307 resultados para Scirtothrips inermis
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Tres especies de trips se citan por primera vez para la Argentina. Scirtothrips inermis y Scolothrips pallidus se recolectaron sobre Viburnum tinus en la provincia de Mendoza. La primera de ellas es fitófaga y potencial plaga de citrus y la segunda es una especie benéfica y preda ácaros. También se registra por primera vez Thrips trehernei sobre Taraxacum officinale en Buenos Aires. Se elabora una clave para los géneros de la familia Thripidae en la Argentina. Asimismo, se presentan claves para las especies de los géneros Thrips y Scirtothrips en Argentina.
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South African citrus thrips (Scirtothrips aurantii) established adventitiously in Australia. Although it is a major horticultural pest in Africa, it is now advocated as a possible biological control agent against Bryophyllum delagoense Eckl. & Zeyh. (Crassulaceae). To evaluate the biocontrol potential of S. aurantii a two year field study was conducted on the western Darling Downs of southern Queensland. Imidacloprid insecticide was applied to two quadrats at each of 18 field sites to assess, in the absence of S. aurantii, the persistence of individual plants and to quantify propagule production and recruitment by this declared weed. A third quadrat was left, as a control, to be infested naturally by S. aurantii. When released from herbivory by thrips in the field, plants grew significantly more, flowered more, and were significantly more fecund than plants in the quadrats with S. aurantii. Increases in growth and fecundity translated into significantly increased plant numbers but not increased recruitment. Recruitment even declined in experimental quadrats, through the indirect effects of releasing plants from herbivory. Field sampling also revealed that S. aurantii may be sensitive to seasonal climatic fluctuations. These and other local climatic influences may limit the biological control potential of the insect.
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The relationships of various morphometric characters with dorsal mantle length (DML) of Sepiella inermis from Mumbai waters was established. The coefficient of correlation (r²) for various morphometric characters against dorsal mantle length ranged from 0.747 to 0.942 indicating high degree of relationship among the characters compared. The regression of characteristics obtained by least squares method for S. inermis indicates that the characters have positive allometric growth.
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Results from the Continuous Plankton Recorder (CPR) survey for 1966 and 1967 are used to describe seasonal changes in abundance, size and aspects of the population structure of Thysanoessa inermis (Krøyer) and T. raschi (M. Sars) at a depth of 10 m in the North Sea and in American coastal waters from the Grand Banks to the Gulf of Maine. Production and dry weight were estimated from these data. Two year-groups were usually present in the breeding population, the proportion surviving into a second year being higher in American waters than in the North Sea. Annual production for each species was within the range 0.69 to 4.66 mg m-3 and the ratio between production and biomass (P:B) was between 1.3 and 4.2; values outside these ranges were obtained only for American coastal waters in 1967, when the frequency of sampling was low.
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Samples taken in the northern North Sea with the Continuous Plankton Recorder (CPR), the Undulating Oceanographic Recorder (UOR) and the Longhurst-Hardy Plankton Recorder (LHPR) during the Fladen Ground Experiment in 1976 (FLEX 76) are used to describe the vertical distribution and population dynamics of Thysanoessa inermis (Krøyer) and to provide estimates of the production and carbon budget of the population from 19th March to 3 June 1976. Spawning occurred in late April and early May, in near synchronisation with the start of the spring bloom of phytoplankton. Eggs, nauplii and calyptopes reached maximum abundance in succession, and furciliae were numerous when sampling ceased in early June. Adults increased in length from a mean of 12.1 mm in mid-March to 17.5 mm in early June and the estimated production was 2.40 mg m-3 over the 74 d period. Total carbon ingested by the population of T. inermis was estimated to be 10 mg C m-2 d-1 in the upper 100m which was only 1.5% of the daily primary production of 0.68 gC m-2 measured over the FLEX period 26 March to 4 June 1976. The grazing by T. inermis on the phytoplankton population was assumed to have little effect on the control and depletion of the spring phytoplankton bloom during FLEX 77.
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Von Herm. Lachmann
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In this paper, some observations are made following a flash-flood that occurred in Stake Clough, a small tributary of the River Goyt, during the evening of 6 August 1996. The site was visited eight times between 8 August - 30 October 1996 to take samples and make observations on the stream. The flood scoured the bed of Stake Clough but more significantly, caused it to change course along the middle part of the floodplain. Initially after the flood, the numbers of insects in all stretches of the stream channel were low (100-200 m super(2)), but then gradually rose to population densities approaching ten times this figure. The benthos was dominated by the Chironomidae and also leuctrid stoneflies (Leuctra nigra, L. hippopus and L. inermis). On 8th August 1996, 12 mesh bags, each containing oak leaves, were placed in the stream and collected after 24 hours. These were also dominated by chironomids, and contained relatively high numbers of the caddis, Potamophylax cingulatus.
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自工业革命以来,大气的C02浓度以前所未有的速度增加,已经由280μmol mol-1升高到了360μmol mol-l。据预测,到下个世纪中/末期,C02浓度将为目前的二倍。C02浓度升高及其引起的全球气候变化必将影响到植物的生长发育,进而对整个生态系统产生巨大影响。因此,有关C02浓度升高对各类生态系统的影响的研究引起了广泛关注,成为近年来的研究热点。早期的研究多数集中于考察C02浓度升高对植物个体水平生长发育的影响。然而,高C02对植物的效应严重依赖于具体物种和具体环境条件,使得基于由短期盆栽实验获得的研究结果不能够有效地预测自然生态系统的行为。因此,长期、原位处理实验越来越受到重视。由于原位研究的难度较大,目前这方面的研究还不是很多。有限研究结果显示,由于生境条件和种间关系方面的巨大差异,自然生态系统对C02浓度升高的反应迥异。 草原生态系统由于C02浓度控制上比较容易实现,而且其物质循环相对较快,因而一直是C02富集实验研究最多的一类植被,生态系统水平的研究更是如此。然而涉及的区域和草原类型并不多,不足以进行可靠预测。目前,关于C02升高效应,研究比较系统的草原生态系统主要集中在:美国Kansas的高草草原、美国California的一年生草原、瑞士西北部的石灰质草原、美国Colorado的矮草草原和一些牧场。我国总土地面积的40%为草地,类型丰富,然而相关研究不多,尤其是对自然生态系统的原位研究几乎为空白。 为揭示C02浓度升高对羊草草原生产力和碳平衡的效应,我们在中国科学院内蒙古草原生态系统定位研究站的永久羊草样地开展了两年的C02倍增实验(2001,2002)。在羊草样地选择相对均匀地段设置12个开顶式气室(直径1.8m),每个气室内分成4个小样方(0.5m×0.5m),其中6个气室在生长季给予加倍C02处理(约600μmol mol-l),另6个气室不补充C02(约300μmol moI-l)。地上部分用收割法取样,分种记录数量、高度和重量等指标,地下部分取样用环刀法。用Li-cor6400光合系统测定群落光合和呼吸速率。野外实验结束后,统一分析植物和土壤样品中的C、N等元素含量。另外,在内蒙古草原站院内设置了两组桶培实验,一组是取自羊草样地的带苗原状土,一组是取自羊草样地的混匀土,种上冰草(Agropyron cristatum)、紫花苜蓿(Medicago sativa)和无芒雀麦(Bromus inermis)的种子。2组桶培实验分别用两个水分梯度和两个C02梯度处理。水分处理分别为:浇水处理——每4天浇lOOOml水,相当于平均降雨量的160%;干旱处理——持续干旱,适时补水以保持植物不萎蔫,共浇水4000ml水。C02处理和取样方法与样地原位实验相同。主要研究结果和结论如下: 1)两年的C02加倍处理没有使羊草草原的生物量、植物种和功能型组成发生显著改变,桶培实验中,浇水处理显著促进了植物生长,原状土植物、种子苗实验的冰草和无芒雀麦对C02加倍处理同样不敏感,而种子苗实验的豆科植物紫花苜蓿在C02加倍处理下生物量显著提高。以上结果显示,由于水分和养分(特别是N)的限制,以及优势植物对C02的相对不敏感,C02浓度升高对羊草草原地上生物量和结构的效应相对不大。 2)羊草草原的根垂直分布在加倍C02条件下发生显著改变,但根生物量对C02加倍处 理相对不敏感。在4次取样中只有一次对C02加倍处理表现出显著变化,根长的变化与根生物量的变化不完全一致,根的比根长在加倍C02条件下增加。根垂直分布的变化趋势与降雨的时间分布相适应,干旱少雨时期C02使下层根量增加,多雨时期C02则使上层根量增加。以上结果显示,根的空间分布比根生物量对C02加倍处理更敏感。水分是根空间分布变化的驱动因子,加倍C02条件下,根空间分布的变化趋势倾向于优化对水分的充分利用。 3)加倍C02处理使羊草草原的群落光合速率显著提高,群落呼吸速率显著降低,因而使群落碳净输入量增加。土壤碳贮量占羊草草原碳总贮量的70%以上,碳总贮量及其组分(包括地上碳贮量、根碳贮量、土壤碳贮量)在两个C02浓度处理之问均没有显著差异。另外,加倍C02处理使羊草草原群落及其优势植物羊草的c:N比增加。以上结果显示,在加倍C02条件下羊草草原的碳净输入量增加,这意味着在未来高 C02条件F,羊草草原将作为碳汇对大气C02起反馈调节作用。其碳贮量对加倍C02 处理的不敏感与许多以前的研究结果相似,一般认为是由于土壤碳贮量本底太大, 掩盖了C02效应,这还有待于更长期原位实验的证实。羊草草原群落c:N比在高C02 浓度下的变化将影响凋落物降解、N素循环和动植物营养关系等,进而对生态系统 功能产生深远影响。
Resumo:
Data on the biochemical composition and food value of the edible portions of two gastropods, Pila virens and Achatina fulica and two cephalopods, Sepiella inermis and Loigo indica have been presented. These molluscs possess nutritive meat very rich in protein and minerals, which compare favourably with popular food fishes in caloric value. The significance of the variations met with in the biochemical constituents of the different species has been discussed.
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The paper presents the seasonal variations in moisture, protein, salt and ash in the meat of Murex virgineus, Solen sp., Loligo sp., Sepiella inermis and Octopus sp. Moisture and fat contents of twenty two species of molluscs are reported. Inverse relationship between protein and ash has been observed. Cephalopoda recorded higher meat, moisture and protein contents than amphineura, gastropoda and pelecypoda. Pelecypoda contains higher fat than amphineura, gastropoda and cephalopoda.
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海洋污损苔虫(marine fouling bryozoans或bryozoan foulers)是海洋污损生物群落的一个重要组成部分。在海洋污损动物中,海洋污损苔虫是仅次于软体动物和甲壳动物的主要污损生物。海洋污损苔虫有独特的群体生长方式,既有能利用表面积宽阔的附着基形成单层片状、多层结核状或丘状群体的成员;也有能利用表面积狭窄的附着基形成树枝状、树丛状或中空管状群体的成员;某些污损苔虫还能随附着基表面积的改变而改变其群体生长方式,即同一种污损苔虫在表面积宽阔的附着基上形成片状被覆群体,而在表面积狭窄的附着基上或空间竞争激烈的环境中则形成被覆和直立两种生长方式式兼有的被覆-直立群体。随着海水养殖事业的发展,各种养殖生物尤其是养殖贝类及其养殖笼网的投入为海洋污损生物提供了极其丰富的附着基。而与其它污损生物相比污损苔虫更能充分利用养殖贝类及其养殖笼网作为附着基,从而成为养殖贝类及其养殖笼网污损生物群落的优势类群,给贝类养殖业带来极大危害。近年来对养殖贝类污损苔虫的研究已开始受到人们的重视,但由于污损苔虫的调查一直是与其它污损生物调查同时进行的,污损生物学家在对污损苔虫的分类鉴定中面临着许多困难。作者对中国科学院海洋研究所历年来所收集的中国沿岸水域养殖贝类及其养殖笼网的污损苔虫标本进行了系统的分类研究,并对中国学者曾报道过的中国沿岸水域工污损苔虫进行了对比分析,得到的结果如下:1.中国沿岸水域养殖贝类及其养殖笼网的污损苔虫现有143种,分隶于2纲3目9亚目46科76属。其中养殖贝类的污损苔虫122种,分隶于44科68属;养殖笼网的污损苔虫90种,分隶于37科53属。养殖贝类和养殖笼网两类物体上的污损苔虫科属组成几乎相同,主要优势种组成几乎相同,膜孔苔虫Membranipora、琥珀苔虫Electra、草苔虫 Bugula、三胞苔虫 Tricellaria、软苔虫 Alcyonidium、隐槽苔虫 Cryptosula、血苔虫 Watersipora 拟分胞苔虫Celleporaria、和仿分胞苔虫 Celleporina等属的成员常形成污损苔虫生物群落的优势类群。2.本项研究中,我们发现一新科、一新属和7新种。新科为:太平洋苔虫科,新科Pacificincolidae fam. nov.。新属为:太平洋苔虫属,新属Pacificincola gen. nov.。7个新种分别为:(1)空穴拟小孔苔虫,新种Microporella vacuatus sp. nov.;(2)小筛网拟小孔苔虫,新种 Microporella cribellata sp. nov.;(3)无齿拟小孔苔虫,新种 Microporella inermis sp. nov.;(4)异北方拟小孔苔虫,新种 Microporella antiborealis sp. nov.;(5)项链拟小孔苔虫,新种 Microporella monilifera sp. nov.;(6)中华斑孔苔虫,新种 Fenestrulina sinica sp. nov.;(7)东方斑孔苔虫,新种 Fenestrulina orientalis sp. nov.。3. 笔者发现,本项研究以前其他中国学者所报道的污损苔虫在分类鉴定中存在许多异物同名和同物异名现象。例如,过去许多学者所报道的大室膜孔苔虫实际上包括3个不同的独立种;而过去一直被标定为聚合软苔虫的污损苔虫经鉴定为迈氏软苔虫。笔者对在本项研究以前的污损调查报告中所出现的污损苔虫的分类鉴定错误进行了适当的更正,并在系统分类研究的基础上编制了中国沿岸水域养殖贝类及其养殖笼网143种污损苔虫的分类检索表。