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1.
Abstract:  Aiming to minimize visual competition between large red apples and red sphere traps from influencing effectiveness of traps for apple maggot fly (AMF) control, we compared AMF captures by red spheres in standard recommended position (no fruit within 15 cm), red spheres in similar position but with all fruit removed within a 30-cm radius (fruitless), red spheres with additional visual competition provided by three plastic red spheres hung 15 cm from sphere traps, and yellow panels. Traps were coated with adhesive, baited with synthetic fruit odour, and hung on trees of an apple cultivar bearing red fruit (Akeene) and trees of an apple cultivar bearing pale yellow fruit (Golden Delicious). On Akeene trees, red spheres in recommended position and fruitless red spheres caught more AMF than red spheres surrounded by plastic spheres and than yellow panels. Towards harvest, effectiveness of red spheres in recommended position decreased as reflectance of the surface of Akeene apples approached that of red spheres. By contrast, effectiveness of fruitless spheres increased over time. On Golden Delicious trees, fruitless spheres were the most effective, followed by spheres surrounded by uncoated plastic spheres and red spheres in recommended position. We conclude that removing all fruit within a 30-cm radius around red sphere traps results in similar or increased trap effectiveness relative to red spheres in recommended position.  相似文献   

2.
Tagging or marking small laboratory-bred fish species is not an easy task. This also holds for the zebrafish, Danio rerio, which is widely used throughout the world as a model organism for genetics, developmental biology, etc. We present a simple marking technique based on scale regeneration. A comparative morphological study of various types of zebrafish scales indeed shows that regenerated scales are easily distinguishable from nonregenerated ones. We propose to take advantage of this typical morphology to mark a single or several individuals. This technique, based on a natural biological process, is easy to perform and does not enhance fish mortality in laboratory breeding conditions. It permits assembly of several specimens in a single tank with the possibility of identifying each of them by regenerated-scale coding. Nevertheless, a prerequisite is that the species does not lose and regenerate scales in large numbers in laboratory breeding conditions. To check this, 5,200 scales were removed from a large region of the left flank in 100 zebrafish and the number and position of regenerated scales were statistically analysed. Our results indicate that (1) laboratory-bred zebrafish have only a few regenerated scales (7.48%), (2) the probability of finding a regenerated scale is similar whatever its position in a row (antero-posterior axis), but (3) it differs from one row to another (scales from the back are more frequently lost than those from the pectoral region). This paper presents a procedure to mark small breeding colonies of zebrafish using scale regeneration with the number and position of the scales to be removed with high probability of marking success. J. Exp. Zool. 286:297-304, 2000.  相似文献   

3.
The turbulent flow properties of dilute (0.06% by volume) suspensions of human red blood cells in 4-mm-bore glass tubing were estimated by laser anemometry. The flow properties of the dilute red cell suspension were similar to those of a dilute suspension of polystyrene spheres (0.5 micron diameter) in isotonic NaCl solution. Flow was found to be laminar when the Reynolds number was below 2,000, transitional in the range of Reynolds numbers from 2,000 to 3,000, and fully turbulent above Reynolds number 3,000. These results differ from previous studies of more concentrated red cell suspensions. The length scales of the turbulence were also estimated: at a Reynolds number near 4,000 the macroscale is about 1.25 mm, the Taylor microscale is about 0.85 mm, and the Kolmogoroff scale is near 0.075 mm. The results are discussed in relation to previous measurements of the rate of oxygen uptake by dilute red cell suspensions in the flow-type rapid reaction apparatus. Our results suggest that under the conditions of most of these oxygen uptake measurements, the turbulent flow is characterized by eddies about 1 mm across, mixing with each other on a time scale of about 45 ms. Since most of the reported oxygen uptake measurements involve a similar time scale, it is possible that an effective "unstirred layer" influenced the reported rate of oxygen uptake.  相似文献   

4.
Abstract. 1. Laboratory experiments and field studies were conducted to explain the coexistence of an endoparasitoid, Encarsia perniciosi Tower, and an ectoparasitoid, Aphytis melinus DeBach, both of which were introduced into California to control the California red scale, Aonidiella aurantii (Mask.).
2. Encarsia parasitized all scale stages but it preferred first and second instar scales. This is in contrast to Aphytis melinus , in which previous studies have shown that it parasitizes second and third instar females and second instar males but prefers third instar female scales. Encarsia developed most rapidly when it parasitized an early second instar and slowest when it parasitized the mature female scale. However, on early second instar scales it was about 80% as fecund as a wasp that emerged from a mature female scale.
3. Second instar scales parasitized by Encarsia were accepted by Aphytis as readily as unparasitized scales.
4. Encarsia did not distinguish between unparasitized hosts and those previously parasitized by Aphytis.
5. Encarsia always outcompeted by Aphytis when both species parasitize the same host.
6. Encarsia prefers scale on stems whereas Aphytis prefers those on leaves and fruits. This, too, may be a result of interspecific competition with Aphytis.
7. The partitioning of the scale resource by the two species explains why they coexist in coastal southern California but it does not explain why Encarsia disappeared from citrus groves in the inland valleys coincident with the introduction of Aphytis melinus into southern California.  相似文献   

5.
Abstract:  Evaluation of two IPM methods to control main pests in citrus orchards This study aims to the consolidation of the acquired knowledge regarding integrated pest management (IPM) against the main pests in citrus orchards. We provide evidence that the principles of this method already tested on small scales, are quite applicable on larger ones. In addition to this aspect, the purpose of our work has been the evaluation of two IPM methods: the first one, has been tested in Morocco for 3 years in areas not exceeding 1.2 ha; the second one originating from Australia, is presently recommended by the Plant Protection Authorities in Morocco. The results obtained confirm the complementarity between these two methods which are not mutually exclusive, despite some advantages recorded in favour of this method or the other. Our results show that the Moroccan method is more efficient in monitoring aphids and citrus leaf miner (CLM) population as it leads to the same results while reducing by half the number of the samples inspected. In contrast, mites monitoring is more convenient with the Australian method, allowing a good evaluation of the numbers of phytoseiid predators. Moreover, this method enabled us to reduce the quantity of pesticides used against Mediterranean fruit fly through treatment by lured spots reducing pulp volume by more than 92.8% and costs by 20%. These two methods gave the same results for monitoring population dynamics of California red scale and Mediterranean fruit fly but, fruit infestation at harvest was higher with the Australian method than the method developed locally (70.95% against 74.75 for California red scale and 2.35 against 3.35 for Mediterranean fruit fly).  相似文献   

6.
The scales of whitefish Coregonus lavaretus were used in place of dorsal muscle, which necessitates killing the fish, to study food webs from the δ13C and δ15N isotopic ratios in the organic fraction. As scales are composed of both organic and calcified fractions, a protocol for scale decalcification was first devised. The δ13C and δ15N values of the decalcified scales were then shown to be closely correlated to those of the dorsal muscle, demonstrating that scales could be used in place of muscle to study food webs. Changes in the δ13C of whitefish were determined from a scale collection that extended over the period during which the trophic state of Lake Geneva was recovering.  相似文献   

7.
不同空间尺度下的肉果植物扩散过程和机理   总被引:5,自引:2,他引:3  
肉果植物扩散的生态学过程在最近得到生态学者们的广泛关注,其扩散过程包括果实搬运、果实消耗、种子雨、种子取食、种子库动态、萌发和幼苗定居等。许多过程涉及到果食性动物和肉果植物之间的互惠的协同进化关系。对最近15a关于肉果植物扩散的研究论文进行了综述,探讨在生境、微生境、景观和区域等常用的空间尺度上,肉果植物扩散和定居过程的格局与机理。  相似文献   

8.
Entocytherids are epifauna on larger crustaceans. We assessed the effectiveness of chlorobutanol and carbonated water for removing entocytherid, Ankylocythere sinuosa, from crayfish, Procambarus clarkii. This was done using different exposure times and by assessing entocytherid and crayfish survival, together with the number of entocytherids removed. According to our results, chlorobutanol submersion of crayfishes in shorter time periods is more effective for removing entocytherids without killing the crayfish host. However, carbonated water submersion is better to extract larger amounts of living entocytherids. Finally, both chemicals are appropriate tools to establish standardised protocols for removing entocytherids from crayfish for ecological studies because the proportions of removed entocytherids per crayfish become constant whatever the entocytherid load of the crayfish. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)  相似文献   

9.
Abstract:  The process of invasion of the fruit surface by three species of armored scale insects [ Lepidosaphes beckii (Newman), Parlatoria pergandii Comstock and Aonidiella aurantii (Maskell)], was studied in citrus orchards in València, Spain. Three periods of intense crawler migration were detected annually for L. beckii and P. pergandii . Abundance of crawlers increased throughout the year and they moved outwards in the tree canopy. The fruit was continuously invaded during the period of fruit growth, starting at a very early stage of fruit development, by crawlers of the first generation of all the three species. Differences in fruit invasion and settling behaviour were found between the three species. First-generation crawlers tended to settle under the fruit calyx in L. beckii and P. pergandii , and on the exposed fruit surface in A. aurantii . During the second generation, most A. aurantii scales originated from reproducing females already settled on the fruit, whereas in L. beckii and P. pergandii new scales came preferentially from other tree substrates or from females settled under the fruit calyx. These findings suggest changes to optimize the timing of chemical sprays for controlling the scales.  相似文献   

10.
Although avian color preferences have been studied and documented in controlled experiments, they have not been demonstrated under natural conditions in most cases. We hypothesized that avian fruit choice reflects intraspecific variation in fruit characteristics other than color, rather than fruit color differences. By planting one Ilex serrata Thunb. (red form) and one I. serrata forma leucocarpa Beissner (white form), which produce red and white fruits, respectively, at each of five points, we examined the proportion of fruits removed per tree and fruit choice by three avian species based on fruit color and other fruit characteristics. The proportion of fruits removed increased with pulpy sugar concentration and fruit diameter, but it did not differ between fruit colors. The main foragers, resident brown-eared bulbuls Hypsypetes amaurotis, consumed fruits regardless of color, but correspondingly to fruit removal, and appeared to base their fruit choice on pulpy sugar concentration and fruit diameter rather than on color. In contrast, the minor foragers, migrant Daurian redstarts Phoenicurus auroreus (Pallas) and Siberian bluechats Tarsiger cyanurus (Pallas), tended to choose red fruits and were possibly attracted by them. In conclusion, fruit removal per tree reflected individual variation in fruit profitability more strongly than differences in fruit color, even though the individual variation was not remarkable. The importance of color in fruit choice differed based on species, residency status, and major/minor foragers.  相似文献   

11.
In most cryopreservation applications, the final concentrations of cryoprotective agents (CPAs) must be reduced to biocompatible levels. However, traditional methods for removing CPAs usually have disadvantages of operation complexity, time consumption, and ease of contamination, especially for the applications involving large volumes of cell suspensions. A dilution-filtration system, which involves pure ultrafiltration for separation, was developed for continuous, automatic, and closed process of removing CPAs. To predict the optimal protocols under given experimental conditions, a theoretical model was established first. Cell-free experiments were then conducted to investigate the variation in CPA concentration during the process, and the experimental data were compared with the theoretical values for the validation of the model. Finally, ten units (212.9?ml/unit±9.5?ml/unit) of thawed human red blood cells (cryopreserved with 40% (w/v) glycerol) were deglycerolized using the theoretically optimal operation protocols to further validate the effectiveness and advantage of the system. In the cell-free experiments, glycerol was continuously removed and the concentration variations fitted the simulated results quite well. In the in-vitro experiments, glycerol concentration in RBC suspension was reduced to 5.57?g/l±2.81?g/l within an hour, and the cell count recovery rate was 91.19%±3.57%, (n=10), which proves that the system is not only safe for removing CPAs, but also particularly efficient for processing large-scale samples. However, the operation parameters must be carefully controlled and the optimal protocols should be specialized and various from case to case. The presented theoretical model provides an effective approach to find out the optimal operation protocols under given experimental conditions and constrains.  相似文献   

12.
The multi‐scale spatial match between bird and food abundances is a main driver of the structure of fruit‐eating bird assemblages. We explored how the activity of fruit‐eating birds was influenced by the abundance of fruits at the local and landscape scales in Andean mountain forests during the breeding season, when most birds forage close to their nest. We measured: (1) the spatial scale of variation in the abundance of fruits, (2) the spatial scale of variation in the activity of fruit‐eating birds, and (3) the spatial match between both variables. The sampling design consisted of eleven 1.2‐ha sites, each subdivided into 30 cells of 20 × 20 m, where we sampled fruits and fruit‐eating birds. We found that fruit consumption, and to a lesser extent bird abundance, were associated with local spatial variation in abundance of selected fruit species. However, fruit‐eating birds did not modify their spatial distribution in the landscape following changes in availability of these fruits. Our study shows that fruit‐eating birds detect local spatial variation in fruit availability in their home breeding ranges, and exploit patches with large clusters of selected fruits. However, it may be unprofitable for breeding birds to stray too far from their nests to exploit fruit‐rich patches, accounting for the absence of fruit tracking at larger spatial scales.  相似文献   

13.
Two life stages of a laboratory colony of California red scale, Aonidiella aurantii (Maskell) (Hemiptera: Diaspididae), were exposed to 10 concentrations of pyriproxyfen to evaluate the effect of this insect growth regulator (IGR) on scale development and fecundity. First instars exposed to pyriproxyfen responded with mortality during the first and second molts. Second instars were more tolerant of pyriproxyfen than were first instars, indicating that growers should treat California red scale in the field before the first molt to achieve maximum efficacy. Male scales responded with an LC50 12-fold lower and an LC90 47-fold lower than was observed for female scales. Female scales that survived first instar exposure to pyriproxyfen experienced reduced fecundity with increasing pyriproxyfen concentration. Reduced fecundity was due to reduced survival of the females rather than sterility. Results from this study provide baseline California red scale susceptibility data for pyriproxyfen, and they suggest that 1 ppm pyriproxyfen can be used as a concentration that would discriminate between susceptible and resistant populations of scales. Field monitoring for incipient pyriproxyfen resistance in California red scale should be implemented in the San Joaquin Valley of California, and if resistance is detected, integrated resistance management strategies should be used to slow the progression of resistance.  相似文献   

14.
Several forms (isoproteins) of ferredoxin in roots, leaves, and green and red pericarps in tomato plants (Lycopersicon esculentum Mill.) were earlier identified on the basis of N-terminal amino acid sequence and chromatographic behavior (Green et al. 1991). In the present study, a large scale preparation made possible determination of the full length amino acid sequence of the two ferredoxins from leaves. The ferredoxins characteristic of fruit and root were sequenced from the amino terminus to the 30th residue or beyond. The leaf ferredoxins were confirmed to be expressed in pericarp of both green and red fruit. The ferredoxins characteristic of fruit and root appeared to be restricted to those tissue. The results extend earlier findings in demonstrating that ferredoxin occurs in the major organs of the tomato plant where it appears to function irrespective of photosynthetic competence.Abbreviations CBB Coomassie brilliant blue R-250 - Cm Carboxymethylated - Fd Ferredoxin - FNR ferredoxin-NADP+ oxidoreductase - FPLC Fast protein liquid chromatography - HPLC High performance liquid chromatography - rt root  相似文献   

15.
During bell pepper (Capsicum annuum L.) fruit ripening, beta-galactosidase activity increased markedly as compared with other glycosidases. We purified 77.5 kDa exo-1,4-beta-D-galactanase from red bell pepper fruit classified as beta-galactosidase II. A marked decrease in galactose content appeared during fruit ripening, especially in the pectic fraction. The purified enzyme hydrolyzed a considerable amount of galactose residues in this fraction. We isolated bell pepper beta-galactosidase (PBG1) cDNA. This PBG1 protein contained the putative active site, G-G-P-[LIVM]-x-Q-x-E-N-E-[FY], belonging to glycosyl hydrolase family 35. Quantitative RT-PCR revealed that the expression of PBG1 in red fruit was significantly stronger than that from any other tissues. Moreover, expression of PBG1 occurred prior to that of pepper endo-polygalacturonase 1 (PPG1), the major fruit-ripening enzyme. Based on these results, it appears that the hydrolysis of galactose residues in pectic substances is the first event in the ripening process in bell pepper fruit.  相似文献   

16.
不同配比红蓝LED光对黄瓜果实产量和品质的影响   总被引:2,自引:0,他引:2  
以荧光灯为对照,研究不同配比红蓝LED光处理﹝包括100%红光、75%红光-25%蓝光( R31)、50%红光-50%蓝光(R11)、25%红光-75%蓝光(R13)和100%蓝光﹞对黄瓜(Cucumis sativus Linn.)果实性状、产量及营养品质的影响。结果表明:100%红光处理组黄瓜植株生长缓慢,果实发育异常,果实单株产量及VC、可溶性糖和可溶性蛋白质的含量均低于其他处理组。100%蓝光处理组的果实发育正常,果实单株产量显著低于红蓝LED光组合处理组,而果实中可溶性糖、蔗糖、游离氨基酸和可溶性固形物的含量总体上显著高于其他处理组,可溶性蛋白质含量也较高。 R31处理组黄瓜果实的单果鲜质量显著高于其他处理组;R31和R11处理组的果实单株产量显著高于其他处理组,R11处理组的黄瓜果实中VC和可溶性蛋白质含量明显高于其他处理组。上述研究结果显示:黄瓜果实的单株产量和营养品质受红蓝光协同作用的影响,设施栽培黄瓜生产的较适宜光照比例为50%红光-50%蓝光。  相似文献   

17.
A long-standing observation in community ecology is that the scaling of species richness, as exemplified by species-area curves, differs on local and regional scales. This decoupling of scales may be largely due to sampling processes (the increasing constraint imposed by sampling fewer individuals at fine scales), as distinct from ecological processes, such as environmental heterogeneity, that operate across scales. Removal of the sampling constraint from fine-scale richness estimates should yield species-area curves that behave like those of the regions in which they are embedded, but an effective method for this removal has not been available. We suggest an approach that incorporates the manner in which small areas accumulate species over time as a way to remove the signature of sampling processes from fine-scale species-area curves. We report for three species-rich grasslands from two continents how local plant species richness is distributed through time at multiple, nested spatial scales, and we ask whether sampling-corrected curves reflect the spatial scaling of richness of each larger floristic province. Our analysis suggests that fine-scale values of richness are highly constrained by sampling processes, but once these constraints are removed, the spatial scaling of species richness is consistent from the scale of individuals to that of an entire province.  相似文献   

18.
Pterocarpus is often used to make high-grade furniture, with beneficial health functions on the human body. Therefore, this article with large fruit red sandalwood as an example, to explore its extract on the human body beneficial health care ingredients. FT-IR analysis, in the 2855–3421?cm?1 wave segment, ethyl acetate after extraction of large fruit red sandalwood powder infrared transmittance increased the maximum value; GC–MS analysis, large fruit red sandalwood in the human body with a cough and phlegm, detoxification and enhance human immunity and other effects. Among them, Homopterocarpin in the inhibition and killing of cancer cell activity outstanding performance. Cryptomeridiol is a natural product with anti-Alzheimer's disease and antispasmodic properties, with significant medicinal value.  相似文献   

19.
Aphytis melinus DeBach (Hymenoptera: Aphelinidae) is a biological control agent of diaspidid scale insects. The parasitoid has a narrow host range but its hosts are polyphagous. We determined the source of volatile cues the wasp uses to locate its few host species when those hosts occur on more than one host plant species. We addressed four questions in regard to the use of volatile cues in host location of California red scale, Aonidiella aurantii (Maskell) (Homoptera: Diaspididae): (1) Does A. melinus use volatile cues to assist in host location? (2) Are these cues innately recognized or learned? (3) Are cues produced by female California red scale, or from other sources? (4) Are the cues specific to the host or host plant? These questions were tested through the use of a Y-tube olfactometer. Female A. melinus used volatile cues to orient toward both infested and uninfested host plant material. Wasps learned these cues by associating odors from the host plant with host presence. They had no innate preferences for scale insect or host plant volatile stimuli. Contrary to previous studies, we found no evidence of orientation toward the female-produced sex pheromone of California red scale, nor to volatile cues from the attacked host stage. Wasps given experience with scale insects growing on lemon fruit subsequently oriented toward lemon and orange fruit and leaves. The scale species with which the wasp was given experience did not affect this preference. Wasps given experience with California red scale growing on squash did not orient toward infested lemon fruit. The host ranges of the parasitoid and its hosts are used to explain the adaptive value for the evolution of learned rather than fixed responses to cues used in foraging behavior.  相似文献   

20.
This paper presents a novel multiscale methodology for quantitative analysis of pulmonary gas exchange. The process of oxygen uptake in the lungs is a complex multiscale process, characterized by multiple time and length scales which are coupled nonlinearly through the processes of diffusion, convection and reaction, and the overall oxygen uptake is significantly influenced by the transport and reaction rate processes at the small-scales. Based on the separation of length scales, we characterize these disparate scales by three representative ones, namely micro (red blood cell), meso (capillary and alveolus) and macro (lung). We start with the fundamental convection-diffusion-reaction (CDR) equation that quantifies transport and reaction rates at each scale and apply spatial averaging techniques to reduce the dimensionality of these models. The resultant low-dimensional models embed each scale hierarchically within the other while retaining the important parameters of the small-scales in the averaged equations, and drastically reduce the computational efforts involved in solving them. We use our multiscale model for pulmonary gas exchange to quantify the oxygen uptake abnormalities in patients with hepatopulmonary syndrome (HPS), a disease which is characterized by coupled abnormalities in multiple length scales. Based on our multiscale modeling, we suggest a strategy to stratify patients with HPS into two categories--those who are oxygen-responsive and those who are oxygen non-responsive with intractable hypoxemia.  相似文献   

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