Cannibalism in the pea aphid,Acyrthosiphon pisum

Previous observations of cannibalism have been made in the aphid Acyrthosiphon pisum （L.）： this article seeks to quantify factors contributing to such be- haviors. We observed and quantified the responses of a number of clones and life stages to varying levels of starvation, in the form of increasingly desiccated Vicafaba L. plants （receiving 50, 25, or 10 mL every second day） or a complete absence of host plant. We found that, while the longest incidences of cannibalism are carried out by juveniles （F = 3.45, P = 0.019, df = 3） and targeted at adults, the starvation treatments had the most significant effect on the prevalence of cannibalism in mature A. pisum （F ---- 2.24, P = 0.025, df = 9）. Furthermore, there was no difference between the prevalence or dura- tion of cannibalistic activities within and between different clones （P 〉 0.05 in all cases）, though juveniles were more likely to target unrelated aphids （V = 6 112, P = 0.011）, and spent more time feeding on aphids from the same culture （V = 6 062, P = 0.018）.     

动物工程学校之化学武器来御敌(下)

<正>科莫多巨蜥老师对门外的"怪物"恨之入骨,要不是这群家伙来学校滋事,大家还都坐在教室里认真地听它讲课。更重要的是,要不是这群坏蛋来,它的乖学生小蜜蜂也不会白白送命。想着这些,它满身怒气地伸出自己的"人"字形舌头,朝领头的"怪物"冲去……     

How does the host-specialized aphid deal with food deficiency？

Aphis gossypii Glover shows obvious host specialization, with cucurbit- and cotton-specialized biotypes or host races in many regions. Because its annual natal hostcrops senesce earlier the cucurbit-specialized biotype may suffer food deficiency. The method this biotype uses to overcome this challenge is still poorly understood. In orderto understand the potential of the cucurbit-specialized biotype aphids in host shift and usage, the performance of this biotype on cotton （Gossypium hirsutum）, a common butpoor quality host plant, was explored in this study. The cucurbit-specialized aphids could establish populations on cotton only when these plants had at least nine leaves, and subsequent populations developed rather slowly. The presence of whitefly populations on cotton improved the success rate of cucurbit-specialized aphids. The cucurbit-specialized aphidswere mainly distributed on the older leaves of cotton, with only a few settling on the upper leaves. The cucurbit-specialized aphids reared on cotton for 40, 54 and 61 days stillmaintained strong preference for their natal host plant, cucumber （Cucumis sativus）, rather than cotton, and their net reproductive rates and intrinsic rates of natural increase weredramatically lower when they were transferred onto new six-leaf cotton plants or detached leaves. Therefore, we concluded that the cucurbit-specialized aphids have the potentialto utilize mature or whitefly-stressed cotton plants, but that this feeding experience on cotton did not alter their specialization for cucurbits. Some cotton plants could act as atemporary host for the cucurbit-specialized aphids to overcome food deficiency arising from senescing cucurbits.     

Application of DNA barcoding to the identification of Hymenoptera parasitoids from the soybean aphid （Aphis glycines） in China

Aphis glycines Matsumura is an important pest of soybean in Asia and North America. Hymenoptera parasitoids play a key role in the control of the soybean aphid. Thecorrect identification of parasitoids is a critical step that precedes the assessment of their potential biological control agents. Accurate identification of the majority of the speciesattacking the soybean aphid often requires elaborate specimen preparation and expert taxonomic knowledge. In this study, we facilitated the identification of soybean aphidparasitoids by applying a DNA barcoding approach following a preliminary morphological identification. We generated DNA sequence data from the mitochondrial COI gene andthe D2 region of 28S rDNA to assess the genetic variation within and between parasitoid species emerging from the soybean aphid in China. Fifteen Hymenoptera parasitoid speciesbelonging to 10 genera of five families were identified with little intra-specific variation （0.09% ± 0.06% for 28S and 0.36% ± 0. 18% for COI） and large inter-specific divergence（30.46% ± 3.42% for 28S and 20.4% ± 1.20% for COI）.     

Cybertaxonomy to accomplish big things in aphid systematics

Biodiversity sciences have progressed at such a pace that the taxonomic community has been unable to grow concomitantly to keep up with the influx of biologicaldata. This ＂taxonomic impediment＂ has led some to suggest that taxonomy is no longer pertinent and to the development of methodologies that circumvent the taxonomic process.This article does not seek to argue for the importance of taxonomy but rather is a call to the aphid taxonomy community to rise to the challenge by dramatically increasing the volume and comprehensiveness of its output without sacrificing quality. Recent informatics technology allows us to mobilize the 2 most important aphid taxonomy resources： expertsand specimens, both distributed globally. ＂Cyberspecimens,＂ museum specimens digitally rendered at a resolution sufficient for remote identification, and open ＂cybertaxonomic＂tools will allow the international aphid taxonomic community to carry out large, ambitious, projects. The global aphid cybertaxonomy proposed here will serve not only the ends ofresearch aphidologists, but also provide a model for other taxonomic communities to adapt and adopt as we confront both the taxonomic impediment and the taxonomic naysayers.     

田间二化螟雄蛾对不同配比性信息素的嗅觉反应 及性信息素识别相关基因表达水平差异

【目的】本研究旨在从行为和嗅觉分子水平探究二化螟Chilo suppressalis雄蛾对性信息素嗅觉反应的地理种群差异及其机理,以明确该害虫田间种群雄成虫的嗅觉适应性及其特点。【方法】采用7种Z11-16∶Ald, Z9-16∶Ald和Z13-18∶Ald配比不同的三元性信息素诱芯(Z11-16∶Ald和Z9-16∶Ald配比分别为540 μg∶540 μg, 864 μg∶216 μg, 945 μg∶135 μg, 980 μg∶98 μg, 1 003 μg∶77 μg, 1 016 μg∶64 μg和1 045 μg∶35 μg,而Z13-18∶Ald含量保持不变),在中国6省水稻田间诱捕二化螟雄成虫;利用实验室风洞测定864 μg∶216 μg, 980 μg∶98 μg和1 016 μg∶64 μg配比诱芯在田间诱捕的越冬代和第2代二化螟雄蛾分别对这3个配比的性信息素诱芯的行为反应;并采用RT-qPCR方法测定这7种性信息素配比不同的诱芯诱捕的雄蛾触角中二化螟雄蛾12个性信息素识别相关基因的表达水平。【结果】在田间试验中,Z11-16∶Ald和Z9-16∶Ald不同配比的性信息素诱芯对水稻二化螟雄蛾均有引诱作用,但不同配比引诱的二化螟雄蛾占比不同。6省诱芯中Z11-16∶Ald和Z9-16∶Ald的最佳配比不同,并且同一配比性信息素诱芯在不同省份引诱的二化螟雄蛾占比也不同。结果表明,不仅在不同地区诱芯的性信息素最佳配比不同,而且在不同地区不同配比性信息素的诱蛾量占比也不同。实验室风洞试验中,864 μg∶216 μg和1 016 μg∶64 μg配比诱芯田间诱捕雄蛾分别对864 μg∶216 μg和1 016 μg∶64 μg配比诱芯的行为反应均显著强于对其余两种配比诱芯,980 μg∶98 μg配比诱芯田间诱捕雄蛾对1 016 μg∶64 μg, 980 μg∶98 μg和864 μg∶216 μg配比诱芯的行为反应无显著差异。在RT-qPCR测定中,除GOBP1外,其余11个性信息素识别相关基因在Z11-16∶Ald和Z9-16∶Ald不同配比诱芯诱捕雄蛾触角中的表达水平均存在显著差异,其中PBP3, PBP4, PR1, PR2, PR4, PR5和PR6 7个基因的表达水平与性信息素配比之间存在显著的线性相关。【结论】本研究明确了中国二化螟不同地理种群性信息素嗅觉差异,不仅有助于提高该害虫的性诱防控效率,而且也有助于理解其嗅觉地理种群差异的成因。     

蚜虫学研究现状与学科发展趋势

蚜虫由于本身具有的一些特性,如周期性的孤雌生殖、多样的生活史、卵生或卵胎生、多样化的虫瘿、行为分化等特征,成为众多昆虫学家和进化生物学家研究的对象,以蚜虫为研究模型可以解决很多重大的生物学问题。综合最新的研究成果,本文从蚜虫系统学、蚜虫与寄主植物的关系、蚜虫生物地理学和多样性、蚜虫生物学和生态学、蚜虫行为学、蚜虫与内共生菌关系以及蚜虫功能基因组学等方面综述了蚜虫学的研究进展,并指出了蚜虫学研究中的热点。     

植物和刺吸式口器昆虫的诱导防御与反防御研究进展

刺吸式口器昆虫在长期的进化过程中形成特殊的口针结构,用于专门吸食植物韧皮部筛管细胞的汁液成分.以蚜虫为例,它们在取食过程中分泌的胶状唾液和水状唾液将有效的降低植物防御反应,其中水状唾液包含的大量酶类不仅可以帮助蚜虫穿刺植物韧皮部,刺探到筛管细胞,同时也是植物感受蚜虫为害的激发因子,诱导出植物防御反应和相关抗性基因的表达...     

萼花臂尾轮虫对晶囊轮虫反捕食行为及形态响应的母体效应

为研究轮虫通过母体效应诱导能否产生行为响应, 以萼花臂尾轮虫(Brachionus calyciflorus)为例, 研究其反捕食漂浮行为响应的母体效应。通过控制轮虫母体在捕食者诱导液中的暴露时间及带卵状态, 收集母体产生的后代, 再将这些后代再次用捕食者诱导液处理, 观察后代的漂浮行为及形态特征。研究发现: 暴露于捕食者诱导液诱导较长时间的母体产生的后代个体, 当再次暴露于捕食者诱导液时, 其产生的行为响应强于没有母体暴露经历的后代; 母体暴露时间越长, 后代形态和行为响应均更加强烈。研究显示萼花臂尾轮虫可通过母体效应产生漂浮行为响应。     

落叶松球果花蝇头胸和腹部粗提液阻碍与引诱作用的试验

将雌性落叶松和黑松球果花蝇头胸和腹部充分研磨 ,加入溶剂正己烷得到粗提液。应用该粗提液进行了球果花蝇产卵阻碍信息素和性引诱信息素的野外试验。初步结果显示球果花蝇有产卵阻碍信息素作用的存在 ,但还需进一步试验证明 ;同时结果未显示有性引诱效果。