of a threat, even if not at the predation site. To test this hypothesis, multiple regression analyses were used, due to a lack of phylogenetic information on these taxa, to address which ecological traits (amount of wax on an aphid, degree of colony aggregation, feeding shelter, ant attendance) are correlated with cornicle length.
3. Aphids living in dense colonies tended to have shorter cornicles than aphids living in more scattered colonies. Also, aphids with more protection (i.e. wax) on their bodies had shorter cornicles. Aphids also tended to have shorter cornicles when tended by ants. The presence of a feeding shelter was not a good predictor of cornicle length.
4. It is suggested that longer cornicles function to scent-mark predators with alarm pheromone to increase the inclusive fitness of a clone; however the negative correlation between the amount of individual protection, and also ant attendance, and cornicle length argues for a trade-off between different forms of defence.     

Comparison of the Morphology and Deoxyribonucleic Acid Composition of 27 Strains of Nitrifying Bacteria

The gross morphology, fine structure, and per cent guanine plus cytosine (GC) composition of deoxyribonucleic acid of 27 strains of nitrifying bacteria were compared. Based on morphological differences, the ammonia-oxidizing bacteria were separated into four genera. Nitrosomonas species and Nitrosocystis species formed one homogenous group, and Nitrosolobus species and Nitrosospira species formed a second homogenous group in respect to their deoxyribonucleic acid GC compositions. Similarly, the nitrite-oxidizing bacteria were separated into three genera based on their morphology. The members of two of these nitrite-oxidizing genera, Nitrobacter and Nitrococcus, had similar GC compositions, but Nitrospina gracilis had a significantly lower GC composition than the members of the other two genera.     

Exotesta morphology of the Gardenieae — Gardeniinae (Rubiaceae)

Persson, C. 1995. Exotesta morphology of the Gardenieae-Gardeniinae (Rubiaceae). -Nord. J. Bot. 15: 285–300. CGpenhagen. ISSN 0107–055X.
Exotesta morphology of 68 species in 59 genera of the Gardeniinae were examined with the aid of scanning and light microscopy. The shape of the exotesta cells in surface is either isodiametrical or elongate and both shapes occur among New World and Old World genera. All genera, except for Monosalpinx, Posoqueria and Macrosphyra , are provided with secondary thickenings in the cell walls of the exotesta. The majority of the genera has a thickened radial wall. In the Asian genera Catunaregam, Deccania, Tamilnadia and the mainly Pacific genera, Atractocarpus and Trukia thickenings of the radial wall are very low or absent. In nearly half the genera the inner tangential wall is provided with thickenings, usually in the shape of a continuous plate. However, in four African genera, Atractogyne, Didymosalpinx, Mitriostigma and Sherbournia , the wall is provided with elongate anastomosing ribs. Atractocarpus differs markedly from the rest of the Gardeniinae by its ring-like thickenings in the inner tangential wall. Thickenings, in the shape of a continuous plate, in the outer tangential wall is restricted to three neotropical genera, Alibertia, Amaioua and Borojoa . Presence of distinct knobs is common in palaeotropical genera, whereas in neotropical genera this feature is only present in Casasia and Kotchubaea . It is concluded that data on exotesta morphology alone does not support any of the previously proposed informal groups, but may still be an important character to deduce phylogenetic relationships, primarily on a level just above the genus.     

A New Classification of the Schizogregarina

SUMMARY. The author proposes a new systematic division of the suborder Schizogregarina on the basis of the comparative morphology of the different stages of the life-cycle of the different genera. Two families, Dischizae and Monoschizae, are divided into a total of 6 tribes: The Dischizae into Ophryocystinae with the genera Ophryocystis, Mattesia, Menzbieria, Lipocystis and Sawayella , and Machadoellinae with the genera Machadoella and Farinocystis; Monoschizae into the tribe Caulleryellinae with genera Caulleryella, Tipulocystis and Merogregarina , the tribe Syncystinae with the genera Syncystis and Lipotropha , the tribe Schizocystinae with the genera Schizocystis and Siedleckia and the tribe Selenidiinae with the genera Selenidium and Meroselenidium.     

Cornicle secretions of Uroleucon nigrotuberculatum (Homoptera: Aphididae) as the last bullet against lady beetle larvae

Aphids have evolved various defense strategies against natural enemies, including secretions from their cornicles. We assessed the defensive function of cornicle secretions by the goldenrod aphid, Uroleucon nigrotuberculatum (Olive), against larvae of the lady beetles Coccinella septempunctata bruckii Mulsant and Propylea japonica (Thunberg) (Coleoptera: Coccinellidae). The aphid secreted red droplets from its cornicles when attacked by the larvae. Two‐thirds of the C. septempunctata bruckii larvae and 46.7% of the P. japonica larvae that preyed on the aphids died before reaching the pre‐pupal stage. The secretions caused molting failure when smeared on the larvae's heads or glued to the larvae's mouthparts, killing 56.7% of C. septempunctata bruckii larvae and 36.7% of P. japonica larvae. Second instar larvae were affected most. About 40% of third and fourth instar larvae of C. septempunctata bruckii vomited soon after ingesting the aphids. In the field, up to 40% of first and second instar larvae were smeared with red secretions. Our results show that these cornicle secretions are an effective and active defense against earlier instars of coccinellid larvae.     

大风子科13个种的花粉形态

利用光镜和扫描电镜对大风子科 9属 1 3个种的花粉形态进行了观察。花粉形状长球形或圆球形 ,除大风子属 (Hydnocarpus)萌发孔为三拟孔沟 ,其余均为三孔沟 ;外壁纹饰在不同属、同属不同种间表现出明显的多样化 ,基本上可分为粗网状、细网状、穿孔状、穴状4种类型。研究认为花粉形态对于该科与近缘科以及属下的划分具有一定的意义     

天麻抗真菌蛋白对木霉菌丝的作用位点

天麻抗真菌蛋白(Gastrodia Antifungal Protein,GAFP)能强烈抑制腐生真菌菌丝的生长,在天麻限制和防止蜜环菌［Armillariella mellea (Vahl. ex Fr.)Karst.］侵染球茎的防卫机制中起重要作用。本文报告GAFP抗菌机理研究的部分内容——GAFP对木霉菌丝的作用位点。用荧光试剂异硫氰酸荧光素(Fluorescein isothiocyanate,FITC)标记GAFP,试验表明,标记后的GAFP与未标记的GAFP对木霉菌丝生长均有抑制作用。在荧光显微镜下观察GAFP在木霉菌丝上的作用位点,发现被“标记GAFP”作用后的菌丝边缘有荧光,并主要集中在木霉菌丝的顶端和菌丝横隔处,表明GAFP对木霉的作用位点在菌丝的细胞壁上。     

Functional and systematic implications of the ear in golden moles (Chrysochloridae)

Golden moles (Chrysochloridae) are fossorial mammals known to have unusual mallei. The aim of this study was to describe and quantify aspects of the auditory morphology of golden moles in order to determine their systematic and functional implications. Observations were made on skeletal material as well as histological sections. The results of this study do not support the separation of the genus Calcochloris from Amblysomus . It was found that the morphology shared by all the studied genera is indicative of specialization for hearing low frequency sound. The tympanic membrane to stapes footplate ratios, ossicular lever arm ratios and incudomallear joint morphology suggest low frequency specializations in genera with small mallear heads and high frequency specializations in genera with large mallear heads. However, the size and degree of trabeculation of the tympanic cavity are not consistent with this result. It is proposed that all golden moles are low frequency hearers with differences in their range of sensitivity according to how much time they spend foraging above ground.     

Molecular systematics of the Sordariales: the order and the family Lasiosphaeriaceae redefined

The Sordariales is a taxonomically diverse group that has contained from seven to 14 families in recent years. The largest family is the Lasiosphaer-iaceae, which has contained between 33 and 53 genera, depending on the chosen classification. To determine the affinities and taxonomic placement of the Lasiosphaeriaceae and other families in the Sordariales, taxa representing every family in the Sordariales and most of the genera in the Lasiosphaeriaceae were targeted for phylogenetic analysis using partial sequences of the large-subunit (LSU) nrDNA. Based on molecular data, only genera within the families Chaetomiaceae, Lasiosphaeriaceae and Sordariaceae are retained within the redefined Sordariales. The order is a coherent group with morphologies that vary along well-defined lines, including large ascomata with large-celled membraneous or coriaceous walls and ascospores that show variation on a distinctive developmental theme, often with appendages or sheaths. The paraphyletic chaetomiaceous complex and the strongly supported Sordariaceae are nested among taxa traditionally placed in the Lasiosphaeriaceae. Analyses also indicate that 11 genera belong in the paraphyletic lasiosphaeriaceous complex. These taxa share a similar developmental pattern in their ascospore morphology that extends to the Sordariales as a whole. Based on these similarities in morphology, 13 additional genera are retained within the lasiosphaeriaceous complex and more than 35 genera have relationships in the order overall. Based on LSU data, 17 genera that have been assigned to the Lasiosphaeriaceae sensu lato are transferred to other families outside the Sordariales and 22 additional genera with differing morphologies subsequently are transferred out of the order. Two new orders, Coniochaetales and Chaetosphaeriales, are recognized for the families Coniochaetaceae and Chaetosphaeriaceae respectively. The Boliniaceae is accepted in the Boliniales, and the Nitschkiaceae is accepted in the Coronophorales. Annulatascaceae and Cephalothecaceae are placed in Sordariomycetidae inc. sed., and Batistiaceae is placed in the Euascomycetes inc. sed.     

模糊聚类分析在中国伞形科当归亚族分类中的应用

针对伞形科前胡族当归亚族上属间界线划分的分歧,采用模糊聚类分析方法,在形态方面以属为分类单位,定量阐明了属间亲缘关系。化学方面,以裂解－气相色谱信息为分类依据肉获得的２７个种的数据揭示了当归亚族中属间的分类关系,结果表明,当归属和在中国分布的山芹属与广义当归属类群相近,并显示了东北长鞘当归和骨缘当归是一个较特殊的类群。     

Geometric morphometrics of the skull of Tinamidae (Aves, Palaeognathae)

The Tinamidae comprise exclusively Neotropical palaegnathous birds, with homogeneous body morphology and no sexual dimorphism. The goal of this work was to explore the variation in skull morphology between taxa and its possible correspondence with features such as diet or gender using geometric morphometric tools. Eleven landmarks were analyzed in 53 skulls of 4 genera that inhabit grasslands: Nothoprocta, Eudromia, Nothura and Rhynchotus. Intrageneric and intergeneric variability was analyzed. The genera studied here can be distinguished based on the geometric shape of their skull, with prenarial region length and neurocranium shape as the most outstanding features. In the genus Eudromia, males and females could be differentiated, while in the genus Nothoprocta, the species differentiated according to their trophic habits. This study allows establishing that genera and, in some cases, the gender of the Tinamidae can be differentiated based on cranial shape.     

木兰科种子内种皮合点区形态观察

在扫描电镜下观察了１０属３２种木兰科植物种子内种皮合点区的形态,发现可分为孔状和具管的窝状两大类型,且在不同的属种间有所差别,可以用来作为木兰科分类的新依据     

蝽科精巢细胞减数分裂染色体行为及其反映的属种间亲缘关系

为探讨蝽科精巢细胞减数分裂各时期染色体形态和行为差异, 以及据此反映的属种间亲缘关系, 采用常规染色体制片法对蝽科6属9种精巢细胞减数分裂各期染色体形态特征、 行为及精子的形成进行了观察和比较研究。结果表明： 蝽科精巢细胞为交叉型减数分裂, “O”型交叉为其典型交叉减数分裂形式。各属种减数分裂各期染色体行为相似, 但形态不同。减数分裂各期染色体形态、 排列方式, 中期染色体相对长度、 组成与核型以及精子形态等特征具有属种间差异性。蝽科精巢细胞中期Ⅰ染色体组平均相对长度都为12.5, 在进化过程中染色体组长度信息总量不变。基于染色体相对长度的聚类分析结果显示, 菜蝽属Eurydema、 麦蝽属Aelia、 珠蝽属Rubiconia和条蝽属Graphosoma亲缘关系密切, 而二星蝽属Stollia与果蝽属Carpocoris关系较近。     

中国苔类孢子形态的研究

通过电镜扫描方法 ,研究了 3个属 9种的中国叶状体苔类植物 :稀枝钱苔 (RicciahuebenerianaLindb .)、宽翅钱苔 (R .hantamensisPerold .)、曲脊钱苔 (R .cavernosaHoffm .)、R .warnstorfiiLimpr.exWarnst.、小孢钱苔 (R .frostiiAust.)、中华钱苔 (R .chinensisHerz .)、东亚花萼苔 (Asterellayoshinagana (Horik .)Horik .)、矮网花萼苔 (A .sanguiniaL .etL .)、背托苔 (Preissiaquadrata) (Scop .)Nees.)。对上述种类的孢子形态特征进行了描述。研究发现 ,上述 3属的孢子形态特征具有明显差异。而且同一属的孢子形态特征也存在差异 ,甚至可以作为种类划分的依据之一。同时采自不同地点的同一种类其孢子形态有时具微小的差别。这可能是由于生态环境差异所造成的     

Studies on the Pollen Morphology of Tribe Zizipheae of Rhamnaceae in China

Pollen morphology of Chinese 19 species representing 6 genera in the tribe Zizipheae Brongn., Rhamnaceae, was examined under light microscope and scanning electron microscope. The pollen grains oblate or suboblate, rarely subspheroidal. Polar axis 13.1-26.1μm long, equatorial axis 16.5-29.6μm long, 3-colporate, colpus generally narrow, ora lalongate, with two ends connected with the thinned part of exine, forming a H-shape. There are 4 thickenings where colpi and ora pass across, or sometimes the thickenings indistinct, forming a ring. Stratification couspicuous or inconspicuous. Ornamentation of exine obscure, rarely obscurely reticulate under light microscope, but conspicuously fine-reticulate, finely reticulate-foveolate, foveolate, striate-reticulate and shortly striate under scanning electron microscope. A key to the genera based on pollen grains is provided and the general morphology of 6 genera: Paliurus, Ziziphus, Chaydaia, Berchemia, Berchemiella and Rhamnella are described. Based on 4 thickenings and H-shape, pollen grains of the tribe Zizipheae may be divided into two groups: 1. the four thickenings rather larger and conspicuous, or stretched along the colpus in some species, H-shape distinct, e.g. in Berchemiella, Chaydaia and Rhamnella, and 2. the four thickenings smaller, sometimes forming a ring, H-shape more or less conspicuous, e.g. in Berchemia, Paliurus and Ziziphus. With respect to the concept of the genera Berchemiella and Berchemia, there were two different ideas among a number of taxonomists. H. Koidzumi, J. Ohwi and S. Kitamura place the former in Berchemia as a section, but on the contrary, T. Nakai, T. Yamazaki and K. Suessenguth consider Berchemiella and Berchemia as two separate genera. The data from pollen morphology support the latter treatment. Berchemia is closely related to Berchemiella, Chaydaia and Rhamnella in the habit and the floral morphology, but differs from the others by its disc well-developed, eularged and becoming cup-shaped in fruit. They are also different from each other in the characters of pollen grains. T. Yamazaki places the genus Chaydaia in Rhamnella as a section, but according to the pollen morphology to treat Chaydaia and Rhamnella as two independent genera woild be reasonable.     

Taxonomic significance of pollen types in the Guyana Highland-centred composite genera of Mutisioideae (Asteraceae)

The Guyana Highland-centred genera, or Stenopadus group, are a complex of species that belong to the tribes Mutisieae and Stifftieae of Asteraceae. The pollen morphologies of 29 species, from 12 of 13 genera of this complex, are described and illustrated using light and scanning electron microscopy. The exine sculpture and structure are highly significant. Four exine types, previously characterized, were distinguished: Gongylolepis , Wunderlichia , Mutisia , and Stenopadus . The characterization of the Stenopadus exine type is enlarged here. These exine types led to the recognition of four well-defined pollen types, whereas the spine length and exine thickness characterized six subtypes. Pollen types circumscribe genera or groups of genera, and some subtypes distinguish species. The pollen morphology within the complex is discussed in relation to the rest of Mutisioideae and other palynologically allied tribes of Cichorioideae. There is little correlation between pollen types and tribes; only the Stenopadus exine type is exclusive to the Stifftieae tribe. The remaining types are shared by the two tribes of the complex. Pollen morphology supports the hypothesis that this group of genera is close to the Gochnatia complex and the Cardueae tribe.  © 2008 The Linnean Society of London, Botanical Journal of the Linnean Society , 2008, 156 , 327–340.     

（鱼句）亚科花（鱼骨）型鱼类骨骼系统的比较

对我国花型Hemibarbuspattern鱼类作了骨骼系统比较,结果表明,此类型鱼类脑颅较长,副蝶骨平直或稍弯曲,眶蝶骨腹纵嵴发达(铜鱼Coreius septentrionalis例外),下颞窝和咽突中等大,基枕骨后突发达;脑颅中的上筛骨的后突、侧筛骨的外筛突,蝶耳骨的外突、上耳骨的后突、围眶骨和后颞窝等均有明显的差异;咽颅中的舌颌骨、尾舌骨、鳃盖骨和下咽齿的列数等又有显著的区别;附肢骨骼中的腰带骨、脊椎骨中的复合神经骨和第4椎骨腹侧的悬器等也有不同之处。据此,这些差异和区别可作为属间或种间的分类依据。     

中国柽柳科（Tamaricaceae）花粉形态研究及其分类意义的探讨

研究观察了中国柽柳科（Tamaricaceae)4属27种植物的花粉形态。中国柽柳科植物花粉为三沟类型,无三拟孔沟类型,形态及外壁雕纹属间差异明显。根据花粉资料,探讨了属间的进化关系和分类地位及本科植物花粉外壁的演化途径。     

Cladistics of the genera of Mesochorinae (Hymenoptera: Ichneumonidae)

Abstract. A cladistic analysis is presented for the genera of the ichneumonid subfamily Mesochorinae. Nine genera are recognized as valid. Previous work on larval morphology is reviewed and a number of larvae are newly illustrated and discussed. Four new synonyms are proposed: Oncocotta, Piestetron, Plectochorus and Rhaibaspis are all synonymized with Mesochorus , and Stictopisthus is placed back as a synonym of Mesochorus. Four new genera are described: Artherola from South Africa, Chineater from Chile, Thamester from Japan, and Varnado from Morocco. A new key is provided to the mesochorine genera of the world.