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dc.contributor.advisorBrink, Sonja L.
dc.contributor.authorBotham, Jason Lee
dc.date.accessioned2016-09-01T12:03:09Z
dc.date.available2016-09-01T12:03:09Z
dc.date.issued2016-01
dc.identifier.urihttp://hdl.handle.net/11660/4034
dc.description.abstractEnglish: While burial is utilised by criminals as a means of disposing of a body, knowledge of the impact it has on arthropod succession and decomposition within South Africa is currently lacking. The study was conducted within a 24 hectare grassland field, located on the University of the Free State grounds. A total of seven pig carcasses (Sus scrofa Linnaeus) were utilised for each of the two seasonal trials, with six of them being buried in randomly spaced graves at depths of 60cm and one placed above-ground as a control. Each of the graves was excavated on predetermined days over each 60 day trial to minimise disturbance and evaluate the impact of differing time periods on decomposition and arthropod succession. After its initial excavation, grave one was excavated every third day until the conclusion of the trial to determine the impact of disturbance on buried remains. Decomposition and biomass loss progressed faster on buried carcasses compared to aboveground during the winter season. A faster rate of decomposition and biomass loss was seen for the above-ground carcass versus the below-ground carcass during the summer season, mainly due to heavy rainfall causing waterlogging of the graves. Between the two seasons, a higher decomposition and biomass loss rate was recorded on the summer buried carcasses compared to those buried in winter. Dipteran species were seen to dominate on the summer control carcass, while, during the winter trial, the coleopteran species, Dermestes maculatus De Geer (Dermestidae), was noted to extensively colonise and outcompete present dipteran individuals. With cold, dry climatic conditions leading to the winter control carcass undergoing a form of mummification, adult D. maculatus individuals were seen to congregate on the carcass and reproduce, leading to larval aggregation during the active decay stage. During the trials, only dipteran species were found to colonise the winter buried carcasses, whereas the summer buried carcasses were colonised by two dipteran species, a predatory coleopteran species and an Acari species. Of those species colonising the winter buried carcasses, two Phoridae species were found to be the most abundant, being identified as Megaselia scalaris (Loew) and Conicera tibialis Schmitz, and colonised the buried carcasses from day 21 onwards. Later occurring dipteran species in winter included Muscina stabulans (Fallén) and a species of the genus Leptocera Olivier. Summer buried carcasses saw initial colonisation occurring from day 21 by phorid M. scalaris and a coleopteran beetle species from the genus Aleochara Gravenhorst (Staphylinidae). Further colonisation of the summer buried carcasses was seen after 30 days, with sarcophagid pupae and the Acari species Sancassania mycophagus (Mégnin) being sampled from the buried carcasses. From the analyses of data gained from the two seasonal trials, predictions were made regarding the time frames of decomposition and arthropod succession applicable to buried carcasses within central South Africa. Concurrently, alternative methodologies for burial excavations and entomological evidence collection were suggested for investigators, to take into consideration during burial crime scene investigations within central South Africa.en_ZA
dc.description.abstractAfrikaans: Alhoewel misdadigers dikwels van „n liggaam ontslae raak deur dit te begrawe, is relatief min bekend oor die impak daarvan op arthropoodsuksessie en die ontbindingsproses in Suid- Afrika.. Die studie het plaasgevind op „n 24-hektaar grasland op die gronde van die Universiteit van die Vrystaat. Sewe varkkarkasse (Sus scrofta Linnaeus) is gedurende elk van die twee seisoenale proefperiodes gebruik, waarvan ses op „n diepte van 60cm op ewewydige afstande van mekaar begrawe is en een bogronds gelos is as die kontrole. Begraafte karkasse is opgegrawe op spesifieke voorafbepaalde tye oor die 60 dae van die proeftydperke en sodoende is verseker dat versteuring tot „n minimum beperk is terwyl die impak van „n grafomgewing op arthropoodsuksessie en ontbinding vasgestel is. Na die aanvanklike opgrawing van die eerste graf, was die graf vervolgens elke derde dag opgegrawe tot aan die einde van die proefperiode om die impak van versteuring te evalueer. Ontbinding en biomassa-verlies het „n vinniger tempo getoon vir karkasse wat begrawe was, teenoor die bo-grondse karkas gedurende winter. „n Vinniger tempo van ontbinding en biomassa-verlies was vir die bo-grondse karkas getoon in vergelyking met die begraafde karkasse gedurende die somer, hoofsaaklik as gevolg van die swaar reën wat veroorsaak het dat die grafte deurdrenk geraak het. Vir die twee seisoene was „n vinniger tempo van ontbinding en biomassa-verlies gedurende die winter vir die begraafde karkasse ondervind. Diptera-spesies was, getalle gewys, in die meerderheid op die kontrole-karkas tydens die somer, maar gedurende die winter het „n Coleoptera-spesie, Dermestes maculatus De Geer (Dermestidae) tot so „n mate oorheers dat die besetting deur Diptera-spesies minimaal was. As gevolg van die koue, droë klimaatstoestande wat daartoe aanleiding gegee het dat die winter kontrole-karkas „n vorm van mummifikasie ondergaan het, is volwasse D. maculatus indivudië na die karkas aangetrek en voortplanting het tot larwale massas tydens die aktiewe ontbindingsfase aanleiding gegee. Gedurende die winter proeftydperk, was net Diptera-spesies op die karkasse teenwoordig wat begrawe was, teenoor die besetting deur twee Diptera-spesies, „n predatoriese Coleopteraspesie, sowel as „n Acari-spesie gedurende die somer. Die twee Phoridae-spesies, Megaselia scalaris (Louw) and Conicera tibialis Schmitz, was die volopste op die karkasse wat begrawe was gedurende die winter en was vanaf dag 21 teenwoordig. Muscina stabulans (Fallén) en „n spesie van die genus Leptocera Olivier het die karkas wat begrawe was gedurende die winter op „n latere stadium beset. Die aanvanklike besetting van die karkasse wat begrawe was, het teen dag 21 plaasgevind gedurende die somer deur die Phoridae-spesie, M. scalaris, sowel as deur „n Coleoptera-spesie van die genus Aleochara Gravenhorst (Staphylinidae). Latere besetting van die begraafde somerkarkas het na dag 30 plaasgevind, waartydens sarcophagid papies sowel as die Acari-spesie, Sancassania mycophagus (Mégnin) versamel is. Analise van die data van die twee proeftydperke het getoon dat voorspellings gemaak kan word om „n tydslyn van ontbinding en arthropoodsuksessie te bepaal vir karkasse wat in sentraal Suid-Afrika begrawe is. Alternatiewe metodes om te volg word voorgestel tydens die herwinning van liggame wat begrawe was en die insameling van entomologiese bewysstukke wat in ag geneem behoort te word tydens forensiese ondersoeke in sentraal Suid-Afrika.af
dc.language.isoenen_ZA
dc.publisherUniversity of the Free Stateen_ZA
dc.subjectDissertation (M.Sc. (Zoology and Entomology))--University of the Free State, 2016en_ZA
dc.subjectForensic entomologyen_ZA
dc.subjectBiomass lossen_ZA
dc.subjectPredictive analysisen_ZA
dc.subjectExcavation and entomological collection methodologiesen_ZA
dc.subjectSoil typeen_ZA
dc.titleDecomposition and arthropod succession on buried remains during winter and summer in central South Africa: forensic implications and predictive analysesen_ZA
dc.typeDissertationen_ZA
dc.rights.holderUniversity of the Free Stateen_ZA


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