重庆地区几种蚜虫越冬习性的观察

在重庆地区的自然条件下, 棉蚜Aphis gossypii Glover在冬季既可以在落叶木本植物如木芙蓉Hibiscus mutabilis L.、木槿 Hibiscus syriacus L.上产生两性世代的雄蚜和产卵雌蚜, 并产卵过冬;也可以在宿根草本植物如蜀葵 Althaea rosea(L.)上继续以孤雌胎生世代的有翅或无翅胎生雌蚜繁殖过冬。麦长管蚜 Macrosiphum granarium(Kirby)、菜缢管蚜 Rhopalosiphum pseudobrassicae(Davis)和桔二岔蚜Toxoptera aurantii(Fonsc)通常都继续以孤雌胎生世代繁殖过冬。桃蚜 Myzus persicae(Sulzer)在十字花科蔬菜、莴笋Lactuca sativa var.angustana Irish、菠菜 Spinacia oleracea L.等冬季作物上可以继续营弧雌胎生世代繁殖, 但在桃树上Prunus persica Stokes 可以出现少数两性世代的产卵雌蚜和雄蚜。由于雄蚜的出现时期较晚, 将近在落叶以前, 而产卵雌蚜不经交配通常均不能产卵, 因此在桃树落叶前产卵雌蚜常未及产卵而随落叶从桃树上消失。从接种饲养试验的结果证明:麦长管蚜在提早至8月播种, 至冬季已进入乳熟期的小麦Triticum aestivum L.穗上, 可以产生少数雄蚜, 但未见产卵雌蚜。菜缢管蚜在生长衰弱的油菜 Brassica napella Choix的黄脚叶上, 可以产生少数产卵雌蚜及卵, 但未见雄蚜。在田间瓢儿白Brassica chinensis var, rosularis Tsen et Lee的黄脚叶上也发见同样情况。在养虫室内将采自田间棉株、木芙蓉、或木槿上的棉蚜, 接种在蜀葵上, 不产生两性世代。反之, 将蜀葵上棉蚜接种在木槿上便产生两性世代。与田间的情况相吻合。 根据观察试验结果并参考文献资料, 作者认为温度、光照、以及寄主植物的种类和生长情况是引起蚜虫产生性蚜的主要原因。这些因子的综合作用对各种蚜虫的影响有所不同。故不同的蚜种在同一地区可以产生不完全相同的越冬情况。一种蚜虫在同一地区, 达到一定的自然低温条件下, 寄主植物的种类及其不同的生长情况的营养条件, 可能是影响性蚜产生与否的主要因素。 从1955年至1962年曾在重庆北碚地区进行棉蚜、麦长管蚜、菜缢管蚜、桃蚜、及桔二岔蚜等的越冬习性的田间观察及室内接种, 或饲养试验。现将这几种蚜虫的观察试验结果报导如下, 并对蚜虫性蚜产生的原因作初步讨论。     

用微卫星引物PCR分析棉蚜不同蚜型的DNA多态性

用微卫星引物PCR方法, 对棉蚜Aphis gossypii干母、干雌、孤雌蚜(有翅迁飞孤雌蚜和无翅孤雌蚜)、性母、性雌蚜和雄蚜的DNA多态性进行分析。 结果表明：① 棉蚜的有性蚜型和无性蚜型之间在遗传上有较大的差异; ② 性母与性雌蚜和雄蚜的遗传关系都十分接近,说明同一性母既产性雌蚜,也产雄蚜;③ 干母和干雌的遗传关系很近, 但孤雌蚜已与二者有分化。     

双斑恩蚜小蜂形态学特征、生活习性及其寄生行为

双斑恩蚜小蜂EncarsiabimaculataHeratyetPolaszek是烟粉虱Bemisiatabaci(Gennadius)的主要寄生性天敌之一。作者对双斑恩蚜小蜂的形态特征进行了描述。在实验室条件下,对双斑恩蚜小蜂的生活习性、寄生行为进行了观察。双斑恩蚜小蜂成蜂26℃时平均寿命约为7d,每雌产卵量273粒,雌蜂比例占据绝对优势,雌雄性比约为8∶1。双斑恩蚜小蜂的寄生过程大致分为寄主定位、寄主检查、穿刺、产卵、清扫、梳理和休憩等几个阶段。     

枸杞棉蚜形态和生物学特性研究

【目的】棉蚜Aphis gossypii Glover是一种分布广泛的重要农业害虫,其寄主范围较广。近年发现棉蚜严重为害一种新的寄主植物枸杞Lycium barbarum L.。枸杞是名贵中药材和食物,枸杞上生活的棉蚜的生活史特征尚不清楚。为了更好地预测预报和有效防控枸杞棉蚜,减轻枸杞的受害损失,本研究对栽培枸杞上棉蚜的生物学特性进行了系统研究。【方法】在田间条件下,对青海栽培枸杞树上的棉蚜各蚜型和虫态进行了详细调查,记述了各虫态的形态特征、发育历期、生活史、寄主植物、习性、发生规律及天敌种类。【结果】枸杞树上的棉蚜为害嫩枝梢、叶片、花蕾和果实,引起枸杞果产量和品质严重下降。枸杞棉蚜有6种蚜型,即孤雌蚜(有翅型和无翅型)、性母蚜、性蚜(性雄蚜和性雌蚜)和干母蚜,蚜型间的形态有明显差异,可用于区别不同的生活史阶段。枸杞棉蚜原寄主是枸杞,在青海一年发生10~16代,以滞育卵在枸杞树干和树枝上越冬,翌年4月上中旬开始孵化产生干母,5月产生无翅孤雌蚜进行孤雌生殖,6月开始产生有翅孤雌蚜,在田间迁飞扩散,7月和8月田间出现两次蚜虫数量高峰,孤雌蚜一直延续至9月,田间开始产生性母蚜、性雄蚜和性雌蚜,在枸杞树上进行有性生殖,10月中旬是交配、产卵高峰期,随后卵进入滞育越冬。若虫共4龄。无翅型若蚜期平均10.22±3.32 d,有翅型若蚜期平均9.55±2.53 d;无翅型成蚜寿命平均10.10±1.07 d,有翅型成蚜寿命平均8.97±1.34 d;1代无翅型蚜虫总寿命平均20.32±6.31 d,有翅型蚜虫总寿命平均18.52±4.51 d;孤雌蚜繁殖后代中无翅型若蚜数量平均为17.86±5.66头/雌,有翅型若蚜数量平均为15.33±3.76头/雌。枸杞田捕食和寄生棉蚜的优势天敌有多异瓢虫Hippodamia variegata(Goeze)、七星瓢虫Coccinella septempunctata L.、丽草蛉Chrysopa formosa Brauer和蚜茧蜂。【结论】枸杞树上棉蚜生活周期为全周期型。与其他寄主上的棉蚜比较,枸杞棉蚜体型更大、发育期更长、繁殖后代个数明显较少。在枸杞树上种群数量一年发生有2个高峰期,分别在7月和8月,有别于前人报道的其他寄主上棉蚜种群数量的1个高峰期出现在5-6月。这些差异可能与棉蚜对枸杞寄主和青藏高原环境产生生态适应性有关,其适应机制需进一步探索。     

桃蚜不同蚜型DNA多态性的RAPD研究

采用RAPD方法,对全周期桃蚜的有翅产雌性母蚜、无翅性母蚜、雄蚜、卵、干母、干雌、有翅迁移蚜等蚜型的DNA遗传多态性进行了分析。结果表明：卵的DNA多态性最大,性蚜次之,孤雌生殖蚜最小;卵与其它蚜型之间在遗传上具最大差异,其中与孤雌生蚜的差异大于与性蚜的;干母、干雌和迁移蚜之间的遗传关系最近。     

光周期对红色型豌豆蚜性蚜分化的诱导

为了探索红色型豌豆蚜种群繁殖策略以及性蚜分化规律,在8L∶16D、10L∶14D、12L∶12D和14L∶10D 4个光周期条件下,研究了红色型豌豆蚜经光周期连续诱导2代后(G1和G2),后代G3中的性蚜分化情况。结果表明:兰州地区红色型豌豆蚜性雌蚜均为无翅型,而雄蚜均为有翅型;光周期对豌豆蚜性蚜分化有显著影响(P0.05);在14L∶10D光周期条件下,豌豆蚜后代中无性蚜分化;在12L∶12D、10L∶14D和8L∶16D 3个光周期条件下均有性蚜分化,而且随着光照时间的变短,豌豆蚜G3中雄蚜所占百分比逐渐减小,但性雌蚜所占百分比基本不变;在12L∶12D光周期条件下,雄蚜和性蚜比例均最高(分别为15.03%、91.43%),而胎生蚜比例最低(8.57%);在10L∶14D光周期条件下,G3中胎生蚜比例最高,而性蚜比例最低;在8L∶16D光周期条件下,性雌蚜比例最高(78.88%),但同其他处理间差异不显著(P0.05);在同一短光照条件下,G1产仔日龄对G3中性蚜分化具有显著影响(P0.05),同时性蚜分化具有一定的时间顺序,即先产性雌蚜,后产雄蚜,由性雌蚜向雄蚜过渡过程中伴随产生胎生蚜。研究表明,红色型豌豆蚜性蚜产生的临界光照时长介于12~14 h,相对较长的光照条件有利于雄蚜产生,但随着光照时间缩短雄蚜分化时间逐渐延后、雄蚜分化天数逐渐缩短,说明光周期变化与豌豆蚜生殖模式转变和性蚜分化密切相关,亲代经历光周期处理时间的长短影响后代中性蚜的分化。     

温度和光周期对烟蚜性蚜的诱导

本文研究了温度和光周期对烟蚜性蚜诱导的影响,结果表明：郑州地区的红色和黄绿色烟蚜在１０小时光照和１５、２０℃组合下可产生性雌和雄蚜,而在１２、１４和８小时及２５℃条件下均未有性蚜产生。     

韭菜迟眼蕈蚊雄虫日龄对其交配能力和雌虫生殖力的影响

为了提高韭菜迟眼蕈蚊性信息素监控水平,本文在25℃、RH70%±5%、光周期L∶D=14∶10的条件下研究韭菜迟眼蕈蚊不同日龄雄虫的交配能力及其对雌虫生殖力的影响。结果表明,未交配雄虫平均寿命4.5d,雌虫4.2d,雌雄成虫的平均寿命无显著差异。雄虫一生最多可交配13次,且随着雄虫日龄增加,雌虫交配成功率逐渐减少。随着雄虫交配经历的增加,雌虫交配的时间延长,最长达97min。雄虫的日龄并不影响与之交配雌虫的产卵量和卵孵化率,但是雄虫的交配经历与雌虫的产卵量和卵孵化率相关,尤其当雄虫交配经历超过8次时,与之交配的雌虫的产卵量和卵孵化率显著下降。研究阐明了韭菜迟眼蕈蚊的生殖行为特征,为其性信息素应用提供了参考。     

各型桃蚜触角感器的比较研究

该文对桃蚜Myzus persicae(Sulzer)各型触角感器进行了比较研究。扫描电镜观察结果表明桃蚜具有钟形感器、毛形感器、原生感觉圈和次生感觉圈4种类型的触角感器。桃蚜各型触角感器的最大差异主要表现在次生感觉圈上,雄蚜、雌性母和有翅孤雌蚜具有次生感觉圈,雌性蚜、干母和无翅孤雌蚜无;但雄蚜具有的次生感觉圈数目多于雌性母和有翅孤雌蚜,且不仅仅分布在触角第3节,第4、5节也有分布。本文探讨了桃蚜触角感器在化学生态学上的功能作用,各型触角感器的差异与桃蚜寄主选择、迁移及交配行为的关系,并进一步分析了桃蚜触角感器的性二型现象。     

有性棉蚜交配和产卵习性的观察

有性棉蚜有多次交配习性,交配时间平均为41分钟。雌蚜寿命为28．1±6．0天,产卵前期为3．0±1．2天,产卵历期为15．3±3．8天,产卵后期为9．7±3．4大,每雌产卵8．1±1．6粒,卵的产出率平均为88．4％。群体产卵的始盛、高峰和盛末期分别在羽化后3～4天、7～8天和15～16天。未经交配的雌蚜在产卵方面有明显的负效应,产出的受精卵也不能孵化。     

Sex differences of hematological and biochemical parameters in healthy rainbow trout (Salmo gairdneri, R)

A hematological study of the rainbow trout has permitted to establish a sexual difference in the parameters related to it, such as haemoglobin, haematocrit, erythrocyte and leukocyte count. The types of leukocytes were homologated to the human blood. Haemoglobin, haematocrit, erythrocyte sedimentation rate, erythrocyte and leukocyte count values were lower in female than male. The normal values of some biochemistry parameters were equally studied and in some cases they similarly showed a sexual difference. Creatinine, triglycerides, phosphatase alkaline, sodium and globulin values were higher in female than male. Establishing a sexual difference from the biochemical and hematological parameters is possible.     

Innovative Individuals Are Not Always the Best Demonstrators: Feeding Innovation and Social Transmission in Serinus canaria

Background

Feeding innovation occurs when individuals choose a novel, unknown type of food and/or acquire new feeding skills. Here we studied feeding innovation and social transmission of the new feeding habit in canaries. Adult canaries eat a wide variety of seeds but avoid larger ones such as those of sunflowers. We determined whether adults of both sexes are equally prone to innovate when confronted with sunflower seeds and whether free-interactions facilitate transmission of the new feeding habit in a sex-dependent manner.

Methodology/Principal Findings

First we determined which sex was more innovative, i.e., was more successful at husking and eating the novel seeds. Males were clearly more innovative than females. Due to this, experienced males served as model for either male or female observers in three different conditions (free interaction with a demonstrator, visual interaction with a demonstrator placed behind a transparent wall and access to seeds in the presence of a non-demonstrating bird). During free interactions, the new feeding habit was only transmitted to females. In contrast, transmission of seed handling to male observers only occurred if demonstrator and observer were separated by the transparent wall. Indeed, aggressive behaviors between males prevented social transmission during free interactions. Finally, we studied the influence of the less innovative females in feeding-habit transmission. First, we obtained female demonstrators by making them freely interact with male demonstrators. Once they acquired innovative responses to sunflower seeds we studied feeding-habit transmission towards male and female observers. Observers of both sexes learned during free interactions with female demonstrators. No aggressive behavior occurred. Males were also able to learn after visual interactions with the female demonstrator.

Conclusions/Significance

Our results show that the most innovative individuals (males) are not always the best demonstrators, and that social relationship and sex are crucial factors for the spread of a new feeding habit among canaries. These factors determine the kind of interaction between individuals and the time spent together, thus affecting the transmission of novel habits within the population.     

Inheritance features of mating behavior components in Drosophila melanogaster and their significance for fitness

Components of mating behavior of Drosophila melanogaster mutant and wild-type strains were studied with respect to fitness. The magnitude of the effect of genotype on the male mating activity, female sexual receptivity, fertility and viability was determined. Strong positive correlation was found between the male mating activity and fitness components. It was shown that mating of strains contrasting in sexual behavior features can be accompanied by both heterosis and maternal effect. Inheritance coefficients were determined for sexual behavior components.     

Sex Change and Population Dynamics in Arisaema (Araceae) II. An Examination on the Evolutionary Stability of Sex Changing Schedule of A. serratum (Thunb.) Schott

Abstract The evolutionary stability of the sex-changing habit of Arisaema serratum was examined. To evaluate reproductive success through male functioin properly, the mathematical formulation of Kakehashi and Harada (1987) was employed. Individuals were classified by both their size and sexual state, and the genetic contribution of individuals was estimated by calculating their reproductive value. It was shown that in the size classes where sex change actually occurs, the reproductive values of males and females are basically the same. This means that the genetic contribution of individuals in these size classes is the same whether they are male or female, and no selection pressure is working to change the male ratio in these classes. Thus, it is concluded that the size at which sex change occurs is evolutionarily stable. The adaptive significance of the size of first reproduction was also discussed.     

Biological sexual maturation in rats: Interaction among genetic line,sex, age,and body weight

Interaction among genetic line, sex, age and body weight was studied for biological sexual maturation in rats. In female rats vaginal opening, first estrus, and duration of estrus cycle were determined. In male rats first presence of sperm was determined. Age and body weight at vaginal opening, first estrus or first detection of sperm were determined. Differences among five genetic lines were found on all measures of sexual maturation. The random bred control rats differed from the selectively bred lines of rats on majority of the measures, thus suggesting the influence of selective breeding on sexual maturation. The Maudsley lines selected for open-field defecation and Roman lines selected for two-way active avoidance learning showed different patterns of sexual maturation. Age was found to be crucial for the sexual maturation of female rats, whereas body weight was more important for the sexual maturation of male rats. This study is the first to investigate systematically the biological sexual maturation in live male rats and related sex differences. Findings suggest an important genetic component, and effect of selective breeding on the biological sexual maturation of rats.     

Contrasting mutual sexual selection on homologous signal traits in Drosophila serrata

The nature of male mating preferences, and how they differ from female mating preferences in species with conventional sex roles, has received little attention in sexual selection studies. We estimated the form and strength of sexual selection as a consequence of male and female mating preferences in a laboratory-based population of Drosophila serrata. The differences between sexual selection on male and female signal traits (cuticular hydrocarbons [CHCs]) were evaluated within a formal framework of linear and nonlinear selection gradients. Females tended to exert linear sexual selection on male CHCs, whereas males preferred intermediate female CHC phenotypes leading to convex (stabilizing) selection gradients. Possible mechanisms determining the nonlinear nature of sexual selection on female CHCs are proposed.     

Changes of heart rate during sexual behavior in the female rat.

The authors studied the physiological and behavioral responses during sexual behavior in female rats. For this purpose, electrocardiographs were recoded from conscious and unrestrained females using a radiotelemetry system. Heart rate during sexual behavior rose sharply following the introduction of a sexually active male, displayed a peak level of 425 bpm during male ejaculation, and then rapidly decreased. This pattern of heart rate in females before and after receiving ejaculation was similar to that in males before and after ejaculation. In the rate of decrease in heart rate, however, there was a significant difference between females and males. The present study is the first to show changes of heart rate during sexual behavior in female rats.     

A PHYLOGENETIC PERSPECTIVE ON THE EVOLUTION OF SEXUAL DICHROMATISM IN TANAGERS (THRAUPIDAE): THE ROLE OF FEMALE VERSUS MALE PLUMAGE

The evolution of sexual dichromatism in tanagers (family Thraupidae) was studied from a phylogenetic perspective using a molecular-based phylogeny. Mapping patterns of sexual dimorphism in plumage onto the phylogeny reveals that changes in female plumage occur more frequently than changes in male plumage. Possible explanations for this pattern include sexual selection acting on female plumage and natural selection for background matching. The results of this study and other recent phylogenetic and comparative studies suggest that factors affecting female plumage are important in shaping patterns of sexual dimorphism.     

虎斑颈槽蛇肾脏两性异型性的结构特点

目的了解虎斑颈槽蛇肾脏两性异型性的结构基础。方法虎斑颈槽蛇(Rhabdophis tigrinus)为性成熟个体,共19条,雄性12条,雌性7条。于2005～2008年的7月份对蛇及其肾脏进行测量和称重,应用光镜和电镜对肾脏进行观察。结果雄性蛇肾脏不仅颜色呈黄色,而且相对长度和重量也均大于雌性;雄性蛇肾脏富含由远曲小管膨大而成的肾性节,而雌性则没有。肾性节细胞呈高柱状,具有典型的分泌性细胞的超微结构特点。结论虎斑颈槽蛇肾脏的两性异型性是由于雄性的肾脏富有特化的肾性节所致。     

The effect of social isolation during juvenile period on the sexual arousal in adult rats

The effects of chronic postweaning social isolation combined with subsequent resocialization on the sexual arousal were studied in male rats with inherited stress-induced arterial hypertension (ISIAH strain) and in Wistar rats. Young males were isolated on the Day 21 of postnatal life for 6 weeks. Then they were kept in groups of 5. 4-month males underwent the partition test: a receptive female was introduced into the male's cage, but the male and the female were separated by a transparent partition. The number of approaches to the partition and total time spent near the partition during the test served as an index of sexual motivation. Hormonal component of sexual arousal was estimated by measuring plasma testosterone level. No interstrain differences in magnitude of the sexual arousal were observed. However, chronic social isolation during juvenile period caused a genotype-dependent diminution of sexual motivation in the adult male rats of both strains. The decrease of sexual motivation in ISIAH rats was more pronounced as compared to Wistar rats. Moreover, the social isolation during the juvenile period completely abolished the female-induced rise in plasma testosterone in ISIAH and Wistar male rats. Plasma corticosterone level was increased during the period of sexual arousal, but this rise of corticosterone was not affected by the social conditions during postweaning period.