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.

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.

scholarly journals Insight into the Transmission Biology and Species-Specific Functional Capabilities of Tsetse (Diptera: Glossinidae) Obligate Symbiont Wigglesworthia

mBio ◽  
2012 ◽  
Vol 3 (1) ◽  
Author(s):  
Rita V. M. Rio ◽  
Rebecca E. Symula ◽  
Jingwen Wang ◽  
Claudia Lohs ◽  
Yi-neng Wu ◽  
...  
Keyword(s):  
Transcriptional Regulation ◽  
Host Species ◽  
Tsetse Fly ◽  
Sister Species ◽  
Tsetse Flies ◽  
Specific Gene ◽  
Glossina Morsitans ◽  
Content Type ◽  
African Trypanosomes ◽  
Species Specific

ABSTRACT Ancient endosymbionts have been associated with extreme genome structural stability with little differentiation in gene inventory between sister species. Tsetse flies (Diptera: Glossinidae) harbor an obligate endosymbiont, Wigglesworthia, which has coevolved with the Glossina radiation. We report on the ~720-kb Wigglesworthia genome and its associated plasmid from Glossina morsitans morsitans and compare them to those of the symbiont from Glossina brevipalpis. While there was overall high synteny between the two genomes, a large inversion was noted. Furthermore, symbiont transcriptional analyses demonstrated host tissue and development-specific gene expression supporting robust transcriptional regulation in Wigglesworthia, an unprecedented observation in other obligate mutualist endosymbionts. Expression and immunohistochemistry confirmed the role of flagella during the vertical transmission process from mother to intrauterine progeny. The expression of nutrient provisioning genes (thiC and hemH) suggests that Wigglesworthia may function in dietary supplementation tailored toward host development. Furthermore, despite extensive conservation, unique genes were identified within both symbiont genomes that may result in distinct metabolomes impacting host physiology. One of these differences involves the chorismate, phenylalanine, and folate biosynthetic pathways, which are uniquely present in Wigglesworthia morsitans. Interestingly, African trypanosomes are auxotrophs for phenylalanine and folate and salvage both exogenously. It is possible that W. morsitans contributes to the higher parasite susceptibility of its host species. IMPORTANCE Genomic stasis has historically been associated with obligate endosymbionts and their sister species. Here we characterize the Wigglesworthia genome of the tsetse fly species Glossina morsitans and compare it to its sister genome within G. brevipalpis. The similarity and variation between the genomes enabled specific hypotheses regarding functional biology. Expression analyses indicate significant levels of transcriptional regulation and support development- and tissue-specific functional roles for the symbiosis previously not observed in obligate mutualist symbionts. Retention of the genetically expensive flagella within these small genomes was demonstrated to be significant in symbiont transmission and tailored to the unique tsetse fly reproductive biology. Distinctions in metabolomes were also observed. We speculate an additional role for Wigglesworthia symbiosis where infections with pathogenic trypanosomes may depend upon symbiont species-specific metabolic products and thus influence the vector competence traits of different tsetse fly host species.

Disruption of Glossina morsitans morsitans (Diptera: Glossinidae) eclosion behaviour: a novel method for evaluating the action of neurotoxic agents

1992 ◽  
Vol 82 (4) ◽  
pp. 547-552 ◽  
Author(s):  
J. Ždárek ◽  
D.L. Denlinger
Keyword(s):  
Glossina Morsitans Morsitans ◽  
Tsetse Fly ◽  
Tsetse Flies ◽  
Behavioural Pattern ◽  
Glossina Morsitans ◽  
The Central Nervous System ◽  
Lethal Time ◽  
Novel Method ◽  
Sublethal Doses ◽  
Peripheral Action

AbstractAs the tsetse fly, Glossina morsitans morsitans Westwood extricates itself from the puparium and moves upward through the soil the ptilinum expands and contracts rhythmically and thus generates a stereotypic behavioural pattern that persists for up to 10 h if the tsetse fly remains confined. The response, which is easily recorded tensometrically from the movements of the ptilinum, can be exploited as a tool for evaluating the behavioral response of tsetse flies to various neurotoxic agents. The behavioural assay proves useful in providing precise information about the latency of the response and lethal time, and can suggest likely modes of action. For example, sublethal doses of pyrethroids reversibly suppressed the contraction cycles, a response consistent with the peripheral action of this insecticide. In contrast, chlorinated hydrocarbons greatly increased contraction frequency, a result consistent with the action of these agents on the central nervous system (CNS). Assays utilizing eight commercial insecticide preparations (Pybuthrin, K-othrin, Vaztak, Reldan, Safrotin, Acetellic, DDVP, Antrix) demonstrate the utility of this method for detecting subtle perturbations of the CNS and neuromuscular system.

Genetic relationships between subspecies of the tsetse fly Glossina morsitans inferred from variation in mitochondrial DNA sequences

1984 ◽  
Vol 26 (6) ◽  
pp. 692-697 ◽  
Author(s):  
Martin Trick ◽  
Gabriel A. Dover
Keyword(s):  
Mitochondrial Dna ◽  
Dna Sequences ◽  
Dna Hybridization ◽  
Genetic Relationships ◽  
Glossina Morsitans Morsitans ◽  
Tsetse Fly ◽  
Tsetse Flies ◽  
Glossina Morsitans ◽  
Site Variation ◽  
Local Restriction

A 750 base pair segment of DNA from the tsetse fly Glossina morsitans morsitans was isolated by means of molecular cloning. It was shown by DNA hybridization to have substantial sequence homology with a defined region of the mitochondrial genomes of several Drosophila species. When used as a probe against DNA prepared from single tsetse flies, the cloned sequence revealed local restriction site variation between members of the G. morsitans subspecies complex. This feature was used to demonstrate maternal inheritance of the sequence in progeny of hybrid crosses and to assemble comparative restriction maps for a 3-kilobase segment of each mitochondrial genome. The data obtained from these exercises point to a higher genetic identity between G. m. morsitans and G. m. centralis than between either form and G. m. submorsitans.Key words: mitochondrial DNA, tsetse fly species, Glossina morsitans.

scholarly journals Studies on Trypanosoma (nannomonas) congolense: IV. Experimental immunization of mice against tsetse fly Challenge

Parasitology ◽  
1980 ◽  
Vol 80 (1) ◽  
pp. 133-137 ◽  
Author(s):  
V. M. Nantulya ◽  
J. J. Doyle ◽  
L. Jenni
Keyword(s):  
Glossina Morsitans Morsitans ◽  
Trypanosoma Congolense ◽  
Tsetse Fly ◽  
Uninfected Control ◽  
Tsetse Flies ◽  
Glossina Morsitans ◽  
Variable Antigen ◽  
Experimental Immunization

SummaryGroups of mice were exposed to multiple bites by tsetse flies (Glossina morsitans morsitans) infected with a clone of Trypanosoma congolense spread over a period of 8 days. The mice were subsequently treated with Berenil 10 days after the first fly bite as were uninfected control mice. The group of mice which received 12–15 infectious fly bites on two occasions, 21 days apart, were subsequently resistant to infection when re-challenged by flies infected with the same clone of T. congolense. These mice were also immune to challenge by flies infected with a different bloodstream variable antigen type derived from this same stock. The immunity was stock-specific and directed against the metacyclic forms of the parasite, but was short-lived.

The susceptibility of tsetse flies to topical applications of insecticides. VI.—Data on more chlorinated hydrocarbons and organophosphates, and a general discussion

1963 ◽  
Vol 53 (4) ◽  
pp. 753-762 ◽  
Author(s):  
G. F. Burnett
Keyword(s):  
Young Adults ◽  
Nitro Group ◽  
Musca Domestica ◽  
Organophosphorus Compounds ◽  
Chlorinated Hydrocarbons ◽  
Tsetse Fly ◽  
Tsetse Flies ◽  
Glossina Morsitans ◽  
Low Toxicity ◽  
Topical Applications

Five insecticides (Thiodah, Bromodan, dimethoate, Dipterex (trichlorphon) and Sumithion) were applied topically in solution to young adults of the tsetse fly Glossina morsitans Westw. The toxicity of Thiodan (LD50 for males, 0·0012 µg.; for females, 0·0014 µg.) lay between that of Telodrin and dieldrin, and that of Bromodan (LD50 for both sexes combined, 0·0032 µg.) between that of dieldrin and γ BHC. Dimethoate, Dipterex and Sumithion were all less toxic than Baytex, but were not fully evaluated.Results recorded in this paper and earlier ones in this series, and those of workers using Musca domestica L., are discussed in an attempt to rationalise the search for new toxicants for tsetse flies. Chlorinated hydrocarbons fall into two classes, in both of which there is an approximate positive correlation between toxicity to Musca and to Glossina. One class, including Telodrin, Thiodan and Bromodan, is exceptionally toxic to tsetse and more than 40 times as toxic to Glossina as to Musca. These have a molecule with a particular type of nucleus (hexachloro-l,4-methano-cyclohexene) with a single bridged unsaturated ring. The more common chlorinated hydrocarbons (γ BHC, DDT and aldrin) are two to five times, and dieldrin 12 times, as toxic to G. morsitans as to M. domestica, and all are very toxic to both species.Among organophosphorus compounds there is very little correlation between toxicity to M. domestica and that to G. morsitans, but it appears probable that no compound of low toxicity to Musca (i.e., LD50 of the order of 0·5 µg.) would be likely to compete with those compounds already known to be most toxic to Glossina. Replacement of the nitro group on the benzene ring of Sumithion by a thiomethyl group, to form Baytex, increases toxicity to Glossina fivefold, but that to Musca by only one-fourth. There is less information on organocarbamates, and it may be a coincidence that 2-isopropoxyphenyl N-methylcarbamate, the most toxic of those tested on G. morsitans, was also most toxic to Musca.

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.

scholarly journals Lesions and Saliva-Specific Antibody Responses in Rabbits with Immediate and Delayed Hypersensitivity Reactions to the Bites of Glossina morsitans centralis

1986 ◽  
Vol 23 (6) ◽  
pp. 661-667 ◽  
Author(s):  
J. A. Ellis ◽  
S. Z. Shapiro ◽  
O. Ole Moi-Yoi ◽  
S. K. Moloo
Keyword(s):  
Sodium Dodecyl ◽  
Tsetse Fly ◽  
Antibody Responses ◽  
Delayed Type Hypersensitivity ◽  
Salivary Proteins ◽  
Tsetse Flies ◽  
Glossina Morsitans ◽  
Glossina Morsitans Centralis ◽  
Cutaneous Hypersensitivity ◽  
Poly Acrylamide

Rabbits exposed to feeding tsetse flies developed cutaneous hypersensitivity responses to fly bites. These responses had characteristics of immediate and delayed type hypersensitivity. Saliva components from the tsetse fly Glossina morsitans centralis were electrophoretically separated by sodium dodecyl sulfate-poly-acrylamide gel electrophoresis. Major salivary proteins of 160, 92, 66, 64, 55, 42, 33, 28, and 15 kilodaltons were identified. Separated salivary components were transferred to nitrocellulose filters and probed with lectins and with whole sera and purified IgG from rabbits which had been exposed, via fly feeding, to tsetse antigens for variable periods. Many of the salivary proteins were identified as glycoproteins. Several major salivary proteins were recognized by antibodies from sensitized rabbits.

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.

Laboratory studies on the potential of three insect growth regulators for control of the tsetse fly, Glossina morsitans morsitans Westwood (Diptera: Glossinidae)

1979 ◽  
Vol 69 (1) ◽  
pp. 55-64 ◽  
Author(s):  
A. M. Jordan ◽  
M. A. Trewern ◽  
A. B. Bořkovec ◽  
A. B. DeMilo
Keyword(s):  
Growth Regulators ◽  
Topical Application ◽  
Glossina Morsitans Morsitans ◽  
Tsetse Fly ◽  
Tsetse Flies ◽  
Glossina Morsitans ◽  
Insect Growth Regulators ◽  
Insect Growth ◽  
Reproductive Life ◽  
Length Of Life

AbstractExperiments were carried out to determine the effects of the insect growth regulators (IGRs), diflubenzuron and two of its analogues, on adult female Glossina morsitans morsitans Westw. The most effective method of dosing was by topical application, and less pronounced effects followed tarsal contact with treated surfaces and contact during mating with treated males. The compounds had no effect on female length of life or the number of offspring produced, but following topical application at 0·5 μg/female or above, most offspring produced throughout reproductive life (more than 100 days) failed to pupariate. Little difference was detected between the effects of the three IGRs tested. Following the application of diflubenzuron to oviparous insects, egg hatch is inhibited; it is suggested that in the larviparous tsetse fly such compounds act by inhibiting the biosynthesis of chitin at the time of pupariation. IGRs show promise as potential agents for the control of Glossina in the field, and the quantities required would probably not exceed the quantities of insecticides used in current operations against tsetse flies.

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