Aircraft applications of insecticides in East Africa

1961 ◽  
Vol 52 (2) ◽  
pp. 305-316 ◽  
Author(s):  
G. F. Burnett ◽  
D. Yeo ◽  
A. W. D. Miller ◽  
P. J. White
Keyword(s):  
Large Scale ◽  
Lethal Dose ◽  
Central Province ◽  
Cent Solution ◽  
Glossina Morsitans ◽  
Pregnant Females ◽  
The North ◽  
Reliable Performance ◽  
Median Diameter ◽  
Coarse Aerosol

SummaryIn the North Block at Chungai, comprising about 11 sq. miles of thorn savannah and thicket in Central Province, Tanganyika, an Auster J5G aircraft was used between July 1959 and March 1960 to apply a 2·5 per cent. solution of dieldrin in oil at the rate of 0·125 gal. per acre in an attempt to eradicate Glossina morsitans Westw. and G. pallidipes Aust. Eight applications were made at approximately four-weekly intervals. Swath width was 55 yd., and the aircraft emitted the insecticide as a coarse aerosol of volume median diameter 50–60μ as it flew in both directions over the block.The operation suffered delays, and three applications were incomplete to varying degrees. Kills of G. morsitans per application appeared to be 85 per cent. or higher, but the final reduction of 99·5 per cent. could theoretically have been attained with consecutive mortalities of only 65 per cent. It is suggested that this discrepancy may be due to the higher lethal dose required by pregnant females. G. pallidipes was also reduced by 99·5 per cent. Numbers of fly were reduced sufficiently for large-scale settlement with cattle, which should complete the work of exterminating the fly.The experiment is compared with that of the previous year in the same block, using γBHC, which reduced fly catches by less than 50 per cent. It is concluded that a combination of reduced swath width, greater volume dosage, more lethal insecticide and smaller lethal drop, together with improved flying technique and the more reliable performance of the disseminating equipment, was responsible for the improved result. It is thought that without delays, interruptions, incomplete applications and reinfestation, even better results would be obtained.This was the cheapest and one of the most successful aerial operations carried out against savannah tsetse. Costs actually over the ground were £301 per sq. mile; incidental costs due to the locality of operations were £66 per sq. mile. There is little chance of reducing the costs of flying directly, but economies are possible by the use of other insecticides or, more probably, by more efficient dispensing equipment.

Aircraft Applications of Insecticides in East Africa. VI.—Applications of a coarse Aerosol containning DDT to control the Tsetse Flies, Glossina morsitans Westw., Glossina swynnertoni Aust. and Glossina pallidipes Aust.

1954 ◽  
Vol 45 (3) ◽  
pp. 585-603 ◽  
Author(s):  
K. S. Hocking ◽  
D. Yeo ◽  
D. G. Anstey
Keyword(s):  
Random Effects ◽  
Glossina Pallidipes ◽  
Tsetse Flies ◽  
Glossina Morsitans ◽  
Median Diameter ◽  
Coarse Aerosol ◽  
Savannah Woodland ◽  
Mass Median ◽  
Glossina Swynnertoni ◽  
Mass Median Diameter

An experiment is described where applications of a coarse aerosol were made to savannah woodland containing the tsetse flies, Glossina moritans Westw., G. swynnertoni Aust. and G. pallidipes Aust.Seven applications were made, each at a nominal dosage of 0·25 lb. of technical DDT per acre and 0·25 gallons of solution per acre. The applications in any particular part of the treaed woodland covered an interval of 90 days, or rather more than two pupal periods.The coarse aerosol was produced by emitting the insecticidal solution under pressure through fine nozzles fitted to a boom. It had a mass median diameter of approximately 60 microns, and droplet dismeters varied from a few microns to approximately 200 microns.The population of G. pallidipes was so drastically reduced that it has subsequently dies out. The reduction of G. morsitans was approximately 95 per cent. The differences between the reductions are attributed mainly to differences between the ease with which the three species can be killed. It is pointed out that this is not necessarily equivalent to differences in susceptibility.Comparisons are made with previous experiments, and the different results of the various experiments are difficult to explian satisfactory. The increased cover in savannah areas during the leafy period may have reduced the effectiveness of the applications, and the total periods covered by the various series of applications were probably also important. Random effects, leading to ineffective treatments, may also be important.Costs are discussed.

Aircraft applications of insecticides in East Africa

1961 ◽  
Vol 52 (2) ◽  
pp. 293-303 ◽  
Author(s):  
R. Foster ◽  
P. J. White ◽  
D. Yeo
Keyword(s):  
Meteorological Conditions ◽  
Small Scale ◽  
Central Province ◽  
Biological Factors ◽  
Cent Solution ◽  
Glossina Morsitans ◽  
Operational Costs ◽  
Low Volume ◽  
Aircraft Application ◽  
Savannah Woodland

SummaryFollowing successful small-scale trials, an attempt was made, by aircraft application of insecticide, to eradicate Glossina morsitans Westw. and G. pallidipes Aust. from an isolated block of savannah woodland, approximately 11 sq. miles in extent, at Chungai in the Central Province of Tanganyika between July 1958 and January 1959. A single-engined aircraft, fitted with two belt-driven rotary-cage atomisers, was used to apply a 5 per cent, solution of γ BHC in power kerosene at a nominal dosage of 0·08 gal. per acre (0.04 lb. γ BHC per acre). Seven applications were made at approximately 28-day intervals, the time taken to complete an application varying from five to eight days. The operation failed to control the flies. Although each of the first two applications reduced the apparent density of G. morsitans by about 90 per cent, and that of G. pallidipes by a lesser, although still considerable, factor, later applications gave varying and often low mortalities, and the populations increased slowly for some time, the insecticide applications causing only temporary depressions in numbers. Numbers fell towards the end of the operation, but final reductions were only about 50 per cent, or less. Kills of female flies were low, and this undoubtedly led to the eventual failure.The low volume-dosage, a drop spectrum that possibly contained too few droplets of the required size, meteorological conditions, and biological factors that apparently favoured the survival of female flies are suggested as contributory elements to the low mortalities.Operational costs were considerably lower than in previous work.

Third report on Glossina investigations in Nyasaland

1916 ◽  
Vol 7 (1) ◽  
pp. 29-50 ◽  
Author(s):  
W. A. Lamborn
Keyword(s):  
Large Scale ◽  
Dry Season ◽  
The South ◽  
Glossina Morsitans ◽  
Lake Shore ◽  
The North ◽  
Sandy Ground ◽  
Artificial Breeding

I remained in the proclaimed area till 6th August 1915, then returning to the vicinity of Monkey Bay for the purpose of endeavouring to establish artificial breeding places on a large scale.While in the proclaimed area I took the opportunity of completing my survey of the distribution of Glossina morsitans, especially in the neighbourhood of Rifu and Kuti described by Dr. Shircore (Bull. Ent. Res., v, p. 87) as “primary centres 1 and 2,” which I had been unable to examine last season before the advent of the rains. As in the case of “ centres 3 and 4,” at Nyansato and Lingadzi respectively, I have not been able to find that the fly is sufficiently localised, even when the dry season is far advanced, as to render feasible any attempt to control it by prophylactic clearing of the bush. In the Rifu district there is a range of rocky hills and high ground running more or less parallel to the lake, with corresponding modification of the soil, so that a zone of scrub has sprung up, from half a mile to two miles in width, consisting very largely of thorn bush, among which are a few big trees. Towards the north this gradually dwindles, to be replaced by the borassus palms usually growing in the sandy ground along the Lake shore, and towards the south it gradually widens out and becomes continuous with the Kuti bush some five miles distant. Throughout its whole extent the fly was plentiful.

The use of ageing techniques to evaluate the effects of aerial spraying against Glossina morsitans centralis Machado (Diptera: Glossinidae) in northern Botswana

1978 ◽  
Vol 68 (3) ◽  
pp. 373-383 ◽  
Author(s):  
J. E. Davies
Keyword(s):  
Large Scale ◽  
Okavango Delta ◽  
Glossina Morsitans ◽  
Natural Conditions ◽  
Fluctuating Temperature ◽  
Delta Area ◽  
Pupal Period ◽  
Pregnant Females ◽  
Glossina Morsitans Centralis ◽  
Low Rate

AbstractDuring a large-scale air-spray trial using endosulfan against Glossina morsitans centralis Machado in the Okavango Delta area of Botswana, a programme of ageing all flies caught on fly-rounds was undertaken. The aim was to evaluate closely the effect of repeated sprays on the population and especially to determine the origin of the small residual population that often remains after spraying. Ageing males by the wing-fray method indicated that none survived the spraying. Ageing females by ovarian dissection showed that (a) no breeding occurred between sprays, (b) one pupal period was just covered by four spray applications, (c) the residual population was composed of females that had survived the spraying and (d) all survivors had been pregnant at the time of treatment. Dissections also showed a very low rate of insemination between sprays, but the few females that survived spraying were all inseminated. Larval and pupal periods under natural conditions of fluctuating temperature are discussed together with methods of improving air spraying results by eliminating pregnant females.

Aircraft Applications of Insecticides in East Africa. VII.—An Experiment against the Tsetse Flies, Glossina morsitans, Westw. and G. swynnertoni Aust., in the Rainy Season

1954 ◽  
Vol 45 (3) ◽  
pp. 605-612 ◽  
Author(s):  
K. S. Hocking ◽  
G. F. Burnett ◽  
R. C. Sell
Keyword(s):  
East Africa ◽  
Rainy Season ◽  
Diesel Oil ◽  
Tsetse Fly ◽  
Tsetse Flies ◽  
Glossina Morsitans ◽  
The North ◽  
Aerosol Mass ◽  
Number Of Factors ◽  
Coarse Aerosol

The “ North Block ” at Kikore, Central Province, Tanganyika, was treated with insecticide dispersed from an Anson 1 aircraft during the period 23rd January to 4th May 1951. The area consisted of some 4,000 acres of mixed bush, including about 230 acres of miombo, infested by two species of tsetse fly, Glossina morsitans Westw. and swynnertoni Aust.The insecticide used was equivalent to a 19·4 per cent. solution of technical BHC (equal to 2·45 per cent. γ isomer) in 50 per cent. diesel oil, 50 per cent. power kerosene. The solution was dispensed through a boom and nozzles under pressure as a coarse aerosol (mass median diam. 70 microns), at a nominal mean dose of 0·25 lb. technical BHC per acre per application. Eight applications were planned and seven completed.The first application was relatively ineffective, and for the second and subsequent cycles the emission rate was increased and over part of the block the swathe width was reduced. The result was a much improved kill but neither species of tsetse was exterminated.Owing to the number of factors involved, it is not possible to give any principal reason why this experiment was less successful than previous ones, but many of the difficulties encountered are inherent in rainy-season operations in East Africa.

Why Has There Been No People’s Power Rebellion in North Korea?

2018 ◽  
pp. 1-34
Author(s):  
Andrew Jackson
Keyword(s):  
Rural Areas ◽  
North Korea ◽  
Large Scale ◽  
Political Elite ◽  
Information Control ◽  
Al Jazeera ◽  
The North ◽  
New Information ◽  
Effective System ◽  
The Right

One scenario put forward by researchers, political commentators and journalists for the collapse of North Korea has been a People’s Power (or popular) rebellion. This paper analyses why no popular rebellion has occurred in the DPRK under Kim Jong Un. It challenges the assumption that popular rebellion would happen because of widespread anger caused by a greater awareness of superior economic conditions outside the DPRK. Using Jack Goldstone’s theoretical expla-nations for the outbreak of popular rebellion, and comparisons with the 1989 Romanian and 2010–11 Tunisian transitions, this paper argues that marketi-zation has led to a loosening of state ideological control and to an influx of infor-mation about conditions in the outside world. However, unlike the Tunisian transitions—in which a new information context shaped by social media, the Al-Jazeera network and an experience of protest helped create a sense of pan-Arab solidarity amongst Tunisians resisting their government—there has been no similar ideology unifying North Koreans against their regime. There is evidence of discontent in market unrest in the DPRK, although protests between 2011 and the present have mostly been in defense of the right of people to support themselves through private trade. North Koreans believe this right has been guaranteed, or at least tacitly condoned, by the Kim Jong Un government. There has not been any large-scale explosion of popular anger because the state has not attempted to crush market activities outright under Kim Jong Un. There are other reasons why no popular rebellion has occurred in the North. Unlike Tunisia, the DPRK lacks a dissident political elite capable of leading an opposition movement, and unlike Romania, the DPRK authorities have shown some flexibility in their anti-dissent strategies, taking a more tolerant approach to protests against economic issues. Reduced levels of violence during periods of unrest and an effective system of information control may have helped restrict the expansion of unrest beyond rural areas.

Information And Map-Made Control With The Functions Of Business Analytics For Urban Management

2019 ◽  
pp. 72-78
Keyword(s):  
Large Scale ◽  
Information Support ◽  
Urban Management ◽  
Business Analytics ◽  
Administrative District ◽  
The North ◽  
Model Of Management ◽  
Complex Development ◽  
Coordination System ◽  
Key Aspects

The key aspects of the process of designing and developing an information and cartographic control tool with business analytics functions for the municipal level of urban management are considered. The review of functionality of the developed tool is given. Examples of its use for the analysis and monitoring of implementation of the program of complex development of territories are given. The importance of application of information support of management and coordination at all levels of management as an integral part of the basic model of management and coordination system of large-scale urban projects of dispersed construction is proved. Information and map-made tool with business intelligence functions was used and was highly appreciated in the preparation of information-analytical and presentation materials of the North-Eastern Administrative District of Moscow. Its use made it possible to significantly optimize the list of activities of the program of integrated development of territories, their priority and timing.

DESIGN AND IMPLEMENTATION OF THE OCEANOGRAPHIC MODELING AND OBSERVATION NETWORK (REMO) FOR PHYSICAL OCEANOGRAPHY STUDIES AND OCEAN FORECASTING

2014 ◽  
Vol 31 (2) ◽  
Author(s):  
Jose Antonio Moreira Lima
Keyword(s):  
Atlantic Ocean ◽  
Large Scale ◽  
North Pacific Ocean ◽  
Integrated Approach ◽  
Sea Surface ◽  
Global Ocean ◽  
Height Anomaly ◽  
The North ◽  
Observation Network ◽  
Ocean Forecasting

This paper is concerned with the planning, implementation and some results of the Oceanographic Modeling and Observation Network, named REMO, for Brazilian regional waters. Ocean forecasting has been an important scientific issue over the last decade due to studies related to climate change as well as applications related to short-range oceanic forecasts. The South Atlantic Ocean has a deficit of oceanographic measurements when compared to other ocean basins such as the North Atlantic Ocean and the North Pacific Ocean. It is a challenge to design an ocean forecasting system for a region with poor observational coverage of in-situ data. Fortunately, most ocean forecasting systems heavily rely on the assimilation of surface fields such as sea surface height anomaly (SSHA) or sea surface temperature (SST), acquired by environmental satellites, that can accurately provide information that constrain major surface current systems and their mesoscale activity. An integrated approach is proposed here in which the large scale circulation in the Atlantic Ocean is modeled in a first step, and gradually nested into higher resolution regional models that are able to resolve important processes such as the Brazil Current and associated mesoscale variability, continental shelf waves, local and remote wind forcing, and others. This article presents the overall strategy to develop the models using a network of Brazilian institutions and their related expertise along with international collaboration. This work has some similarity with goals of the international project Global Ocean Data Assimilation Experiment OceanView (GODAE OceanView).

scholarly journals Impact of air–sea coupling on the climate change signal over the Iberian Peninsula

2021 ◽  
Author(s):  
Alba de la Vara ◽  
William Cabos ◽  
Dmitry V. Sein ◽  
Claas Teichmann ◽  
Daniela Jacob
Keyword(s):  
Climate Change ◽  
Iberian Peninsula ◽  
Mediterranean Sea ◽  
Large Scale ◽  
Regional Distribution ◽  
Coupled Model ◽  
Climate Change Signal ◽  
The North ◽  
The Mediterranean ◽  
The Impact

AbstractIn this work we use a regional atmosphere–ocean coupled model (RAOCM) and its stand-alone atmospheric component to gain insight into the impact of atmosphere–ocean coupling on the climate change signal over the Iberian Peninsula (IP). The IP climate is influenced by both the Atlantic Ocean and the Mediterranean sea. Complex interactions with the orography take place there and high-resolution models are required to realistically reproduce its current and future climate. We find that under the RCP8.5 scenario, the generalized 2-m air temperature (T2M) increase by the end of the twenty-first century (2070–2099) in the atmospheric-only simulation is tempered by the coupling. The impact of coupling is specially seen in summer, when the warming is stronger. Precipitation shows regionally-dependent changes in winter, whilst a drier climate is found in summer. The coupling generally reduces the magnitude of the changes. Differences in T2M and precipitation between the coupled and uncoupled simulations are caused by changes in the Atlantic large-scale circulation and in the Mediterranean Sea. Additionally, the differences in projected changes of T2M and precipitation with the RAOCM under the RCP8.5 and RCP4.5 scenarios are tackled. Results show that in winter and summer T2M increases less and precipitation changes are of a smaller magnitude with the RCP4.5. Whilst in summer changes present a similar regional distribution in both runs, in winter there are some differences in the NW of the IP due to differences in the North Atlantic circulation. The differences in the climate change signal from the RAOCM and the driving Global Coupled Model show that regionalization has an effect in terms of higher resolution over the land and ocean.

scholarly journals Phylogeography in an “oyster” shell provides first insights into the genetic structure of an extinct Ostrea edulis population

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Sarah Hayer ◽  
Dirk Brandis ◽  
Alexander Immel ◽  
Julian Susat ◽  
Montserrat Torres-Oliva ◽  
...  
Keyword(s):  
Large Scale ◽  
Wadden Sea ◽  
Atlantic Coast ◽  
Phylogenetic Reconstruction ◽  
Oyster Shell ◽  
Glacial Refugia ◽  
Late Nineteenth Century ◽  
Ostrea Edulis ◽  
Geographic Ranges ◽  
The North

AbstractThe historical phylogeography of Ostrea edulis was successfully depicted in its native range for the first time using ancient DNA methods on dry shells from museum collections. This research reconstructed the historical population structure of the European flat oyster across Europe in the 1870s—including the now extinct population in the Wadden Sea. In total, four haplogroups were identified with one haplogroup having a patchy distribution from the North Sea to the Atlantic coast of France. This irregular distribution could be the result of translocations. The other three haplogroups are restricted to narrow geographic ranges, which may indicate adaptation to local environmental conditions or geographical barriers to gene flow. The phylogenetic reconstruction of the four haplogroups suggests the signatures of glacial refugia and postglacial expansion. The comparison with present-day O. edulis populations revealed a temporally stable population genetic pattern over the past 150 years despite large-scale translocations. This historical phylogeographic reconstruction was able to discover an autochthonous population in the German and Danish Wadden Sea in the late nineteenth century, where O. edulis is extinct today. The genetic distinctiveness of a now-extinct population hints at a connection between the genetic background of O. edulis in the Wadden Sea and for its absence until today.

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