Sandfly Control with DDT Residual Spray. Field Experiments in Palestine

1947 ◽  
Vol 38 (3) ◽  
pp. 479-488 ◽  
Author(s):  
F. Jacusiel
Keyword(s):  
Marked Reduction ◽  
Large Scale ◽  
Field Experiments ◽  
Residual Effect ◽  
Degree Of Protection ◽  
Internal Surfaces ◽  
Spray Field ◽  
Stone Walls ◽  
High Degree ◽  
Residual Action

Field experiments carried out in 1945 at Rosh Pina in Palestine have proved the great efficiency of DDT residual spray in houses against sandflies.A high degree of protection against P. papatasii, P. major and P. chinensis was obtained by inside spraying of rooms with DDT in kerosene.The residual action lasted for 52–58 days during the hot summer months. At the end of this period the effect was still undiminished but the end of the sandfly season made further observations impossible. Judging from observations made elsewhere it may be assumed that the residual effect would have lasted not more than another two weeks.Dosage of 1 g. per m2 (100 mg. DDT per sq. ft.) was fully effective, and 2 g. per m2 gave no better results. The best method of application is the treatment of all internal surfaces (walls and ceiling). As sandflies tend to congregate in the angle between wall and ceiling, treatment of walls and this angle only gives equally good results.An attempt to protect a house by spraying “barriers” (vertical surfaces of stone walls etc., within a radius of 50 metres) failed. Sandflies on the outside surfaces disappeared after the DDT treatment but the observations recorded here and those reported by other authors suggest that much larger areas would have to be sprayed in order to make this method effective.A marked reduction of sandflies in untreated rooms followed the spraying of other Tooms in the same house with DDT. The mechanism of this phenomenon is explained. A general reduction of the sandfly population can be expected when large-scale DDT treatment is carried out in a village or camp area.

scholarly journals Fenitrothion Bio-Efficacy on Different Intradomicile Surface Types Against Anopheles (Nyssorhynchus) Albimanus in the Main Malaria Endemic Regions of Panama

2020 ◽  
Author(s):  
Lorenzo Cáceres Carrera ◽  
José Luis Ramírez ◽  
Rolando Torres-Cosme
Keyword(s):  
Toxic Effect ◽  
Malaria Transmission ◽  
Large Scale ◽  
Malaria Mosquito ◽  
Mosquito Vectors ◽  
Degree Of Protection ◽  
Different Types ◽  
Pirimiphos Methyl ◽  
Percent Mortality ◽  
High Degree

Abstract Background: The use of intradomicile residual insecticide on a large scale is a proven and efficacious intervention against malaria mosquito vectors. The objective of the study was determined the bio-efficacy and resistance of fenitrothion insecticide against the mosquito An. (Nyssorhynchus.) albimanus Wiedemann. Methods: This study included seven communities located in different endemic regions where fenitrothion is used to control An. (Nys.) albimanus populations. The test of bio-efficacy and susceptibility were conducted following the WHO standard bioassay methodology.Results: The average percent mortality of An. (Nys.) albimanus exposed to fenitrothion in the seven communities tested were 96% and 92% for the first two months. This bio-efficacy was maintained until the fifth month with 81% mortality in communities with high IRS coverage. Anopheles (Nys.) albimanus was susceptible to the organophosphate insecticides fenitrothion and malathion, as well as to carbamate Propoxur but resistant to pirimiphos-methyl and chlorpyrifos.Conclusion: This study demonstrates that fenitrothion maintains an elevated insecticide residuality and toxic effect on different types of surfaces until the fifth month post-application. Furthermore, An. (Nys.) albimanus remains highly susceptible to this insecticide, providing a high degree of protection against mosquito bites inside households, and interrupting malaria transmission in places with high IRS coverage and where the mosquito is still susceptible to fenitrothion application.

Residual effect of zinc applied to rice on zinc nutrition of succeeding wheat crop inoculated with zinc solubilizing microbial consortium

2019 ◽  
Vol 66 (3-4) ◽  
pp. 227-237
Author(s):  
Sachin Kumar Vaid ◽  
Prakash Chandra Srivastava ◽  
Satya Pratap Pachauri ◽  
Anita Sharma ◽  
Deepa Rawat ◽  
...  
Keyword(s):  
Crop Production ◽  
Large Scale ◽  
Field Experiments ◽  
Residual Effect ◽  
Wheat Crop ◽  
Bacterial Strains ◽  
Wheat Varieties ◽  
Seed Inoculation ◽  
Zn Uptake ◽  
Zn Concentration

Large scale deficiency of Zn results in low crops yields and the problem of Zn malnutrition in humans and livestock. To economize crop production on Zn deficient soils, two-year field experiments were undertaken with two wheat varieties to evaluate the performance of seed inoculation with a consortium of three bacterial strains in combination with varying doses of Zn fertilizer applied to 1 year rice crop on yields, Zn concentration and Zn uptake of wheat. Seed coating of wheat with bacterial consortium significantly increased grain yields, Zn concentration and uptake in grains and straw and total Zn uptake over the control. It also helped to increase the apparent recoveries of soil applied Zn fertilizer to 1 year rice by succeeding wheat crops and DTPA extractable Zn in soil after 2 year wheat in comparison to the control. Seed inoculation in combination with low dosage of Zn also significantly decreased phytic acid: Zn ratio but increased methionine concentration in wheat grains.

scholarly journals Large-scale transcriptomics to dissect 2 years of the life of a fungal phytopathogen interacting with its host plant

BMC Biology ◽  
2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Elise J. Gay ◽  
Jessica L. Soyer ◽  
Nicolas Lapalu ◽  
Juliette Linglin ◽  
Isabelle Fudal ◽  
...  
Keyword(s):  
Host Plant ◽  
Large Scale ◽  
Field Experiments ◽  
Plant Residues ◽  
Plant Infection ◽  
Effector Genes ◽  
Controlled Conditions ◽  
Niche Adaptation ◽  
Depth Analysis ◽  
Fungal Genes

Abstract Background The fungus Leptosphaeria maculans has an exceptionally long and complex relationship with its host plant, Brassica napus, during which it switches between different lifestyles, including asymptomatic, biotrophic, necrotrophic, and saprotrophic stages. The fungus is also exemplary of “two-speed” genome organisms in the genome of which gene-rich and repeat-rich regions alternate. Except for a few stages of plant infection under controlled conditions, nothing is known about the genes mobilized by the fungus throughout its life cycle, which may last several years in the field. Results We performed RNA-seq on samples corresponding to all stages of the interaction of L. maculans with its host plant, either alive or dead (stem residues after harvest) in controlled conditions or in field experiments under natural inoculum pressure, over periods of time ranging from a few days to months or years. A total of 102 biological samples corresponding to 37 sets of conditions were analyzed. We show here that about 9% of the genes of this fungus are highly expressed during its interactions with its host plant. These genes are distributed into eight well-defined expression clusters, corresponding to specific infection lifestyles or to tissue-specific genes. All expression clusters are enriched in effector genes, and one cluster is specific to the saprophytic lifestyle on plant residues. One cluster, including genes known to be involved in the first phase of asymptomatic fungal growth in leaves, is re-used at each asymptomatic growth stage, regardless of the type of organ infected. The expression of the genes of this cluster is repeatedly turned on and off during infection. Whatever their expression profile, the genes of these clusters are enriched in heterochromatin regions associated with H3K9me3 or H3K27me3 repressive marks. These findings provide support for the hypothesis that part of the fungal genes involved in niche adaptation is located in heterochromatic regions of the genome, conferring an extreme plasticity of expression. Conclusion This work opens up new avenues for plant disease control, by identifying stage-specific effectors that could be used as targets for the identification of novel durable disease resistance genes, or for the in-depth analysis of chromatin remodeling during plant infection, which could be manipulated to interfere with the global expression of effector genes at crucial stages of plant infection.

The academic profession in Russia’s two capitals: The impact of 20 years of transition

2017 ◽  
Vol 16 (5) ◽  
pp. 626-644 ◽  
Author(s):  
Elizaveta Sivak ◽  
Maria Yudkevich
Keyword(s):  
Large Scale ◽  
Academic Career ◽  
Academic Profession ◽  
University Faculty ◽  
Key Characteristics ◽  
Personal Strain ◽  
High Degree ◽  
The Impact ◽  
Russian Universities

This paper studies the dynamics of key characteristics of the academic profession in Russia based on the analysis of university faculty in the two largest cities in Russia – Moscow and St Petersburg. We use data on Russian university faculty from two large-scale comparative studies of the academic profession (‘The Carnegie Study’ carried out in 1992 in 14 countries, including Russia, and ‘The Changing Academic Profession Study’, 2007–2012, with 19 participating countries and which Russia joined in 2012) to look at how faculty’s characteristics and attitudes toward different aspects of their academic life changed over 20 years (1992–2011) such as faculty’s views on reasons to leave or to stay at a university, on university’s management and the role of faculty in decision making. Using the example of universities in the two largest Russian cities, we demonstrate that the high degree of overall centralization of governance in Russian universities barely changed in 20 years. Our paper provides comparisons of teaching/research preferences and views on statements concerning personal strain associated with work, academic career perspectives, etc., not only in Russian universities between the years 1992 and 2012, but also in Russia and other ‘Changing Academic Profession’ countries.

Development and Testing of an Unmanned Aerial Vehicle for Large Scale Particle Image Velocimetry

2014 ◽  
Author(s):  
Christopher Pagano ◽  
Flavia Tauro ◽  
Salvatore Grimaldi ◽  
Maurizio Porfiri
Keyword(s):  
Particle Image Velocimetry ◽  
Large Scale ◽  
Field Experiments ◽  
Particle Image ◽  
Low Cost ◽  
Surface Flow ◽  
Natural Environments ◽  
Natural Stream ◽  
Image Velocimetry ◽  
Scale Particle

Large scale particle image velocimetry (LSPIV) is a nonintrusive environmental monitoring methodology that allows for continuous characterization of surface flows in natural catchments. Despite its promise, the implementation of LSPIV in natural environments is limited to areas accessible to human operators. In this work, we propose a novel experimental configuration that allows for unsupervised LSPIV over large water bodies. Specifically, we design, develop, and characterize a lightweight, low cost, and stable quadricopter hosting a digital acquisition system. An active gimbal maintains the camera lens orthogonal to the water surface, thus preventing severe image distortions. Field experiments are performed to characterize the vehicle and assess the feasibility of the approach. We demonstrate that the quadricopter can hover above an area of 1×1m2 for 4–5 minutes with a payload of 500g. Further, LSPIV measurements on a natural stream confirm that the methodology can be reliably used for surface flow studies.

Research on Moving Target Monitoring Collaborative Simulation Technology Based on Multi-Channel

2010 ◽  
Vol 20-23 ◽  
pp. 700-705
Author(s):  
Tian Yuan ◽  
Shang Guan Wei ◽  
Zhi Zhong Lu
Keyword(s):  
Large Scale ◽  
Target Space ◽  
Laboratory Simulation ◽  
Moving Target ◽  
Simulation Technology ◽  
Collaborative Simulation ◽  
Mobile Target ◽  
Target Monitoring ◽  
Six Degree Of Freedom ◽  
High Degree

Multi-channel Virtual reality simulation technology is a kind of simulation technology, which support the grand scene and high degree of immersion, has better visualization effect. In this paper, a moving target monitoring collaboratory simulation technology based on multi-channel is studied. Firstly, study the mathematical modeling foundation of Multi-Channel technology systematically, based on the mobile target spatial model and co-simulation technology, select the appropriate applications of multi-channel technology, building laboratory simulation platform and achieved a space-based six-degree of freedom simulation of multi-channel moving target monitoring simulation. The experiment has proved that in multi-channel target monitoring co-simulation technology used in this paper has strong practicality, combine with a moving target-space model and co-simulation technology, the advantages of objective observation to solve the requirements like large-scale, realism, immersion requirements, etc.

scholarly journals Reduced Dosage of Methyl Bromide for Controlling Verticillium Wilt of Potato in Experimental and Commercial Plots

Plant Disease ◽  
1997 ◽  
Vol 81 (5) ◽  
pp. 469-474 ◽  
Author(s):  
A. Gamliel ◽  
A. Grinstein ◽  
Y. Peretz ◽  
L. Klein ◽  
A. Nachmias ◽  
...  
Keyword(s):  
Verticillium Wilt ◽  
Methyl Bromide ◽  
Large Scale ◽  
Field Experiments ◽  
Tuber Yield ◽  
Total Yield ◽  
Effective Control ◽  
Large Scale Field ◽  
Commercial Applications

The use of gas-impermeable films to reduce the dosage of methyl bromide (MB) required to control Verticillium wilt in potatoes was examined in field experiments, conducted in soils naturally infested with Verticillium dahliae. The incidence and severity of Verticillium wilt were significantly reduced (by 74 to 94%) by fumigation with MB at 50 g/m2 under standard low density polyethylene (LDPE) or at 25 g/m2 under gas-impermeable films. Fumigation at 25 g/m2 under LDPE was less effective. Disease severity was inversely correlated (r2 = 0.89 to 0.91) with chlorophyll content in the leaves. Fumigation also reduced (by 89 to 100%) stem colonization by the pathogen. Potato yield in the fumigated plots was significantly higher (26 to 69%), than in their nonfumigated counterparts, and was inversely correlated with disease index (r2 = 0.69 to 0.9). The percentage of high-value tubers (above 45 g) was 52 to 56% of total yield in the fumigated plots as compared with 32 to 40% in the nonfumigated controls. Thus, fumigation also improved the commercial quality of tuber yield. Effective control of V. dahliae and yield increases following MB fumigation at the recommended dosage or at a reduced dosage with gas-impermeable films was also observed in a consecutive crop. These results were verified in a large-scale field experiment using commercial applications, further demonstrating the feasibility of reducing MB dosages under farm conditions, without reducing its effectiveness in terms of disease control and yield improvement.

A Synthesis of Knowns, Unknowns, and Policy Recommendations from the Sea Lamprey International Symposium

1980 ◽  
Vol 37 (11) ◽  
pp. 2202-2208 ◽  
Author(s):  
Carl J. Walters ◽  
George Spangler ◽  
W. J. Christie ◽  
Patrick J. Manion ◽  
James F. Kitchell
Keyword(s):  
International Symposium ◽  
Large Scale ◽  
Fishery Management ◽  
Field Experiments ◽  
Lake Trout ◽  
Sea Lamprey ◽  
Future Research ◽  
Fish Stock ◽  
Total Production ◽  
Pilot Studies

The Sea Lamprey International Symposium (SLIS) has provided a broad spectrum of facts and speculations for consideration in future research and management programs. Many aspects of the laboratory biology and field life history of the sea lamprey (Petromyzon marinus) are now well understood. There is little question that it can now be controlled by chemical larvicides, and perhaps in the future by more efficient integrated control programs. There is correlative evidence (wounds, scars, catch curves) that lamprey caused major mortalities in some fish species, and that control in conjunction with stocking has lead to remarkable recoveries of salmonid stocks in the Great Lakes. However, there are great gaps in understanding about just what the lamprey does under field conditions, and it is not yet possible to reject several hypotheses that assign lamprey a minimum or transient role in fish stock changes. Further studies on details of lamprey biology are, in themselves, unlikely to fill the gaps; one alternative is to conduct a large-scale field experiment involving cessation of lamprey control while holding other factors (fishing, stocking) as steady as possible. If it is decided to proceed with management on the assumption that lamprey are important, without the major field experiments to confirm it, then at least the following steps should be taken: (1) the chemical treatment program should be reviewed in detail, with a view to finding treatment schedules that will minimize frequency and dose rates for lampricide applications; (2) pilot studies on alternative control schemes (sterile male, attractants, barriers) should only be funded if they are statistically well designed (several replicate and control streams), and involve quantitative monitoring of lamprey spawning success and subsequent total production of transforming larvae; (3) the lake trout (Salvelinus namaycush) stocking program should be maintained at its present level, and should involve diverse genotypes rather than a few hatchery strains; (4) growth in the sport fisheries for lake trout should be curtailed, and commercial fisheries should not yet be permitted; (5) a multispecies harvesting policy should be designed that takes into account the buffering effect of each species on lamprey mortality suffered by others (i.e. should some species not be harvested at all, and viewed instead as buffers for more valuable species?); and (6) a program should be developed for restoring, by culture if necessary, native forage species in case the introduced smelt and alewife should collapse under pressure from fishing and prédation by the growing salmonid community.Key words: sea lamprey, proposed research, fishery management, mathematical models, population dynamics

Effects of irrigation regimes on powdery scab disease and yield of potatoes

1986 ◽  
Vol 26 (6) ◽  
pp. 745 ◽  
Author(s):  
PA Taylor ◽  
SP Flett ◽  
RFde Boer ◽  
D Marshall
Keyword(s):  
Large Scale ◽  
Field Experiments ◽  
Field Trials ◽  
Powdery Scab ◽  
Infested Soil ◽  
Spongospora Subterranea ◽  
Potato Tubers ◽  
Potato Plants ◽  
Tuber Set ◽  
Large Scale Field

The period of susceptibility of potato tubers to powdery scab (Spongospora subterranea) was studied by inoculating potato plants with spores, or by watering plants in infested soil, at different stages of plant development in greenhouse conditions. Maximum susceptibility began about 1 week before the stage when 50% of stolons had swollen to at least 5-mm diameter (tuber set), and ended 3-4 weeks later. With holding irrigation water during this period reduced the severity of powdery scab by 65-75% in field experiments in 1981-82 and 1982-83, but had no apparent effect on disease severity in 3 out of 6 large-scale field trials during 1984-85.

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