Dissertation (Ph.D.)--Auburn University, 2006. / Abstract. Includes bibliographic references.

Thesis (M.S.) in Entomology--University of Maine, 2007. / Includes vita. Includes bibliographical references (leaves 46-52).

Thesis (Ph. D.)--University of Chicago. / "Reprinted from the Journal of comparative Neurology and Psychology, Vol. XVII, No. 5, 1907." "Literature cited": p. 425-426.

Thesis (Ph. D.)--University of Chicago. / "Reprinted from the Journal of comparative Neurology and Psychology, Vol. XVII, No. 5, 1907." "Literature cited": p. 425-426. Also available on the Internet.

Thesis (Ph. D.)--University of Texas at Austin, 2007. / Vita. Includes bibliographical references.

No description available.

No description available.

No description available.

The influence of foraging ants on the insect fauna within the canopy of the tree species Terminalia sericea, Burkea africana and Ochna pulchra was studied in an area of typical South African savanna, over a two year period. The number of individual insects and their species composition was compared on unbanded, ant-infested plants and on banded plants where ants had been excluded. Differences in the level of herbivory recorded on banded and unbanded trees were related to the guild composition of insects within the canopy, and the results are discussed in terms of plant protection as a consequence of ant - insect interactions. Twenty-six ant species were recorded on the study trees at Nylsvley, with individuals belonging to the genus Crematogaster being numerically abundant and dominant within the canopy of each species of tree. These dominant ant species influenced the insect fauna by their strong dependence on honeydew, encouraging a build up in numbers of Homoptera on the branches and leaves of foraged trees, and supporting homopterous populations within the confines of their nest compartments . The exclusion of ants from trees led to fewer "mobile" homopterans (Aphididae, Membracidae, Psyllidae and Cicadellidae) and "sessile" homopterans (mainly Coccidae but also Pseudococcidae). Pyrethrum spraying showed that the guild composition of non-homopterous insects was similar on banded and unbanded trees. Differences in the level of herbivory on banded and unbanded trees suggested that, although slight, foraged trees were protected from some damage by the presence of ant species within the canopy. A trend did exist towards a greater number of insect individuals and species on unbanded trees, and it is postulated that during the period 1982 1984 when drought conditions prevailed over Nylsvley, ants do not reduce insect numbers through predation or disturbance but simply deter phyllophagous feeding. A separate experiment showed that Crematogaster constructor would feed on the eggs and early instar larvae of the saturnid moth, Cirina forda, but low numbers of lepidopterous larvae on the trees may have forced ants to seek honeydew. The negative impact of large homopterous populations on foraged trees was only seen in an isolated field observation where Polyrachis schistacea was found to associate with the lac insect Tachardina sp . . In conclusion it can be said that where homopterans are not the dominant phyllophages, plants do benefit from foraging populations of ants in that damage to the leaves is reduced.

Título original: Análise transcriptômica do metabolismo de carboidratos e aminoácidos na formiga Mycocepurus goeldii / Orientador: Maurício Bacci Junior / Banca: Flavio Henrique da Silva / Banca: Patricia Pasquali Parise Maltempi / Resumo: Relações de simbiose com micro-organismos são descritas como uma forma de inovação evolutiva que permite a alguns animais acesso aos nutrientes que de outra forma não estariam disponíveis. As formigas da tribo Attini são conhecidas pelo hábito de cultivar fungos que lhes fornecem nutrientes. Parte destes nutrientes são obtidos quando o fungo fornece enzimas que são instáveis ou mesmo ausentes nas formigas. No presente trabalho nós mostramos que as formigas Attini apresentam amilases submetidas a uma baixa pressão seletiva e grande quantidade de substituições de aminoácidos potencialmente deletérias. Esses dados reforçam a hipótese de que a função da amilase das formigas foi substituída pela amilase fúngica. Nós também demonstramos que, tal como ocorre com as Attini derivadas, a Attini basal Mycocepurus goeldii é deficiente em duas enzimas da via de síntese de arginina, a argininossuccinato liase e a argininossuccinato sintase. Esses dados indicam que a complementação pelo fungo de deficiências enzimáticas das formigas é um evento ancestral na história evolutiva das Attini / Abstract: Symbiotic relationships with microorganisms are described as a form of evolutionary innovation that allows some animals access to nutrients which otherwise would not be available. The Attine ants are known for the habit of cultivating fungi which provide them with nutrients. Some of these nutrients are obtained when the fungus provides enzymes that are unstable or even absent in ants. In this work we show that the Attini ants presents amylases subjected a low selective pressure and a large amount of potentially harmful amino acid substitutions. These data corroborates the hypothesis that the function of amylase of ants was replaced by fungal amylase. We also demonstrate that, just as with derived Attine, in the basal Attine Mycocepurus goeldii two enzymes is deficient in arginine synthetic pathway, the argininosuccinate lyase and argininosuccinate synthase. These data indicate that supplementation of deficient enzymes in ants made by fungal is an ancient event in the evolutionary history of Attine / Mestre