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Ralph Waldo Emerson’s bee poem, “The Humble-Bee,” expresses the nineteenth-century transcendentalist philosophy of finding wholeness and oneness in nature while Sylvia Plath’s twentieth-century bee poems function as a response to Plath’s feelings of alienation and repression, indicating that transcendental peace is lost in the postmodern era. Emerson’s poem indicates the spiritual fulfilment found through observing bees and highlights the harmony between humans and nature, but women of the nineteenth century find difficulty achieving this same level of freedom; Emily Dickinson reclaims the language of transcendentalism in her bee poetry to explore a world otherwise denied to her. The effects of the industrial revolution then sparked a mass disconnect between humans and nature, a disconnect reflected in the bee poetry of Sylvia Plath; she rejects the inherited tradition of transcendentalist poetry by using her bee poems to demonstrate discomfort within nature and society.

The phylogeny of the Ammobatini was studied, with regard to the principles of cladistics using parsimony, and the classification is revised. It is concluded that the tribe forms a monophyletic group that comprises six distinct monophyletic genera: Pasite Jurine, Sphecodopsis Bischoff, Ammobates Latreille, Melanempis Saussure, Spinopasites Warncke and Oreopasites Cockerell, of which Pasites, Sphecodopsis, Ammobates and Melanempis occur in the Afrotropical Region. The Afrotropical species of these four genera are revised. Pseudopasites Bischoff and Pseudodichroa Bischoff are synonymized with Sphecodopsis. Pasites includes 17 Afrotropical species, Sphecodopsis 10 species, and Ammobates and Melanempis are each known from a single Afrotropical species. Ten new species are described: Passites nilssoni, P. paulyi, P. humecta, P. gnoma, P. namibiensis, P. somalica, Sphecodopsis vespericena, S. longipygidium, S. namaquensis and Ammobates auster. Thirty-three names are synonymized: they are P. nigerrima (Friese), P. argentata (Baker) (= P. barkeri (Cockerell)); P. chubbi Cockerell, P. nigritula Bischoff, P. peratra Cockerell (= P. atra Friese); P. nigripes (Friese), P. fortis Cockerell, P. subfortis Cockerell, P. stordyi Cockerell, P. voiensis Cockerell, P. altior Cockerell (= P. carnifex (Gerstaecker)); P. natalensis (Cockerell), P. aiboguttatus (Friese), P. ogilviei (Cockerell) (= P. jenseni (Friese)); P. alivalensis (Cockerell), P. rufitarsis (Cockerell) (= P. histrio (Gerstaecker)); P. marshaUi (Cockerell) (= P. jonesi (Cockerell)); P. abessinica (Friese), P. fulviventris (Bischoff), P. rhodesialla (Bischoff), P. apicalis (Bischoff), P. turneri (Cockerell), P.politula (Cockerell), P. indecisa (Cockerell), P. nudicauda (Cockerell), P. bechuanica (Cockerell), P. breviceps (Cockerell) (= P. appletoni (Cockerell); S. rufula (Cockerell) (= S. minutissima (Cockerell)); S. pygmaea (Friese), S. rufescens Bischoff, S. algoensis Bischoff, S. perpunctata Cockerell (= S. aculeata (Friese)); S. leonis (Cockerell) (= S. semirufa (Cockerell)). Keys to the genera and species are provided. / Thesis (Ph.D.)-University of Natal, Pietermaritzburg, 1994.

In contrast to the wealth of knowledge concerning sucrose-rewarded learning mechanisms, the question of what bees learn when they collect pollen from flowers has been little addressed. Pollen-rewarded learning is of interest not only in furthering our understanding of associative conditioning pathways in the insect brain, it may also shed light on the role that cognitive processes may have played in shaping the early evolutionary relationship between plants and their pollinators, given that pollen is thought to have been the ancestral reward for flower visitors. Thus the central aim of this thesis was to demonstrate the conditions under which pollen may reinforce learning of floral features in two model species, the honeybee (Apis mellifera) and bumblebee (Bombus terrestris). Having developed a number of paradigms for the study of pollen-rewarded learning, here I ask what bees might learn during pollen collection, both in terms of the sensory characteristics of pollen itself and additional cues paired with this reward. Freely flying bees were shown to be sensitive to differences in the type of pollen offered for collection and were able to associate the presence of a coloured stimulus with both the availability and quality of the pollen reward. The sensory pathways involved in the evaluation of pollen were also investigated. When bees were restrained, in order to more tightly control exposure to the reward, pollen was not found to support learning in an olfactory conditioning task. Furthermore, when delivered in solution with sucrose, pollen was found to inhibit learning relative to bees rewarded with sucrose alone. It seems that pollen contains compounds which are perceived as distasteful by bees and that through the contamination of nectar, pollen may influence bees foraging decisions via differential learning and recognition of floral cues.

In the analysis of movement patterns of animals, stochastic processes play an important role, providing us with a variety of tools to examine, model and simulate their behaviour. In this thesis we focus on the foraging of specific animals - bumblebees - and analyse experimental data to understand the influence of changes in the bumblebees’ environment on their search flights. Starting with a discussion of main classes of stochastic models useful for the description of foraging animals, we then look at a multitude of environmental factors influencing the dynamics of animals in their search for food. With this background we examine flight data of foraging bumblebees obtained from a laboratory experiment by stochastic analyses. The main point of interest of this analysis is the description, modelling and understanding of the data with respect to the influence of predatory threats on the bumblebee’s foraging search flights. After this detail-oriented view on interactions of bumblebees with food sources and predators in the experimental data, we develop a generalized reorientation model. By extracting the necessary information from the data, we arrive at a generalized correlated random walk foraging model for bumblebee flights, which we discuss and compare to the experimental data via simulations. We finish with a discussion of anomalous fluctuation relations and some results on spectral densities of autocorrelation functions. While this part is not directly related to the analysis of foraging, it concerns a closely related class of stochastic processes described by Langevin equations with non- trivial autocorrelation functions analyse experimental data to understand the influence of changes in the bumblebees’ environment on their search flights. Starting with a discussion of main classes of stochastic models useful for the description of foraging animals, we then look at a multitude of environmental factors influencing the dynamics of animals in their search for food. With this background we examine flight data of foraging bumblebees obtained from a laboratory experiment by stochastic analyses. The main point of interest of this analysis is the description, modelling and understanding of the data with respect to the influence of predatory threats on the bumblebee’s foraging search flights. After this detail-oriented view on interactions of bumblebees with food sources and predators in the experimental data, we develop a generalized reorientation model. By extracting the necessary information from the data, we arrive at a generalized correlated random walk foraging model for bumblebee flights, which we discuss and compare to the experimental data via simulations. We finish with a discussion of anomalous fluctuation relations and some results on spectral densities of autocorrelation functions. While this part is not directly related to the analysis of foraging, it concerns a closely related class of stochastic processes described by Langevin equations with nontrivial autocorrelation functions.

The perceived colour of an object depends on its spectral reflection and spectral composition of the illuminant. Upon illumination change, the light reflected from the object also varies. This results in a different colour sensation if no colour constancy mechanism is available to form consistent representations of colours across various illuminants. We explore various colour constancy mechanisms in an agent-based model of foraging bees selecting flower colour based on reward. The simulations are based on empirically determined spatial distributions of various flower species in different plant communities, their rewards and spectral reflectance properties. Simulated foraging bees memorise the colours of flowers experienced as being most rewarding, and their task is to discriminate against other flower colours with lower rewards, even in the face of changing illumination conditions. The experimental setup of the simulation of bees foraging under different photic environments reveals the performance of various colour constancy mechanisms as well as the selective pressures on flower colour as a result of changing light. We compared the performance of von Kries photoreceptor adaptation and various computational colour constancy models based on the retinex theory with (hypothetical) bees with perfect colour constancy, and with modelled bees with colour blindness. While each individual model generated moderate improvements over a colour-blind bee, the most powerful recovery of reflectance in the face of changing illumination was generated by computational mechanisms that increase perceptual distances between co-occurring colours in the scene. We verified the results of our model using various comparisons between modelled bees’ performance and that predicted by our models, as well as exploring the implications for flower colour distribution in a variety of representative habitats under realistic illumination conditions.

Made available in DSpace on 2014-06-11T19:30:56Z (GMT). No. of bitstreams: 0 Previous issue date: 2006-06-29Bitstream added on 2014-06-13T19:19:43Z : No. of bitstreams: 1 britto_fb_dr_rcla.pdf: 9470706 bytes, checksum: a24839a07881484e26f17ad6fe4f590b (MD5) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / As glândulas hipofaríngeas são estruturas presentes apenas na ordem Hymenoptera e apresentam-se como células epidérmicas modificadas em alguns grupos, enquanto em outros, apresentam morfologia mais elaborada, caracterizando-se como órgãos com anatomia bem definida. Muito bem estudadas em abelhas, as glândulas hipofaríngeas são glândulas exócrinas que fazem parte do sistema salivar e são responsáveis, em Apis, pela produção de substâncias que constituem a geléia real. Este produto é oferecido a todas as larvas como alimento, de maneira desigual, sendo este um fator responsável pela diferenciação das castas nas abelhas. Os objetivos do presente estudo foram analisar as glândulas hipofaríngeas de vespas, que carecem de estudos, procurando reconhecer seu papel na regulação social da colônia, bem como identificar a presença de aspectos glandulares que indicassem a ocorrência de morte celular. Utilizando Polistes versicolor, uma das espécies do gênero considerado como chave para o entendimento da evolução do comportamento social em insetos, foram realizadas análises histoquímicas, enzimológicas e ultra-estruturais das glândulas hipofaríngeas. Juntamente com estas análises foi realizado o estudo comportamental dos indivíduos analisados. Estes estudos auxiliaram no entendimento do ciclo de desenvolvimento das glândulas hipofaríngeas, bem como determinaram a constituição química da secreção glandular, representando uma contribuição inédita à identificação da morfologia e função dessas estruturas e de seu possível papel no contexto social das colônias de P. versicolor. Os resultados encontrados levam a crer que as glândulas destas vespas não estão envolvidas na produção de alimento para as larvas, como ocorre em abelhas. As características morfológicas... / The hypopharyngeal glands are structures present only in the order Hymenoptera. They are constituted by modified epidermal cells in some groups, while in others, they present a more elaborated morphology and are characterized as distinct organs with a defined anatomy. These exocrine glands are part of the salivary system and have been well studied in bees. In Apis, they are the main responsible for the production of components of royal jelly. Brood is not fed equally with royal jelly resulting in cast differentiation in this genus. The aims of the present work were to analyze the hypopharyngeal glands of the wasp Polistes versicolor in order to recognize their role in the social regulation of the colony, as well as to identify the presence of glandular features that could indicate cell death. Polistes is considered a key genus for the understanding of the evolution of social behavior in insects. In the present work we used histochemical, enzymological and ultrastructural analyses. Behavioral studies were also carried out to determine the relationship between glandular development and individual activities. These studies provided important information about the development of the hypopharyngeal glands in P. versicolor and determined the histochemical characteristics of the glandular secretion. It represents an important contribution to the identification of the morphology and the roles played by these structures in the social context of P. versicolor colonies. The results suggest that these glands are not involved in food production for the brood, unlike the observed in bees. The morphological General Abstract characteristics of the secretory cells and their secretion, as well as the behavioral characteristics of these wasps suggest that the hypopharyngeal glands of P. versicolor might be involved in the production of digestive enzymes.

<p>Propagation methods for honeybee viruses have not changed since these viruses were discovered. There are no suitable cell lines or cell culture techniques available for honeybee viruses. Honeybee viruses have to be manually injected with virus in order for the virus to multiply and be extracted. With the presence of inapparent viruses which could co-infect pupae, a method for pure virus propagations needs to be found. Recombinant baculovirus systems have been used extensively to produce foreign proteins from different viruses using vectors and recombinant technology. In this chapter we inserted the capsid gene from BQCV into a transfer vector under the control of the p10 promoter of Autographa californica. Fractions of the sucrose gradient containing the virus like particles (VLPs) were seen under the electron microscope. A Western blot showed the four capsid proteins at the expected sizes for BQCV capsid. This study therefore has shown that a heterologous system such as baculovirus can be used for virus like particle production. Infectious virus technology has helped gain insight into how viruses work. Using this technology altering honeybee viruses could be used to observe different functionalities of the viruses. An attempt was made to interchange the open reading frames of ABPV and BQCV to observe any changes in virus assembly and infectivity. A fusion PCR strategy was employed to interchange the 5&rsquo / and 3&rsquo / ORFs of APBV and BQCV. The strategy however was unsuccessful. Alternative strategies could improve the chances of obtaining a chimeric virus.</p>