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dc.contributor.advisorVenter, G. J.
dc.contributor.advisorVreysen, M. J. B.
dc.contributor.advisorBrink, S. L.
dc.contributor.authorDe Beer, Chantel Janet
dc.date.accessioned2017-09-28T07:39:00Z
dc.date.available2017-09-28T07:39:00Z
dc.date.issued2016
dc.identifier.urihttp://hdl.handle.net/11660/7029
dc.description.abstractEnglish: In South Africa, African Animal Trypanosomosis (AAT), caused by Trypanosomae parasites transmitted by Glossina brevipalpis and Glossina austeni (Diptera: Glossinidae), is restricted to the north east of KwaZulu-Natal Province with an estimated 250 000 cattle being at risk. For the control of these flies an area-wide integrated pest management (AW-IPM) strategy with a sterile insect technique (SIT) component has been proposed. Accurate knowledge of the distribution of target populations is fundamental to the success of any control programme. In the present study tsetse fly distribution was determined with odour baited H traps and cattle screened using the buffy coat analyses to produce updated tsetse fly distribution, abundance and trypanosome prevalence maps for north eastern KwaZulu-Natal. Glossina brevipalpis and G. austeni were collected in areas where they had previously not been captured. Vegetation and temperature was shown to influence their distribution and abundance. The fact that no significant correlation between tsetse fly abundance and nagana prevalence could be established underlines the complex interactions between these two entities. This was epitomised by the fact that despite large differences in the apparent densities of G. austeni and G. brevipalpis, overall trypanosome prevalence was similar in all districts in north eastern KwaZulu-Natal. This indicated that both species can play a role in transmission of AAT and need to be controlled. The G. brevipalpis and G. austeni populations of north eastern KwaZulu-Natal extends into southern Mozambique (both species) and Swaziland (G. austeni). Morphometrical analyses showed an absence of any significant barriers to gene flow between the various KwaZulu-Natal populations as well as between the South African populations and those of the two neighbouring countries. Tsetse fly control in a localised area will therefore be subjected to reinvasion from uncontrolled areas. An area-wide approach, i.e. against the entire tsetse fly population of South Africa, southern Mozambique and Swaziland will therefore be essential. The maintenance of colonised G. brevipalpis and G. austeni at the Agricultural Research Council-Onderstepoort Veterinary Institute (ARC-OVI), necessitate a high quality blood source. For the potential improvement of the current rearing diet various anticoagulants, phagostimulants and blood sources were evaluated and production assessed using standardised 30-day bioassays. Defibrinated bovine blood was found to be the most suitable. Anticoagulants such as sodium citrate, a combination of citrate and sodium acid, phosphate dextrose adenine and citric acid can be used to simplify blood collection. While G. brevipalpis preferred bovine to porcine blood, G. austeni preferred a mixture of equal parts bovine and porcine blood. The phagostimulants adenosine triphosphate, as well as tri-posphates of inosine, and the mono-posphates of guanosine and cytosine improved production in both species. Attempts to colonise the local KwaZulu-Natal strain of G. brevipalpis failed due to a reluctance of field flies to feed on the artificial feeding system. In preparation for the SIT component the irradiation sensitivity of colonised G. brevipalpis and G. austeni when treated as adults and late-stage pupa was determined. A dose of 40 Gy induced 97% sterility in G. brevipalpis males when irradiated as late-stage pupae and 80 Gy induced a 99% sterility in flies irradiated as adults. Higher doses were required for G. austeni, with 80 Gy and 100 Gy inducing higher than 97% sterility in females that mated with males treated as adults or late-stage pupae. As colonised and irradiated males must be able to compete with their wild counterparts the mating performance of the colonised G. brevipalpis and G. austeni was determined under near natural conditions in walk-in field cages. Although the mating latency for both species was shorter, their mating performance did not differ significantly between mornings and afternoons. For both species mating frequency was significantly higher in nine-day-old males compared to six- or three-day-old males. Age did not affect the males’ ability to transfer sperm, their mating duration or mating latency. There was no significant difference in mating performance of sterile and fertile males. This study indicated that AAT and tsetse flies are abundant in KwaZulu-Natal and tsetse fly presence seems to be a dynamic process that is influenced by a number of environmental factors. The earlier proposed AW-IPM strategy with a SIT component, although still applicable, will need to be adapted to incorporate the new distributions records. Initial results indicate that the colonies at the ARC-OVI will be suitable for programmes that have a SIT component.en_ZA
dc.description.abstractAfrikaans: In Suid-Afrika is Afrika Trypanosomiase van diere (ATD), wat deur Trypanosomae parasiete veroorsaak word en deur Glossina brevipalpis en Glossina austeni (Diptera: Glossinidae), oorgedra word, beperk tot die noordoostelike KwaZulu-Natal Provinsie. Na beraming is sowat 250 000 beeste tans blootgestel aan die siekte. 'n Area-wye geïntegreerde plaagbestuur (AW-IPB) strategie met 'n steriele insek tegniek (SIT) komponent word vir die beheer van die vlieë voorgestel. Die sukses van ‘n beheerprogram sal afhang van akkurate inligting oor waar tsetsevlieё voorkom. In die huidige studie is H tipe valle saam met geurlokaas gebruik om tsetsevlieё te versamel. Trypanosomiase infeksiesyfers in beeste is ook gemonitor. Die inligting is gebruik om bestaande kaarte van tsetsevlieg verspreiding, volopheid en trypanosomiase voorkomsyfer in diere op te dateer. Glossina brevipalpis en G. austeni is versamel in gebiede waar hulle voorheen afwesig was. Daar is gevind dat plantegroei en temperatuur die verspreiding en volopheid van tsetsevlieё beïnvloed. Die feit dat geen betekenisvolle korrelasie tussen vlieg getalle en ATD voorkomsyfer bepaal kon word nie beklemtoon die komplekse wisselwerking tussen hierdie twee entiteite. Dit word beklemtoon deur die waarneming dat, ten spyte van groot verskille in die oënskynlike digthede van G. austeni en G. brevipalpis, die algehele trypanosomiase voorkomsyfers tussen die distrikte in die noordoostelike KwaZulu-Natal nie verskil het nie. Dit dui aan dat beide spesies 'n rol kan speel in die oordrag van die siekte en dus beheer sal moet word. Die verspreiding van die tsetsevliegbevolking wat in die noordooste van KwaZulu-Natal voorkom, strek tot in Swaziland en die suide van Mosambiek. Morfometriese ontledings toon 'n afwesigheid van betekenisvolle grense aan en dat dat inteling tussen die verskillende KwaZulu-Natal bevolkings asook tussen die Suid-Afrikaanse bevolking en dié van die twee buurlande voorkom. Tsetsevlieg beheer in 'n gelokaliseerde afgebakende area sal dus onderworpe wees aan herbesmetting vanaf die onbeheerde aangrensende gebiede. 'n Area-wye benadering, dit wil sê teen die hele tsetsevliegbevolking van Suid-Afrika, Swaziland en die suide van Mosambiek sal dus noodsaaklik wees. Die instandhouding van die kolonies van G. brevipalpis en G. austeni by die Landbounavorsingsraad-Onderstepoort Veeartsenykunde-Instituuut (LNR-OVI) vereis 'n bloedvooraad van hoë gehalte. Vir die moontlike opgradering van die huidige dieet, is ‘n aantal antistolmiddels, voedingstimulante en bloedbronne geëvalueer deur produksie met ‘n gestandardiseerde 30-dag biologiese keuringsproses te bepaal. Gedefibriniseerde beesbloed was die mees geskikste. Antistolmiddels soos natriumsitraat, 'n kombinasie van sitraat en natriumsuur, fosfaat-dekstrose-adenien en sitroensuur kan gebruik word om bloed versameling te vergemaklik. Terwyl G. brevipalpis bees- bo varkbloed verkies, verkies G. austeni 'n mengsel van gelyke dele bees- en varkbloed. Die voedingstimulante adenosientrifosfaat, asook tri-fosfate van inosien, en die mono-fosfaat van guanosien en sitosien het verbeterde produksie in beide spesies tot gevolg gehad. Pogings om die plaaslike KwaZulu-Natal G. brevipalpis te koloniseer was onsuksesvol as gevolg van 'n onwilligheid van veldvlieё om op die kunsmatige voedingstelsel te voer. As ‘n voorvereiste vir SIT was die bestraling-sensitiwiteit van G. brevipalpis en G. austeni volwassenes en laat-stadium papies bepaal. 'n Dosis van 40 Gy het ‘n 97% steriliteit in G. brevipalpis tot gevolg gehad wanneer laat-stadium papies bestraal is, en 80 Gy 'n 99% steriliteit as volwasse vlieë bestraal is. Glossina austeni het hoёr dosisse vereis, 80 Gy en 100 Gy veroorsaak ‘n hoёr as 97% steriliteit in wyfies wat met mannetjies wat as volwassenes of laat-stadium papies bestraal is, gepaar het. Gekoloniseerdes bestraalde mannetjies moet in staat wees om met met hul veld eweknieë te kan meeding. Die parings gedrag van gekoloniseerde G. brevipalpis en G. austeni was onder bykans natuurlike veldtoestande in instap-veldhokke bepaal. Alhoewel die tydsverloop voor paring het vir beide spesies korter was, was daar nie betekenisvolle verskille in hulle paring-prestasie soos in die oggend of middag bepaal nie. Vir beide spesies was die paring-frekwensie vir 9-dae-oue mannetjies aansienlik hoër as dié van 6 of 3-dae-oue mannetjies. Ouderdom het geen invloed op die vermoë van die mannetjies om sperm oor te dra nie of tydverloop voor paring gehad nie. Daar was geen beduidende verskil in paring-prestasie van steriele en vrugbare mannetjies nie. Die huidige studie dui aan dat ATD en tsetsevlieë algemeen in KwaZulu-Natal voorkom en dat tsetsevlieg teenwoordigheid 'n dinamiese proses is wat deur omgewingsfaktore beïnvloed word. Die voorgestelde AW-IPB met 'n SIT komponent, alhoewel steeds van toepassing, sal aangepas moet word om die ogedateerde data te inkorporeer. Voorlopige resultate dui aan dat die kolonies by die LNR-OVI geskik sal wees vir gebruik in SIT.af
dc.description.sponsorshipAgricultural Research Council-Onderstepoort Veterinary Institute (ARC-OVI)en_ZA
dc.description.sponsorshipFAO/IAEA Division of Nuclear Techniques in Food and Agriculture in Austriaen_ZA
dc.description.sponsorshipDepartment of Science and Technology in South Africaen_ZA
dc.language.isoenen_ZA
dc.publisherUniversity of the Free Stateen_ZA
dc.subjectGlossina brevipalpisen_ZA
dc.subjectGlossina austenien_ZA
dc.subjectDistributionen_ZA
dc.subjectTrypanosomosisen_ZA
dc.subjectMorphometricsen_ZA
dc.subjectColoniesen_ZA
dc.subjectRadiation sensitivityen_ZA
dc.subjectMating performanceen_ZA
dc.subjectPest managementen_ZA
dc.subjectInsect sterilizationen_ZA
dc.subjectInsect pestsen_ZA
dc.subjectTsetse-fliesen_ZA
dc.subjectThesis (Ph.D. (Zoology and Entomology))--University of the Free State, 2016en_ZA
dc.titleMating behaviour and competitiveness of male Glossina brevipalpis and Glossina austeni in relation to biological and operational attributes for use in the Sterile Insect Techniqueen_ZA
dc.typeThesisen_ZA
dc.rights.holderUniversity of the Free Stateen_ZA


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