The fig–fig wasp interaction is a classic example of obligate mutualism and coevolution. It is also a nursery pollination mutualism and supports a diversity of exploiter/parasite/non-pollinating fig wasp species. Mutualists and exploiters comprise the fig wasp community. All the wasp community members are obligately dependent on the fig syconium (a globular closed structure comprising of hundreds to thousands of uniovulate florets) for completing their life cycle. The fig florets can be sessile (without a stalk) or pedicellate (stalked) and can support a community comprising 3–30 wasp species. Fig wasps can access the floral resources for oviposition directly by entering into the syconium (internal oviposition) or by penetration of the syconium surface (external oviposition). Most studies on the fig–fig wasp interaction have investigated the stability of the interaction, pollination biology, pollen dispersal, co-evolution or the effect of exploiters on this mutualism. However, studies dealing with community ecology and species coexistence mechanisms in these communities are rare. Factors contributing to coexistence of mutualists and exploiters in a fig wasp community were studied using a reasonably speciose fig wasp community associated with Ficus racemosa in south India. The wasp community of Ficus racemosa comprises a single species of pollinator and six species of exploiters; together they represent three genera of fig wasp species. The community members show differences in their feeding habit; they could be 1) gallers (feed on floral tissue after pollination and/or after inducing abnormal tissue development of the floret that is also called the gall), 2) inquilines (feed on gall tissue but cannot induce galling; survive by feeding on gall tissue and starving the host larva to death), or 3) parasitoids (lay eggs in or on developing offspring of a galler or inquiline species; develop by feeding on host tissue). Resource partitioning across temporal and spatial axes on this fig wasp community have been quantified. Ovipositor traits of each community member were also investigated since variation in ovipositor traits might facilitate resource partitioning. Finally, the role of life-history traits in species coexistence in this community was also explored. Temporal resource partitioning among members of the fig wasp community was studied (1) across the resource phenology, i.e. over the development phases of the fig syconium, and (2) on a diel scale. The seven members of the wasp community were found to partition their oviposition periods across fig syconium development phenology; some species used very young syconia (soft and smaller in size) for oviposition whereas others used mature (hard and bigger in size) syconia for oviposition. The first species to colonise the syconia were gallers and these were followed by parasitoids in a definite oviposition sequence. Pollinators arrived concurrently with an exploiter galler species and had the shortest oviposition window in terms of days. Although fig wasps are known to be largely diurnal, night oviposition in several fig wasp species was documented for the first time. Wasp species showed a peak in their activity period across the diel cycle and phenology. This is probably the first study to simultaneously investigate temporal partitioning across the syconium phenology as well as the diel scale in a fig wasp community. Partitioning of syconium space was investigated by quantifying the quality (type of floret—sessile or pedicellate) of floral resources. The number of individuals of each species developing in a syconium was quantified along with host accessibility during oviposition by each wasp species. The association between community members developing within a syconium was also tested. The differential occupancy of florets by each species based on their distance from the base of the syconium was evaluated. For the first time the relative distribution of males and females of the entire fig wasp community was quantified. The wasp community members used similar types of florets for oviposition. Seeds were found mostly in sessile florets and wasps were present in large numbers in pedicellate florets. Except for one wasp species, all others occurred uniformly within the syconium with respect to the distance from the base of the syconium. Species distribution models revealed higher prediction ability for the location of mutualists (seed and pollinator) within the syconium compared to exploiters. Within a syconium, all species pairs exhibited positive associations indicating either an absence of or low competitive exclusion. Some florets were modified by their gall occupants such that they were longer in length indicating the possibility of creation of an enemy-free zone by the gall occupant. Yet, most florets were accessible to ovipositing wasps based on ovipositor lengths and flexibility. The probability of finding a male decreased with increase in floret length when all wasp species were grouped together; however, this trend did not hold true when males and females of species were tested individually. Based on these results, the fig wasps of F. racemosa could be grouped into—(1) Early-arriving galler species which used immature florets, inducing large galls that protruded into the cavity, and with fewer individuals per syconium, (2) Galler species arriving concurrently with the pollinator, inducing galls that were morphologically indistinguishable from those of the pollinator, and with many individuals developing per fig syconium, and (3) Parasitoids and/or inquilines of the galler species, with variable abundance per syconium. Thus, these results show that the wasp species do not clearly partition floral resources between syconia and within syconium but they can modify their oviposition sites and also differ in the proportion of florets within a syconium used for oviposition. Oviposition sites of the fig wasps can be reached only by using their ovipositor. The resources for oviposition are hidden and hence might require tools for resource location and utilisation. The frequency and diversity of sensilla on the ovipositor, as well as ovipositor structure (morphology and sclerotisation of the tip) was documented for the entire wasp community. The internally-ovipositing pollinator had the simplest ovipositor, negligible sclerotisation and only one type of sensillum on its ovipositor; the externally ovipositing exploiter species had teeth on their ovipositors, sclerotisation and various types of ovipositor sensilla. Ovipositor sclerotisation and lateness of arrival for oviposition in syconium development were positively correlated. Ovipositor teeth height increased from gallers to parasitoids. Presence of different types of sensilla was noted which included mechano- and chemosensilla, as well as combined mechano-chemosensilla. Chemosensilla were most concentrated at ovipositor tips while mechanoreceptors were more widely distributed. Ovipositor traits of one putative parasitoid/inquiline species differed from those of its syntopic galler congeners and clustered with those of parasitoids within a different wasp subfamily. Thus ovipositor tools show lability based on adaptive necessity, and are not constrained by phylogeny. Life-history traits such as fecundity, pre-adult and adult lifespan were studied for each wasp member of the community. Trade-offs in life-history traits were also investigated. Interspecific variation in life-history traits was observed. Gallers were pro-ovigenic (all eggs were mature upon adult emergence) whereas parasitoids were synovigenic (eggs matured progressively during adult lifespan). Initial egg load was correlated with body size for some species, and there was a trade-off between egg number and egg size across all species. Although all species completed their development and left the syconium concurrently, they differed in their adult and preadult lifespans. Providing sucrose solutions increased parasitoid lifespan but had no effect on the longevity of some galler species. While feeding regimes and body size affected longevity in most species, an interaction effect between these variables was detected for only one species. Life-history traits of wasp species exhibited a continuum in relation to their arrival sequence at syconia for oviposition during syconium development, and therefore reflected their ecology. The largest number of eggs, smallest egg sizes, and shortest longevities were characteristic of the earliest-arriving galling wasps at the smallest, immature syconia; the converse characterised the later-arriving parasitoids at the larger, already exploited syconia. Thus life-history is an important correlate of community resource partitioning and can be used to understand community structure. The comparative approach revealed constraints and flexibility in trait evolution. This is probably the first comprehensive study of life-history traits in a fig wasp community.

This dissertation as a whole aims to provide the means to better understand hot-Jupiter planets through observing, performing thermochemical calculations, and modeling their atmospheres. We used Spitzer multi-wavelength secondary-eclipse observations to characterize planetary atmospheres. We chose targets with high signal-to-noise ratios, as their deep eclipses allow us to detect signatures of spectral features and assess planetary atmospheric structure and composition with greater certainty. Chapter 1 gives a short introduction. Chapter 2 presents the Spitzer secondary-eclipse analysis and atmospheric characterization of WASP-14b. The decrease in flux when a planet passes behind its host star reveals the planet dayside thermal emission, which, in turn, tells us about the atmospheric temperature and pressure profiles and molecular abundances. WASP-14b is a highly irradiated, transiting hot Jupiter. By applying a Bayesian approach in the atmospheric analysis, we found an absence of thermal inversion contrary to theoretical predictions. Chapter 3 describes the infrared observations of WASP-43b's Spitzer secondary eclipses, data analysis, and atmospheric characterization. WASP-43b is one of the closest-orbiting hot Jupiters, orbiting one of the coolest stars with a hot Jupiter. This configuration provided one of the strongest signal-to-noise ratios. The atmospheric analysis ruled out a strong thermal inversion in the dayside atmosphere of WASP-43b and put a nominal upper limit on the day-night energy redistribution. Chapter 4 presents an open-source Thermochemical Equilibrium Abundances (TEA) code and its application to several hot-Jupiter temperature and pressure models. TEA calculates the abundances of gaseous molecular species using the Gibbs free-energy minimization method within an iterative Lagrangian optimization scheme. The thermochemical equilibrium abundances obtained with TEA can be used to initialize atmospheric models of any planetary atmosphere. The code is written in Python, in a modular fashion, and it is available to the community via http://github.com/dzesmin/TEA. Chapter 5 presents my contributions to an open-source Bayesian Atmospheric Radiative Transfer (BART) code, and its application to WASP-43b. BART characterizes planetary atmospheres based on the observed spectroscopic information. It initializes a planetary atmospheric model, performs radiative-transfer calculations to produce models of planetary spectra, and using a statistical module compares models with observations. We describe the implementation of the initialization routines, the atmospheric profile generator, the eclipse module, the best-fit routines, and the contribution function module. We also present a comprehensive atmospheric analysis of all WASP-43b secondary-eclipse data obtained from the space- and ground-based observations using BART.

Parasitoid wasps are hyperdiverse, with current estimates suggesting that they may account for up to 20% of all insect species. Though their ecological significance and their importance in integrated pest management cannot be denied, these taxa remain understudied and, due to their small size, are often overlooked. However, recent advances in molecular techniques are helping to reverse this trend by providing tools which scientists can use to better understand species limits and host interactions. Parasitoid wasps are often morphologically cryptic and their accurate delimitation requires the analysis of DNA sequence data from fast-evolving genes in addition to morphological characters. The research presented here demonstrates the utility of a new molecular locus in species delimitation. Also, a morphological key to the species of a genus occurring in America, north of Mexico is presented. The interactions between parasitoid wasps and their hosts are highly complex. On the wasp side, it involves the production venom, which likely contains bountiful natural resources. In this study, the venom proteins of wasps of the genus Megarhyssa (Hymenoptera: Ichneumonidae) are identified. Putative functions are assigned to these proteins and possible applications are discussed. One of the proteins identified is the enzyme, laccase, which is associated with the degradation and digestion of wood. The sequence of the gene coding for this laccase was analyzed and used to create recombinant proteins in a baculovirus-insect cell expression system. Future work investigating this enzyme is necessary to determine its activity against the plant cell wall. The research presented here provides insight into the identification and venom composition of ichneumonid wasps. The results contribute to our knowledge of this understudied taxon and indicate that there is much to be gained from further research in this field which will become increasingly practicable as molecular techniques advance and become more affordable.

Thesis (MSc)--Stellenbosch University, 2015. / ENGLISH ABSTRACT: The invasive social wasp, Vespula germanica (Fabricius, 1793) (Hymenoptera: Vespidae), stands out as a remarkably successful insect invader worldwide. It flourishes in newly invaded ecosystems, where it has become a major problem in urban settings due to its close association with humans. The wasp is characterised by its devastating economic, social and environmental impact. Since its initial discovery in 1974 in Cape Town, all aspects of the wasp’s invasion throughout South Africa have been poorly documented. The wasp’s occurrence in the Cape Floristic Region (CFR) in the Western Cape Province (WCP), an area highly valued for its unique biodiversity, is of great concern due to the possible detrimental environmental effect of the wasp on this vulnerable biome. In this study, the present distribution of V. germanica was determined. Results indicate V. germanica’s distributional range is presently restricted within a small region of the WCP and it is thought that the Cape Fold Mountain range has acted as a natural barrier limiting the range expansion of the wasp. Field trials were conducted to determine V. germanica’s bait preference (protein versus carbohydrate) under local conditions and identify the best method in trapping the wasp. Fresh meats (lean smoked ham and minced beef) were overall the most preferred bait in both 2013 and 2014. Future studies should consider investigating the use of volatile meat extracts instead of fresh meat baits, as it could be as attractive but more practical for use in the field. Heptyl butyrate showed the most promising result of the artificial lures and warrants further investigation. Other lures (heptyl butyrate + acetic acid, isobutanol, isobutanol + acetic acid) were highly unattractive and possible reasons explaining this phenomenon, are discussed. A questionnaire survey was used during face-to-face interviews to explore the perspectives of forty farmers with regard to V. germanica occurring on their property. The current impact of the wasp in the agricultural context in the WCP was also determined. The majority of the respondents presented a negative view of the wasp and eradication seems to be a high priority for them. V. germanica is presently more of a social than an economic pest. Although indications are that with an increase in its density and distributional range, agro-economic problems and an increasing negative impact on local biodiversity can be expected. Management efforts should focus on its peripheral distribution, in order to curb further natural spread. The wasp’s distribution should also continue to be monitored, to enable early detection and rapid response, in the event that it succeeds in establishing itself in a new location. Further investigations into the suitability of a monitoring tool, including bait preferences, as well as continuing studies on the wasp’s overall impact, are recommended. / AFRIKAANSE OPSOMMING: Die sosiale perdeby, Vespula germanica (Fabricius, 1793) (Hymenoptera: Vespidae), is ‘n merkwaardig suksesvolle indringerinsek wêreldwyd. Dit floreer in ekosisteme waar dit aanland en het in stedelike gebiede in ‘n groot probleem ontaard weens die insek se noue verbintenis met die mens. Die perdeby word geassosieer met verwoestende ekonomiese-, maatskaplike- en omgewingsimpakte. Dit is in 1974 in Kaapstad ontdek, maar sedertdien is die insek se verspreiding in Suid-Afrika swak gedokumenteer. Die perdeby se teenwoordigheid in die Kaapse-blommestreek (geleë in die Wes-Kaap provinsie), 'n hoogs bedreigde area bekend vir sy unieke biodiversiteit, is kommerwekkend weens die moontlike nadelige omgewingsimpakte van die perdeby op hierdie kwesbare bioom. In hierdie studie word V. germanica se verspreiding ondersoek. Die resultate dui daarop dat dit tans beperk is tot ‘n klein gebied in die Wes-Kaap. Daar word vermoed dat die Kaapse-plooiberge as 'n natuurlike versperring optree om die verdere verspreiding van die spesie te voorkom. Veldproewe is gedoen om die lokmiddel-voorkeure (proteïene vs. koolhidrate) van V. germanica te bepaal om sodoende die beste metode om die perdebye te lok en te vang te identifiseer. Vars vleis (ham en gemaalde bees) het voorkeur geniet in beide 2013 en 2014. Toekomstige studies kan vlugtige vleisaftreksels as lokmiddel oorweeg, aangesien dit ewe aantreklik as vars vleis kan wees, maar meer prakties is. Daar is bevind dat heptiel-butyraat die mees belowende kunsmatige lokmiddel is, en verdere ondersoeke hiermee word dus aangemoedig. Daarteenoor was V. germanica geensins tot enige van die ander kunsmatige lokmiddels (heptiel-butyraat + asynsuur, isobutanol, isobutanol + asynsuur) aangetrokke nie. Moontlike redes hiervoor word volledig bespreek. Die sosio-ekonomiese impakte van V. germanica is ondersoek deur onderhoude te voer met veertig Wes-Kaapse boere op wie se eiendom die perdeby voorkom. Waardevolle insig vanuit ‘n landbou-perspektief kon ingewin word. Die meerderheid van respondente het ‘n negatiewe siening van V. germanica en was van mening dat dit in hul belang sal wees om die perdebye uit te roei. V. germanica is tans meer van 'n sosiale as 'n ekonomiese pes. Indien hul digtheid of verspreiding egter sou toeneem, kan dit agri-ekonomiese probleme sowel as ‘n toenemende negatiewe impak op inheemse biodiversiteit tot gevolg hê. Pogings om die perdebypopulasie te beheer moet fokus op die perifere van die verspreiding, ten einde hul verdere natuurlike verspreiding te bekamp. Monitering van die verspreiding word aanbeveel om te verseker dat nuut-gevestigde populasies dadelik opgespoor en verwyder kan word. Verdere navorsing oor die lokmiddel-voorkeure as ‘n moniteringsmeganisme en die algehele negatiewe impakte van die perdebye kan bepaal word.

The radial velocity anomaly which affects spectroscopic observations of stars undergoing transit by a companion body is known as the Rossiter-McLaughlin effect. This effect can be used to measure the obliquities of the orbits of transiting planets. In this thesis I present a tomographic method for analysing the effect, which manifests itself in stellar spectral line-profiles. I implement this method on seven systems known to host transiting planets, and some systems with early-type host stars, for which the transit events have not yet been shown to be the result of planetary companions. Despite being well-suited to examining systems with early-type, rapidly-rotating host stars which have a more pronounced Rossiter-McLaughlin effect, I find the tomographic method is able to produce reasonable results for the system parameters of planets orbiting relatively slowly-rotating stars. I show that the method provides a significant increase in the accuracy of determinations of the stellar rotation rate and is able to better constrain values for the transit impact parameter. Though I do not confirm the existence of any new planets around early-type stars, I do use the tomographic method to reject one candidate as a stellar eclipsing binary system, and also reveal that one of the candidate host stars is a non-radial pulsator. I show that the method is able to examine systems involving stars with a range of spectral types and rotation rates.

We present results from the first observations of the Hubble Space Telescope (HST) Panchromatic Comparative Exoplanet Treasury program for WASP-101b, a highly inflated hot Jupiter and one of the community targets proposed for the James Webb Space Telescope (JWST) Early Release Science (ERS) program. From a single HST Wide Field Camera 3 observation, we find that the near-infrared transmission spectrum of WASP-101b contains no significant H2O absorption features and we rule out a clear atmosphere at 13 sigma. Therefore, WASP-101b is not an optimum target for a JWST ERS program aimed at observing strong molecular transmission features. We compare WASP-101b to the well-studied and nearly identical hot Jupiter WASP-31b. These twin planets show similar temperature-pressure profiles and atmospheric features in the near-infrared. We suggest exoplanets in the same parameter space as WASP-101b and WASP-31b will also exhibit cloudy transmission spectral features. For future HST exoplanet studies, our analysis also suggests that a lower count limit needs to be exceeded per pixel on the detector in order to avoid unwanted instrumental systematics.

Previous measurements of heat redistribution efficiency (the ability to transport energy from a planet's highly irradiated dayside to its eternally dark nightside) show considerable variation between exoplanets. Theoretical models predict a positive correlation between heat redistribution efficiency and temperature for tidally locked planets; however, recent Hubble Space Telescope (HST) WASP-43b spectroscopic phase curve results are inconsistent with current predictions. Using the Spitzer Space Telescope, we obtained a total of three phase curve observations of WASP-43b (P = 0.813 days) at 3.6 and 4.5. mu m. The first 3.6. mu m visit exhibits spurious nightside emission that requires invoking unphysical conditions in our cloud-free atmospheric retrievals. The two other visits exhibit strong day-night contrasts that are consistent with the HST data. To reconcile the departure from theoretical predictions, WASP-43b would need to have a high-altitude, nightside cloud/haze layer blocking its thermal emission. Clouds/hazes could be produced within the planet's cool, nearly retrograde mid-latitude flows before dispersing across its nightside at high altitudes. Since mid-latitude flows only materialize in fast-rotating (less than or similar to 1 day) planets, this may explain an observed trend connecting measured day-night contrast with planet rotation rate that matches all current Spitzer phase curve results. Combining independent planetary emission measurements from multiple phases, we obtain a precise dayside hemisphere H2O abundance (2.5 x 10(-5)-1.1 x 10(-4) at 1 sigma confidence) and, assuming chemical equilibrium and a scaled solar abundance pattern, we derive a corresponding metallicity estimate that is consistent with being solar (0.4-1.7). Using the retrieved global CO+CO2 abundance under the same assumptions, we estimate a comparable metallicity of 0.3-1.7x solar. This is the first time that precise abundance and metallicity constraints have been determined from multiple molecular tracers for a transiting exoplanet.

Parasitoid wasps are an important group of organisms in need of systematic revision. This dissertation examines the cosmopolitan parasitoid wasp genus Cremnops. It is a compilation of three projects and significantly advances the taxonomic foundation of the genus. The New World species of the genus Cremnops are revised. Thirty-three species of Cremnops are treated; five are described as new, i.e., C. bertae sp. nov., C. cluttsis sp. nov., C. nymphius sp. nov., C. wileycoyotius sp. nov. and C. witkopegasus sp. nov. Six species are synonymized, i.e., Cremnops caribensis Berta 1998, is synonymized under C. guanicanus Wolcott 1924; C. nigrosternum (Morrison 1917) is synonymized under C. haematodes (Brullé 1846); C. punctatus Berta 1998, is synonymized under C. marshi Berta 1998; C. sharkei Berta 1998, is synonymized under C. montrealensis (Morrison 1917); C. turrialbae Berta de Fernandez 1998, is synonymized under C. ferrugineus (Cameron 1887); and C. misionensis Berta 1987, is synonymized under C. slossonae (Morrison 1917). Cremnops florissanticola is transferred to its original combination Bracon florissanticola Cockerell 1919, st. rev. The species concept Cremnops desertor and its complicated taxonomic history are discussed. A phylogenetic distance tree, based on COI data, is used to help delimit species. The recognition of C. alterans Enderlein and C. malayensis Bhat is proposed. I propose new combinations for five African species that are currently placed in Cremnops, i.e., C. atripennis Szépligeti 1914 and C. elegantissima Szépligeti 1908 are moved to Disophrys; C. borealis (Szépligeti 1914) and C. rubrigaster Masi 1944 are moved to Biroia; and C. pulchripennis Szépligeti 1905 is moved to and renamed Biroia neopulchipennis. These changes result in Disophrys atripennis (Szépligeti 1915) becoming a junior homonym, which is changed to Disophrys szatripennis. Additionally, two species are proposed as nomen dubia: C. rufitarsis Szépligeti 1913 and C. schubotzi Szépligeti 1915. Included are a molecular phylogeny, a dichotomous key, links to distribution maps, an electronic interactive key, images of holotypes, and suggestions for further research.

Hymenopteran insects, which include all ants, bees and wasps, reproduce through a poorly understood form of reproduction known as haplodiploidy. A promising experimental system for understanding this developmental process is the jewel wasp, Nasonia vitripennis. A critical aspect of using Nasonia as a model is establishing an effective means for editing specific genes of interest so that their functions can be studied through genetic means. For my thesis research, I performed a pilot study of the gene editing method known as CRISPR in Nasonia. I targeted the single heterochromatin protein 1 (HP1) gene present in the Nasonia genome in order to assess the feasibility of this gene editing approach. Targeting HP1 would provide a clear phenotype when this gene is mutated due to its essential functions in early development known from studies in other eukaryotes. Additionally, creating a mutant of this gene will provide a means for studying the role of HP1 in wasp spermatogenesis, an aim that interlinks with the broader chromatin-based goals of our laboratory. Through this study I worked out a streamlined procedure for injecting CRISPR molecules into young wasp embryos, conducting genetic crosses with injected wasps, and screening through their progeny for potential mutants. I observed no mutant phenotypes in injected wasps, but instead, I isolated four potential mutants in F1 progeny. My work has helped to create a solid framework for improving this procedure in Nasonia, and they allow for a better overall understanding of the limitations of producing mutants through CRISPR gene editing in non-model organisms such as Nasonia.

An accurate wind resource assessment (WRA) is crucial in energy prediction as the power is directly proportional to the wind speed cubed. This thesis analyses the discrepancy between operational assessment and WRA for a wind farm located on a moderately complex terrain in Ireland. As part of this research, a WRA was undertaken and the results were input to two wind farm design tools, WindPro and WindSim, to estimate the annual energy production. Two and a half years of data was available from a 50m met mast. The data was analysed and filtered to ascertain and limit the usage of erroneous data. The dataset was then correlated with an available online dataset utilising the Measure Correlate Predict (MCP) module in WindPro in order to estimate the long term wind resource at the site. The wind resource was then used to determine the annual energy produced at the site using both WindPro and WindSim. A loss of 8% was applied to the energy calculations for comparison with the original WRA. The results demonstrate the energy production from the original energy prediction, undertaken by a leading wind consultancy prior to construction, was overestimated by an average 10.19% over the three years of operation. The averaged wind speed at hub height in the original WRA was 8.2m/s. However, the prediction undertaken using WindPro in this study estimated an average hub height wind speed of 8.0m/s while WindSim estimated an average of 7.36m/s. These differing results had a significant contribution to the difference in Annual Energy Production (AEP). The calculated annual energy results were an overestimation of energy production by an average of 8.10% utilising WindPro, while WindSim underestimated the energy output by just 0.11%.