菜粉蝶蛹体型大小对蝶蛹金小蜂后代数量、性比及体型大小的影响

为检验“寄主体型大小-质量假说”,采取饥饿方法处理菜粉蝶(Pieris rapae)高龄幼虫,以获得体型大小(用体质量表示)差异大于同一自然地理种群内个体间差异的寄主蛹,然后供聚寄生蜂-蝶蛹金小蜂(Pteromalus puparum)寄生,观察寄生蜂在不同大小寄主蛹内的后代数量、性比以及体型大小。结果表明,蝶蛹金小蜂1次攻击产出的后代蜂数随寄主蛹体质量增加而显著增多,蛹中平均出蜂314.97头·g^-1。蝶蛹金小蜂后代的雌性比例随寄主蛹质量的增大而显著提高,后代雌蜂和雄蜂的体型大小(后足胫节长度)均随寄主蛹质量的增大而显著增大。可见,蝶蛹金小蜂母蜂能够根据寄主蛹质量来调整后代数量和性比,以使后代适应度最大化。最后,就蝶蛹金小蜂产卵策略及其影响因素进行了讨论。     

聚寄生性蝶蛹金小蜂雌蜂体型大小对产卵策略的影响

在寄生蜂行为生态学研究中, 通常将寄主体型大小作为寄主品质的主要性状来探究寄生蜂的搜寻行为机理, 而忽略寄生蜂体型大小的意义。为揭示聚寄生蜂雌蜂体型大小对其产卵决策的影响, 在严格控制寄主菜粉蝶Pieris rapae蛹体型大小（体重）的情况下, 于室内观察了不同体型大小的蝶蛹金小蜂Pteromalus puparum雌蜂的产卵行为, 并调查了子代蜂数量（窝卵数）、 性比和体型大小的变化。结果表明： 雌蜂在寄主上的驻留时间随其自身体型增大而缩短, 但随寄主体重增大而延长。窝卵数和余卵量受到雌蜂体型大小的显著影响, 均随雌蜂体型增大而显著增加（P<0.05）; 但子代蜂性比不受雌蜂体型大小的显著影响 (P>0.05)。子代雌、 雄性体型大小均与雌蜂体型大小无关, 但子代雌蜂体型随寄主体重增大而增大。结果证实, 雌性蝶蛹金小蜂体型大小影响其部分产卵决策。因此, 在建立聚寄生蜂产卵决策模型中应考虑雌蜂体型大小这一重要变量因素。     

蝶蛹金小蜂的卵巢发育在不同寄主之间差异性的比较

为明确不同寄主对蝶蛹金小蜂Pteromalus puparum卵巢发育的影响,以柑橘凤蝶Papilio xuthus和菜粉蝶Pieris rapae这两种常见的寄主为研究对象,调查了两种寄主对蝶蛹金小蜂卵巢管长度、不同发育级别卵的卵室数,以及各自占整个卵巢卵室总数的比例进行了调查.结果表明,从两种寄主中羽化出的寄生蜂在卵巢管长度间差异显著,而在Ⅲ级卵的卵室比例上以柑橘凤蝶为寄主的寄生蜂明显高于以菜粉蝶为寄主的寄生蜂,而Ⅰ级和Ⅱ级的卵比例则低于后者.     

蝶蛹金小蜂寄生对菜粉蝶体液免疫反应的影响(英文)

以蝶蛹金小蜂及其寄主菜粉蝶为研究对象 ,研究了内寄生蜂对寄主体液免疫反应的影响。当寄主蛹被寄生后 1 2h或第 4和 5d时 ,血淋巴中酚氧化酶活性明显增高。寄生蛹血淋巴中血细胞凝集素活性始终高于针刺和未寄生蛹 ;同样 ,寄生蛹血淋巴的抗菌活性也明显增强 ,而后两者处理蛹的活性则很微弱。由此可知 ,该蜂寄生能引起寄主体液免疫因子活性的不同程度的变化     

六盘山翠金小蜂生物学特性的研究

六盘山翠金小蜂Tritneptis sp.是华北落叶松人工林主要食叶害虫落叶松红腹叶蜂Pristiphora erichsonii Hartig茧期的体外复寄生性天敌。对该蜂的生物学特性研究表明,该蜂在宁夏六盘山1年2代,以幼虫在寄主茧内越冬,翌年4月中旬开始活动取食,5月中旬开始化蛹,成蜂从6月中旬开始羽化,每头虫茧平均出蜂6.14头,雌雄比1.79∶1,雌蜂6月下旬开始产卵,一只雌蜂一生可在12.2头寄主虫茧上产卵,第1代寄生蜂幼虫7月上旬开始孵化并吸食寄主营养发育,7月下旬开始化蛹,8月上旬开始羽化并交尾、产卵寄生。该蜂体型较大,对寄主跟随性强,无重寄生天敌,自然寄生率7.3%～33.6%,是一种优良天敌寄生蜂。     

寄主大小对蝇蛹俑小蜂Spalangia endius(Walker)产卵选择和发育的影响

【背景】对寄生蜂与寄主之间关系的研究是寄生蜂有效利用的基础。寄生蜂雌蜂通常选择最适于子代蜂发育的寄主进行产卵。【方法】在室内26℃条件下,研究了橘小实蝇蛹体型大小对蝇蛹俑小蜂产卵和生长发育的影响。采用饥饿方法处理3龄橘小实蝇幼虫以获得体型大小(用体质量表示)差异较大的寄主蛹,供寄生蜂选择寄生。【结果】蝇蛹俑小蜂显著偏好寄生体型中等的寄主蛹,然而,随着寄主体型的增大,后代雌性比率增大,且寄主蛹个体大小与后代雌蜂体型大小存在显著的正相关;橘小实蝇蛹个体大小对蝇蛹俑小蜂后代发育历期和寿命无显著影响。【结论与意义】蝇蛹俑小蜂雌蜂能够根据寄主蛹质量来调整后代数量和性比,以使后代适应度最大化。     

南京地区菜粉蝶Pieris rapae Linné寄生蜂考查

1956-1958年间, 作者在南京考查菜粉蝶天敌, 发现重要种类有:黄金小蜂(Pteromalus puparum(L.))、广大腿蜂(Brachymeria euploeae Westwood)、菜粉蝶黑疣姬蜂(Pimla sp.)和黄绒茧蜂(Apantelesglomeratus(L.))等数种。幼虫期寄生蜂的寄生率平均为3.3%, 蛹期为53.86%。黄金小蜂为蛹寄生蜂, 一年发生11-12代(室内), 以幼虫或蛹在寄主蛹壳内越冬, 寄生率平均为50.52%, 高者可达80%以上;雌峰率为65.12%;羽化率为93.17%。广大腿蜂寄生率平均为3.34%, 蛹寄生, 雌蜂率为58.43%。菜粉蝶黑疣姬蜂在国内寄生于菜粉蝶, 尚属初次报导。单寄生于越冬寄主蛹内, 寄生率为1.91%。黄绒茧峰只在一头菜粉蝶幼虫中发现, 寄生率为3.3%。黄金小蜂为菜粉蝶生物防治较合理想的一种寄生蜂, 但不能终年抑制菜粉蝶的猖獗。作者建议:(1)增加早春黄金小蜂的虫口数量;(2)解决8月间寄主数量的不足, 从而使黄金小蜂充分发挥其寄生能力, 达到菜粉蝶生物防治的目的。     

前裂长管茧蜂个体发育研究

前裂长管茧蜂Diachasmimorpha longicaudata（Ashmead）是许多双翅目实蝇类害虫的重要寄生性天敌。在实验室条件下,以桔小实蝇Bactrocera dorsalis（Hendel）为繁育寄主,系统观测了前裂长管茧蜂个体发育过程中各虫态的特征及其相应的发育历期。观察结果表明,前裂长管茧蜂整个生活史由卵、幼虫、蛹及成虫四个阶段组成。其幼虫可划分为四个龄期,一龄幼虫具几质丁的坚硬头壳和镰刀状的颚,形态特征与行为习性与二、三、四龄幼虫完全不同。前裂长管茧蜂约需20天完成世代发育。卵、一龄幼虫、二龄幼虫、三龄幼虫及四龄幼虫的历期依次为1．91、2．02、1．75、2．04和2．31d;蛹的历期介于8～10d,雌性个体发育时间长于雄性。前裂长管茧蜂通常比未被寄生的寄主迟3～5d羽化,雌、雄蜂在羽化后即能交配、产卵,被寄生的桔小实蝇幼虫体表上会留下明显的深褐色产卵孔,寄主化蛹后产卵孔仍保留在其蛹壳上。     

广大腿小蜂对菜粉蝶蛹体型大小的产卵选择及后代发育表现

产卵选择与后代发育适合度之间的相关性是进化生态学的主要科学问题之一。为探究广大腿小蜂(Brachymeria lasus)对不同体型大小寄主的选择和后代发育表现的关系,采用饥饿方法处理4龄菜粉蝶(Pieris rapae)幼虫以获得体型大小(用体质量表示)差异较大的寄主蛹,供寄生蜂选择寄生。结果表明,广大腿小蜂显著偏好体型较大的寄主蛹,而且在体型较大的蛹内产雌性后代的概率更大;子代蜂体型大小与寄主蛹大小存在显著的正相关性,但子代蜂发育历期与寄主蛹大小无相关性。研究说明,广大腿小蜂对菜粉蝶蛹的寄生选择与后代发育表现,符合寄主大小-质量模型的预测。     

斑痣悬茧蜂对斜纹夜蛾不同虫龄幼虫的选择及后代发育表现

为探究容性寄生蜂对不同龄期寄主幼虫的选择性及其子代蜂发育表现的关联,通过双选试验观察了斑痣悬茧蜂(Meteorus pulchricornis)对斜纹夜蛾(Spodoptera litura)不同虫龄幼虫的寄生选择,并观察了与子代蜂适合度相关的特性表现.结果表明:斑痣悬茧蜂在4龄与5龄之间未表现出偏好,在2龄和3龄、3龄和4龄之间显著偏好较低虫龄;结茧率在不同寄主虫龄间无显著差异,羽化率随寄主虫龄增大而减小,寄生2、3龄幼虫的子代蜂显著高于寄生5龄;寄生5龄幼虫的子代蜂死亡率比寄生2龄的高2.5倍,比寄生3龄的高5.4倍.寄生3龄幼虫的子代蜂发育历期最短(11.9 d),比寄生4龄幼虫的短6.8 d,比寄生2龄幼虫的短4.7 d;子代蜂体型大小在寄生的寄主虫龄间无显著差异.根据研究结果推测,斑痣悬茧蜂在寄生时可能不是根据寄主龄期来评价寄主品质,而是基于寄主体型大小进行评价.     

Ectogenesis and the case against the right to the death of the foetus

Ectogenesis, or the use of an artificial womb to allow a foetus to develop, will likely become a reality within a few decades, and could significantly affect the abortion debate. We first examine the implications for Judith Jarvis Thomson’s violinist analogy, which argues for a woman’s right to withdraw life support from the foetus and so terminate her pregnancy, even if the foetus is granted full moral status. We show that on Thomson’s reasoning, there is no right to the death of the foetus, and abortion is not permissible if ectogenesis is available, provided it is safe and inexpensive. This raises the question of whether there are persuasive reasons for the right to the death of the foetus that could be exercised in the context of ectogenesis. Eric Mathison and Jeremy Davis have examined several arguments for this right, doubting that it exists, while Joona Räsänen has recently criticized their reasoning. We respond to Räsänen’s analysis, concluding that his arguments are unsuccessful, and that there is no right to the death of the foetus in these circumstances.     

On the diversity of the Cladocera in the tropics

The mythical concept of an impoverished tropical cladoceran fauna is refuted. On a planetary scale, around half of the cladoceran species presently known occur exclusively in the tropics-subtropics, often with considerable restriction to particular geographical subzones. On a regional (political) scale, the situation is often unclear because of the continued fragmentary nature of studies, and because political units are not a good basis for biogeographical comparisons. At the finest level of resolution (lake-perlake comparisons), there appears to be an upper limit of c. 50 cladoceran species per individual lake. No significant difference between lakes in the temperate zone and in the tropics could be established here. Daphnia is largely absent from the tropics, but is replaced by more Sidids, Moinids, and Bosminids, such that the average cladoceran community in the limnetic zone of a tropical lake is not characterized by less species but rather by lower population densities. This, in turn, is considered a consequence of higher prevalent predation levels in the tropics.     

Tubular networks in the terminal endings of the visual receptor cells in the human,the monkey,the cat and the dog

Summary A tubular network was found in the terminal endings of the visual receptor cells in the human, the monkey (Macaca mulatta), the cat and the dog. These tubules are arranged in close groups in the vicinity of the synaptic lamellae and the invaginated dendrites. According to the form, diameter, density of the tubules and to the consistence of the network formed by them one can distinguish at these places an initial type (type I), a transitory (type II) and a vesicular one (type III). In the the type III branching, bizarre forms are frequent. The diameter of all the tubules reaches 500–600 Å, their density and walls being the same as in the synaptic vesicles.Similar networks also occur in the axons of the visual receptor cells of the monkey.

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Zusammenfassung In den Endigungen der Photorezeptorzellen von Mensch, Affe (Macaca mulatta), Katze und Hund kommen aus Tubuli bestehende Komplexe vor. Organellenartig in geschlossenen Gruppen angeordnet, liegen sie in Nähe der synaptischen Lamellen und der invaginierten Dendriten. An diesen Stellen kann man nach Form, Durchmesser, Dichte und Konsistenz der von den Tubuli gebildeten Komplexe drei Typen unterscheiden: 1. einen initialen (Typus I), 2. einen Übergangstypus (Typus II) und 3. einen vesiculären Typus (Typus III). In letzterem kommen häufig verzweigte, bizarre Formen vor. Der Durchmesser sämtlicher Tubuli erreicht 500–600 Å. Ihre Dichte und ihre Wand gleicht denen der synaptischen Vesikel.Ähnliche Komplexe fanden wir auch in den Axonen der Photorezeptorzellen vom Affen.

     

Assessing the Physiological State of the Fucoids from the Barents Sea Littoral by the End of the Polar Night

Methods of amperometry and potentiometric titration were used to follow dark respiration (DR) and apparent photosynthesis (AP) in the fucoids Ascophyllum nodosum (L.) Le Jol, Fucus vesiculosus L., and F. serratus L. from the Barents Sea littoral by the end of the 40-day-long polar night. The macroalgae were shown to manifest species-specific low rates of photosynthesis and respiration. However, in spite of their low photosynthetic status due to the effects of subzero temperature and prolonged low or zero illumination, the macroalgae have been able to restore DR and AP to the initial level already by the day 9; the ability to restore AP depended on the level of illumination. The study of the changes in the carbonate–bicarbonate system in the light and darkness demonstrated that the macroalgae grown in darkness, in contrast to those grown in twilight, could absorb bicarbonate in darkness; however, they lost this capacity after two-day-long illumination at an irradiance of 7 mol/(m² s). Bicarbonate uptake in darkness and the capacity to restore the systems of photosynthesis and respiration in fucoid cells are discussed in the context of algal energy metabolism under the polar night conditions.     

Arranging the elements of the potassium channel: the T1 domain occludes the cytoplasmic face of the channel

The voltage-gated potassium channel is currently one of the few membrane proteins where functional roles have been mapped onto specific segments of sequence. Although high-resolution structures of the transmembrane portions of three bacterial potassium channels, the tetramerization domain and the cytoplasmic ball are available, their relative spatial arrangement in mammalian channels remains a matter of ongoing debate. Cryo-electron microscopic images of the six transmembrane voltage-gated Kv channel have been reconstructed at up to 18 Å resolution, revealing that the T1 domain tetramerizes and is suspended below the transmembrane segments. However, the resolution of these images is insufficient to reveal the location of the third piece of the puzzle, the inactivating ball domain. We have used the aberrant interactions observed in a series of chimæric channels to establish that an assembled T1 domain restricts access to the cytoplasmic face of the channel, suggesting that the N-terminal ball and chain may be confined in the space between the T1 domain and the transmembrane portion of the channel.     

Feeding the vertebrate retina from the Cambrian to the Tertiary

The retina of the vertebrate eye is metabolically active and requires nutritive support. During the last 540 million years it has evolved into forms as complicated and nutritionally demanding as those found in avian or primate eyes. Diffusion from the choroid is generally able to supply the metabolic needs of thin retinae. However, when the thickness exceeds the limits of diffusion, structures are needed to supplement the vascular supply from the choroid. These supplemental nutritive devices include the choroidal gland, the falciform process and preretinal vascular plexus of fish, the conus papillaris of lizards, the pecten oculi of birds, the intraretinal vessels of mammals and a few novel systems that remain difficult to classify. These vascular systems are among the most variable features of the vertebrate eye. Here, we review classical and recent findings regarding such retinal nutrition systems, propose a three category classification for them based on histologic origins and speculate on the evolutionary forces which drove their development.     

Separation of the pineal vesicle from the wall of the third ventricle during the post-hatching development of the chicken

Summary According to light- and electron-microscopic observations the pineal organ of the 3-day-old chicken consists of a prominent end vesicle and a tapering parenchymal stalk. During this stage the pineal lumen is in open communication with the third ventricle. However, in the 40-day-old chicken, which still possesses a well-developed end vesicle, the proximal portion of the pineal stalk displays regressive changes leading to local fragmentation. At this stage the pineal stalk is reduced, and the pineal lumen is missing. In 1-year-old chickens the parenchyma of the proximal portion of the stalk is further diminished, and in 3-year-old domestic fowl is completely displaced by bundles of collagenous fibers, only some nerve fibers being present. This post-hatching pineal development may reflect the sequence of changes leading from pineal sense organs to pineal glands.This work was supported by a grant-in-aid for Scientific Research from the Ministry of Education, Science and Culture of Japan     

Observations on the permeability of the choriocapillaris of the eye

Summary The choriocapillaris is a fenestrated capillary bed located posterior to the retinal pigment epithelium. It serves as the main source of supply to the photoreceptors, retinal pigment epithelium, and other cells of the outer retina. The permeability of these capillaries to intravenously injected ferritin (MW — approx. 480,000; mol. diam. 11 nm) was examined in the mouse, rabbit, and guinea pig, each of which is characterized by a different type of retinal vascularization. In all three species, the bulk of the ferritin remained in the capillary lumina, where it appeared to be blocked at the level of the diaphragmed fenestrae. Some ferritin was present in endothelial cell vacuoles. The results confirm previous work on the rat choriocapillaris and indicate that the barrier function of the choriocapillary endothelium is present even among species in which the retinal circulation differs significantly.Supported by NIH grant EY03418