温湿度对虎纹捕鸟蛛繁殖力影响的研究

研究不同温湿度对虎纹捕鸟蛛繁殖力的影响,结果表明：虎纹捕鸟蛛繁殖力在26℃恒温和RH80％的因子水平组合中较大。在24－26℃变温和RH80％的组合中为最大。     

中国东北主要植被类型的分布与气候的关系

本文根据吉良的热量指标和作者提出的湿度指数,研究了我国东北主要植被类型的分布与气候之间的关系：1．确定了东北地区10个水平地带性植被类型的热量分布范围和水热指标的平均值。2．研究了东北山地垂直地带性植被类型的水热指标分布特点,并用定量指标讨论了东北东部山地岳桦林带的分布、大兴安岭存在山地冻原和东北植被区域的分界线问题。     

豆蚜在不同品种扁豆上的取食行为

在温室栽培不同品种的扁豆(Dolichos lablab),采用接蚜,光暗对照,隔离饲育,离体饲育,蜡膜人工饲液饲育以及用昆虫取食行为自动测试仪对其取食行为进行测试等方法来鉴定不同扁豆品种对豆蚜(Aphis craccivora Koch)的抗性,确认紫色品种对豆蚜具有拒食作用.分离,提取了扁豆所含的色素成分并对豆蚜进行生物测定,确定扁豆的红色“色素”是抗蚜的物质基础.用进一步提纯的红色“色素”对豆蚜进行取食行为测试,得出拒食强度的初步数据.     

THE COMPLEX INTERPLAY OF SEX ALLOCATION AND SEXUAL SELECTION

It is well recognized that sex allocation strategies can be influenced by sexual selection, when females adjust offspring sex ratios in response to their mates’ attractiveness. Yet the reciprocal influence of strategic sex allocation on processes of sexual selection has only recently been revealed. Recent theoretical work demonstrates that sex allocation weakens selection for female preferences, leading to the decline of male traits. However, these results have been derived assuming that females have perfect knowledge of mate attractiveness and precise control over cost‐free allocation. Relaxing these assumptions highlights the importance of another feedback: that adaptive sex allocation must become difficult to maintain as traits and preferences decline. When sex allocation strategies erode not only traits and preferences but also their own selective advantage, predictions can no longer be expressed as a simple linear correlation between ornament exaggeration and adaptive sex allocation. Instead, strongest sex ratio biases may be found at intermediate trait levels.     

THE GENETIC BASIS OF DIFFERENCES IN GROWTH AND BEHAVIOR OF SPECIALIST AND GENERALIST HERBIVORE SPECIES: SELECTION ON HYBRIDS OF HELIOTHIS VIRESCENS AND HELIOTHIS SUBFLEXA (LEPIDOPTERA)

Two species of moths and their hybrids were studied to determine the genetic basis of host range. One species, Heliothis virescens (HV), has a broad host range and is an agricultural pest on cotton (Malvaceae), soybean (Fabaceae), and tobacco (Solanaceae). The other species, Heliothis subflexa (HS), has a narrow host range, feeding on plants in the genus Physalis (Solanaceae). Experiments were done to determine whether the abilities to feed on cotton, soybean, and tobacco were each under separate genetic control in HV (genetically uncorrelated) or whether feeding on all three hosts was genetically correlated. By repeatedly backcrossing hybrids to HS while selecting for high larval survival and weight on soybean, loci conferring the ability to feed on soybean were moved from HV into the genetic background of the specialist, HS. After six generations of selection on soybean we tested the selected line on soybean, cotton, Physalis, and tobacco to determine if ability to feed on soybean was correlated with feeding ability on these other hosts. We found no evidence to support the hypothesis that feeding on all three hosts was correlated and controlled by a single locus. Compared to HS, the survival and weight of the selected line were significantly higher on soybean, similar on tobacco and Physalis, and slightly, but not significantly, higher on cotton. We also conducted a behavioral choice test to determine if larval preference for soybean was correlated with preference for other hosts. The selected line larvae had higher preference for soybean and cotton than HS. Preference for tobacco was equal in the selected line and in HS. These results support the trends seen in survival and growth tests where performances on soybean and cotton appeared partially correlated and performances on soybean and tobacco were uncorrelated. In conclusion, the generalist, HV, did not have a single set of loci that governed feeding on soybean, cotton and tobacco. It is likely that some of the loci governing performance and preference for soybean also contributed to performance and preference for cotton and that the soybean loci examined did not interact negatively to lower performance and preference for Physalis, the specialist's host. This approach can be applied more widely to address evolutionary questions about host range and other ecological traits.     

APHID DISTRIBUTION AND THE EVOLUTION OF GOLDENROD RESISTANCE

Although there is considerable evidence indicating that herbivory is detrimental to plant fitness, some recent studies of the evolution of plant resistance have concluded that insects do not impose selection on their host plants. A previously untested assumption that underlies most studies of the evolution of plant resistance is that insect distribution patterns are controlled directly by the effects of plant genotype on insect preference and performance. The experiments described here explicitly tested this assumption using the specialist herbivore Uroleucon tissoti (Homoptera: Aphididae) and its host plant Solidago altissima (Asteraceae). Measures of aphid preference and performance were used to predict aphid distribution patterns, and then the predicted distribution patterns were compared with the natural distribution pattern. Although goldenrod genotype had a strong effect on aphid distribution, aphid distribution was not controlled directly by the effect of goldenrod genotype on aphid preference and performance. Instead, a second experiment demonstrated that aphid and spittlebug (Philaenus spumarius and Lepyronia quadrangularis Homoptera: Cercopidae) distribution is controlled largely by genetic variation for resistance to a suite of “branch-causing” herbivores. These herbivores induce branching and aphids and spittlebugs are more abundant on branched plants than unbranched plants. These results indicate that any natural selection imposed by aphids and spittlebugs on goldenrod will depend on the presence or absence of branch-causing herbivores. Thus, selection for plant resistance may depend as much on the assemblage of insect species present as on the identity of each individual species.     

BEYOND REINFORCEMENT: THE EVOLUTION OF PREMATING ISOLATION BY DIRECT SELECTION ON PREFERENCES AND POSTMATING, PREZYGOTIC INCOMPATIBILITIES

Abstract The evolution of premating isolation after secondary contact is primarily considered in the guise of reinforcement, which relies on low hybrid fitness as the driving force for mating preference divergence. Here I consider two additional forces that may play a substantial role in the adaptive evolution of premating isolation, direct selection on preferences and indirect selection against postmating, prezygotic incompatibilities. First, I argue that a combination of ecological character displacement and sensory bias can cause direct selection on preferences that results in the pattern of reproductive character displacement. Both analytical and numerical methods are then used to demonstrate that, as expected from work in single populations, such direct selection will easily overwhelm indirect selection due to low hybrid fitness as the primary determinant of preference evolution. Second, postmating, prezygotic incompatibilities are presented as a driving force in the evolution of premating isolation. Two classes of these mechanisms, those increasing female mortality after mating but before producing offspring and those reducing female fertility, are shown to be identical in their effects on preference divergence. Analytical and numerical techniques are then used to demonstrate that postmating, prezygotic factors may place strong selection on preference divergence. These selective forces are shown to be comparable if not greater than those produced by the low fitness of hybrids.     

THE OCCURRENCE AND DISTRIBUTION OF ATROPINESTERASE,AND THE SPECIFICITY OF TROPINESTERASES

Atropinesterase was found to exist in approximately one out of every four rabbits, and no relation could be observed between the incidence of the enzyme and season, sex, color, age, or weight. The occurrence of the enzyme was also shown to be unrelated to that of cholinesterase. The distribution of atropinesterase in the blood and organs of rabbits was studied; the animals devoid of the enzyme in their blood contained no demonstrable activity in any of the organ extracts tested. The presence of atropinesterase in frog liver, and its absence from the serum, has been confirmed. Hydrolysis of homatropine, but not atropine, by guinea pig liver was observed, while the serum was without action on either of the compounds. On this basis the possibility arises that guinea pig liver contains a homatropinesterase enzyme separate from atropinesterase. It was shown that lack of atropinesterase activity in certain rabbits is not likely to be due to the presence of a naturally occurring inhibitor. It has been demonstrated that contrary to previous indications neither fresh egg white nor yolk possess atropinesterase activity. The specificity of tropinesterases was investigated and evidence was presented for the possible existence of two distinct enzymes, cocainesterase and tropacocainesterase.     

茭白害虫长绿飞虱与稻田缨小蜂关系的研究

茭白害虫长绿飞虱 Saccharosydne procerus是稻虱缨小蜂Anagrus nilaparvatae 在稻田外的主要寄主之一。茭白田可为稻田提供大量的稻虱缨小蜂,从而提高对稻田稻飞虱的控制能力。从褐飞虱和长绿飞虱卵中羽化的稻虱缨小蜂均明显地选择寄生褐飞虱卵,对长绿飞虱卵的寄生率也较高。长绿飞虱在水稻上不能完成其生活史。因此,稻田和茭白田的合理布局可有效地提高稻田缨小蜂的数量,从而提高该寄生蜂对有关害虫的生防效益。     

大仓鼠在繁殖期的行为关系及交配行为

在Ｙ型迷宫中进行气味选择测定时,被试大仓鼠偏好异性的气味,证明身体气味有性吸引和性识别作用。在Ｙ型迷宫进行性别选择测定时,在雌雄靶鼠个体之间,被试大仓鼠不表现出性别偏好,这是攻击行为和交配行为共同影响的结果;与空白相比较,被试鼠都选择靶鼠,说明独居大仓鼠之间存在频繁的探究行为。通过观察箱内对两鼠间的行为关系的观察发现,异性之间主要有攻击行为和交配行为;同性之间主要发生攻击行为,同时胜鼠或优势鼠的胁腺标记行为显著多于从属鼠,说明胁腺标记可以表明优势地位;雄鼠与非性接受状态的雌鼠相遇时,攻击行为很少,但无友好行为,只有简单的雄鼠爬跨雌鼠的行为;任何陌生的雄鼠与性接受状态的雌鼠相遇发生交配行为,交配结束又相互攻击;交配行为表现为多次爬跨多次射精;雄鼠有库利奇（Ｃｏｏｌｉｄｇｅ）效应,雌鼠可以连续接受几只雄鼠的交配,表明大仓鼠为多配制的婚配制度。从行为关系和交配行为看大仓鼠在繁殖期独居,无固定的配偶     

POLLEN MORPHOLOGY AND THE RELATIONSHIPS OF CIRCAEASTER,OF KINGDONIA,AND OF SARGENTODOXA TO THE RANUNCULALES

The pollen of three monotypic genera, Circaeaster, Kingdonia, and Sargentodoxa has been examined by light and scanning electron microscopy and in the case of the last genus, also by transmission electron microscopy. The type of tectum found in Circaeaster and Kingdonia, derivations of a compound layer of striae, has a restricted distribution in the Order Ranunculales. Of 64 genera examined in this order only six had species with a similar tectum. They include Achlys, Epimedium, Jeffersonia, and Vancouveria of the Berberidaceae s.l., the controversial Hydrastis, and Trollius of the Ranunculaceae. Circaeaster and Kingdonia have been considered as related since both have rare and primitive vegetative characteristics, the most notable being open dichotomous leaf venation. They are probably best treated as a ditypic family, Circaeasteraceae. The pollen of Sargentodoxa, especially the structure of the exine, closely resembles that of the Lardizabalaceae. However, the fruits of Sargentodoxa have been considered to be distinct from those of the Lardizabalaceae, suggesting that it be treated as a separate, but closely allied, family.     

A QUANTITATIVE GENETIC ANALYSIS OF OVIPOSITION PREFERENCE AND LARVAL PERFORMANCE ON TWO HOSTS IN THE BRUCHID BEETLE,CALLOSOBRUCHUS MACULATUS

The presence of positive genetic correlations between oviposition or feeding preference for hosts, and performance on those hosts, is of fundamental importance to models of host race formation, sympatric speciation, and the maintenance of genetic variation within phytophagous insect populations. In this paper, I estimate the amount of genetic variation in oviposition preference and larval performance present in two California populations of a cosmopolitan pest of stored legumes, Callosobruchus maculatus (Bruchidae: Coleoptera), and examine whether positive genetic correlations exist between preference and performance. High levels of genetic variation in both preference and performance were detected in one population (Bay Area population, h² = 0.73 for oviposition preference), but not in another population (Davis population). A second estimate of the amount of genetic variation for oviposition preference in the Bay Area population, after three generations of laboratory rearing, supports the hypothesis that the absence of significantly nonzero heritabilities in the Davis population is probably due to the three generations of laboratory rearing prior to the start of the experiment. No positive genetic correlations were detected between preference and any performance character measured. Data are also presented on the genetic correlations between performance on azuki (Vigna angularis) and cowpea (Vigna unguiculata). Genetic correlations were found to be positive for all characters in both populations of C. maculatus (range 0.132 to 0.542).     

西安市学生膝部长骨的干骺融合时间与身高等发育指标的关系

本文根据西安市2612例学生的活体测量以及电子计算机对数据的统计分析,得出了西安市学生身高等发育指标及有关指数,绘制了有关的发育曲线,讨论了身高等发育指标与膝部长骨干骺融合的关系。