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A distinct pattern of obligate mutualism exists between fig tree hosts and their pollinating fig wasps. Normally one section or subsection of fig tree hosts is associated with one fig wasp genus. In general, each species is pollinated by a specific fig wasp species. This led to the hypothesis that the fig wasp and fig tree lineages diverged simultaneously. African fig wasps pollinating hosts of the Galoglychia section frequently break the normal one fig wasp species-to-one host species ratio. The phylogeny for these species was reconstructed using three DNA segments and compared to the morphological classification of their Ficus hosts. Pollinator genera were monophyletic for all analyses, however, the relative positioning of genera was inconsistent. Analyses suggest frequent host jumps between fig trees and fig wasps. Fig wasps of the genus Alfonsiella that pollinate Ficus craterostoma, Ficus stuhlmannii and Ficus petersii are morphologically similar in South Africa. Based on host association, genetic differentiation for this group was investigated. Molecular data indicated that the pollinator of F. craterostoma is a good species, while the F. stuhlmannii and F. petersii pollinators were genetically indistinguishable. Based on molecular data and morphological re-evaluation, a new Alfonsiella species is described, Alfonsiella pipithiensis sp. n. A key to all described species of Alfonsiella is provided. In order to resolve the population genetic differentiation of pollinating fig wasp species in South Africa, Platyscapa awekei was used as a model species. A few studies indicate that pollinating fig wasps can disperse between 30 and 55 kilometers. However, a recent study on two P. awekei populations in South Africa reported an FST value of 0.011, indicating that pollinators disperse approximately ten times further. This study aims to confirm these results with more detailed sampling of populations. In addition, possible temporal differentiation was tested for the South African population. Six microsatellite loci were used to detect spatial and temporal genetic differentiation in seven populations (collected from 2004 to 2006) over a 340 kilometer range. Genetic differentiation between sampled populations was low (FST = 0.0055), however, the data suggest stronger temporal genetic isolation than spatial genetic isolation. / Dissertation (MSc (Genetics))--University of Pretoria, 2011. / Genetics / unrestricted

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The Large Copper butterfly, Lycaena dispar, is extinct in Britain and rapidly declining in the rest of Europe, due predominantly to loss of its wetland habitats. In the Netherlands the sub-species L. d. batavus is at the edge of its range in Northern Europe and, as with most marginal butterflies, has more specialised food plant and habitat requirements than the core populations of L. d. ruti/us. The aim of this study was to investigate some of the reasons for its continuing rarity, particularly looking at the reasons for its specialisation on Rumex hydrolapathum in a fen land habitat, whilst L. d. ruti/us is more generalist and utilises a range of Rumex species. Laboratory experiments reveal that L. d. batavus has retained its ability to feed on other Rumex species, without detriment to their overall survival and can utilise these alternative host plants more efficiently than their natural host plant. This indicates that plant chemistry is not responsible for their lack of utilisation in the wild. Field experiments have also shown these potential hosts can support larvae, throughout each of their larval stages, to maturity within a natural habitat, with no significant differences in survival rates compared with R. hydrolapathum. Investigations into adult female oviposition preferences were undertaken. Females showed a willingness to oviposit on alternative Rumex and expressed no preference for any particular plant species. There are plans to re-establish L. dispar into Britain in the near future, dependent upon the location of a suitable donor population. Allozyme electrophoresis work on L. dispar and several of its captive colonies, has revealed that the wild Dutch, and one captive population, have sufficiently high levels of genetic diversity that may enable a reestablishment programme to go ahead with a captive colony, if necessary.

There is a growing interest in the nature of parasite-host interactions, the role these relationships play in ecological communities, and how human activities alter these associations. Furthermore, because inference about these interactions is usually gained by methods of statistical hypothesis testing, additional importance should be placed on the analysis and interpretation of parasite-host interactions. In this dissertation I address these ideas in three separate but interrelated studies with the three following questions: 1) How do two parasites with complex life-cycles alter the behavior of a novel amphipod host, and how do host and non-host predators respond to infected amphipod prey? In contrast to other studies, I found that two parasites of an endemic amphipod at Montezuma Well had little affect on their amphipod host, and that these associations had little affect on predation rates by both host and non-host predators. Results from this study underscore the importance of further investigating novel parasite-host interactions and placing them in their phylogenetic and evolutionary context. 2) Does human recreation affect spatial patterns of infection in an otherwise natural ecosystem? This study demonstrates that human visitors to Montezuma Castle National Monument alter patterns of waterfowl space use that in turn affect spatial patterns of disease in invertebrate hosts. This is the first study to document such an effect, and I discuss the important implications of this finding. 3) How is hypothesis testing applied in studies of wildlife disease, what conclusions can we make about the relative usefulness of these methodologies, and how can the analysis and interpretation of wildlife disease studies be improved? In this final study I conducted a literature review, computed statistical power for methodologies used in the literature, and re-analyzed published data to provide an example of the advantages of my suggested approach. I conclude that many studies report findings using methods that could be more informative and some studies may lack statistical power, demonstrating the importance of using prospective power analysis in the design of future studies. Furthermore, using statistical techniques that estimate the observed effect size can aid in increasing information transfer in studies of wildlife disease.

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