印楝提取物及双稠哌啶类生物碱对桑天牛存活及生殖的影响

用１．０μｇ／ｍｍ２剂量的黄华碱和野靛碱处理的构树枝分别喂饲桑天牛,黄华碱不表现拒食作用,但野靛碱表现出显著的拒食作用。同样剂量条件下,两种生物碱均能使桑天牛的产卵量和卵孵化率显著下降,但没有引起死亡。用８．０×１０－２,４．０×１０－２,２．０×１０－２,１．０×１０－２,５．０×１０－３μｇ／ｍｍ２剂量的印楝提取物（含ａｚａｄｉｒａｃｈｔｉｎ１０％）处理的构树枝喂饲桑天牛,前二种剂量引起１００％死亡率,２．０×１０－２μｇ／ｍｍ２剂量引起８０％死亡率并导致雌虫不再产卵,而后两种剂量引起的死亡率为３０％和０％,并导致产卵量和卵孵化率较对照急剧地下降。报道了双稠哌啶类生物碱对昆虫引起产卵量和卵孵化率下降作用及天牛科中印楝提取物抑制产卵和卵孵化的作用。     

不同蛋种鸡饲料对SPF鸡群产蛋性能的影响

为了提高SPF鸡的生产能力和质量 ,在相同的SPF鸡饲养条件下 ,选择分别来源于北京正大和北京科澳协力生产的全价营养蛋种鸡饲料 ,经高压消毒后 ,饲喂品种相同的SPF种鸡 ,结果显示两个鸡群在生产性能方面存在明显差异 (p <0 0 1)。其中饲喂北京科澳协力饲料的SPF鸡群的产蛋率和利用率都明显高于另一个鸡群 ,主要表现在SPF鸡群开产早期的蛋重上和产蛋高峰期后产蛋率的维持上。     

Extended embryo retention,caecilian oviparity and amniote origins

A recent discussion of the evolution of the amniotic egg (Laurin and Reisz, 1997) was criticized by Wilkinson and Nussbaum (1998), and these criticisms provoked a rebuttal (Laurin et al., 2000). Here we show that the objections raised by Laurin et al. (2000) do not substantiate the conclusions of Laurin and Reisz (1997). Wealso discuss additional evidence on the ancestral ontogeny of caecilians from the literature. This evidence is inconsistent with the view that extended embryo retention is the ancestral condition for caecilians and that it is a parsimonious interpretation of the condition of the ancestral amniote as argued by Laurin and Reisz (1997) and by Laurin et al. (2000). The available data are more consistent with the traditional hypothesis that the amniotic egg originated as an adaptation of eggs to the terrestrial environment. We also discuss problems in the definition of ontogenetic characters reflecting variation with respect to extended embryo retention, and we present new observations on the early development of the caecilian Gegeneophis ramaswamii Taylor.     

The occurrence of Parvatrema homoeotecnum James, 1964 (Trematoda: Gymnophallidae) in a population of Littorina saxatilis tenebrosa (Mont.)

Summary

Marking experiments, seasonal variations in the population density and observations on the breeding cycle indicated that healthy adult Littorina saxatilis tenebrosa (Mont.) migrate down to the lower supralittoral fringe in order to give birth to the young in July–August and in January–February. The young and adults then migrate up towards the upper supralittoral fringe. Specimens infected with Parvatrema homoeotecnum, unlike those infected with two other digenean species investigated, migrate in the same way as healthy specimens. This ensures that although initial infestation takes place in the lower supralittoral fringe, parasitized specimens occur throughout the supralittoral fringe. Only juvenile hosts, below 7·0 mm long and usually below 5·0 mm long are infected, highest percentages occurring in specimens measuring 1·1–2·0 mm long. The seasonal variations in percentage infection are corellated with the breeding cycle, growth, mortality and migration of the host.     

三种蜉蝣卵壳表面雕纹的显微观察

本文报道了用干涉相衬显微镜对三种蜉蝣卵壳表面雕纹进行初步观察的结果。尤氏新河花蜉(Neopotamanthus youi Wu & You)卵壳表面雕纹为不规则的网状嵴。霍山河花蜉(Potamanthus huoshanensis Wu)卵壳表面雕纹为纽扣状的突起。细蜉蝣(Caenis sP)卵壳表面雕纹呈不规则的多角形突起。     

微生态制剂热快消对蛋鸡抗热应激的作用

选择在室内平均温度为32.75℃的条件下饲养的59周龄海兰褐蛋鸡2322只,随机分为试验组和对照组2组.经7天预试后试验.试验组饮水中每天加入微生态制剂热快消250 ml/1000只鸡,试验期为15天.结果表明,对照组蛋鸡的直肠温度和皮肤温度较试验组有极显著增高(P<0.01),LDH活性、血糖、血清钙、T3、T4和Cor的含量显著低于试验组(P<0.05).试验组产蛋率、蛋重高于对照组,差异显著(P<0.05).微生态制剂热快消可缓解高温热效应,提高蛋鸡生产性能.     

厦门海区浮游桡足类卵形态与孵化率的研究

在厦门海区,调查了19种常见的自由产卵的浮游桡足类卵型及其孵化率。发现卵有二种基本型:卵表光滑和具附属刺或鞘结构。卵的形态随种类而异,即使同种也常不同。卵径大小(D)似与产卵雌体大小呈正相关;而与海区水温(t)呈负相关,并可拟合为D=a·t~b。卵孵化率具有明显的季节变化,但和卵型的相关与否则依种的不同而异,这可能与种群不同的生态适应性有关。     

歪水蚤产卵率的研究

在实验室培养条件下测定厦门海区三种歪水蚤的产卵率表明,右突歪水蚤最高,特氏歪水蚤次之,而钳形歪水蚤最低。右突歪水蚤的产卵率取决于温度的变化,且具显著的季节差异,其最大潜在产卵率与海区水温的变化呈线性相关;但特氏歪水蚤产卵率的季节变化及其温度效应不甚显著。这在维持种群数量上,可能具有一定的意义。实验还表明,捕食率也影响了特氏歪水蚤的产卵率,但随温度而有变化。     

IV.—On specific character,fecundation, and abnormal development in Œdogonium

Summary

• 1. A morphological study of five body regions of the Lepidoptera has been made, these being (a) the radial system of the mesothoracic wing, (b) the mesothoracic sternopleural region, (c) the ventral thoraco-abdominal articulative (and adjacent) structures, including the integumental components of the tympanum where present, (d) the dorsal thoraco-abdominal articulation, etc., and (e) the metathoracic furca or endosternite. These regions were selected because the nature of the variation they exhibit suggested that, of the much larger number of regions primarily investigated, they are the most likely to provide information on the evolution of the higher taxa in the order. None of these regions had been investigated at all fully previously, and therefore a considerable amount of basic morphological study was necessary as a preliminary to phylogenetic discussion. This morphological work has been extended to include the primitive Lepidoptera (with the Trichoptera) in the case of the mesosternopleural region, and in the regions of thoraco-abdominal articulation, in order to clarify basic homologies where these were obscure in the Ditrysia.

• 2. Included also in the preliminary morphological treatment are two other body regions, the variation of which is not complex, and can be more briefly described. These regions are the prothoracic sclerites and the metanotal subdivisions—both of these showing interesting variation throughout the order which can be easily interpreted from the phylogenetic standpoint.

• 3. Following reference to the basic morphology of each region studied, a broad outline of the evolutionary dynamics of each character complex is given in order to provide a basis for discussion of the evolutionary trends manifested within the superfamilies.

• 4. In sections four and five of this work, the character complexes which were the subject of morphological study earlier are examined further with regard to their dynamics as manifested within each of the Ditrysian superfamilies. The formation of the concepts which are outlined here is based on consideration of all information derivable from all of these character complexes along with previously published information on other aspects of Lepidopterous anatomy. Resulting from this, a re-organization of the superfamilies has been possible on a phylogenetic basis. The chaotic state of the past literature on the classification of the Lepidoptera, the result of superficial taxonomic work, renders the comparison of the present system with previous ones clearly impossible within the scope of the present paper, but it is noted that many of the superfamily groupings do not differ very widely from those in some of the more comprehensive early studies, such as Forbes (1923). Through lack of material, no radical re-organization of the primitive Ditrysian superfamilies included in the Tinaeoid complex has been attempted, and for the same attempting to convey a very great deal of information by means of varied labelling of the two components of the suture. Reference both to the text, and to the figures given in the introductory (morphological) section of this paper, should however, enable anyone to appreciate these factors from the figures given. (3) Abbreviations used with reference to wing veins and pupal tracheae follow the standard Comstock-Needham system, apart from the identification of Cu2, which follows Tillyard's (1969) interpretation.

Note also that a few of the less common structures have been explained with the captions to the figures.     

Na2SO4对蛋鸡生产性能的影响

将25周龄的商品蛋鸡400只随机分成5组，待分组产蛋稳定后，在饮水中添加1．2g／L、0．9g／L、0．6g／L、0．3g/L、0g／L的Na2SO4溶液进行饲喂实验。结果表明，添加Na2SO4的四个试验组饲料转化率和产蛋率均高于对照组，当添加量为0．6g／L时，饲料转化率和经济效益最佳。