Orientador: Odair Correa Bueno / Banca: Ana Paula Protti de Andrade / Banca: Terezinha Maria Castro Della Lucia / Resumo: Um conjunto de microcâmeras e aparelhos para gravação e análise de imagens foi usado para observar, descrever e quantificar os comportamentos de cuidado da prole por parte das operárias adultas da saúva-limão Atta sexdens rubropilosa. Para isso foram utilizadas colônias de laboratório com câmaras especialmente projetadas para a observação do ambiente interior do formigueiro, o jardim de fungo. As microcâmeras utilizadas permitiram que os comportamentos fossem vistos com grande riqueza de detalhes, mostrando-se bastante adequadas para observar pequenos objetos como as menores operárias do formigueiro, e comportamentos que ocorrem em uma pequena área como os propostos neste trabalho. A análise do material filmado em fitas de vídeo possibilitou que comportamentos rápidos fossem facilmente observados e que comportamentos que aconteciam simultaneamente fossem analisados independentemente. Foram descritos diversos comportamentos que ocorrem na área da cria, com suas respectivas freqüências, discutindo-se o papel do tamanho e da idade das operárias na divisão de trabalho. As principais categorias de comportamentos de cuidado da prole observados foram: limpeza dos estágios imaturos pelas operárias adultas, o aprovisionamento das larvas e a ocorrência de trofalaxia no interior do formigueiro. Além disso, uma nova forma de transferência de alimento das larvas para as operárias adultas, denominada trofalaxia proctodeal, foi descrita para Atta. / Abstract: A set of microcameras and other equipment for recording and image analyses were used to observe, describe and quantify the brood care behaviors of the adult workers of the Lemon Leaf-Cutting Ant Atta sexdens rubropilosa. In order to observe the fungus garden inside the ant colony, laboratory colonies with especially designed observation chambers were used. The microcameras enabled the behaviors to be observed in great detail, proving themselves to be very adequate for the observation of small objects such as the smallest workers, as well as behaviors occurring on a small area as the ones proposed in this work. The analyses of the material recorded on videotapes made it easier to follow fast behaviors and to independently analyze distinct behaviors happening simultaneously. Several behaviors occurring around the brood are described with their respective frequencies. The role of worker age and size on the division of labor are discussed. The main categories of brood care behavior observed were: grooming of the immature stages by the adult workers, larval feeding and the occurrence of trophalaxis in the colony. A new means of food transfer from the larvae to the adult workers, named proctodeal trophalaxis was also described. / Mestre

Orientador: Odair Correa Bueno / Resumo: Há muito tempo vem sendo constatada a ocorrência de formigas em ambientes urbanos; esses insetos podem acarretar danos em residências e em vários utensílios de uso domésticos, além de causar sérios problemas, pois se tornam um perigo à saúde pública quando a infestação se dá em hospitais. Métodos eficientes de controle de formigas urbanas envolvem um manejo adequado do ambiente e a utilização de iscas atrativas tóxicas. Estas funcionam como fonte de alimento e, desta forma, podem provocar intensa competição entre as várias espécies. As formigas possuem uma enorme variedade de estratégias ofensivas e defensivas na procura de alimento e proteção do ninho. A maior parte dessas agressões pode ser vista como uma série de comportamentos que atuam como técnicas competitivas. Competição compreende a demanda ativa por dois ou mais indivíduos da mesma espécie (competição intraespecífica) ou membros de duas ou mais espécies de mesmo nível trófico (competição interespecífica) por um recurso comum potencialmente limitado. Foram realizados seis testes em laboratório, com colônias de formigas urbanas, com o objetivo de estudar as interações comportamenatis na fonte de alimento. As colônias se encontravam em uma bandeja de plástico e foram providas de mel e larvas de besouro Tenebrio. O suprimento de água deu-se com um tubo de ensaio com algodão na extremidade livre. Os alimentos atrativos utilizados foram: uma mistura composta de fígado de boi desidratado, bolo, mel, e 1% de óleo de amendoim, e açúcar líquido diluído em água (75%). Para a realização dos testes foi utilizado um recipiente denominado de arena de forrageamento. Durante cada teste, os recipientes de criação das duas das espécies a serem estudadas foram conectados à esta arena, e as fontes de alimento foram colocadas no centro...(Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The attractive food used was a composed mixture of dehydrated ox liver, cake, honey, and 1% of peanut oil. The second food was a diluted liquid sugar in water (75%). For the accomplishment of these tests a container called arena of forage was used. During each test, the containers of creation of two of the species studied were connected to this arena, and the food source was placed in the center. After this procedure, the interaction behaviors of the ants were written down. Six tests of field were carried out where the attractive food was placed in fixed points in the studied environment close to the occurrence place of the ants species and it was taken notes of the behaviors of competition among all species. In accordance with the results of the laboratory tests, the order of domination among the four studied species was: Monomorium floricola, Monomorium pharaonis, Linepithema humile and Tapinoma melanocephalum. The two last ones were considered subordinated in relation to the competitive ability for interference, although they presented a bigger competitive ability for exploration. According to the final results of the tests carried through natural situations, it can be concluded that there is an effective competition for food among the different species of urban ants. However it is very difficult to carry on comments or observations about this process, since the sucession of different species of ants on food occurs in a short period of time and with a great rapidity. / Mestre

Resumo: A presença de microorganismos no trato digestivo de formigas da tribo Cephalotini (Subfamília Myrmicinae) e do gênero Dolichoderus (Subfamília Dolichoderinae), tem sido motivo de várias especulações entre os mirmecologistas. Entretanto não existem dados sobre muitas das características da relação destes microorganismos descobertos a menos de 25 anos, principalmente no que concerne os aspectos histoquímicos, enzimológicos e também ultramorfológicos. Assim sendo, foram realizados estudos comparados do proventrículo, ventrículo e do íleo de três espécies pertencentes ao gênero Cephalotes: C. atratus, C. clypeatus e C. pusillus, e do ventrículo de uma espécie do gênero Dolichoderus: Dolichoderus (=Monacis) bispinosus, objetivando buscar relações entre as espécies, assim como, diferenças enzimológicas e histoquímicas tanto da parede como do conteúdo de destas porções do trato digestivo, que possam ser utilizadas para a compreensão da função intestinal, bem como esclarecer quais e como os recursos alimentares são aproveitados em cada parte do trato digestivo. Das espécies de Cephalotes foram feitas análises ultramorfológicas. Os resultados tanto de natureza enzimológica quanto de natureza histoquímica de todas as regiões estudadas, apresentaram o mesmo padrão para todas as espécies. De 2 mesma maneira, a secreção das células digestivas colunares para todas as espécies estudadas, foi considerada como do tipo apócrino. Na tribo Cephalotini (Myrmicinae) e em Dolichoderus (=Monacis) bispinosus (Dolichoderinae) o pH levemente ácido presente tanto no lúmen do ventrículo, quanto no lúmen do íleo, permite a sobrevivência dos microorganismos nestas regiões do trato digestivo / Abstract: The presence of microorganisms in the digestive tract of Cephalotini tribe (subfamilly Myrmicinae) and Dolichoderus (subfamily Dolichoderinae) ants has been causing several speculations among the myrmecologists. However, the data concerning the relationship of these microorganisms (discovered less than 25 years ago) to the ants are scarce at the histochemical, enzymological and ultramorphological point of view. Thus, we carried out studies on the proventriculus, midgut and ileum in three species of Cephalotes (C. atratus, C, clypeatus and C. pusillus) and the midgut of Dolichoderus (=Monacis) bispinosus. The histochemical and enzymological aspects of the epithelium of these structures and their contents were compared among these species. We tried to understand the function of these organs and establish how each of them takes advantage of the alimentary sources. Some ultramorphological studies were also carried out in Cephalotini. The enzymological and histochemical techniques showed that each studied organ presented the same pattern when compared among species. In the same way, the secretion 4 of the digestive cells was also similar. Besides, all of these digestive cells were classified as apocrine. In Dolichoderus (=Monacis) bispinosus and all species of Cephalotini studied the slightly acid pH allows the survival of the microorganisms as in the midgut lumen, as in ileum's lumen. We propose that, in Cephalotini, the stability of the pH is related to the intensive secretion of Ca++ by the digestive cells in the midgut. The morphological adaptations of the ileum in Cephalotini tribe provide high supply of oxygen and metabolites that also explain the strong presence of microorganisms in this region. Besides it, the absorptive and digestive capacity of this epithelium indicates that it could be a very specialized region adapted to maintain microorganisms / Orientador: Flávio Henrique Caetano / Coorientador: Fernando José Zara / Banca: Vera Nisaka Solferini / Banca: Maeli Dal Pai Silva / Mestre

Doctorat en Sciences / info:eu-repo/semantics/nonPublished

Doctorat en Sciences / info:eu-repo/semantics/nonPublished

Few studies have evaluated the community dynamics of pest ant species in tropical urban environments. Pest ant community dynamics were examined within three Puerto Rican housing developments. Housing developments (one, four, and eight years old), representing different stages of urban succession were sampled to determine which species were present and the relative species abundance. Eight trips were made to Puerto Rico over a one-year period, and more than 1,000 samples were collected during each trip. The ants collected in each sample were counted and identified. A total of 25 different species were identified from the developments, with the major pest species being big-headed, rover, and red imported fire ants (RIFA). Fourteen different species were identified from the one-year-old site. However, RIFA and rover ants were the most abundant, accounting for >75% of ants collected. In the four-year-old site, 20 species were identified. However, three species (RIFA, big-headed, and destructive trailing ants) were dominant, accounting for >75% of ants collected. Sampling data from the eight-year-old site indicated that out of 21 species identified, four species were dominant (RIFA, crazy, and two species of big-headed ants) and accounted for >75% of the ants collected. The dominant species within each site were different, indicating that the pest ant community changed during the stages of succession. However, these dominant species did not specifically impact the distribution of other species within the same site. Spatial analysis indicated that the number of species coexisting within a site increased as the age of the development increased. / Master of Science in Life Sciences

Thesis (MSc)--Stellenbosch University, 2013. / Ants emerged during the Cretaceous Period more than 100 million years ago (Grimaldi & Engel 2005; Perrichot et al. 2008) and diversified independently on different landmasses following the Early Cretaceous fragmentation of Pangaea (Grimaldi & Agosti 2000). Today, ants represent one of the most ecologically successful groups globally (Wilson 1987), and their diversity far exceeds that of other social insects (Hölldobler & Wilson 1990). Currently 21 subfamilies, 305 genera and 12465 recorded ant species exist (Bolton 2012). Ants occur in almost all terrestrial habitats (Brown 2000) and are not uniformly distributed across regions, biomes and continents. As with all other taxa, historical abiotic factors have played a major role in their diversification and biogeographic structure (Tolley et al. 2006), including climatic changes (Holldobler & Wilson 1990) and the necessity to adapt to new environmental conditions (Tolley et al. 2006). Many global areas still lack data on regional biodiversity and the historical processes that may have shaped it. This is particularly so for southern Africa where the ant fauna is still relatively poorly known (Robertson 2000) and where there have been no published biogeographic analyses for any ant taxon. There is a highly endemic ant fauna that has evolved in the dry regions of southern Africa, which shows unique adaptations to the extreme thermal niches of these regions. For example, ants in the genus Ocymyrmex have adapted to forage on barren ground at temperatures as high as 67 ºC, when most insects and other arthropods are unable to survive (Marsh 1985). Ocymyrmex have long legs and usually hold the head, thorax and gaster high above the substrate, which helps with body temperature regulation. These ants are most active at the hottest time of the day and they move very rapidly. For example, O. barbiger has been observed running at speeds of 23 m/min (Marsh, 1985). In some ant species such extreme temperatures may limit foraging activity (Ward, 2007) but, in the case of Ocymyrmex, adaptations to this extreme thermal niche allowed exploitation of resources (dead and heat stressed arthropods). Moreover, these ants have subterranean nests that are ideal to escape environmental extremes and to move their brood deeply under the ground (Marsh, 1985). The distribution of some ant taxa in these dry regions closely reflects borders between particular biomes. For instance, in South Africa the ponerine ant, Pachycondyla hottentota, and the sugar ant, Camponotus storeatus, follow the borders of the Nama and Succulent Karoo biomes respectively (Robertson 2000). In the light of this background the overall objective of this study is to revise the taxonomy and determine the historical drivers of diversification in an important group of arid-adapted ants, the Tetramorium solidum-group, which is mainly restricted to dry semi-desert areas in southern Africa. Members of the Tetramorium solidum-group are commonly encountered seed harvesters yet despite their apparent ecological importance, their taxonomy and biogeography remains largely unresolved. Thirty years elapsed since the last revision of the group by Bolton (1980) and since, ant surveys have considerably expanded the material available for study and provide an opportunity for a fresh perspective on this group. The specific aims of this project were twofold: 1) to revise the species of the Tetramorium solidum-group; and 2) to explore the phylogenetic relationships among members of the group and the bioclimatic factors restricting their current distributional ranges in southern Africa. My study is timely, as to date no attempt has been made to unravel the history of arid-adapted ant diversification in southern Africa. Such information is much needed for identifying areas of high species diversity and endemism (Azuma et al. 2006) and prioritizing areas for conservation (Faith 1992). The thesis consists of three chapters. In chapter one I use morphological characters to review the current taxonomy of the Tetramorium solidum-group. From these data I have compiled an updated identification key for the group and described five new species. In chapter two I have constructed a fossil-calibrated dated phylogeny for Tetramorium solidum-group species in order to explore the historical processes that may have contributed in structuring the current distribution patterns and endemism within and among the species of the group. In this chapter I also explore bioclimatic factors that may restrict the current distribution of members on the Tetramorium solidum-group, using correlative bioclimatic modeling approaches. Chapter three provides a brief and overall conclusion to the study. / Financial support from NRF

The fungus-growing ants have long provided a spectacular example of co-evolutionary integration between distantly related taxa. Their ecological success has been thought to depend largely on the evolutionary alignment of reproductive interests between ants and fungi, following vertical transmission and the ancient suppression of fungal sexuality. In my dissertation I explored the role of lateral cultivar switching on the evolution of the fungus-gardening ant mutualism. First, I provided the first evidence for sexual reproduction in the attine cultivars, together with evidence of extensive independent long-distance horizontal transmission of fungal genes. In fact, fungi have greater gene flow relative to their host ants, crossing the Gulf of Mexico between Latin America and Cuba, over which the ants cannot readily disperse. Second, for the special case of leaf-cutting ants, I show that the cultivar population was largely unstructured with respect to host ant species, and leaf-cutting ants interact largely with a single species of fungus. Finally, I examined the effect of post-glacial expansion on the population structure of the northern fungus-gardening ant Trachymyrmex septentrionalis and compared it with that of its two microbial mutualists: a community of lepiotaceous fungal cultivars and associated antibiotic-producing Pseudonocardia bacteria. This comparison allowed me to examine the effect of historical biogeographic forces, such as climate-driven range shifts, on the population structure of the ants and their microbial symbionts. While neither the cultivar nor the Pseudonocardia genetic structure was correlated with that of the ants, they were significantly, though weakly, correlated with each other. These results suggest that biogeographic forces may act differently on macro- and microscopic organisms, even in the extreme case where some microbial mutualists may be vertically transmitted from generation to generation and share the same joint ecological niche. Thus, binding forces that appear to enforce host fidelity are relatively weak and pairwise associations between cultivar lineages and ant species have little opportunity for evolutionary persistence. Taken together, my studies suggest that mechanisms other than long-term pairwise interactions between ants and fungi (so-called partner fidelity feedback) govern the evolution of the mutualism over evolutionary time. / text

Thesis (Ph.D.)--Mississippi State University. Department of Entomology and Plant Pathology. / Title from title screen. Includes bibliographical references.

South Africa produces large amounts of solid mine waste, covering vast areas of land in the form of tailings dam facilities (TDF). Tailings material contains high levels of elements which poses potential risk for the environment and human health due to their potential toxic character. Agricultural practices such as tilling and chemical additions can also cause leaching of potentially harmful toxins into the surrounding environment. Both these soils are disturbed on a physical level, influencing the soil structure, chemical composition and soil biota present. This study analyzed in a comparative manner the chemical and physical properties of soils collected from gold mine tailings, agricultural areas and natural areas, and the consequences for soil life. Soil samples for the different land use types were taken in duplicate from the KwaZulu- Natal and North West provinces in South Africa. Topsoil layer formation was analyzed for all sites by sampling at depths of 0-5cm, 5-15cm and 15-25cm. Soil element content was assessed by means of metal indices. The physical and chemical characteristics of the soil were further analyzed by life cycle parameters of the oligochaete species Eisenia andrei and Enchytraeus doerjesi in gold mine tailings and agricultural soils. Ants were collected from all the land use types for species identification and analysis of element content. Soil layering regarding the vertical distribution of elements was observed in concentrations analyzed for the different land use types. Mining sites, especially in KwaZulu-Natal, indicated a decrease in element concentrations with increased depth. The opposite tendency was observed for the agricultural and natural soils, indicating increased concentrations with increased depth. Analysis of the elements indicated high levels of pollution in the mining sites which according to the metal indices were Co, Cd, and Ni. It was determined that tailings material from KwaZulu- Natal was more polluted than the tailings material from the mine in North West province, according to soil indices. Tailings material from both mining sites resulted in negative impacts on E. andrei and E. doerjesi, based on growth, hatching success, mortality and reproduction rate. A unique approach was taken during this study by exposing cocoons of E. andrei to soil samples. The negative effects of the mining samples on test species could be a result of the low organic matter, poor structure and high element content of the mining waste, compared to the agricultural and natural soil. Species numbers of ants were higher on the tailings material than agricultural and natural soils. Element analysis of ants collected, indicated high accumulation of elements such as Fe, Al, Cr, Cd, Pb, Cu and Zn in total body element content of one or more species, reflecting the combination of elements found in the different land use types. Accumulation levels were highest in Pheidole sp. compared to other species investigated. Ants are potential indicators of soil pollutants within a South African context. Risk assessment is necessary for analyzed soils to determine steps for sustainable re-use. A key system with regards to soil pollutant analyses should be incorporated in government policy for protection of South African soil. / PhD (Environmental Sciences), North-West University, Potchefstroom Campus, 2014