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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Análise morfológica das espermátides e dos espermatozóides de Chrysomya megacephala (Fabricius) (Diptera: Calliphoridae) nos tratos reprodutores

Name, Khesller Patrícia Olázia January 2008 (has links)
Dissertação (mestrado)—Universidade de Brasília, Instituto de Ciências Biológicas, Programa de Pós-Graduação em Biologia Animal, 2008. / Submitted by Jaqueline Oliveira (jaqueoliveiram@gmail.com) on 2008-12-16T15:33:20Z No. of bitstreams: 1 DISSERTACAO_2008_KhesllerPatriciaOlaziaName.pdf: 4643181 bytes, checksum: 7929b5a30eb0eadefed71af0b29adf98 (MD5) / Approved for entry into archive by Georgia Fernandes(georgia@bce.unb.br) on 2009-02-19T15:43:23Z (GMT) No. of bitstreams: 1 DISSERTACAO_2008_KhesllerPatriciaOlaziaName.pdf: 4643181 bytes, checksum: 7929b5a30eb0eadefed71af0b29adf98 (MD5) / Made available in DSpace on 2009-02-19T15:43:23Z (GMT). No. of bitstreams: 1 DISSERTACAO_2008_KhesllerPatriciaOlaziaName.pdf: 4643181 bytes, checksum: 7929b5a30eb0eadefed71af0b29adf98 (MD5) / Os Diptera constituem uma das quatro maiores ordens de insetos. Chrysomya megacephala (Fabricius), a mosca-das-latrinas do Oriente, pertence à família Calliphoridae e encontra-se associada a questões médico-veterinárias, sanitárias e forenses. O objetivo desse trabalho foi caracterizar os aspectos ultra-estruturais da espermiogênese e do espermatozóide na referida espécie, incluindo a anatomia dos testículos e dos órgãos de armazenamento de espermatozóides nas fêmeas – as espermatecas. Estes dados são particularmente importantes em análises taxonômicas e filogenéticas, uma vez que tais células apresentam estruturas altamente conservadas. Nesta espécie, assim como na maioria dos insetos, a espermiogênese é caracterizada pelos seguintes eventos: formação do acrossoma, alongamento nuclear com condensação da cromatina, formação do flagelo e perda do excesso de citoplasma. No final do processo de espermiogênese, o espermatozóide em C. megacephala apresenta-se longo e delgado, medindo aproximadamente 590μm de comprimento. O espermatozóide é formado por acrossoma, núcleo com cromatina densamente compactada, centríolo, adjunto do centríolo, dois derivados mitocondriais preenchidos por material paracristalino e um axonema contendo: dois microtúbulos centrais, nove duplas periféricas e nove microtúbulos acessórios intercalados por fibras densas. O sistema reprodutor interno de machos e fêmeas possui modificações morfológicas que podem ser constantes em todos os ciclórrafos. O testículo de C. megacephala consiste de um único folículo e a parede do órgão é formada por uma camada de células pigmentadas e uma camada de tecido muscular. A espermateca consiste, externamente, de uma camada de células secretoras e internamente, de uma camada de cutícula que circunda a cavidade do órgão. ________________________________________________________________________________ ABSTRACT / Diptera constitutes one of the four largest orders of insects. The Oriental latrine-fly Chrysomya megacephala (Fabricius) belongs to the family Calliphoridae and is associated with medic, veterinary, sanitary and forensic issues. The aim of this research was to characterize the utrastructural aspects of the spermiogenesis and spermatozoa of the C. megacephala, including the anatomy of testis and female sperm storage organs – the spermatheca. This data is particularly important in taxonomic and phylogenetic analysis, since in these cells their structure is highly conserved. In this species as with insects in general, the spermiogenesis is characterized by the following events: acrosome formation, nuclear elongation with chromatin condensation, flagellar formation and sheading of excess cytoplasm. At the end of spermiogenesis process, the spermatozoon in C. megacephala is a long and thin cell measuring 590 μm in length. The spermatozoon comprises acrosome, nucleus with compact dense chromatin, centriole, centriolar adjunct, two mitochondrial derivatives with paracrystalline material and axoneme with: two central microtubules, nine peripheral doublets, nine accessory microtubules and dense fibers. The internal reproductive system of the male and female has morphological modifications that may be constant in all Cyclorraphous. The testis of the C. megacephala consists of a unique follicle and the wall of the organ is formed by a layer of pigmented cells and a layer of muscular tissue. The spermatheca consists externally of a secretory cell layer, and internally of a cuticle layer witch surrounds the cavity of the organ.
2

Caracterização molecular de duas populações de Chrysomya megacephala (Diptera: Calliphoridae) do Estado de Pernambuco, Brasil

Lima, Tiago Levi Diniz 31 January 2013 (has links)
Submitted by Andre Moraes Queiroz (andre.moraesqueiroz@ufpe.br) on 2015-04-14T15:48:40Z No. of bitstreams: 2 Dissertaçao Tiago Lima.pdf: 4387596 bytes, checksum: 8eaf9b613d6c14a68e79172c7a96a703 (MD5) license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) / Made available in DSpace on 2015-04-14T15:48:40Z (GMT). No. of bitstreams: 2 Dissertaçao Tiago Lima.pdf: 4387596 bytes, checksum: 8eaf9b613d6c14a68e79172c7a96a703 (MD5) license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Previous issue date: 2013 / CNPq / A Entomologia Forense pode ser compreendida como uma vertente da ciência que procura se utilizar do estudo de insetos e outros artrópodes para elucidar questões litigiosas tais como morte violenta, uso de entorpecentes e inúmeros outros casos que se apresentam à investigação criminal. A análise da sucessão de artrópodes permite a associação de cada espécie ou grupo com um estágio de decomposição. Os dípteros caliptrados possui preferência pelos estágios iniciais do processo de decomposição, entre eles C. megacephala corresponde a uma das espécies de maior representatividade na entomofauna cadavérica, além de possuir importância médico-sanitária como agente transmissor de patógenos. A entomologia forense no Brasil ainda é subotimizada, com concentração de trabalhos nas regiões Sul-Sudeste do país. Sendo assim, o trabalho é justificável por apresentar uma contribuição ao levantamento dos dípteros caliptrados de importância forense no Estado de Pernambuco, além de promover a categorização genética (análise do polimorfismo do gene Citocromo Oxidade de DNA Barcode (COI) das populações de C. megacephala com o intuito de procurar atribuir aos espécimes sua população geográfica. Os resultados encontrados apontam elevada adaptação da espécie invasora C. megacephala as localidades estudadas. Os estudos com o marcador COI apresentaram uma elevada similaridade entre as sequências, ilustrando uma incapacidade do marcador em estimar a diversidade genética de populações recém introduzidas. Com o trabalho é possível concluir que outras metodologias, como análises multigênicas devem ser adotadas para se estudar populações com diversificação recente.
3

Diversidade genética de dípteros Calliphoridae de importância forense/

FIGUEIRÊDO JÚNIOR, Carlos Alberto Santiago 13 March 2015 (has links)
Submitted by Haroudo Xavier Filho (haroudo.xavierfo@ufpe.br) on 2015-05-21T18:14:52Z No. of bitstreams: 1 Tese_Carlos.pdf: 1883623 bytes, checksum: dedcccb704c7766cb80549e293aa33a3 (MD5) / Made available in DSpace on 2015-05-21T18:14:52Z (GMT). No. of bitstreams: 1 Tese_Carlos.pdf: 1883623 bytes, checksum: dedcccb704c7766cb80549e293aa33a3 (MD5) Previous issue date: 2015-03-13 / Calliphoridae é uma família de moscas de considerável importância médica e sanitária com espécies que ocorrem em lixos, fezes e carcaças, e também podem atuar como agentes de miíases. Dentro desta família destaca-se a espécie cosmopolita C. megacephala que é de grande importância forense, pois se alimentam, cruzam e fazem oviposição sobre os cadáveres. Tendo em vista a importância destes organismos, este estudo visou analisar e desenvolver marcadores genéticos que fossem úteis para identificação molecular de larvas de califorídeos e informativos para estudos de dispersão populacional de C. megacephala. Os organismos de estudo foram coletados em quatro localidades do estado de Pernambuco e uma no estado do Ceará. Os espécimes foram identificados e devidamente triados. As PCRs foram realizadas com primers amplificadores de marcadores mitocondriais e nuclear descritos na literatura e primers desenvolvidos no presente estudo a partir de análises in silico. As sequências foram confirmadas por Blastn como pertencentes às espécies correspondentes. As análises genética populacionais de C. megacephala indicaram um baixo grau de polimorfismo e consequentemente ausência de estruturação nas populações estudadas. Sugerindo que esta espécie foi introduzida no Brasil recentemente, e que não existem barreiras genéticas entre as populações. O resultado das análises in silico evidenciaram que o marcador Tag-CYTB, desenvolvido neste estudo fornece resultados mais robustos para taxonomia molecular que o utilizado pelo método barcode para família Calliphoridae.
4

Uso da terapia larval no tratamento de ?lceras cr?nicas em pacientes diab?ticos no Hospital Universit?rio Onofre Lopes- Natal, RN

Pinheiro, Mar?lia Augusta Rocha de Queiroz 27 May 2014 (has links)
Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2017-07-04T11:53:11Z No. of bitstreams: 1 MariliaAugustaRochaDeQueirozPinheiro_DISSERT.pdf: 2148471 bytes, checksum: 3eaabda0264457ba7881c728daf88eb8 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2017-07-11T12:42:03Z (GMT) No. of bitstreams: 1 MariliaAugustaRochaDeQueirozPinheiro_DISSERT.pdf: 2148471 bytes, checksum: 3eaabda0264457ba7881c728daf88eb8 (MD5) / Made available in DSpace on 2017-07-11T12:42:03Z (GMT). No. of bitstreams: 1 MariliaAugustaRochaDeQueirozPinheiro_DISSERT.pdf: 2148471 bytes, checksum: 3eaabda0264457ba7881c728daf88eb8 (MD5) Previous issue date: 2014-05-27 / A terapia larval ? a utiliza??o de larvas est?reis no desbridamento de feridas. Atualmente essa t?cnica vem sendo bastante utilizada na Europa, Estados Unidos da Am?rica e Israel, dentre outros pa?ses, entretanto, ainda n?o foi implementada rotineiramente no Brasil e n?o h? relatos de sua aplica??o utilizando larvas da mosca Chrysomya megacephala em pacientes humanos. O presente trabalho objetivou avaliar o desbridamento de ?lceras de dif?cil cicatriza??o utilizando larvas de C. megacephala. Cinco pacientes com ?lceras cr?nicas foram inclu?dos no estudo ap?s responderem a um question?rio, serem esclarecidos sobre os poss?veis riscos e benef?cios da terapia larval e assinarem o Termo de Consentimento Livre e Esclarecido ? TCLE. Antes das aplica??es, foram colhidas amostras para identifica??o das bact?rias presentes nas ?lceras. Ap?s essa etapa, as ?lceras foram avaliadas antes e durante o tratamento atrav?s de registro fotogr?fico, mensura??o de di?metros e avalia??o dos percentuais de tecido necr?tico e de granula??o. A avalia??o foi seguida da aplica??o de aproximadamente cinco larvas est?reis de 2? est?dio de C. megacephala por cm2 de les?o. Os curativos com larvas foram trocados ap?s 48 horas e com 48 horas de intervalo entre as aplica??es. As ?lceras dos pacientes inclu?dos no trabalho apresentaram car?ter polimicrobiano e em todas elas foi isolada a esp?cie Pseudomonas aeruginosa. Todos os pacientes submetidos ? terapia larval apresentaram redu??o significativa do percentual de necrose e aumento do tecido de granula??o na superf?cie das ?lceras e uma consequente melhora no decorrer do tratamento. / Larval therapy is the use of sterile larvae in the debridement of wounds. Currently this technique has been widely used in Europe, the U.S.A., and Israel, among other countries, however, has not been implemented in Brazil yet, and there are no reports of its application using larvae of the fly Chrysomya megacephala in human patients. This study aimed to evaluate the debridement of ulcers difficult to heal by using larvae of C. megacephala. Five patients with chronic ulcers were included in the study after answering a questionnaire, to be informed about the possible risks and benefits of larval therapy and signed a Free, Prior and Informed Consent. Before the applications, samples were collected for identification of the bacteria in the ulcers. After this step, the ulcers were evaluated before and during treatment by photographic recording, measurement and evaluation of diameters, percentage of necrotic tissue and granulation. The evaluation was followed by the application of approximately 5 second instar sterile larvae of C. megacephala per cm2 of lesion. Dressings with larvae were exchanged after 48 hours with 48 hours between applications. The patients? ulcers included in this study had polymicrobial nature and in all of them was isolated Pseudomonas aeruginosa species. All patients underwent larval therapy showed a reduction in the percentage of necrosis, increase of granulation tissue on the surface of ulcers and a consequent improvement during treatment.
5

Determinación del contenido elemental en Hermetia illucens y otros dípteros descomponedores, como fuentes de proteínas en alimentación animal

Rubio, Patricia 30 November 2020 (has links)
El previsible aumento de la población mundial, estimado para el año 2050 en 9.500-10.000 millones de personas, supondrá uno de los principales retos a los que se enfrente el siglo XXI. Además de los recursos e insumos necesarios (espacio, agua, residuos etc.), la seguridad alimentaria del planeta conllevará una elevada demanda de proteínas tanto para la alimentación animal como para la nutrición humana. Nuestras principales fuentes de proteína provienen de la agricultura, la ganadería (incluyendo la acuicultura) y la pesca. Es por ello por lo que la producción y rendimiento de las plantas y animales domesticados, ha aumentado exponencialmente a lo largo de las últimas décadas, estando en la actualidad muy cerca de sus límites biológicos. Sin embargo, esta elevada eficiencia esta inversamente relacionada con la sostenibilidad ambiental de estos sistemas de producción. Entre las consecuencias, la producción de piensos compuestos altamente nutritivos también ha aumentado. Para su elaboración son necesarias grandes cantidades de harina y aceite de pescado, así como de soja, entre otros componentes. El cultivo intensivo de soja conlleva graves problemas medioambientales. Por otro lado, el medio marino está cada vez más deteriorado como consecuencia de la contaminación derivada de la actividad humana y la sobreexplotación pesquera. Todo ello ha provocado una inestabilidad económica a largo plazo y un aumento continuado de los precios de estas materias primas. Pero ¿es técnicamente posible maximizar la sostenibilidad de estos sistemas de producción, optimizando simultáneamente la imprescindible eficiencia económica? Con este objetivo, se hace necesaria la búsqueda de nuevas fuentes de proteínas que puedan utilizarse como ingredientes en la elaboración de piensos compuestos destinados a la alimentación animal e indirectamente a la nutrición humana. Una de las más prometedoras, es la obtención de proteína animal a partir de la biomasa de ciertas especies de insectos domesticados. En particular, la utilización de proteínas y grasas de insectos a escala industrial, mejorará significativamente la sostenibilidad y eficiencia de la ganadería terrestre y la acuicultura. Indirectamente, permitirá mantener los niveles de pesca a unos niveles racionales y los subproductos derivados tienen un gran valor agronómico como fertilizantes de origen natural. Entre los candidatos más plausibles, los dípteros (Insecta: Diptera) presentan características biológicas y nutricionales que los hacen buenos candidatos para su producción a escala industrial. Una de las especies más prometedoras es la mosca soldado negra Hermetia illucens (Linnaeus, 1758) que junto con el coleóptero Tenebrio molitor Linnaeus, 1758 constituyen actualmente los principales integrantes de este nuevo sector de producción. La Unión Europea, también ha aprobado el uso de otras cinco especies de insectos como ingredientes de la alimentación animal, destacando entre estas la mosca común Musca domestica Linnaeus, 1758. Otras especies de dípteros no están todavía aprobadas con este fin, pero también resultan muy interesantes por su gran potencial para la cría artificial, como las especies de Calliphoridae Lucilia sericata (Meigen, 1826) o Chrysomya megacephala (Fabricius, 1794). Entre los componentes que forman parte de los piensos compuestos en la alimentación animal, los minerales suponen un importante grupo limitante desde un punto de vista nutritivo. Mediante un aporte óptimo de minerales, se puede aumentar considerablemente el rendimiento de la producción ganadera a un bajo coste. No obstante, los niveles de estos compuestos deben mantenerse dentro de unos niveles determinados por la legislación para evitar problemas nutricionales o provocar efectos nocivos en la salud animal y humana. En este sentido, existen muy pocos estudios sobre los perfiles minerales de la biomasa de insecto en general y en particular de la mosca soldado negro y otras especies de dípteros. Son especialmente escasos los datos sobre la influencia que pueda ejercer la composición del sustrato de desarrollo de las larvas, así como su importancia en las diferentes etapas de desarrollo del ciclo de vida. Por otro lado, existe la posibilidad de que se produzca bioacumulación de metales pesados en la biomasa del insecto a través de la ingesta. Así, debido a su alta toxicidad, existen diversos trabajos sobre las concentraciones de Cd y Pb en larvas maduras de mosca soldado negra, pero hay muy poca información sobre bioacumulación en el resto de etapas y estadios de desarrollo, así como de la posible influencia del medio de cría larvario. En este proyecto de tesis se analiza la posible influencia del sustrato de cría en las concentraciones de distintos minerales y metales pesados a lo largo de las etapas del ciclo de vida de Hermetia illucens y otras especies de dípteros. Para ello se usaron tres sustratos larvarios con diferentes orígenes: a) pienso comercial de gallina ponedora, b) bagazo derivado de la producción de cerveza y c) una mezcla de carne de origen porcino. En el caso de H. illucens se tomaron muestras de larvas prepupales, pupas, puparios, exuvias prepupales y adultos desarrollados en los tres medios de desarrollo. En todos los casos, tras su secado y digestión en horno microondas, se analizaron mediante espectrometría de emisión óptica de plasma acoplado por inducción (ICP-OES) para obtener las concentraciones de Ca, Cr, Cu, Fe, K, Mg, Mn, Na, Ni y Zn, y en espectrometría de masas con fuente de ionización de plasma (ICP-MS) para obtener las concentraciones de Ti, Co, Sr, Mo, Cd, Sn y Pb. Pocos insectos tienen la capacidad para desarrollarse en medios de tan diferente composición orgánica, por ello a modo comparativo se utilizó M. domestica con pienso comercial de gallina y el bagazo de cerveza, mientras que Lucilia sericata y Chrysomya megacephala se desarrollaron exclusivamente en el medio de origen cárnico. De esta manera no solamente se pudieron comparar diferentes tipos de medio procesados por diferentes tipos de insectos sino que también pudieron compararse los resultados obtenidos por diferentes especies de mosca con el mismo tipo de medio. En cuanto a relaciones entre patrones de acumulación (Factor de Bioacumulación) y concentraciones de los minerales, con la especie de díptero y el sustrato utilizado, en larvas prepupales y adultos no se observa ninguna relación entre resultados y la especie o el sustrato, en cambio, los resultados en pupas y puparios sí están influenciadas por la especie de estudio y el sustrato de alimentación usado. Por otro lado, Ca y Na se comportan de manera distinta en las especies estudiadas en esta investigación. La mosca soldado negra presenta un buen perfil mineral para su uso en alimentación animal, comparable con los de harina de pescado y soja. Los resultados con mosca doméstica son también comparables a las harinas de pescado y soja, en los dos medios estudiados. Los dos califóridos presentan un perfil mineral de menor calidad, pero comparable a la harina de soja y también aptos para su uso en la elaboración de piensos.
6

Factors Influencing Ant Assemblages and Ant Community Composition in a Sub-Tropical Suburban Environment

Clough, Elizabeth Anne, n/a January 2004 (has links)
The main objective of this study was to examine the abundance and diversity of ants in suburban sites following vegetation removal or modification for development. This research examines the capacity of suburban sites to support ant diversity, which is dependent on the site characteristics and their surrounding environment. The study focused on 29 suburban garden and 3 suburban reserve sites on the Gold Coast, Queensland, Australia. This region, through continuing land development, undergoes ongoing habitat disturbance and modification. Ground-dwelling ants were collected by pitfall trapping in study sites over three summers between 1997 and 1999. In total, 28,512 ants from 60 species in 31 genera were collected. Garden sites that maintain vegetation structural diversity were found to be most similar to reserve sites in terms of ant community composition. These sites were highest in ant richness and diversity and contained particularly high proportions of specialized ant species. Sites in close proximity to remnants of native vegetation contained higher species diversity and a greater proportion of specialized ant species. The introduced tramp ant, Pheidole megacephala was found in 28 of the 32 sites and was found to significantly reduce ant species richness and diversity and displace the dominant ant Iridomyrmex sp. 1 in suburban environments. This ant poses a serious threat to the recovery of a diverse ant fauna to suburban environments. Ant community composition was shown to vary significantly among suburban sites. The ant functional groups commonly found in disturbed sites were abundant in open sites with little canopy cover in this study. Sites that provided vegetation structural diversity and areas of closed canopy supported similar functional groups to natural vegetation remnants. These results indicate that ant communities in suburban environments respond to disturbance in a similar manner to ant communities in tropical forests and rainforests. The dominance by functional groups and presence of specialized species may therefore be used as an indicator of disturbance and the restoration of suitable habitat in suburban sites. The presence of specialized species of ants in suburban garden sites and their clear preference for particular site characteristics indicate that these species utilize resources available in the suburban matrix. These results indicate that residential suburban sites are of value in the enhancement of ant diversity in fragmented landscapes and that they may provide supportive habitat to, and act as corridors between, vegetation fragments. In order to preserve biodiversity within suburban environments, landowners should be advised to retain as much existing vegetation within a site as possible. Clearing should be limited to that necessary to allow construction of dwellings and for safety. In addition, landowners should be encouraged to establish or maintain structurally diverse vegetation layers within sites in order to provide diverse microenvironments for fauna habitat.
7

The invasive ant Pheidole megacephala on an oceanic island : impact, control and community-level response to management

Gaigher, Rene 03 1900 (has links)
Thesis (PhD)--Stellenbosch University, 2013. / ENGLISH ABSTRACT: Invasive species are among the most important global conservation threats. Their management is one of the key conservation challenges that will have to be addressed in the next few decades. The study of real invasions and their management in natural ecosystems provides an opportunity to gain important information on theoretical and applied aspects of biological invasions. This project focuses on the broader ecological context of invasive ant management in an ecologically sensitive island habitat. The thesis has three main components: 1) assessing the role of the invasive ant Pheidole megacephala in the ecosystem and evaluating its threat to the system, 2) evaluating a low-impact management program for the ant, and 3) using a community-level approach to assess ecosystem response to ant removal. The ant occupied almost 30% of the island‘s total land area and reached extremely high densities in some areas. The ant was associated with exotic hemipteran scale insects through trophobiotic mutualisms that facilitated high ant and hemipteran abundances. The highly destructive scale insect Pulvinaria urbicola was among the hemipterans that benefited from ant attendance. High levels of hemipteran feeding resulted in dieback of functionally important and threatened native Pisonia trees, which represented a significant threat to the forest ecosystem. A management program was initiated in response to this threat, consisting of baiting with selective hydramethylnon-based bait delivered in bait stations, accompanied by detailed pre-and post-baiting monitoring. The method was highly effective at suppressing the ants, whilst preventing bait uptake by non-target organisms. It was also cost-effective and adaptable to ant density in the field, but was only effective over short distances. The method may be applicable to other sensitive environments with similar challenges. After ant control, the ant-scale mutualism was decoupled and the Pu. urbicola population collapsed. There were variable responses in different taxa to the removal of these highly abundant exotic species, the most important of which was the recovery in Pisonia trees. Shoot condition and foliage density improved and there was a decrease in sooty mold. Herbivory on Pisonia increased due to recovery of native canopy herbivores, but the overall impact was far less than that of the exotic hemipterans. Soil surface arthropods, a group that may have been vulnerable to the treatment method, were unaffected by baiting. Instead, they increased significantly after ant removal, confirming the ant‘s impact on other arthropods. Other ant diversity and non-ant arthropod abundance increased post-baiting, including the endemic ant Pheidole flavens farquharensis and some functionally important insects such as the Indian cockroach. Natural enemies that interacted predictably with the mutualists were influenced by management. Predators of hemipterans increased significantly after ant removal and were instrumental in the scale population collapse, whereas parasitoids of hemipterans that benefited from the mutualism declined. Additionally, groups that were unrelated to the mutualism were indirectly influenced by management. The natural enemy assemblage as a whole showed recovery to pre-invasion conditions. The study shows how widely interconnected and influential the ant was in the ecosystem. It highlights the threat of the species in natural systems as well as the complex responses following invasive ant removal. Yet, it also demonstrates the potential to safely and effectively manage the species, thereby raising the opportunity for ecosystem recovery. / AFRIKAANSE OPSOMMING: Indringerspesies is van die belangrikste globale bedreigings vir natuurbewaring. Hulle bestuur is van die grootste bewaringsuitdagings wat in die volgende paar dekades aangespreek moet word. Die studie van werklike invalle en hul bestuur in natuurlike ekosisteme bied 'n geleentheid om belangrike inligting te verkry oor teoretiese en toegepaste aspekte van biologiese indringing. Hierdie projek fokus op die breër ekologiese konteks van uitheemse mier bestuur in 'n ekologies sensitiewe eiland habitat. Die tesis het drie hoofkomponente: 1) die beoordeling van die rol van die indringer mier Pheidole megacephala in die ekosisteem en evaluering van sy bedreiging vir die sisteem, 2) die evaluering van 'n lae-impak bestuursprogram vir die mier, en 3) die gebruik van 'n gemeenskaps-vlak benadering om ekosisteem reaksie op mierverwydering te assesseer. Die mier het byna 30% van die totale landoppervlak van die eiland beslaan en het in party areas baie hoë digthede bereik. Die mier was geassosieer met uitheemse dopluis spesies in mutualismes wat hoë mier en dopluis getalle gefasiliteer het. Die hoogs beskadigende dopluis Pulvinaria urbicola was een van die spesies wat bevoordeel is deur die mutualisme. Hoë vlakke van dopluis voeding het die terugsterwe van funksioneel belangrike, bedreidge inheemse Pisonia bome veroorsaak, wat ʼn groot bedreiging vir die ekosisteem verteenwoordig het. ‗n Bestuursprogram is geïmplimenteer as gevolg van hierdie bedreiging, wat bestaan het uit selektiewe hidrametielnoon-gebaseerde lokaas wat in die veld geplaas is in lokaashouers, vergesel deur intensiewe monitering voor en na lokaasplasing. Die metode was hoogs effektief in die onderdrukking van die miere en het lokaasinname deur nie-teiken organismes verhoed. Dit was ook koste-effektief en aanpasbaar volgens mierdigtheid in die veld, maar was slegs effektief oor kort afstande. Die metode mag van toepassing wees in ander sensitiewe omgewings met soortgelyke uitdagings. Na mierbeheer is die mier-dopluis mutualisme ontkoppel en die Pu. urbicola bevolking het drasties verminder. Daar was verskillende reaksies in verskillende taxa tot die verwydering van die oorvloedryke eksotiese spesies, maar die belangrikste reaksie was die herstel van Pisonia bome. Spruittoestand en blaardigtheid het verbeter en daar was ʼn afname in roetskimmel. Herbivorie op Pisonia het toegeneem as gevolg van ʼn herstel in inheemse herbivore, maar die algehele impak was veel minder as dié van die eksotiese dopluis. Grondoppervlak gelidpotiges, 'n groep wat kwesbaar kon wees vir die behandelingsmetode, was onaangeraak deur die lokaas, maar het beduidend na mierverwydering vermeerder. Mierdiversiteit het vermeerder en die Seychelles endemiese mier Pheidole flavens farquharensis is hervestig. Ander gelidpotiges het ook vermeerder, insluitend funksioneel belangrike spesies soos die Indiese kakkerlak. Natuurlike vyande wat geassosieer was met die mutualiste is beïnvloed deur die mierbestuur. Predatore van dopluis het beduidend toegeneem na mierverwydering en was hoogs betrokke by die vermindering van dopluis, terwyl parasiete van dopluis, wat voordeel getrek het uit die mutualisme, gedaal het. Daarbenewens is groepe wat onverwant was aan die mutualisme indirek beïnvloed deur mierbestuur. Die algehele natuurlike vyand gemeenskap het herstel na pre-indringing toestand. Die studie toon hoe wydverbind en invloedryk die mier was in die ekosisteem. Dit beklemtoon die bedreiging van die spesies in natuurlike stelsels asook die komplekse reaksies wat uitheemse mierverwydering volg. Tog demonstreer dit die potensiaal om die spesies veilig en doeltreffend te bestuur, en sodoende die geleentheid vir ekosisteemherstel te skep.

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