Mestrado em Ecologia e Evolução (ICB)
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Navegando Mestrado em Ecologia e Evolução (ICB) por Por Orientador "Almeida Neto, Mário"
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Item Efeitos diretos e indiretos de características de plantas sobre a similaridade na composição de insetos herbívoros e parasitoides associados à Asteraceae(Universidade Federal de Goiás, 2018-03-15) Alvarenga, Vinícius Silva de; Almeida Neto, Mário; http://lattes.cnpq.br/1000297113793647; Almeida Neto, Mário; Santos, Carolina Moreno dos; Araújo, Walter Santos deUnderstanding how interactions between trophic levels structure species composition is one of the main goals of ecological studies. Mechanisms that explain the compositional structure of parasitoid insects usually neglect the direct and indirect effects of plants’ characteristics, which can also determine the compositional structure of their host herbivore insects. In this context, our goal was to evaluate how plants’ characteristics (abundance, floral phenology, and phylogenetic distance) and herbivores’ compositional similarity determine parasitoids’ compositional similarity. As study system, we used Asteraceae species, flower-head feeding insects, and parasitoids. Using path analysis, we considered parasitoids and herbivores’ similarities, in qualitative (Sørensen similarity), quantitative (Bray-Curtis similarity), and phylogenetic proximity (taxonomic Sørensen similarity) terms. In general, we demonstrated that herbivores’ similarity is the major predictor of parasitoids’ similarity. Even though the effects of plants’ characteristics explained the smallest part of the variation in parasitoids’ similarity, these characteristics had inconsistent relative importance among the similarity indexes used here. Thus, our results indicate that although plant species constitute a potential additional barrier for the parasitoids of endophagous herbivores to find their insect hosts, herbivore parasitoids in flower heads of Asteraceae do not see the plant species in this way. The parasitoids respond mainly to the compositional variation of their insect hosts in the plant species that the latter consume. Therefore, we show how the composition of the upper trophic levels in this tri-trophic system is structured directly and indirectly by antagonistic interactions.Item A importância das plantas e dos herbívoros hospedeiros na especialização dos parasitoides de afídeos(Universidade Federal de Goiás, 2021-08-30) Bergamo, Norem Ceane da Silveira Barbosa; Bergamini, Leonardo Lima; http://lattes.cnpq.br/7657432431796954; Almeida Neto, Mário; http://lattes.cnpq.br/1000297113793647; Almeida Neto, Mário; Baumgartner, Matheus Tenório; Melo, Adriano SanchesThe variety of host organisms represents one of the most important dimensions of the ecological niche of parasitoids and parasites in general. In the case of insect parasitoids that attack herbivores, the degree of specialization of these in the use of hosts can be determined by cues and restrictions imposed by herbivores and by their host plants. We used plant-aphid-parasitoid interactions sampled from several regions of the globe to investigate the specialization in the use of aphids and plants by parasitoid. Specifically, we aim to answer the following questions: (1) which trophic level, plants or herbivores, exerts greater influence on parasitoid specialization? (2) how important is the scale of network, regional or global, for specialization patterns? We found phylogenetic specialization of the parasitoids toward both aphids and plants, with specialization toward aphids being greater when compared to specialization toward plants. As for the effect of spatial scale, specialization was more evident when evaluated on a global scale than on a regional scale, especially for plants. These results reinforce the importance of coevolutionary history in the interactions between parasitoids and aphids, and also demonstrate the mediation role of plants in determining the interactions between parasitoids and host herbivores.Item Efeito do isolamento filogenético sobre a riqueza e composição de insetos herbívoros em plantas exóticas(Universidade Federal de Goiás, 2015-03-20) Grández Rios, Julio Miguel; Almeida Neto, Mário; http://lattes.cnpq.br/1000297113793647; Almeida Neto, MárioThe replacement of native plants by introduced or invasive exotic plants may have significant impacts on the fauna of herbivorous insects. These impacts can occur both directly, through changes in reproductive success and population size herbivorous insects that consume the exotic plants, and indirectly through changes in the availability of native host plants. This study is divided into two parts. In the first chapter, I evaluated the effect of phylogenetic isolation on the richness and composition of species of herbivorous insects on exotic plants. In addition, I also examined possible differences in response to phylogenetic isolation of exotic plants between herbivore assemblages made up exclusively of endophagous and exophagous insects.In the second chapter, I evaluated the effect of phylogenetic isolation of host plants on the mean specialization of herbivorous insects fauna associated with host plants. In addition,I also analyzed the effect of phylogenetic isolation of host plants differs between native and exotic plants. Taken together, the results of the two chapters exemplify how the richness, composition and specialization of herbivores respond to phylogenetic isolation of their host plants.Item Diversidade beta e estrutura de interações em redes inseto-planta do cerrado(Universidade Federal de Goiás, 2018-03-15) Martins, Lucas Pereira; Almeida Neto, Mário; http://lattes.cnpq.br/1000297113793647; Carvalheiro, Luísa Gigante; Araújo, Walter Santos deUnderstanding how species interact with each other is essential to advance our knowledge on community ecology. However, there are still gaps regarding how interspecific interactions affect and are affected by the variation in the composition of species that constitute the ecological networks. In particular, studies of beta diversity are interesting to understand how sets of biotic filters may affect species’ geographic distribution and persistence on communities. Another interesting question is if variations in species composition may cause changes on how ecological networks are structured. In this dissertation, we propose to evaluate patterns of beta diversity and structure on insect-plant interaction networks. Specifically, in the first chapter we aimed to test if beta diversity is affected by the trophic level to which the assemblage belongs, and by the degree of specialization of species at higher trophic levels to their host species. For this, we used a tritrophic system comprising plants of the family Asteraceae, endophagous herbivores and parasitoids sampled in remnants of Brazilian Cerrado. Our main results show that total beta diversity of parasitoids (higher trophic level) was lower than those of the other trophic levels, while there was no difference between total beta diversity of plants and herbivores. Furthermore, the degree of specialization of the assemblages of herbivores and parasitoids was positively associated to the beta diversity of these groups. In the second chapter, we evaluated if species beta diversity among sites affects dissimilarity in network structure, and if this relationship changes across time. Overall, the relationship between spatial beta diversity and dissimilarity in plant-herbivore network structure was context-dependent, thus indicating that different ecological processes (i.e., niche-based and neutral) may drive the organization of antagonistic networks across time.Item Efeito de plantas exóticas sobre a fidelidade de polinizadores e a qualidade do serviço de polinização(Universidade Federal de Goiás, 2014-02-25) Valente, Cristiele Barbosa; Almeida Neto, Mário; http://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4737911T2; Almeida Neto, Mário; Franceschinelli, Edivani Villaron; Torres, Marina WolowskiThe invasion of terrestrial habitats by exotic plants often has negative effects on growth and fitness of native plants. Exotic plants may change the foraging behavior of pollinators and dynamics of interactions of local assemblages. Due to the lack of shared evolutionary history between exotic plants and native pollinators, it is likely that the morphological and phenological mismatches are especially important in determining the interactions involving exotic plants and specialist native pollinators. In addition, exotic plant species are expected to be pollinated by abundant generalist pollinators whose interactions are phylogenetically constrained compared to specialists pollinators. To evaluate these issues, we compiled 28 plant-pollinator networks with 778 plant species (10% alien) and 3019 pollinator species, comprising 7919 interactions. We expected that: (a) exotic plants tend to be visited by more generalist pollinator species compared to the co-occurring native plant species; (b) an increase in the proportion of exotic plants in the plant-pollinator networks promotesan increase in the global connectivity and nestednessof the interactions. If these predictions are correct, then the introduction of plants should also promote an increase in the risk of heterospecific pollen deposition on native plants. We found that exotic and native plants did not differ in the average degree of specialization of their pollinators. Moreover, an increase in the proportion of alien plants did not affecteither structure or the connectivity of networks. On the other hand, there was an increase in the risk of heterospecific pollen deposition on native plant stigmas when the proportion of exotic plants increases to about 1/3 of the flora pollinated by animals.However, above this percentage the relationship is reversed. This result may be a consequence of progressive decrease in pollinator fidelity of native plants in habitats with low-levels of invasion by exotic species, reducing the amount of shared pollen due to the impoverished pollinator fauna.Item Um modelo estocástico de coextinções em redes mutualísticas(Universidade Federal de Goiás, 2014-05-09) Vieira, Marcos Costa; Almeida Neto, Mário; http://lattes.cnpq.br/1000297113793647; Lima Junior, Dilermando Pereira; Marco Júnior, Paulo De; Almeida Neto, Mário(Sem resumo em outra língua)