Efeitos da distribuição e diversidade de plantas na comunidade de insetos galhadores e o valor adaptativo da galha ao aumento de temperatura

Abstract

The ecology of galling insects is fascinating, galling insects are able to modify plant development, creating a favorable environment for them to feed and develop. The gall, structure developed by the galling insect, offers protection to the galling insect against abiotic and biotic stresses, as well as plant tissue rich in energetic substances for food. However, this ability to form the gall also generates limiting factors in its dispersion and development success. The galling insect can only develop galls on one or a few genetically related hosts, so the presence of galling insects in a location often depends on the composition of plant species in the location, and the presence of host plants. Furthermore, although insects manage to associate with one or a few plant species, some plants are attacked by a great diversity of galling insects, the so-called super hosts. In the following studies, I investigated how changes in the composition and distribution of tree species affect the population and diversity of galling insects. In the first chapter, I investigated the relationships between host concentration, resistance offered to it by other species, and gall abundance. I also investigated the relationship of gall infestation in the expression of flowers and fruits by hosts. In the second chapter, I investigated the effect of geographic distribution and the number of species congenerous to the host on the vulnerability to attack by different gallers. In the third chapter, I investigated the protection offered by the gall to the galling insect against chronic and acute temperature increase. I concluded that like other specialist insects, galling insect populations benefit from the concentration of the resource, and the presence of few barriers between resource units. I also found that the most geographically distributed host plants are also the most attacked by different insects, and that this effect is greater in plants of larger genera. And despite the fact that the gall provides a microenvironment for the development of the galler, the increase in temperature for a prolonged period exceeds the gall's buffering capacity.