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UNIVERSIDADE FEDERAL DO RIO GRANDE DO SUL Instituto de Biociências Programa de Pós-Graduação em Ecologia
| Content Provider | Semantic Scholar |
|---|---|
| Author | Doutorado, Tese De Guimarães, Alexandre Caixeta Castro, Só de Rocha, Ana Luiza Lunardi |
| Copyright Year | 2006 |
| Abstract | Galls are plant structures formed through the action of an insect herbivore on plant tissues. Thus, for a natural enemy, such as a parasitoid wasp, attacking a galling insect requires piercing the plant tissue to penetrate the gall. What changes in gall shape, across time and space imply for interactions with other organisms was the focus of this thesis. In Chapter 1, we sought to clarify concepts related to guilds of organisms associated with galls, focusing on cecidophages, inquilines and kleptoparasites. We have established clear criteria to distinguish one guild from the other, for these terms currently appear confused in the specific literature. In Chapter 2, galls and parasitoids were sampled in two regions of Semideciduous Seasonal Forest to help understand patterns (nestedness and modularity) in these interactions using a trophic network approach. The modularity found in these interactions, as well as the high specialization and low connectivity of these networks, despite the large specificity variation of parasitoids, followed literature expectations for antagonistic interaction networks. In Chapter 3 we used six gallers present in only one host plant, Guapira opposita, to avoid the effects of space and host plant, trying to understand which ecological processes are influencing the interactions, and conclude that gall shape is the main aspect shaping parasitoid/galler interactions in this system. This is in accordance with the perceived importance of gall morphology for the defense against natural enemies, as considered in the "enemy hypothesis" for the adaptive nature of insect galls. Finally, in Chapter 4, in the same G. opposita system we study a single parasitoid species, Galeopsomyia sp. and its intraspecific ovipositor size variation, as related to gall attack, and we found thicker galls to be related to hatching of individuals of longer ovipositors, whereas in thicker galls, we found variation in ovipositor size . Therefore, thicker galls limit the attack to certain individuals of the wasp population, those with longer ovipositors. Finally, we conclude that because this type of interaction is still understudied, we continue with taxonomic problems for both groups, and simple questions of natural history. Although the literature tries to address current problems in terms of sophisticated analyses and simulations, simple and important questions are usually forgotten, and the present thesis has tried to rescue and resurrect some of them. |
| File Format | PDF HTM / HTML |
| Alternate Webpage(s) | https://www.lume.ufrgs.br/bitstream/handle/10183/17332/000712577.pdf?isAllowed=y&sequence=1 |
| Alternate Webpage(s) | https://www.lume.ufrgs.br/bitstream/handle/10183/10000/000580385.pdf?isAllowed=y&sequence=1 |
| Alternate Webpage(s) | https://www.lume.ufrgs.br/bitstream/handle/10183/173158/001050702.pdf?isAllowed=y&sequence=1 |
| Alternate Webpage(s) | https://www.lume.ufrgs.br/bitstream/handle/10183/29992/000779909.pdf?isAllowed=y&sequence=1 |
| Alternate Webpage(s) | https://www.lume.ufrgs.br/bitstream/handle/10183/199552/001090451.pdf?isAllowed=y&sequence=1 |
| Alternate Webpage(s) | https://lume.ufrgs.br/bitstream/handle/10183/7903/000560093.pdf;jsessionid=3E3896335CD037E99B31E5F0F383578A?sequence=1 |
| Alternate Webpage(s) | https://lume.ufrgs.br/bitstream/handle/10183/203939/001085789.pdf?isAllowed=y&sequence=1 |
| Language | English |
| Access Restriction | Open |
| Content Type | Text |
| Resource Type | Article |
