L’abeille domestique (Apismellifera) a un rôle majeur dans les écosystèmes naturels et agronomiques mais est exposée à un nombre croissant de pressions environnementales (nouveaux parasites, xénobiotiques, variations climatiques et malnutrition). Dans ce contexte, la compréhension des phénomènes impliqués dans les réponses au stress ainsi que leurs coûts associés devient cruciale pour mieux appréhender l’impact de ces pressions sur les abeilles. L’émergence d’un stress perturbe généralement l’homéostasie de l’organisme qui doit mettre en place une cascade d’adaptations physiologiques et comportementales pour le surmonter. Cependant, du fait de son mode de vie social, il est raisonnable de penser que les réponses vont se faire dans l’intérêt du groupe et non plus seulement dans l’intérêt de l’individu. Afin de caractériser les réponses au stress et de déterminer leur spécificité en fonction de la nature du stimulus (xénobiotiques, immunitaire, thermique, social), j’ai adopté une approche multidisciplinaire en ciblant l’identification des modifications i) physiologiques associées à la division du travail, ii) du métabolisme énergétique, et iii) comportementales. J’ai démontré quequelque soit leur rôle social (nourrice, gardienne, butineuse), les abeilles répondent de la même manière à un stress donné, si celui-­ci est écologiquement pertinent (hyperthermie et stress immunitaire mais pas xénobiotique). Une tendance à la diminution des ressources énergétiques a également été observée suite à un stress suggérant une modification des performances comportementales. Afin de vérifier cela, je me suis concentrée sur l’activité de butinage; le vol chez les insectes étant un des processus physiologiques les plus coûteux du règne animal. Une altération des performances de butinage a été mise en évidence chez les abeilles soumises à un stress immunitaire avec une réorientation des préférences de butinage au dépens du pollen, plus coûteux àc ollecter et moins riche en ressource énergétique que le nectar ; ceci probablement pour pallier au coût énergétique du stress. En revanche, en réponse àune hyperthermie, une augmentation de l’activité de butinage a été observée mais sans engendrer un coût supplémentaire au niveau des ressources collectées.Ces résultats sont discutés à la lumière du coût énergétique du stress et des conséquences potentielles sur les performances des abeilles, qui infine pourrait perturber l’homéostasie énergétique de la colonie. / Honeybees (Apis mellifera), which play an important role in natural and agronomic ecosystems, are exposed to a growing number of environmental pressures(new parasites, pesticides, climatechangeand poor nutrition). In this context, deciphering the mechanisms underlying stress responses and their costs becomes crucial to better understand theim pact of these pressures. Stress usually represents a challenge to the homeostasis of a norganism. In response, a cascade of physiological and behavioural adaptations enables the organism to cope with the stress. However, dueto their sociallife style, we could suggest that stress response in honeybees will occurin the interest of the colony and not only in the interest of the individual. To characterise the stress response and determine its specificity according to the stimulus (xenobiotic, immune, thermal, social), I developed a multidisciplinary approach to identify changes in i) task-­related physiology, ii) energetic metabolism, and iii) behaviour. I demonstrated that, regardless of their social function (nurse, guard, forager), bees respond in the sameway to a given stress, if itis ecologically-­relevant (heat and immune stress but not pesticides). Atendencytoward decreas ingenergetic resources was also observed following stress exposure, which suggests changes in behavioural performance.In order to test this hypothesis, I analysed changes in foraging activity in response to stress, as insect flight is one of the most costly physiological processes in the animal kingdom. I found that for aging performances were affected by animmune stress : bees changed their foraging preferences at the expense of pollen, probably to reduce the stress energetic cost, given that pollen is more costly to collect and provides alower energetic return than nectar. In contrast, in response to heat stress, an increase in colony for aging activity was observed, without an additional cost on resource collection. These results are discussed in the light of stress energetic cost and its potential consequences onhoneybee performances, which could disrupt the colony’s energetic homeostasis.

O presente trabalho teve como objetivo: 1. Determinar o efeito de diferentes tamanhos de células de cria de operárias (favos novos construídos naturalmente por abelhas Africanizadas e européias e favos velhos) sobre o peso e variabilidade morfológica das abelhas operárias emergentes em colônias de abelhas (Apis mellifera); 2. Examinar a influência das células de operárias de menor tamanho do favo velho em relação às células novas construídas por abelhas Africanizadas e às células de operárias construídas por abelhas européias (italianas e cárnicas) sobre a infestação e reprodução do ácaro Varroa jacobsoni. O trabalho foi todo realizado no Departamento de Genética da FMRP-USP em Ribeirão Preto. Foram utilizadas colônias de abelhas africanizadas do próprio apiário experimental (N=8). Foram usados neste experimento quatro tipos de favos: favo africanizado novo (FAFn), favo italiano novo (FITn), favo cárnico novo (FCAn) e favo velho africanizado (FVE) com as paredes das células engrossadas por efeito de muitas gerações de abelhas emergidas. Um total de três medidas foram feitas nas células de operárias de cada favo: diâmetro da célula (DC), profundidade da célula (PC) e peso da abelha emergente (PA). O volume da célula (VC) foi calculado a partir do DC e da PC. As abelhas, uma vez pesadas, foram posteriormente preservadas em solução de álcool a 70%. As seguintes medidas morfométricas foram tomadas sobre cada abelha individual e sobre a asa anterior direita: Comprimento e Largura total da asa anterior direita. Investigamos os índices de infestação e as taxas de reprodução do ácaro nos quatro tipos de favos com diferentes células de crias de operárias, para verificar possíveis variações na infestação entre os favos estudados. Para as dimensões das células (DC, PC e VC), entre o favo FVE e os novos (FAFn, FITn e FCAn), observou-se de maneira geral que o DC e VC foram as medidas que apresentaram diferenças notáveis entre os diferentes favos. Comparando-se os diâmetros das células de cria entre os favos estudados, percebe-se uma média menor para as células do FVE (4.56 mm) e médias maiores para as células dos favos FITn (5.13 mm) e FCAn (5.27 mm); sendo diferentes estatisticamente (p< 0.001, One-Way ANOVA). Em relação à PC a situação foi inversa, percebe-se que a PC construída pelas operárias a partir da cera alveolada (FITn) foi de 11.62 mm e a PC em favos construídos por operárias cárnicas (FCAn) foi de 11.64 mm, sendo inferiores às do FVE (12.22 mm). As médias dos volumes dos diferentes tipos de alvéolos estudados mostram uma média menor para as células do FVE (220.12 mm3) e médias maiores para os FITn (264.82 mm3) e FCAn (279.59 mm3); sendo diferentes estatisticamente (p< 0.001, One-Way ANOVA). Os resultados indicaram que as abelhas compensaram a menor ou maior largura da célula ao produzir células com maior ou menor profundidade respectivamente. Das asas analisadas, as operárias do FVE apresentaram menor comprimento (9.10 mm), enquanto que esses comprimentos foram bem maiores nas operárias do favo FAFn, FITn e FCAn sendo 9.26 mm, 9.32 mm e 9.32 mm respectivamente. Em relação à largura da asa, encontramos também que as operárias do FVE apresentaram menor largura (3.31 mm), sendo essas medidas maiores nas operárias dos favos novos FAFn, FITn e FCAn (3.43 mm, 3.49 mm e 3.46 mm respectivamente). O comprimento e largura da asa anterior direita das abelhas emergentes diferiram estatisticamente entre os quatro tipos de favos estudados (p= 0.014 e p= 0.003 respectivamente, One-Way ANOVA). Comparando-se o peso médio das operárias ao nascer, entre os diferentes tipos de células de crias do FVE (88.12 mg), FAFn (92.67 mg), FITn (95.82 mg) e FCAn (96.89 mg) percebe-se que ocorre um acréscimo no peso à medida que o tamanho da célula é aumentado. A comparação do peso das operárias mostrou que ocorrem diferenças altamente significantes em nível de 5% de probabilidade entre os diferentes favos de cria (p<0.001, One-way ANOVA). Comparando-se o peso médio das abelhas operárias emergentes infestadas e não infestadas pela varroa, percebe-se que ocorre um forte decréscimo no peso da abelha infestada em 14.9% para o FVE e FAFn. Os índices de infestação da varroa verificados nos diferentes tamanhos de células de operárias diferiram estatisticamente entre os quatro tipos de favos (x2 = 41.122, p< 0.001). A infestação média do ácaro foi maior em células de cria do FVE que em células do favo FAFn que apresentou menor índice de infestação (20.6 ± 6.4% vs 10.4 ± 4.2% respectivamente). Esses índices médios diferiram estatisticamente (p< 0.001). Houve maior número de fêmeas adultas do ácaro em células do FVE, que apresentou menor diâmetro e menor volume da célula, comparado com as células dos favos novos de maiores tamanhos (FAFn, FITn e FCAn). Obtiveram-se taxas de reprodução total de 1.28, 0.98, 1.19 e 1.58 para os favos FVE, FAFn, FITn e FCAn respectivamente, quando computadas todas as varroas adultas originais. Essas taxas de reprodução total do ácaro não apresentaram diferenças significativas entre si (p= 0.074, One-Way ANOVA). As células do FVE atraíram mais varroa em relação às células dos favos novos, apesar de que as células do FVE tiveram um diâmetro menor. Embora o tamanho da célula seja importante, característica inerente à larva, ao favo ou ao alimento nas células de crias do FVE poderiam ter uma importante influência de atração ao ácaro varroa. / The purposes of the present work were: 1. To determine the effect of different sizes of worker brood cells in new and old combs built naturally by Africanized and European bees on the weight and morphology of emerging worker honey bees in africanized honey bee colonies (Apis mellifera). 2. To examine the influence of the smaller worker cells of the old comb in relation to new cells built by Africanized bees and larger new cells built by European races on the infestation and reproduction rates of the mite Varroa jacobsoni. We used eight Africanized honey bee colonies. Four types (sizes) of brood combs were placed in each colony: new Africanized comb (NAC), new Italian comb (NIC), new Carniolan comb (NCC) and old Africanized brood comb (OC), that had thickened brood cell walls and relatively small comb cells. Three measurements were made for 80-100 worker brood cells in each comb: Cell width (CW), cell depth (CD), and emerging bee weight (BW). Cell volume (CV) was calculated from CW and CD. The bees were weighed and then preserved in a 70% ethanol. The length and width of the right fore wing were measured for each individual bee. We studied the infestation and the reproduction rates of the mite in four types of combs with different kinds of worker brood cells, to verify possible variations in the infestation by varroa. The comb cell measurements CW and CV differed significantly among the various types of combs. We found that the OC cells (4.56 mm) had a significantly (p <0.001, One-Way ANOVA) smaller diameter than the NIC cells (5.13 mm) and NCC cells (5.27 mm). An opposite trend was found for cell depth, which was significantly smaller in NIC (11.62 mm) and NCC (11.64 mm) than OC (12.22 mm). For the different types of brood combs, the cell depth increased as the cell diameter decreased, in other words, the bees compensated the reduced cell width by producing deeper cells to accommodate the developing bee. The OC cells had a significantly smaller volume (220.12 mm3) than the NIC cells (264.82 mm3) and NCC cells (279.59 mm3) (p< 0.001, One-Way ANOVA). The worker bees reared in OC had a significantly shorter fore wing (9.10 mm) than in the new worker combs NAC (9.26 mm), NIC (9.32 mm) and NCC (9.32 mm). Fore wing width, was also significantly smaller for workers from OC combs (3.31 mm), than from NAC, NIC and NCC combs (3.43 mm, 3.49 mm and 3.46 mm, respectively). The right fore wing length and width of the emerging workers bees differed significantly among the four types of combs (p = 0.014 and p = 0.003 respectively, One-Way ANOVA). In summary, the wing size of the emerging worker bees increased with increasing volume and diameter of the comb cell. The bees from the OC comb had significantly smaller fore wings (both length and width) than those from NAC comb (p< 0.05, Tukey Test). The same was true for workers from NIC and NCC combs. The mean weights of the worker bees among the different types of brood combs were: 88.12 mg, 92.67 mg, 95.82 mg and 96.89 mg for OC, NAC, NIC and NCC respectively. There was an increment in bee weight as the diameter of the cell increased. Bee weights from the different types of combs were significantly different (p< 0.001, One-way ANOVA). Bees infested during the brood phase with the mite Varroa jacobsoni weighed on average 14.9% less than uninfested bees. The varroa infestation rates differed significantly among the four types of combs (x2= 41.122, p< 0.001). The varroa infestation was significantly (p< 0.001) higher in OC cells (20.6±6.4%) than in NAC cells (10.4±4.2%) and NIC cells (14.7%, p= 0.003). The mean infestation rate in NIC cells did not differ significantly (p= 0.094) from the infestation rate in NCC cells (19.2%). The infestation rate in OC cells was not significantly different from that of NCC cells (p= 0.347). Within each colony the OC comb was generally twice as infested with varroa as NAC. The total varroa reproduction rate (TRR) was 1.28, 0.98, 1.19 and 1.58 for the OC, NAC, NIC and NCC combs respectively, when we included all the original adult females (p= 0.074, One-way ANOVA). The OC cells attracted more varroa than new comb cells, even though the OC cells had a smaller diameter. Though cell size is important, characteristics inherent to the larvae, to the comb or the food in the OC worker cells apparently have an overriding influence on attractiveness to the varroa mite.

Com o objetivo de determinar as características físico-químicas, microbiológicas e a origem floral de méis produzidos por Apis mellifera L., 1758, foram determinados no Laboratório de Insetos Úteis do Departamento de Entomologia, Fitopatologia e Zoologia Agrícola da Escola Superior de Agricultura &#34;Luiz de Queiroz&#34; e no Laboratório de Instrumentação Nuclear do Centro de Energia Nuclear na Agricultura, USP: açúcares totais, açúcares redutores, sacarose aparente, umidade, atividade diastásica, hidroximetilfurfural, proteína, cinzas, pH, acidez, índice de formol, condutividade elétrica, viscosidade, cor, elementos químicos (K, Ca Ti, Cr, Mn, Fe, Co, Ni, Cu, Zn, Se, Br Rb, Sr, Ba, Hg e Pb), microorganismos e realizadas análises polínicas de 58 amostras de méis colhidas no Estados do Ceará (20 amostras) e Piauí (38 amostras). Os resultados demonstraram que a maioria dos valores médios para cada parâmetro físico-químico das amostras analisadas encontram-se dentro dos limites estabelecidos pela legislação vigente entretanto verifica-se, para amostras do Estado do Piauí, valor médio para a atividade diastásica abaixo do estabelecido. Para os elementos químicos foram verificados valores acima dos estabelecidos para os elementos Cr, Ni, Zn e Pb. As amostras estudadas foram negativas para coliformes totais, entretanto, foram constatados fungos e leveduras. Pelas análises polínicas dos méis foram considerados como espécies vegetais dominantes para o Estado do Ceará a Mimosa caesalpiniaefolia, M. verrucosa, Borreria sp. I, Serjania sp. e tipo Fabaceae. No Estado do Piauí a Piptadenia sp., M. caesalpiniaefolia, M. verrucosa, Croton urucurana e Tibouchina sp.. / This research deals with the physicochemical, microbiological and pollinic characteristics of 58 samples of Apis mellifera L., 1758 (Hymenoptera: Apidae) honey from the Brazilian states of Ceara (20 samples) and Piaui (38 samples). The following parameters were determined: total sugars, reducing sugars, apparent sucrose, humidity, diastase activity, hydroxymethylfurfural, protein, ashes, ph, acidity, formol index, electrical conductivity, viscosity, color, chemical elements (K, Ca, Ti, Cr, Mn, Fe, Co, Ni, Cu, Zn, Se, Br, Rb, Sr, Ba, Hg, Pb) and microrganisms. The experiments were set in the &#34;Laboratorio de Insetos Úteis&#34;, Department of Entomology, Phytopathology and Agricultural Zoology and in the &#34;Laboratorio de Instrumentação Nuclear, Centro de Energia Nuclear na Agricultura&#34; University of São Paulo, in Piracicaba, State of São Paulo. The results have indicated that most of the mean values for each physicochemical parameter are In accordance with the limits established by the Brazilian the diastase activity is below those limits. Concerning the chemical elements, one observed values above those limits, as follows: Cr, Ni, Zn and Pb. The samples were negative for total coliforms. However fungi and yeast were detected. The pollinic analyses showed that the dominant plant species of the Ceara State were Mimosa caesalpiniaefolia, M. verrucosa, Borreria sp., Serjania sp. and type Fabaceae. The dominant plant species of the Piaui State were Piptadenia sp., M. caesalpiniaefolia, M. verrucosa, Croton urucurana and Tibouchina sp..

O presente trabalho teve como objetivo: 1. Determinar o efeito de diferentes tamanhos de células de cria de operárias (favos novos construídos naturalmente por abelhas Africanizadas e européias e favos velhos) sobre o peso e variabilidade morfológica das abelhas operárias emergentes em colônias de abelhas (Apis mellifera); 2. Examinar a influência das células de operárias de menor tamanho do favo velho em relação às células novas construídas por abelhas Africanizadas e às células de operárias construídas por abelhas européias (italianas e cárnicas) sobre a infestação e reprodução do ácaro Varroa jacobsoni. O trabalho foi todo realizado no Departamento de Genética da FMRP-USP em Ribeirão Preto. Foram utilizadas colônias de abelhas africanizadas do próprio apiário experimental (N=8). Foram usados neste experimento quatro tipos de favos: favo africanizado novo (FAFn), favo italiano novo (FITn), favo cárnico novo (FCAn) e favo velho africanizado (FVE) com as paredes das células engrossadas por efeito de muitas gerações de abelhas emergidas. Um total de três medidas foram feitas nas células de operárias de cada favo: diâmetro da célula (DC), profundidade da célula (PC) e peso da abelha emergente (PA). O volume da célula (VC) foi calculado a partir do DC e da PC. As abelhas, uma vez pesadas, foram posteriormente preservadas em solução de álcool a 70%. As seguintes medidas morfométricas foram tomadas sobre cada abelha individual e sobre a asa anterior direita: Comprimento e Largura total da asa anterior direita. Investigamos os índices de infestação e as taxas de reprodução do ácaro nos quatro tipos de favos com diferentes células de crias de operárias, para verificar possíveis variações na infestação entre os favos estudados. Para as dimensões das células (DC, PC e VC), entre o favo FVE e os novos (FAFn, FITn e FCAn), observou-se de maneira geral que o DC e VC foram as medidas que apresentaram diferenças notáveis entre os diferentes favos. Comparando-se os diâmetros das células de cria entre os favos estudados, percebe-se uma média menor para as células do FVE (4.56 mm) e médias maiores para as células dos favos FITn (5.13 mm) e FCAn (5.27 mm); sendo diferentes estatisticamente (p< 0.001, One-Way ANOVA). Em relação à PC a situação foi inversa, percebe-se que a PC construída pelas operárias a partir da cera alveolada (FITn) foi de 11.62 mm e a PC em favos construídos por operárias cárnicas (FCAn) foi de 11.64 mm, sendo inferiores às do FVE (12.22 mm). As médias dos volumes dos diferentes tipos de alvéolos estudados mostram uma média menor para as células do FVE (220.12 mm3) e médias maiores para os FITn (264.82 mm3) e FCAn (279.59 mm3); sendo diferentes estatisticamente (p< 0.001, One-Way ANOVA). Os resultados indicaram que as abelhas compensaram a menor ou maior largura da célula ao produzir células com maior ou menor profundidade respectivamente. Das asas analisadas, as operárias do FVE apresentaram menor comprimento (9.10 mm), enquanto que esses comprimentos foram bem maiores nas operárias do favo FAFn, FITn e FCAn sendo 9.26 mm, 9.32 mm e 9.32 mm respectivamente. Em relação à largura da asa, encontramos também que as operárias do FVE apresentaram menor largura (3.31 mm), sendo essas medidas maiores nas operárias dos favos novos FAFn, FITn e FCAn (3.43 mm, 3.49 mm e 3.46 mm respectivamente). O comprimento e largura da asa anterior direita das abelhas emergentes diferiram estatisticamente entre os quatro tipos de favos estudados (p= 0.014 e p= 0.003 respectivamente, One-Way ANOVA). Comparando-se o peso médio das operárias ao nascer, entre os diferentes tipos de células de crias do FVE (88.12 mg), FAFn (92.67 mg), FITn (95.82 mg) e FCAn (96.89 mg) percebe-se que ocorre um acréscimo no peso à medida que o tamanho da célula é aumentado. A comparação do peso das operárias mostrou que ocorrem diferenças altamente significantes em nível de 5% de probabilidade entre os diferentes favos de cria (p<0.001, One-way ANOVA). Comparando-se o peso médio das abelhas operárias emergentes infestadas e não infestadas pela varroa, percebe-se que ocorre um forte decréscimo no peso da abelha infestada em 14.9% para o FVE e FAFn. Os índices de infestação da varroa verificados nos diferentes tamanhos de células de operárias diferiram estatisticamente entre os quatro tipos de favos (x2 = 41.122, p< 0.001). A infestação média do ácaro foi maior em células de cria do FVE que em células do favo FAFn que apresentou menor índice de infestação (20.6 ± 6.4% vs 10.4 ± 4.2% respectivamente). Esses índices médios diferiram estatisticamente (p< 0.001). Houve maior número de fêmeas adultas do ácaro em células do FVE, que apresentou menor diâmetro e menor volume da célula, comparado com as células dos favos novos de maiores tamanhos (FAFn, FITn e FCAn). Obtiveram-se taxas de reprodução total de 1.28, 0.98, 1.19 e 1.58 para os favos FVE, FAFn, FITn e FCAn respectivamente, quando computadas todas as varroas adultas originais. Essas taxas de reprodução total do ácaro não apresentaram diferenças significativas entre si (p= 0.074, One-Way ANOVA). As células do FVE atraíram mais varroa em relação às células dos favos novos, apesar de que as células do FVE tiveram um diâmetro menor. Embora o tamanho da célula seja importante, característica inerente à larva, ao favo ou ao alimento nas células de crias do FVE poderiam ter uma importante influência de atração ao ácaro varroa. / The purposes of the present work were: 1. To determine the effect of different sizes of worker brood cells in new and old combs built naturally by Africanized and European bees on the weight and morphology of emerging worker honey bees in africanized honey bee colonies (Apis mellifera). 2. To examine the influence of the smaller worker cells of the old comb in relation to new cells built by Africanized bees and larger new cells built by European races on the infestation and reproduction rates of the mite Varroa jacobsoni. We used eight Africanized honey bee colonies. Four types (sizes) of brood combs were placed in each colony: new Africanized comb (NAC), new Italian comb (NIC), new Carniolan comb (NCC) and old Africanized brood comb (OC), that had thickened brood cell walls and relatively small comb cells. Three measurements were made for 80-100 worker brood cells in each comb: Cell width (CW), cell depth (CD), and emerging bee weight (BW). Cell volume (CV) was calculated from CW and CD. The bees were weighed and then preserved in a 70% ethanol. The length and width of the right fore wing were measured for each individual bee. We studied the infestation and the reproduction rates of the mite in four types of combs with different kinds of worker brood cells, to verify possible variations in the infestation by varroa. The comb cell measurements CW and CV differed significantly among the various types of combs. We found that the OC cells (4.56 mm) had a significantly (p <0.001, One-Way ANOVA) smaller diameter than the NIC cells (5.13 mm) and NCC cells (5.27 mm). An opposite trend was found for cell depth, which was significantly smaller in NIC (11.62 mm) and NCC (11.64 mm) than OC (12.22 mm). For the different types of brood combs, the cell depth increased as the cell diameter decreased, in other words, the bees compensated the reduced cell width by producing deeper cells to accommodate the developing bee. The OC cells had a significantly smaller volume (220.12 mm3) than the NIC cells (264.82 mm3) and NCC cells (279.59 mm3) (p< 0.001, One-Way ANOVA). The worker bees reared in OC had a significantly shorter fore wing (9.10 mm) than in the new worker combs NAC (9.26 mm), NIC (9.32 mm) and NCC (9.32 mm). Fore wing width, was also significantly smaller for workers from OC combs (3.31 mm), than from NAC, NIC and NCC combs (3.43 mm, 3.49 mm and 3.46 mm, respectively). The right fore wing length and width of the emerging workers bees differed significantly among the four types of combs (p = 0.014 and p = 0.003 respectively, One-Way ANOVA). In summary, the wing size of the emerging worker bees increased with increasing volume and diameter of the comb cell. The bees from the OC comb had significantly smaller fore wings (both length and width) than those from NAC comb (p< 0.05, Tukey Test). The same was true for workers from NIC and NCC combs. The mean weights of the worker bees among the different types of brood combs were: 88.12 mg, 92.67 mg, 95.82 mg and 96.89 mg for OC, NAC, NIC and NCC respectively. There was an increment in bee weight as the diameter of the cell increased. Bee weights from the different types of combs were significantly different (p< 0.001, One-way ANOVA). Bees infested during the brood phase with the mite Varroa jacobsoni weighed on average 14.9% less than uninfested bees. The varroa infestation rates differed significantly among the four types of combs (x2= 41.122, p< 0.001). The varroa infestation was significantly (p< 0.001) higher in OC cells (20.6±6.4%) than in NAC cells (10.4±4.2%) and NIC cells (14.7%, p= 0.003). The mean infestation rate in NIC cells did not differ significantly (p= 0.094) from the infestation rate in NCC cells (19.2%). The infestation rate in OC cells was not significantly different from that of NCC cells (p= 0.347). Within each colony the OC comb was generally twice as infested with varroa as NAC. The total varroa reproduction rate (TRR) was 1.28, 0.98, 1.19 and 1.58 for the OC, NAC, NIC and NCC combs respectively, when we included all the original adult females (p= 0.074, One-way ANOVA). The OC cells attracted more varroa than new comb cells, even though the OC cells had a smaller diameter. Though cell size is important, characteristics inherent to the larvae, to the comb or the food in the OC worker cells apparently have an overriding influence on attractiveness to the varroa mite.

ASP2 est une protéine de 123 acides aminés liant les odeurs (Odorant-Binding Protein). Elle est sans doute impliquée dans la première étape du processus de reconnaissance des odeurs chez l'abeille domestique au niveau de la lymphe sensillaire. Le présent travail de thèse a permis, par résonance magnétique nucléaire, d'élucider la structure ainsi que de sonder la dynamique du squelette d'ASP2 en complexe avec le TSP (triméthylesilyle propionate-d4). A l'exception du segment D30-S45, la structure d'ASP2, monomérique, est bien définie (rmsd<1A). Quatre hélices alpha1 et alpha4, alpha5, alpha6 antiparallèles forment un faisceau convergent. L'extrémité ouverte du faisceau est fermée par l'hélice alpha3. L'arrangement de ces cinq hélices crée une poche essentiellement hydrophobe et faiblement polaire. Le segment D30-S45 présente une dynamique originale expliquant sa mauvaise définition dans la structure : le segment D30 à A38 est en échange conformationnel sur la gamme de la milliseconde tandis que la région A37 à S45 contient des mouvements importants dans la gamme pico-nanoseconde. L'apoprotéine est présente sous deux formes en équilibre lent et de conformations très similaires à celle du complexe. Les populations respectives dépendent du pH. Lors de la fixation du ligand, une seule des conformations est sélectionnée. L'IBMP (2-isobutyle- 3-méthoxy-pyrazine) se fixe au sein de la poche hydrophobe de deux orientations, tête-bêches, avec des affinités comparables. De plus, la poche hydrophobe d'ASP2 s'adapte à la taille du ligand. L'implication fonctionnelle de ces résultats est discutée.

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This thesis describes techniques for defining independent tasks in Java programs forparallelization. Existing Java parallelization APIs like JOMP, Parallel Java,Deterministic Parallel Java, JConqurr and JaMP are discussed. We have seen that JaMPis an implementation of OpenMP for Java, and it has a set of OpenMP directives andruntime library functions. We have discussed that JaMP has source to byte codecompiler, and it does not help in debugging the parallel source codes. There is no designtime syntax checking support of JaMP directives, and we know about mistakes onlywhen we compile the source code with JaMP compiler. So we have decided tocontribute JaMP with adding an option in the compiler to get parallel source code. Wehave created an eclipse plug-in to support design time syntax checking of JaMPdirectives too. It also helps the programmers to get quickly parallel source code withjust one click instead of using shell commands with JaMP compiler.

Sleep is a behavioral condition fraught with mystery. Its definition—either a suite of diagnostic behavioral characters, electrophysiological signatures, or a combination of the two—varies in the literature and lacks an over-arching purpose. In spite of these vagaries, sleep supports a large and dynamic research community studying the mechanisms, ontogeny, possible functions and, to a lesser degree, its evolution across vertebrates and in a small number of invertebrates. Sleep has been described and examined in many social organisms, including eusocial honey bees (Apis mellifera), but the role of sleep within societies has rarely been addressed in non-human animals. I investigated uniquely social aspects of sleep within honey bees by asking basic questions relating to who sleeps, when and where individuals sleep, the flexibility of sleep, and why sleep is important within colonies of insects. First, I investigated caste-dependent sleep patterns in honey bees and report that younger workers (cell cleaners and nurse bees) exhibit arrhythmic and brief sleep bouts primarily while inside comb cells, while older workers (food storers and foragers) display periodic, longer sleep bouts primarily outside of cells. Next, I mapped sleep using remote thermal sensing across colonies of honey bees after introducing newly eclosed workers to experimental colonies and following them through periods of their adult lives. Bees tended to sleep outside of cells closer to the edge of the hive than when asleep inside cells or awake, and exhibited caste-dependent thermal patterns, both temporally and spatially. Wishing to test the flexibility of sleep, I trained foragers to a feeder and made a food resource available early in the morning or late in the afternoon. The bees were forced to shift their foraging schedule, which consequently also shifted their sleep schedule. Finally, I sleep-deprived a subset of foragers within a colony by employing a magnetic “insominator” to test for changes in their signaling precision. Sleep-deprived foragers exhibited reduced precision when encoding direction information to food sources in their waggle dances. These studies reveal patterns and one possible purpose of sleep in the context of a society. / text

Sensory information is processed and encoded by neural networks. In order to understand how the nervous system is able to rapidly integrate and store sensory information, knowledge of the connections and properties of the neurons in these circuits is required. The fruit fly Drosophila melanogaster provides a particularly powerful species to investigate the neural circuits of the olfactory system because in addition to possessing a simple olfactory system amenable to circuit analysis, a host of genetic reagents are available, including the GAL4-UAS system for targeted gene expression. The mushroom bodies, paired structures historically implicated in olfactory learning and memory, receive olfactory information at the mushroom body calyx from second-order olfactory projection neurons (PNs). Within the calyx, individual PN axonal boutons are surrounded by dendritic arborizations from intrinsic Kenyon cells (KCs) and each tiny cluster constitutes a single microglomerulus. Cells that connect the calyx with other areas of the brain, extrinsic neurons (ENs), also contribute to microglomeruli. Most of these contain the neurotransmitter, GABA, and are presumed to be inhibitory. In this study, the synaptic characteristics, neural circuits, and plasticity of calycal cells have been investigated using a combination of serial section electron and confocal microscopy. The findings reveal several new features of the circuits in the calyx: 1) The calyx contains three ultrastructurally distinct types of PN boutons that are heterogeneous in shape and exhibit subtle differences in synaptic densities. 2) All PN boutons form both ribbon and non-ribbon synapses, and from their smaller size and fewer postsynaptic partners, non-ribbon synapses may possibly become converted to ribbon synapses after activity; the olfactory signal may then be transmitted more strongly and efficiently at ribbon synapses. 3) PN boutons with an electron-dense cytoplasm have the most ribbon synapses per unit area of membrane as well as the highest ratio of ribbon to non-ribbon synapses, and thus may be more active and efficient than other boutons. 4) KC neurites are not exclusively postsynaptic in the calyx and can form occasional ribbon synapses, the functional interpretation of which awaits identification of their postsynaptic partners and vesicle contents. 5) Each PN bouton may contribute input to a single dendritic KC claw at about three presynaptic sites. For the postsynaptic side, a single claw receives input from individual presynaptic sites that must be highly redundant. 6) There may be important processing of the olfactory signal by local circuits formed by ENs in the calyx; ENs form synaptic connections with PNs, KCs, and other ENs. 7) Extensive serial synapses link EN terminals into a network, presumed to be GABAergic and inhibitory, that extends between microglomeruli and may be autaptic. 8) The structure and synaptic connectivity of microglomeruli may undergo changes after adult emergence. 9) vGAT and GAD1-GAL4 lines drive ectopic expression of marker genes in KCs and are not reliable reporters of GABA-positive cells. 10) Previously identified calycal ENs (MB-C1, MB-C2/C3, MB-CP1) are not immunopositive for GAD1, a marker of GABA-containing cells. 11) A network of ENs expressing a GABA phenotype differently innervates anatomically and functionally discrete areas of the honeybee calyx, and in addition the density of innervation may change with alterations in age and/or experience.

Honeybees are used as a major agricultural input around the world and their pollination services have been valued at US$14.6 billion to the United States alone. Dramatic declines in honeybee populations around the globe, however, questioned the sustainability of this reliance on a single pollinator species. In this study, I investigated the response of wild pollinator communities to declining honeybee density and changing land use intensity to determine the potential of wild pollinators to compensate for honeybee loss in an increasingly human-modified environment. I generated a gradient of declining honeybee density using increasing distances from commercial bee hives, and conducted flower observations on experimentally-grown plants across this gradient. I investigate how declining honeybee densities and intensifying land use combine to influence the composition of the pollinator community as a whole, then go on to explore individual trends in the most common pollinator species. I then analyze how this impacts the transport of viable pollen by the pollinator community and determine how these changes alter seed set in several common plant species. I then change my focus away from the composition of the pollinator community, and instead investigate how declining honeybee densities and land-use intensification influence the structuring of interactions between plants and pollinators within the community. I identify the pollen species carried by pollinators, and use this to construct a network of pollination interactions. I then use this network to analyze how changes in the way species interact influences the pollination services delivered by the pollinator community to different plant groups (weeds, native plants, and crop species). My findings show that honeybee declines may have a large impact on community structure and interactions within pollination systems. I observed a significant shift in the wild pollinator community composition as honeybee densities declined, from a generally bee/hoverfly dominated community to one more dominated by large flies. This was associated with a significant decline in the total pollen load transported by the community, indicating that pollination services may suffer in the absence of honeybees. As honeybee densities declined, however, I also observed a shift toward greater specialisation of pollinators on abundant resources, increased pollinator constancy, and a higher viability rate of the pollen transported. These findings show that although the total amount of pollen transported by the community declined as honeybee densities decreased, the probability of this pollen transport resulting in effective pollination likely increased. Thus, I observed no decrease in seed set with honeybee declines in any of the three plant species tested, and one of these even showed a significant increase. Finally, I also demonstrated that this change differentially affected different plant types, and that the extent of changes to each plant species differed between land-use types. This reflected changes in the relative abundance of pollen types in different land uses, with greater specialisation in the absence of honeybees disproportionately benefiting common species. These findings have strong implications for several contemporary issues in pollination biology, both locally within New Zealand and on a global scale. These are discussed in the following sections. Finally, I conclude by discussing the implications of this research on several contemporary issues in pollination biology, namely the ability for wild pollinators to compensate for honeybee declines, the impact of honeybees on natural new Zealand ecosystems, the contribution of honeybees to invasive weed pollination and finally the management of surrounding land use types to maximize the effectiveness of wild pollinators.