A trial use of grass-mat passages in protecting humans from attacks by tsetse flies.

1961 ◽  
Vol 51 (4) ◽  
pp. 639-642
Author(s):  
E. A. S. La Croix
Keyword(s):  
Tsetse Fly ◽  
Human Anatomy ◽  
Northern Ghana ◽  
Tsetse Flies ◽  
Temporary Protection ◽  
Points Of Interest ◽  
Time Of Year ◽  
The Cost ◽  
Prevalent Species ◽  
Glossina Palpalis

In March 1957, an outbreak of human sleeping sickness was discovered in the South Mamprussi District of northern Ghana. Temporary measures were initiated at a few villages to provide protection, at water-holes on streams, against attack by the two prevalent species of tsetse, Glossina palpalis (R.-D.) and G. tachinoides Westw., until clearings could be made.These measures consisted of grass-mat passages approximately 8 ft. high, extending from about 75 yd. from the stream down to and around the waterhole. At the water-hole, there was a gap of about 1 ft. between mat and water.These passages were found to be successful in excluding tsetse fly. This suggests several points of interest about G. palpalis and G. tachinoides: that at that time of year and in that type of vegetation, they do not rest higher than 8 ft. above ground; that the portions of human anatomy that showed beneath the matting did not attract the fly; and that these species depend on sight for hunting rather than on smell.The cost of this matting was negligible as compared with the cost of routine clearing, and this method of temporary protection was considered successful for its purpose.

Traps for Tsetse-flies of the “ Crinoline ” and “ Ventilator ” Forms

1933 ◽  
Vol 24 (2) ◽  
pp. 315-318 ◽  
Author(s):  
C. W. Chorley ◽  
C. F. M. Swynnerton
Keyword(s):  
South Africa ◽  
Expert Knowledge ◽  
Tsetse Fly ◽  
Tsetse Flies ◽  
Department Of Agriculture ◽  
Considerable Difficulty ◽  
Excellent Service ◽  
The Government ◽  
Experimental Use ◽  
Glossina Palpalis

Prefatory Note.Having had the privilege of seeing something of Mr. Chorley's very fine work against Glossina palpalis, and having had four of his traps (of the types shown in Pl. xi, figs. 1, 2, 5) in experimental use myself, I would like to state that he has, in my opinion, done particularly excellent service in evolving several good types of trap for this tsetse-fly. They have not been properly tested yet against other species of tsetse. The choice of exactly suitable sites for the traps, as with all tsetse-traps, is a matter of considerable difficulty and demands expert knowledge, but if skilfully sited, the traps catch well. They represent the acme of cheapness. The mere tacking of a skirt on a Conical Hoop Trap (1912), a Hughen's trap (1919) or a Barrel Trap (Burnett 1918) makes a “ Chorley ” Trap for tsetse-fly. A mere sack or trouserleg kept open by a hoop and with a non-return cage on the top suffices ; and the trap collapses, like a lady's dress, into no space at all. It is simply, in some of its forms (as in Pl. xi, figs. 1, 2, 5), a very slight adaptation to tsetse of Richmond's Crinoline Trap for mosquitos, published in 1927 in the Government of India's Health Bulletin, No. 11 ; in its “ ventilator ” forms (e.g., fig. 3), it is an adaptation of the Wahl & du Plessis trap for blow-flies, published in 1923 in the Journal of the Department of Agriculture of South Africa—though even here the form most used has been cylindrical.

scholarly journals Further researches on the development of trypanosoma gambiense in glossina palpalis

1911 ◽  
Vol 83 (567) ◽  
pp. 513-527 ◽  
Keyword(s):  
Sleeping Sickness ◽  
Tsetse Fly ◽  
Tsetse Flies ◽  
Microscopical Examination ◽  
Intestinal Contents ◽  
Trypanosoma Gambiense ◽  
Glossina Palpalis

The object of these experiments was to try to discover if there is any definite cycle of development of the trypanosome of Sleeping Sickness in the tsetse fly, Glossina palpalis , and if the late or renewed infectivity of the fly coincides with any phase in this development. The mode of experimentation was to feed a cageful of laboratory-bred tsetse flies on an animal whose blood contained numerous trypanosomes, and at the end of various times to kill the flies and examine their intestinal contents. This was done for periods of one day, two days, three days, and so on, up to 56 days. The microscopical examination of preparations made from the intestinal contents on the various days gave information as to the number and appearance of the trypanosomes.

K. R. S. Morris and Tsetse Eradication in the Gold Coast, 1928–51

Africa ◽  
2006 ◽  
Vol 76 (3) ◽  
pp. 381-401 ◽  
Author(s):  
Jeff D. Grischow
Keyword(s):  
Agricultural Development ◽  
Tsetse Fly ◽  
Gold Coast ◽  
Northern Ghana ◽  
Tsetse Flies ◽  
North West ◽  
The North ◽  
Added Benefit ◽  
Northern Territories ◽  
Main Programme

AbstractThis article investigates the anti-tsetse fly work of colonial entomologist K. R. S. Morris in the Northern Territories of the Gold Coast between 1928 and 1951. Morris's main programme was directed at the Lawra District of the north-west, where he claimed to have eliminated the tsetse population and trypanosomiasis by the end of his tenure. This achievement allowed farmers to move into the formerly infested land and reclaim the area for agricultural development. As an added benefit, Morris also claimed, eliminating tsetse flies in the Lawra District reduced the incidence of sleeping sickness in the main market towns of north-west Ashanti. The article charts Morris's work, which is historically significant for a number of reasons. First, it reveals much about the connection between anti-tsetse work and colonial development doctrine in northern Ghana. Second, it highlights the importance of studying colonial practices. Morris's clearing programme appears to have worked, but it was almost certainly based on faulty theories of tsetse ecology. In this sense, the story of anti-tsetse work in the Northern Territories shows that we might learn as much from colonial practices as from colonial ideologies.

Aircraft applications of insecticides in East Africa XIV.—Very-low-volume aerosols of dieldrin and isobenzan for the control of Glossina morsitans Westw

1964 ◽  
Vol 55 (3) ◽  
pp. 527-539 ◽  
Author(s):  
G. F. Burnett ◽  
P. R. Chadwick ◽  
A. W. D. Miller ◽  
J. S. S. Beesley
Keyword(s):  
Tsetse Fly ◽  
Tsetse Flies ◽  
Cent Solution ◽  
Glossina Morsitans ◽  
Local Conditions ◽  
Aerosol Generator ◽  
Additional Costs ◽  
Low Volume ◽  
One Year ◽  
The Cost

Two experiments were conducted simultaneously in 1962–63 at Chungai, in central Tanganyika, to test new equipment for disseminating insecticides from aircraft and a new insecticide, isobenzan (Telodrin), in the eradication of Glossina morsitans Westw. and G. pallidipes Aust. The new equipment consisted of an aerosol generator fitted to the exhaust of a Cessna 182E high-wing monoplane, and was used in both experiments. The isobenzan was compared with dieldrin, and the two insecticides were applied at rates inversely proportional to their toxicities to G. morsitans as previously determined in the laboratory.Two blocks of woodland, each 11 sq. miles in area, were treated, one with a 12·3 per cent, solution of dieldrin at the rate of 0·0254 gal. per acre, giving a dosage of 0·5 oz. (14 g.) toxicant per acre, and the other with a 10 per cent, solution of isobenzan at the rate of 0·0124 gal. per acre, giving a dosage of 0·2 oz. (6 g.) per acre. The former block received eight treatments with dieldrin at approximately 3-week intervals, the fourth treatment being incomplete; the latter block received six treatments with isobenzan at intervals ranging from 20 to 45 days. The effects were assessed by means of fly-catches along fixed paths which continued for one year after treatments had ceased.Both species of tsetse fly disappeared from the two blocks before the final treatments took place, and no more were caught until 11 months after spraying ended, when one example of G. morsitans was caught in each block; both were probably immigrants. None was found in the following month, and it is concluded that the flies were exterminated in both blocks. The fact that the blocks were unusually well isolated from sources of reinfestation probably contributed to the success of the operations.The cost per sq. mile was £224 using dieldrin and £190 using isobenzan. These were the basic costs, independent of the locality in which spraying took place. Additional costs were incurred which would vary with local conditions; for the present experiments they were £34 and £30, respectively. It is considered that there is good scope for further reductions in costs, particularly with dieldrin, and that these might make dieldrin economically competitive with isobenzan. Owing to the low fly density in the block treated with isobenzan, the efficacy of this insecticide cannot be regarded as conclusively proved until further experiments have been carried out. It may then merit serious consideration as a toxicant for aerial spraying against tsetse flies.

scholarly journals Comparative performance of traps in catching tsetse flies (Diptera: Glossinidae) in Tanzania

2016 ◽  
Vol 83 (1) ◽  
Author(s):  
Imna I. Malele ◽  
Johnson O. Ouma ◽  
Hamisi S. Nyingilili ◽  
Winston A. Kitwika ◽  
Deusdedit J. Malulu ◽  
...  
Keyword(s):  
Glossina Pallidipes ◽  
Abundant Species ◽  
Tsetse Fly ◽  
Tsetse Flies ◽  
Comparative Performance ◽  
Control Programmes ◽  
Fly Control ◽  
Tsetse Fly Control ◽  
Species Being ◽  
Biconical Traps

This study was conducted to determine the efficiency of different tsetse traps in 28 sites across Tanzania. The traps used were biconical, H, NGU, NZI, pyramidal, S3, mobile, and sticky panels. Stationary traps were deployed at a distance of 200 m apart and examined 72 h after deployment. The results showed that 117 (52.2%) out of the 224 traps deployed captured at least one Glossina species. A total of five Glossina species were captured, namely Glossina brevipalpis, Glossina pallidipes, Glossina swynnertoni, Glossina morsitans, and Glossina fuscipes martinii. Biconical traps caught tsetse flies in 27 sites, pyramidal in 26, sticky panel in 20, mobile in 19, S3 in 15, NGU in 7, H in 2 and NZI in 1. A total of 21 107 tsetse flies were trapped, with the most abundant species being G. swynnertoni (55.9%), followed by G. pallidipes (31.1%), G. fuscipes martinii (6.9%) and G. morsitans (6.0%). The least caught was G. brevipalpis (0.2%). The highest number of flies were caught by NGU traps (32.5%), followed by sticky panel (16%), mobile (15.4%), pyramidal (13.0%), biconical (11.3%) and S3 (10.2%). NZI traps managed to catch 0.9% of the total flies and H traps 0.7%. From this study, it can be concluded that the most efficient trap was NGU, followed by sticky panel and mobile, in that order. Therefore, for tsetse fly control programmes, NGU traps could be the better choice. Conversely, of the stationary traps, pyramidal and biconical traps captured tsetse flies in the majority of sites, covering all three ecosystems better than any other traps; therefore, they would be suitable for scouting for tsetse infestation in any given area, thus sparing the costs of making traps for each specific Glossina species.Keywords: tseste; traps; densties; Glossina; mobile; stationary; Tanzania

scholarly journals Differential virulence and tsetse fly transmissibility of Trypanosoma congolense and Trypanosoma brucei strains

2017 ◽  
Vol 84 (1) ◽  
Author(s):  
Purity K. Gitonga ◽  
Kariuki Ndung’u ◽  
Grace A. Murilla ◽  
Paul C. Thande ◽  
Florence N. Wamwiri ◽  
...  
Keyword(s):  
Survival Time ◽  
Trypanosoma Brucei ◽  
Acute Infection ◽  
Glossina Pallidipes ◽  
Trypanosoma Congolense ◽  
Tsetse Fly ◽  
Economic Losses ◽  
Entire Group ◽  
Tsetse Flies ◽  
African Countries

African animal trypanosomiasis causes significant economic losses in sub-Saharan African countries because of livestock mortalities and reduced productivity. Trypanosomes, the causative agents, are transmitted by tsetse flies (Glossina spp.). In the current study, we compared and contrasted the virulence characteristics of five Trypanosoma congolense and Trypanosoma brucei isolates using groups of Swiss white mice (n = 6). We further determined the vectorial capacity of Glossina pallidipes, for each of the trypanosome isolates. Results showed that the overall pre-patent (PP) periods were 8.4 ± 0.9 (range, 4–11) and 4.5 ± 0.2 (range, 4–6) for T. congolense and T. brucei isolates, respectively (p < 0.01). Despite the longer mean PP, T. congolense–infected mice exhibited a significantly (p < 0.05) shorter survival time than T. brucei–infected mice, indicating greater virulence. Differences were also noted among the individual isolates with T. congolense KETRI 2909 causing the most acute infection of the entire group with a mean ± standard error survival time of 9 ± 2.1 days. Survival time of infected tsetse flies and the proportion with mature infections at 30 days post-exposure to the infective blood meals varied among isolates, with subacute infection–causing T. congolense EATRO 1829 and chronic infection–causing T. brucei EATRO 2267 isolates showing the highest mature infection rates of 38.5% and 23.1%, respectively. Therefore, our study provides further evidence of occurrence of differences in virulence and transmissibility of eastern African trypanosome strains and has identified two, T. congolense EATRO 1829 and T. brucei EATRO 2267, as suitable for tsetse infectivity and transmissibility experiments.

The Effect of Obstructive Clearing on Glossina palpalis (R.-D.)

1957 ◽  
Vol 48 (2) ◽  
pp. 323-339 ◽  
Author(s):  
T. A. M. Nash ◽  
J. O. Steiner
Keyword(s):  
Water Loss ◽  
Large Scale ◽  
Mucuna Pruriens ◽  
Northern Nigeria ◽  
Run Off ◽  
Dry Seasons ◽  
The Cost ◽  
Glossina Palpalis ◽  
Heavy Rains ◽  
Stream Bed

SummaryAn experiment has been undertaken in Northern Nigeria to ascertain whether the felling of the trees forming the overhead canopy and the deliberate blocking, with trash, of the stream-bed to obstruct the tsetse's flight-line, would result in the eradication of Glossina palpalis (R.-D.).Obstructive clearing was employed on approximately 3¾ miles of stream. The results suggest that, provided the experimental reaches are adequately isolated, obstructive clearing does lead to the eradication of G. palpalis.It is noteworthy that if, owing to inadequate isolation, the cleared stream becomes re-infested in the rains, conditions for at least the first two dry seasons are so unfavourable that flies cannot persist.The immediate effect of obstructive clearing is to increase greatly the hunger of the few surviving flies.Records suggest that obstructive clearing leads to a considerable reduction in the number of human hosts visiting uninhabited parts of the stream, presumably because of the destruction of forest produce. The duiker (Sylvicapra and Cephalophus) population also becomes greatly reduced, especially in the vicinity of hamlets. The hunger observed in the surviving fly population may therefore be in part due to an actual reduction in the number of hosts, as well as to the altered environment, which prevents free movement, under shade, of the hungry tsetse that is searching for food; instead, the tsetse is forced out into the open, where the climate in the dry season is intolerable, and presumably the unsuccessful fly rapidly succumbs from water-loss.The effect of obstructive clearing on the vegetation is as follows. Within a few weeks the mound of trash is overgrown with creepers, Mucuna pruriens becoming dominant. In the first year's heavy rains the mound of trash tends to sink down in the stream-bed; on larger streams, spates do some temporary damage to the creeper growth and gaps may appear in the obstruction. The impression gained is that the blockage will persist for many years on small tributaries, but will disintegrate within a few years on larger streams. In very hilly country, with a rapid run off, the obstruction is likely to be displaced. In perennial streams of the type dealt with, the annual fires make only small inroads into the obstruction.The technique evolved for the obstructive clearing of streams is described. The cost of this method worked out at 390 man days per mile, which is about half the cost of the present methods.Should large-scale undertakings in the field confirm the efficacy of this new method, the biggest saving will be the elimination of the present necessity to re-slash streams that have been partially cleared. Observations will be continued to ascertain how long it will be before the vegetation again becomes suitable for G. palpalis.

scholarly journals History of Sleeping Sickness in East Africa

1999 ◽  
Vol 12 (1) ◽  
pp. 112-125 ◽  
Author(s):  
Geoff Hide
Keyword(s):  
East Africa ◽  
Molecular Data ◽  
Sleeping Sickness ◽  
Tsetse Fly ◽  
Tsetse Flies ◽  
Agricultural Practice ◽  
Molecular Approaches ◽  
History Of ◽  
The Stability ◽  
The Right

SUMMARY The history of human sleeping sickness in East Africa is characterized by the appearance of disease epidemics interspersed by long periods of endemicity. Despite the presence of the tsetse fly in large areas of East Africa, these epidemics tend to occur multiply in specific regions or foci rather than spreading over vast areas. Many theories have been proposed to explain this phenomenon, but recent molecular approaches and detailed analyses of epidemics have highlighted the stability of human-infective trypanosome strains within these foci. The new molecular data, taken alongside the history and biology of human sleeping sickness, are beginning to highlight the important factors involved in the generation of epidemics. Specific, human-infective trypanosome strains may be associated with each focus, which, in the presence of the right conditions, can be responsible for the generation of an epidemic. Changes in agricultural practice, favoring the presence of tsetse flies, and the important contribution of domestic animals as a reservoir for the parasite are key factors in the maintenance of such epidemics. This review examines the contribution of molecular and genetic data to our understanding of the epidemiology and history of human sleeping sickness in East Africa.

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