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I use field observations, experiments and molecular techniques to describe the social biology of the sweat bee Lasioglossum calceatum, and to investigate the mechanisms underlying social polymorphism and body size in this species. I also investigate environmental constraints on sociality, and the impact that workers have on productivity, in the obligate social species L. malachurum. Chapter 1 introduces sweat bees as a study system, and reviews social behaviour within the group. I then provide concise introductions to the study species. In Chapter 2 I show that L. calceatum exhibits latitudinal social polymorphism in the UK, with only bees in the south expressing primitive eusociality. I then describe the social life cycle from continuous field observations, with reference to genetic data. In Chapter 3 in I examine environmental and genetic components of social phenotype in L. calceatum by conducting a field transplant of bees from the north of the UK to the south. Social phenotype is likely to be predominantly determined by fixed genetic differences between social and solitary populations. Chapter 4 examines whether the transition between social and solitary nesting results in saw-tooth size clines in L. calceatum and Halictus rubicundus. Overall, both species exhibit converse-Bergmann clines but not saw-tooth clines. In Chapter 5 I transplant the obligate social sweat bee L. malachurum to the north of the UK, to test whether sociality is constrained by season length. Phenology was considerably delayed such that the life cycle could not be completed. In Chapter 6 I investigate queen quality, productivity and costs of worker production in L. malachurum, by manipulating the number of workers per nest. I show that queens probably incurs costs from producing more workers, and that a possible mechanism is that workers from larger groups may be of lower quality. In Chapter 7 I bring together key findings of the thesis, and comment on future directions.

The honey bee, Apis mellifera, is important both ecologically and economically. Pests and diseases are arguably the greatest current challenge faced by honey bees and beekeeping. This PhD thesis is focused on honey bee disease control including natural resistance by means of hygienic behaviour. It contains eleven independent experiments, ten on honey bee pests and diseases and their control and resistance, and one on stingless bees. Each is written as a separate chapter, Chapters 4 and 14 of this thesis. Chapter 4: How effective is Apistan® at killing varroa? This shows that Apistan is not very effective at killing varroa, presumably because of resistance. It also shows that a single Apistan treatment resulted in the next treatment being significantly less effective, indicating strong selection for resistance. Chapter 5: Towards integrated control of varroa: comparing application methods and doses of oxalic acid on the mortality of phoretic Varroa destructor mites and their honey bee hosts. This shows that oxalic acid can be highly effective at killing varroa mites under beekeeping conditions in broodless hives in winter. However, varroa mortality is affected by application method and dose. In addition, bee and colony mortality and colony performance are also affected by application method and dose. The results of this chapter shows that sublimation is the best method, in that it gives greater varroa mortality at lower doses, and results in no harm to the colonies. In fact, colonies treated via sublimation had significantly more brood in spring that controls, and lower winter mortality, although this difference was not significant. Chapter 6: Towards integrated control of varroa: varroa mortality from treating broodless winter colonies twice with oxalic acid via sublimation. This shows that two treatments of 2.25 g oxalic acid via sublimation at an interval of 2 weeks in broodless honey bee colonies in winter result in greater varroa mortality than a single treatment, 99.6% vs. 97%. Making a second oxalic acid treatment was not harmful as the performance (frames of brood, queen and colony survival) of the twice-treated colonies over the next 4 months was not significantly different to the once-treated control colonies. Chapter 7: Towards integrated control of varroa: Efficacy of early spring trapping in drone brood. This indicates that trapping in drone brood in spring is probably not sufficiently effective to be able to control varroa populations on its own. It shows that trapping varroa in capped drone cells in early spring is not highly effective at controlling varroa. The first and second test frames of drone foundation removed 44% and 48% of the varroa, respectively. Chapter 8: Towards integrated control of varroa: Monitoring honey bee brood rearing in winter and the proportion of varroa in small patches of sealed cells. This shows that December is the month with the least brood. However, winter reduction in brood rearing varied among years and even in December some colonies still had sealed brood. Although the amounts of sealed brood were low, even a small patch of c. 500-600 sealed cells could contain 14% of the varroa in a colony. This will halve the duration of control provided by an oxalic acid treatment. Chapter 9: Towards integrated control of varroa: effect of variation in hygienic behaviour among honey bee colonies on mite population increase and deformed wing virus incidence. This shows clearly that hygienic behaviour reduces the one-year population growth of varroa in honey bee colonies by more than 50% and reduces the levels of deformed wing virus by more than 1000 times. Chapter 10: Hygienic behaviour saves the lives of honey bee colonies. This shows that hygienic behaviour saves the lives of honey bee colonies with shrivelled wings, a visible symptom of deformed wing virus that is considered a predictor of colony death. Over one year, only 2 of 11 colonies requeened with a non-hygienic queen survived, versus 13 of 15 requeened with a hygienic queen. Chapter 11: Hygienic behaviour by non-hygienic honey bee colonies: all colonies remove dead brood from open cells. This shows that all honey bee colonies are highly hygienic in response to dead or diseased brood in open cells. All larvae killed by freezing with liquid nitrogen and larvae with chalkbrood disease were removed. This was true even for colonies with low levels of removal of dead brood from sealed cells, which would be considered as non-hygienic colonies. Chapter 12: Removal of larvae infected by different strains of chalk brood and other fungi by hygienic and non-hygienic bee colonies. This shows that hygienic and non-hygienic honey bee colonies are highly hygienic in response to diseased larvae killed with different strains of fungus in open cells. Chapter 13: Hygienic behaviour in Brazilian stingless bees. This shows that the three stingless bee species studied (Melipona scutellaris, Scaptotrigona depilis, Tetragonisca angustula) all have high levels of hygienic behaviour, quantified as the removal of freeze-killed brood, in comparison to the honey bee Apis mellifera. In S. depilis there was considerable variation in hygienic behaviour among colonies, and hygienic colonies removed more brood affected by a naturally-occurring disease which we discovered and for which the causative agent remains to be identified. Chapter 14: First record of small hive beetle, Aethina tumida Murray, in South America. This reports the discovery of adult small hive beetles, Aethina tumida, in honey bee, Apis mellifera, hives in an apiary in Brazil, in March 2015. This is the first record for South America of this honey bee pest.

This thesis focuses on hygienic behaviour in honey bees. In beekeeping, brood diseases incur heavy economical and biological costs and are no longer effectively treated with chemicals. Previous research has shown how hygienic behaviour, a trait expressed by c. 10% of unselected colonies, can be effective in reducing the impact and presence of such diseases. Hygienic behaviour is experimentally measured using the freeze-killed brood (FKB) bioassay and can be increased by selective breeding, generating lines of hygienic colonies. Chapter 4 demonstrates that the relative rarity of hygienic behaviour in unselected colonies is not because it incurs a cost via the removal of healthy brood. Chapter 5 - 6 focus on the impact of external factors on hygienic behaviour. Specifically, we demonstrate that the presence of brood, amount of food, and strength of the colony affect hygienic levels (Chapter 5). Chapter 6 shows that hygienic behaviour does not correlate with agressiviness or agitated behaviour. When breeding honey bees, it is possible to exploit instrumental insemination to have complete control over the genetic composition of the resulting progeny. This technique is however laborious and requires particular equipment and training. In Chapter 7 we show that it is possible to obtain acceptable levels of hygienic behaviour without artificial insemination. Chapter 8 illustrates how we obtained the first breeing line of hygienic honey bees through a selective breeding program that saw its first milestone in autumn 2013 when we detected high levels of hygienic behaviour. The results obtained represent the foundation for future research projects. Chapter 9 presents a valid, minimal methodology to keep virgin queens. We tested a variety of methods and factors to determine the best, mos cost-effective way to maintain queens for the week prior their introduction into a queenless hive. The results obtained provide some insights on both basic and applied aspects of honey bee breeding for hygienic behaviour and represent the foundation of what will be an ongoing selection programme towards a disease-resistant honey bee.

As is much of the world's biodiversity, bees and other flower-visiting insects are in global decline, largely due to human activities. The impacts of humans on wildlife can be ameliorated, at least to an extent, by wildlife-friendly management practices in both rural and urban areas. This thesis comprises two introductory chapters (Part 1), followed by a series of ten research chapters (Parts 2 - 5) aimed at informing management practices that encourage bees and other flower-visiting insects in urban areas, and ends with a concluding chapter (Part 6). The projects are grouped in four parts making contributions to four broad areas of research. Part 2 is concerned with evaluating the attractiveness of ornamental garden plants to insect flower-visitors. Individual projects examine the advice currently available to gardeners via recommended plant lists, and describe surveys of plant varieties grown in a public garden (Southover Grange garden, Lewes), a Plant Heritage national collection of asters (Picton Garden, Malvern), and the experimental gardens planted on campus of the University of Sussex, Brighton, as well as in towns of Plumpton and Magham Down. Part 3 evaluates the attractiveness to insects of urban wild flowers, including those growing in amenity grass areas in parks, and the effects on their abundance and diversity of the various mowing regimes, as well as the attractiveness of the common autumn flowering ivy. Part 4 uses waggle dance decoding to investigate honey bee foraging in the urban landscape of Brighton, with an additional particular focus on foraging on spring-blooming oilseed rape in the surrounding agricultural land. Part 5 examines an aspect of good practice in urban apiary set up, the use of lattice fence or hedge barriers, which should facilitate beekeeping in urban areas, including in private gardens and allotments.

Bumblebees are important pollinators of crops and wildflowers and are currently in global decline. The main drivers of decline include agricultural intensification, climate change, invasive species, pesticides, parasites and pathogens and it is thought that these multiple stressors act together to impact populations. However, their relative importance is unknown and there are wide knowledge gaps in relation to the current status of species populations and their response to environmental variables such as climate, habitat and land use change. Citizen science offers a potential method of collecting data at a broad enough scale to measure species population responses to environmental stressors and it has successfully been applied to other taxa, particularly UK birds and butterflies. This thesis investigates the use of citizen science to address the current knowledge gaps in the status of UK bumblebee populations by analysing volunteer-collected data on current distribution and abundance trends in relation to habitat and climate change. Results are compared to previous studies to infer long-term changes in population dynamics. The value of applying citizen science methods to bumblebee monitoring is highlighted, revealing evidence for decline of some common species and the recent retraction of rare species to their climatic optima. The main findings reveal a potential impact of climate on the distribution of winter-active bumblebees. They also indicate that, while urban parks and gardens provide refuge for bumblebees in an otherwise impoverished landscape, urbanisation may favour short-tongued generalist species over long-term specialists. The outcomes of this thesis have important management implications for UK bumblebee populations including the need for reassessment of the conservation status of B. soroeensis and the sympathetic management of urban parks and gardens for longtongued specialists through the provision of suitable forage material.

Thesis (M.S. in entomology)--Washington State University, May 2010. / Title from PDF title page (viewed on July 12, 2010). "Department of Entomology." Includes bibliographical references.

Orientador: José Chaud Netto / Banca: Valter Vieira Alves Junior / Banca: Andrigo Monroe Pereira / Resumo: O ácaro Varroa destructor (Anderson & Treuman, 2000) tem causado danos à apicultura em todo o mundo. No Brasil, as condições climáticas e as linhagens de abelhas não oferecem condições ideais para o parasitismo de ácaros, que se reflete no baixo número de mortes de colônias, causadas pela varroatose, bem como a estabilidade do nível de infestação. O objetivo deste estudo foi avaliar os danos causados pela infestação de ácaros em colméias mantidas em condições naturais. Para este efeito, o número de ácaros por abelhas foi calculado e utilizado para quantificar o nível de infestação em cada colônia. Inspeções periódicas foram realizadas a fim de monitorar as taxas de mortalidade de abelhas parasitadas durante os ciclos de desenvolvimento. Os dados foram analisados pelo Teste G de Independência e o Teste de Proporções. Os resultados indicaram que as taxas de mortalidade de pupas e larvas foram proporcionais ao grau de infestação em cada colônia, e todas as colônias apresentaram taxas de mortalidade significativamente maior do que a apresentada pela colônia controle. Houve interação significativa entre as taxas de mortalidade registradas entre o terceiro e quarto dias de vida larval e a mortalidade total de larvas (Teste G = 80.35, P< 0, 0001). Assim, pode-se concluir que a endogamia contribuiu significativamente para o aumento da taxa de mortalidade das larvas. Em colônias de abelhas africanizadas infestadas pelo ácaro Varroa destructor taxas de mortalidade, durante o experimento, variaram de 2,59 a 23,28% em pupas (até 6,04 vezes maiores que na colônia controle) e 1,82 a 22,89% em larvas (até 6,12 vezes maiores que na colônia de controle), contra 3,85% e 3,74% na colônia controle, respectivamente / Abstract: The mite Varroa destructor (Anderson & Treuman, 2000) has caused extensive damage to beekeeping worldwide. In Brazil, weather conditions and the strains of bees do not provide ideal conditions for mite parasitism, which is reflected in the low number of deaths of colonies caused by varroatosis well as the stability of infestation levels. The aim of this study was to evaluate the damage caused by the mite infestation in hives maintained in natural conditions. For this purpose the number of mites per bee was calculated and used to quantify the level of infestation in each colony. To record the mortality rates of parasitized bees during development daily checks were performed. The data were analyzed by G Test of Independence and a Test of Proportions. The results indicate that the rate of mortality of pupae and larvae was proportional to the degree of infestation in each colony, and all colonies showed mortality rates significantly higher than the control rate. A significant interaction among death rates recorded between the third and fourth days of larval life and the total death of larvae was found (G Test = 80,35; P < 0, 0001). So, it can be concluded that bee inbreeding contributed significantly to the increase of the larval rate of mortality. In Africanized honeybee colonies infested by the mite Varroa destructor mortality rates, during the experiment, varied from 2.59 to 23.28% in pupae (up to 6.04 times greater than the control colony) and from 1.82 to 22.89% in larvae (up to 6.12 times greater than the control colony), against 3.85% and 3.74% in the control colony, respectively / Mestre

Made available in DSpace on 2014-06-11T19:30:15Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-07-29Bitstream added on 2014-06-13T21:00:36Z : No. of bitstreams: 1 mattos_im_me_rcla.pdf: 472490 bytes, checksum: 733e43c4674ba211a8a9457fbbfe4b67 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O ácaro Varroa destructor (Anderson & Treuman, 2000) tem causado danos à apicultura em todo o mundo. No Brasil, as condições climáticas e as linhagens de abelhas não oferecem condições ideais para o parasitismo de ácaros, que se reflete no baixo número de mortes de colônias, causadas pela varroatose, bem como a estabilidade do nível de infestação. O objetivo deste estudo foi avaliar os danos causados pela infestação de ácaros em colméias mantidas em condições naturais. Para este efeito, o número de ácaros por abelhas foi calculado e utilizado para quantificar o nível de infestação em cada colônia. Inspeções periódicas foram realizadas a fim de monitorar as taxas de mortalidade de abelhas parasitadas durante os ciclos de desenvolvimento. Os dados foram analisados pelo Teste G de Independência e o Teste de Proporções. Os resultados indicaram que as taxas de mortalidade de pupas e larvas foram proporcionais ao grau de infestação em cada colônia, e todas as colônias apresentaram taxas de mortalidade significativamente maior do que a apresentada pela colônia controle. Houve interação significativa entre as taxas de mortalidade registradas entre o terceiro e quarto dias de vida larval e a mortalidade total de larvas (Teste G = 80.35, P< 0, 0001). Assim, pode-se concluir que a endogamia contribuiu significativamente para o aumento da taxa de mortalidade das larvas. Em colônias de abelhas africanizadas infestadas pelo ácaro Varroa destructor taxas de mortalidade, durante o experimento, variaram de 2,59 a 23,28% em pupas (até 6,04 vezes maiores que na colônia controle) e 1,82 a 22,89% em larvas (até 6,12 vezes maiores que na colônia de controle), contra 3,85% e 3,74% na colônia controle, respectivamente / The mite Varroa destructor (Anderson & Treuman, 2000) has caused extensive damage to beekeeping worldwide. In Brazil, weather conditions and the strains of bees do not provide ideal conditions for mite parasitism, which is reflected in the low number of deaths of colonies caused by varroatosis well as the stability of infestation levels. The aim of this study was to evaluate the damage caused by the mite infestation in hives maintained in natural conditions. For this purpose the number of mites per bee was calculated and used to quantify the level of infestation in each colony. To record the mortality rates of parasitized bees during development daily checks were performed. The data were analyzed by G Test of Independence and a Test of Proportions. The results indicate that the rate of mortality of pupae and larvae was proportional to the degree of infestation in each colony, and all colonies showed mortality rates significantly higher than the control rate. A significant interaction among death rates recorded between the third and fourth days of larval life and the total death of larvae was found (G Test = 80,35; P < 0, 0001). So, it can be concluded that bee inbreeding contributed significantly to the increase of the larval rate of mortality. In Africanized honeybee colonies infested by the mite Varroa destructor mortality rates, during the experiment, varied from 2.59 to 23.28% in pupae (up to 6.04 times greater than the control colony) and from 1.82 to 22.89% in larvae (up to 6.12 times greater than the control colony), against 3.85% and 3.74% in the control colony, respectively