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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
121

Toxicidade de inseticidas para abelhas Apis mellifera L

Bovi, Thaís de Souza [UNESP] 19 April 2013 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:33:34Z (GMT). No. of bitstreams: 0 Previous issue date: 2013-04-19Bitstream added on 2014-06-13T21:06:30Z : No. of bitstreams: 1 bovi_ts_me_botfmvz.pdf: 296305 bytes, checksum: cd79bf7c5ea0761f01a0c3fe43cec56e (MD5) / Este trabalho teve por objetivos estabelecer a Dose Letal (DL50) de inseticidas em abelhas campeiras de Apis mellifera africanizadas e verificar a ocorrência de alterações comportamentais. O experimento foi desenvolvido no Setor de Apicultura da Faculdade de Medicina Veterinária e Zootecnia, Fazenda Experimental Lageado, UNESP, Campus de Botucatu. Foram utilizadas abelhas campeiras e testados os agrotóxicos Acefato, Cipermetrina, Deltametrina, Carbaril, Fipronil e Imidacloprido, por meio de testes de contato (2L na região dorsal do tórax) e ingestão (1 mL de mel), ambos contendo as diferentes doses dos inseticidas. O controle dos testes de contato e ingestão receberam apenas água destilada e mel, respectivamente. Após 30, 60, 90, 120 e 150 minutos do início dos testes quantificou-se o número de abelhas com alterações comportamentais. Para cálculo da DL50, 24 horas após o início dos testes, os resultados foram submetidos à análise Probit, utilizando-se o programa BioStat. Os dados de alteração de comportamento foram analisados por meio do teste de Tukey para comparação entre médias (P<0,05). As DL50 de contato e ingestão (g/abelha) foram, respectivamente, Acefato 0,00370,0012 e 0,01470,0045; Carbaril 0,24560,1254 e 0,36330,1680; Cipermetrina 0,00040,0001 e 0,01030,0087; Deltametrina 0,00420,0021 e 0,04860,01; Fipronil 0,00800,0021 e 0,23160,0626; Imidacloprido 0,03080,0218 e 0,10790,0375. Os testes de contato para Acefato, Carbaril, Cipermetrina e Deltametrina e os testes de ingestão para Carbaril, Fipronil e Imidacloprido mostraram alterações comportamentais significativas, em relação ao controle. Conclui-se que todas as substâncias foram prejudiciais às abelhas, devido aos baixos valores de DL50 obtidos, e a ocorrência de alterações comportamentais / This research aimed establishes the lethal dose (LD50) of insecticides in africanized foraging bees Apis mellifera and verify the occurrence of behavioral changes. The research was conducted in the Sector of Apiculture, Veterinary Medicine and Animal Science University, Lageado Experimental Farm, UNESP, Botucatu. Were used foraging bees and tested the pesticides Acephate, Cypermethrin, Deltamethrin, Carbaryl, Fipronil and Imidacloprid through contact test (2L in dorsal region of the chest) and food intake (1mL of honey), both containing different doses of pesticides. The control group test of contact and food intake received only distilled water and honey, respectively. After 30, 60, 90, 120 and 150 minutes of the test starting were quantified the numbers of bees with behavioral changes. For calculation of LD50, 24 hours after the starting of tests, the results were submitted to Probit analysis using the program BioStat. Data behavioral changes were analyzed by Tukey test for comparison of means (P<0.05). The LD50 of contact and food intake (g/bee) were, respectively, Acephate 0.00370.0012 and 0.01470.0045; Carbaryl 0.24560.1254 and 0.36330.1680; Cypermethrin 0.00040.0001 and 0.01030.0087; Deltamethrin 0.00420.0021 and 0.04860.01; Fipronil 0.00800.0021 and 0.23160.0626; Imidacloprid 0.03080.0218 and 0.10790.0375. The tests contact to Acephate, Carbaryl, Cipermethrin and Deltamethrin and the food intake tests for Carbaryl, Fipronil and Imidacloprid showed significant behavioral changes, compared to control. It can be concluded that all the substances were harmful to bees, due to low LD50 values obtained, and the occurrence of behavioral changes
122

Produtos naturais no controle do ácaro Varroa destructor em abelhas Apis mellifera L. (africanizadas) /

Castagnino, Guido Laércio Bragança, 1960- January 2008 (has links)
Resumo: O presente trabalho teve como objetivo avaliar os efeitos do ácido oxálico e de óleos essenciais de plantas como arruda (Ruta graveolens), timol (Thymus vulgaris) eucalipto (Eucalyptus spp) e hortelã (Mentha piperita) na infestação do Varroa destructor em colônias de abelhas Apis mellifera africanizadas. Testes in vitro foram realizados para verificar o efeito desses produtos sobre as abelhas e os ácaros Varroa destructor. Vinte abelhas foram colocadas em gaiola de observação e, no seu interior, um bloco de esponja floral com 10μL, 50μL e 200μL dos diferentes óleos essenciais, segundo os tratamentos: T0: água, T1: óleo de arruda, T2: óleo de hortelã, T3: timol e T4: óleo essencial de eucalipto. Após, as abelhas e os ácaros foram observados por seis horas e quantificadas as mortalidades em decorrência do efeito de cada tratamento. Ambos os testes in vitro foram constituídos de quatro repetições por tratamento. No trabalho de campo, foram realizados seis tratamentos com cinco repetições, aplicados em 30 colônias, sendo: (T0) colméias sem tratamento; (T1) colméias tratadas com óleo essencial de arruda; (T2) timol; (T3) ácido oxálico; (T4) óleo essencial de eucalipto e (T5) óleo de hortelã. Os dados coletados antes da aplicação de cada produto foram confrontados com os obtidos após, verificando os diferentes níveis de mortalidade de varroas, taxa de mortalidade de crias de abelhas, taxa de infestação de varroas em crias e em abelhas adultas. Testes in vitro demonstraram que as substâncias testadas promoveram a mortalidade dos ácaros a partir de 10μL. Em trabalho de campo, constatou-se que as colônias tratadas com óleo de arruda, timol, ácido oxálico, óleo de eucalipto e de hortelã reduziram de forma significativa a mortalidade de crias quando parasitadas pelo ácaro. Os tratamentos com ácido... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: This study aimed to evaluate the effects of oxalic acid, and plant essential oils such as arruda (Ruta graveolens), thymol (Thymus vulgaris), eucalyptus (Eucalyptus spp) and mint (Mentha piperita) in the Varroa destructor infestation in hives of honeybees Apis mellifera africanizated. In vitro tests were performed to determine the effect of these products on bees and Varroa destructor mite. Twenty bees were allocated in observational cages and inside a block of floral foam with 10μL, 50 μL and L 200 μL of different essential oils, according to the treatments: T0: water, T1: arruda oil, T2: mint oil, T3: thymol and T4: eucalyptus essential oil. Afterward, the bees and mites were observed for six hours and mortality recorded. Both in vitro tests were performed in quadruplicate measurements per treatment. Field study was conducted in Santana do Livramento / RS, from 20th June to 21st July, 2005. Six treatments with five repetitions were performed in 30 colonies, where: (T0) beehives without treatment; (T1) beehives treated with arruda essential oil, (T2) thymol, (T3) oxalic acid, (T4) eucalyptus essential oil, and (T5) mint oil. Data collected before the implementation of each product were confronted with those obtained after products administration, checking the different levels of varroas mortality, mortality rate of young bees, infestation rate of varroas in young and adult bees. In vitro tests showed that the tested substances promoted bees and mites mortality in equal or superior amounts of 10μL. In this context, it was found that the colonies treated with arruda oil, thymol, oxalic acid, eucalyptus and mint oil reduced significantly mortality of mite parasitized young bees. Treatments with oxalic acid and thymol promoted a significant reduction in varroas infestation... (Complete abstract click electronic access below) / Orientador: Silvia Regina Cunha Funari / Coorientador: Ricardo de Oliveira Orsi / Banca: Dejair Message / Banca: Lídia Maria Carreli Barreto / Banca: Silvia Maria Alves Gomes / Banca: Nabor Veiga / Doutor
123

Toxicidade de inseticidas para abelhas Apis mellifera L. /

Bovi, Thaís de Souza, 1983- January 2013 (has links)
Orientador: Ricardo de Oliveira Orsi / Banca: Edson Ramos de Siqueira / Banca: Lídia Maria Ruv Carelli Barreto / Resumo: Este trabalho teve por objetivos estabelecer a Dose Letal (DL50) de inseticidas em abelhas campeiras de Apis mellifera africanizadas e verificar a ocorrência de alterações comportamentais. O experimento foi desenvolvido no Setor de Apicultura da Faculdade de Medicina Veterinária e Zootecnia, Fazenda Experimental Lageado, UNESP, Campus de Botucatu. Foram utilizadas abelhas campeiras e testados os agrotóxicos Acefato, Cipermetrina, Deltametrina, Carbaril, Fipronil e Imidacloprido, por meio de testes de contato (2L na região dorsal do tórax) e ingestão (1 mL de mel), ambos contendo as diferentes doses dos inseticidas. O controle dos testes de contato e ingestão receberam apenas água destilada e mel, respectivamente. Após 30, 60, 90, 120 e 150 minutos do início dos testes quantificou-se o número de abelhas com alterações comportamentais. Para cálculo da DL50, 24 horas após o início dos testes, os resultados foram submetidos à análise Probit, utilizando-se o programa BioStat. Os dados de alteração de comportamento foram analisados por meio do teste de Tukey para comparação entre médias (P<0,05). As DL50 de contato e ingestão (g/abelha) foram, respectivamente, Acefato 0,00370,0012 e 0,01470,0045; Carbaril 0,24560,1254 e 0,36330,1680; Cipermetrina 0,00040,0001 e 0,01030,0087; Deltametrina 0,00420,0021 e 0,04860,01; Fipronil 0,00800,0021 e 0,23160,0626; Imidacloprido 0,03080,0218 e 0,10790,0375. Os testes de contato para Acefato, Carbaril, Cipermetrina e Deltametrina e os testes de ingestão para Carbaril, Fipronil e Imidacloprido mostraram alterações comportamentais significativas, em relação ao controle. Conclui-se que todas as substâncias foram prejudiciais às abelhas, devido aos baixos valores de DL50 obtidos, e a ocorrência de alterações comportamentais / Abstract: This research aimed establishes the lethal dose (LD50) of insecticides in africanized foraging bees Apis mellifera and verify the occurrence of behavioral changes. The research was conducted in the Sector of Apiculture, Veterinary Medicine and Animal Science University, Lageado Experimental Farm, UNESP, Botucatu. Were used foraging bees and tested the pesticides Acephate, Cypermethrin, Deltamethrin, Carbaryl, Fipronil and Imidacloprid through contact test (2L in dorsal region of the chest) and food intake (1mL of honey), both containing different doses of pesticides. The control group test of contact and food intake received only distilled water and honey, respectively. After 30, 60, 90, 120 and 150 minutes of the test starting were quantified the numbers of bees with behavioral changes. For calculation of LD50, 24 hours after the starting of tests, the results were submitted to Probit analysis using the program BioStat. Data behavioral changes were analyzed by Tukey test for comparison of means (P<0.05). The LD50 of contact and food intake (g/bee) were, respectively, Acephate 0.00370.0012 and 0.01470.0045; Carbaryl 0.24560.1254 and 0.36330.1680; Cypermethrin 0.00040.0001 and 0.01030.0087; Deltamethrin 0.00420.0021 and 0.04860.01; Fipronil 0.00800.0021 and 0.23160.0626; Imidacloprid 0.03080.0218 and 0.10790.0375. The tests contact to Acephate, Carbaryl, Cipermethrin and Deltamethrin and the food intake tests for Carbaryl, Fipronil and Imidacloprid showed significant behavioral changes, compared to control. It can be concluded that all the substances were harmful to bees, due to low LD50 values obtained, and the occurrence of behavioral changes / Doutor
124

Minerais em méis de abelhas Apis mellífera L. produzidos na região do Pólo Cuesta, Estado de São Paulo

Ito, Erica Harue [UNESP] 24 February 2012 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:30:17Z (GMT). No. of bitstreams: 0 Previous issue date: 2012-02-24Bitstream added on 2014-06-13T19:18:52Z : No. of bitstreams: 1 ito_eh_me_botfmvz.pdf: 244276 bytes, checksum: 5dd109d2948cfebeebabb81a16a5238d (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Universidade Estadual Paulista (UNESP) / Os objetivos do presente trabalho foram avaliar a presença dos minerais cálcio (Ca), cobre (Cu), enxofre (S), ferro (Fe), fósforo (P), magnésio (Mg), potássio (K) , sódio (Na) e zinco (Zn) em amostras de méis de eucalipto (Eucalyptus sp.), laranjeira (Citrus sinensis L. Osbeck) e silvestre de abelhas Apis mellifera L. da região do Pólo Cuesta, estado de São Paulo, Brasil. As análises dos minerais foram realizadas por espectrofotometria de absorção atômica e os resultados avaliados por meio da Análise de Variância (ANOVA), seguido pelo teste de Tukey-Kramer para comparação das médias (P<0,05). Houve diferenças para os minerais Ca, S, P, Mg, K e Na entre as diferentes origens botânicas. Pode-se concluir que os méis da região do Pólo Cuesta apresentam minerais essenciais ao organismo humano, sendo que o mel de eucalipto apresentou os maiores teores para a maioria dos minerais analisados / The aim of this study were to evaluate the presence of minerals calcium (Ca), copper (Cu), sulfur (S), iron (Fe), phosphorus (P) , magnesium (Mg), potassium (K), sodium (Na) and zinc (Zn) in eucalyptus (Eucalyptus sp.), orange (Citrus sinensis L. Osbeck) and wild honeys samples of Apis mellifera L. bees from Pólo Cuesta region, São Paulo state, Brazil. Analyses of minerals were carried out by atomic absorption spectrophotometry and the results evaluated by analysis of variance (ANOVA) followed by Tukey-Kramer test for comparison of means (P<0.05). There were differences for Ca, S, P, Mg, K and Na minerals between different botanical origins. It was concluded that the honey’s Pólo Cuesta region shows minerals essentials to human organism, and the eucalyptus honey had the majority minerals analysed
125

Bioindikace antropogenního zatížení prostředí chemickými polutanty (těžké kovy) s pomocí včel a jejich produktů (včelí med) / Bioindication of man effect on environmental pollution by chemical pollutants (heavy metals) with the use of bees and their products (bee honey)

KOS, Václav January 2008 (has links)
The main objective of my work was to evaluate if it is possible to use the honey bee - Apis mellifera as a bioindicator of the environmental contamination by heavy metals. Two areas were being compared. The first one was more affected by emission (The Capital city of Prague) and the second one was less hit by emission (The Highlands). During the course of three years five samples of bee honey were taken from each area. The analysis was made to show how much cadmium, lead and mercury the samples contained. In most samples higher concentration of these chemicals were dealt out in honey taken from the more polluted area. Although not all the concentrations of heavy metals in honey reflect the emission burden of the examined areas. It would be necessary to take samples from a larger number of areas in order to confirm the conclusion that bee honey is a suitable bioindicator of the environmental contamination by heavy metals.
126

Behavioural response of honeybees (Apis mellifera scutellata Lep.) to wild pollinators on sunflowers (Helianthus annuus L.)

Shenkute, Awraris Getachew 10 November 2010 (has links)
Pollination is an essential ecosystem service, increasing reproductive success of many crops, which can be provided by managed pollinators, wild bees (including honeybees) and other insect pollinators. However, the pollination services and the economic value of wild pollinators are often underestimated. Better understanding of the factors that influence honeybee foraging behaviour and pollination efficiency can contribute to the improvement of management practices that aim to enhance crop pollination and ecosystem services. The objectives of this study were to investigate the importance of managed honeybees and wild honeybees to sunflower pollination as well as to evaluate the response of honeybees to different levels of floral rewards and to behavioural interactions with wild flower visitors. The study was conducted in 16 commercial sunflower farms and one experimental farm of South Africa during the 2009 sunflower flowering season. The results showed that insects, particularly honeybees, were efficient pollinators, improving sunflower production in all self-fertile sunflower cultivars used in this study. Furthermore, wild honeybee colonies were found to be as efficient as managed honeybee colonies in sunflower pollination near to natural habitat. Both sunflower yield and the abundance of pollinators decreased with distance from natural habitat, suggesting that sunflower yield is directly correlated with the abundance of pollinators. The amount of nectar present in the florets of sunflower significantly affected pollinator behaviour, influencing honeybee visitation length and foraging rate which prefer to exploit floral rewards from the same source if they find the higher amount per foraging trip, possibly having a negative impact on cross-pollination. Moreover, the concentration of nectar collected from honeybees was significantly lower than the nectar concentration from florets, suggesting that honeybees diluted highly concentrated sunflower nectar with their saliva to their optimum concentration level. Interspecific exploitative competition between honeybees and wild pollinators (wild bees, butterflies and moths) significantly increased the movement of honeybees among sunflower heads, which enhances cross-pollination. Furthermore, behavioural interactions influenced the length of foraging time spent by individual honeybees per sunflower head. Butterflies were the most influential in enhancing honeybee foraging movement, followed by wild bees and then moths. The importance of a given flower visitor species to honeybee movement is likely related to the size of the visitor, as the bigger size of butterflies and movement of their wings increases the chance of disturbing a neighbouring honeybee. Conservation of natural habitat is important to maintain the diversity of flower visitors which indirectly contribute to crop production by enhancing honeybee foraging activity and consequent direct pollination service. Furthermore, the pollination effectiveness of wild pollinators, density of wild honeybees surrounding sunflower fields and effects of human activities on pollination disruption are suggested as topics for future research. / Dissertation (MScAgric)--University of Pretoria, 2010. / Zoology and Entomology / unrestricted
127

Regulation of protein and carbohydrate intake in caged honeybees Apis mellifera scutellata : assessment based on consumption and various performance measures

Altaye, Solomon Zewdu 12 November 2010 (has links)
When provided with the opportunity to select their diet, most insect herbivores regulate their nutrient intake. However, in a nutritionally heterogeneous environment and with changing demands for growth, development and reproduction, obtaining the required amount and balance of nutrients is a challenge. This is especially true for social insects where the workers bring food into the colony to be shared by nestmates. The ability of insects to self-select their diet is an important trait related to fitness. In this study we investigated whether and how caged worker honeybees meet their nutritional requirements in response to the nutritional composition of the food they find. Using the ‘geometric framework’ we looked at the behavioural and physiological mechanisms used by caged worker honeybees in balancing their diet when provided with different pairs of complementary imbalanced foods. First, we investigated whether caged worker honeybees maintain their intake target by providing them with pairs of complementary imbalanced foods with varying protein to carbohydrate (P:C) ratios. Diets were formulated using different protein sources: casein, royal jelly and Feed-Bee®. Honeybees self-selected or balanced their diet by switching between the complementary foods in accordance with the composition of the food and the type of protein that they encountered. Honeybees selected average P:C ratios of 1:12, 1:14 and 1:11 on casein, royal jelly and Feed-Bee® diets respectively. The level of self-selection was confirmed using two performance measures: survival and ovarian activation. Both survival and ovarian activation differed depending on the type of protein source used. Second, we investigated if honeybees regulated their growth target, which is the amount of nutrients incorporated into growth and storage tissue, by measuring physiological parameters in honeybees confined on imbalanced complementary food combinations having different P:C ratios. Feed-Bee® was used as a protein source. The physiological parameters measured were head fresh mass, hypopharyngeal gland (HPG) development, and protein concentration in the haemolymph. The bees fed on different diet combinations with different P:C ratios maintained each of the performance measures to the same level, which supports the ability of worker honeybees to self-select their diet. The measured physiological parameters were compared with other studies to asses the appropriateness Feed-Bee® diet as a protein source for the bees. In the absence of brood the intake target is directly related to the physiological requirements of the worker bees. The behavior of these individual adult bees gives an insight in to the complex system; similar responses may be seen in nurse bees in the colony condition to obtain protein, carbohydrate and other nutrient requirements from stored pollen and nectar in the hive, either for their own nutritional requirements or for other colony members, especially larvae. / Dissertation (MScAgric)--University of Pretoria, 2010. / Zoology and Entomology / unrestricted
128

Improvement and use of laboratory methods for toxicological assessments on eusocial bees / Plasticidade cerebral e comportamental e danos múltiplos de pesticidas em abelhas eussociais

Tomé, Hudson Vaner Ventura 23 February 2015 (has links)
Submitted by Marco Antônio de Ramos Chagas (mchagas@ufv.br) on 2015-11-25T08:40:33Z No. of bitstreams: 1 texto completo.pdf: 7983251 bytes, checksum: 5f6d6830b746d01b9e45183b84281ef3 (MD5) / Made available in DSpace on 2015-11-25T08:40:33Z (GMT). No. of bitstreams: 1 texto completo.pdf: 7983251 bytes, checksum: 5f6d6830b746d01b9e45183b84281ef3 (MD5) Previous issue date: 2015-02-23 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / A importância das abelhas para a polinização é inquestionável. Apesar disso, populações desses organismos têm sofrido consideráveis reduções no mundo por diversos fatores que incluem o uso de pesticidas. Abelhas eussociais geralmente vivem em ninhos, onde parte do desenvolvimento pós-embrionário ocorre em favos fechados, constituindo empecilho para o estudo do desenvolvimento. Portanto, para se estudar o efeito de pesticidas nesses organismos sem interferência de fatores ambientais é necessário a criação em condições controladas em laboratório, sendo que em condições naturais parte da exposição a pesticidas ocorre via alimentação larval. Nesse sentido, o aprimoramento de métodos de criação pode contribuir para o entendimento de como pesticidas afetam processos morfofisiológicos e moleculares nas abelhas mediante exposição das larvas a esses compostos. A presente tese objetivou desenvolver e/ou melhorar técnicas de criação de abelhas in vitro e realizar testes toxicológicos para avaliar a plasticidade cerebral e comportamental em abelhas sem ferrão. Além disso, desordens ocasionadas por pesticidas em abelhas sem ferrão e abelhas melíferas também foram estudadas. De maneira geral, os resultados obtidos na presente tese permitiram concluir que: 1) a criação de abelha sem ferrão M. quadrifasciata em laboratório retarda o desenvolvimento de algumas regiões cerebrais em relação às abelhas mantidas em condições naturais; 2) o inseticida sintético imidaclopride e o bioinseticida spinosade são altamente tóxicos a abelha sem ferrão M. quadrifasciata e também promovem efeitos subletais em operárias dessa espécie; 3) é possível reduzir consideravelmente a mortalidade de Apis mellifera criadas in vitro mediante o uso de procedimentos descritos de forma inédita no presente estudo e 4) todos os pesticidas causaram mortalidade e efeitos subletais (reduções no peso corporal, alterações na atividade de genes associados a destoxificação, distúrbios no desenvolvimento e estruturas das antenas) em abelhas melíferas em virtude da exposição de concentrações realistas de campo durante a fase larval. / The importance of bees for pollination is unquestionable. Nevertheless, populations of these organisms have suffered considerable reductions in the world by several factors including the use of pesticides. Eusocial bees usually live in nests, where part of the post-embryonic development occurs in closed combs, what makes difficult the study of bee development. Therefore, to study the impact of these pesticides without interference from environmental factors, the rearing of these organisms under controlled conditions in laboratory is necessary whereas part of pesticide exposure occurs via larval feeding in natural conditions. In this sense, the improvement of rearing methods can contribute to the understanding of how pesticides affect morphophysiological and molecular processes in bees by exposure of larvae to these compounds. This work aimed to develop and/or improve in vitro bee rearing techniques and perform toxicological tests to assess brain and behavioral plasticity in stingless bees. In addition, disorders caused by pesticides in stingless bees and honeybees were also studied. In general, it can be concluded that: 1) the rearing of stingless M. quadrifasciata laboratory de reased de elop e t of so e ees’ rai regio s compared with bees kept in natural conditions; 2) the synthetic insecticide imidacloprid and bio-insecticide spinosad are highly toxic to stingless M. quadrifasciata and also promote sublethal effects on workers of this species; 3) the mortality of Apis mellifera reared in vitro can be greatly reduced by using procedures described in the present study and 4) all pesticides tested caused mortality and sublethal effects (reductions in body weight, changes in gene activity associated with detoxification, developmental disorders and structures of the antennas) in honey bees after exposure during the larval stage to realistic field pesticide concentrations.
129

Absence of Consistent Diel Rhythmicity in Mated Honey Bee Queen Behavior

Johnson, Jennifer N., Hardgrave, Emily, Gill, Curtis, Moore, Darrell 01 July 2010 (has links)
Relatively little is known about the temporal control of behavior of honey bee queens under natural conditions. To determine if mated honey bee queens possess diel rhythmicity in behavior, we observed them in glass-sided observation hives, employing two focal studies involving continuous observations of individual queens as well as a scan-sampling study of multiple queens. In all cases, all behaviors were observed at all times of the day and night. In four of the five queens examined in focal studies, there were no consistent occurrences of diel periodicity for any of the individual behaviors. A more encompassing measure for periodicity, in which the behaviors were characterized as active (walking, inspecting, egg-laying, begging for food, feeding, and grooming self) or inactive (standing), also failed to reveal consistent diel rhythmicity. Furthermore, there were no consistent diel differences in the number of workers in the queen's retinue. Behavioral arrhythmicity persisted across seasons and despite daily changes in both light and temperature levels. Both day and night levels of behavioral activity were correlated with daytime, but not with nighttime, ambient temperatures. The behavior of the one exceptional queen was not consistent: diurnal activity patterns were present during two 24-h observation sessions but arrhythmicity during another. Based on the behavior observed by all but one of the queens examined in this work, the arrhythmic behavior by the mated honey bee queen inside the colony appears to be similar to that exhibited by worker bees before they approach the age of onset of foraging behavior.
130

Polinización y polinizadores de colza y especies espontáneas de Brassicaceae : su incidencia en la producción

Marinozzi, Luciano Alberto 17 November 2023 (has links)
Entre todas las especies de brasicáceas, la de mayor importancia es Brassica napus L. (colza), que se destaca por su elevada participación en la producción mundial de aceites comestibles. Muchas especies de brasicáceas, cultivadas y silvestres, no sólo tienen importancia en la alimentación humana, sino que han sido mencionadas como fuentes de polen y néctar. Es decir, que el solo hecho de formar parte de la comunidad vegetal aumenta las posibilidades de alimento para un gran número de polinizadores y visitantes florales. La presencia de visitantes florales de brasicáceas en el centro-sur de la Provincia de Buenos Aires (República Argentina) fue evaluada en parcelas de colza y en parches de brasicáceas espontáneas ubicados en la localidad de Tres Arroyos, en la Chacra Experimental Integrada Barrow (-38.319305, - 60.239380). Para realizar los muestreos se utilizaron redes entomológicas, trampas de agua de colores y el método de observación directa. Además, con el objetivo de determinar el efecto de los polinizadores sobre el rendimiento y sus componentes, en las parcelas de colza se colocaron jaulas excluidoras de polinizadores. Otra parte del trabajo se realizó en dependencias del Departamento de Agronomía de la Universidad Nacional del Sur con el fin de evaluar la germinabilidad in vitro del polen expuesto a condiciones ambientales de la colmena. Para esto, se seleccionaron colmenas de Apis mellifera L. y se colocaron en su interior muestras de polen de colza que se obtuvieron de plantas cultivadas en macetas de 10 litros. En la zona de estudio se comprobó que numerosas especies de insectos, de diversas familias y órdenes, visitaron el cultivo de colza al igual que los parches de especies espontáneas. Todas las especies capturadas se encontraron tanto en el cultivo como en las malezas aledañas. Esto indica que los polinizadores utilizan ambos recursos. Las zonas con vegetación espontánea aledañas a las parcelas de colza presentaron una floración más extensa, brindando recursos a los visitantes florales antes, durante y después de la floración del cultivo. Los resultados de este trabajo muestran que la visita de insectos polinizadores en el cultivo de colza mejora la producción de semilla y esto se traduce en un mayor rendimiento, que es, en definitiva, el objetivo de todo productor. También se demostró que el aumento de rendimiento de semilla tuvo implicancia directa sobre la producción de aceite por hectárea, dado que la visita de los polinizadores mejoró la cantidad de semilla y no generó variaciones significativas en el tenor de materia grasa. Por otro lado, se demostró que las condiciones ambientales dentro de la colmena de Apis mellifera son adversas para la germinabilidad de los granos de polen de colza, independientemente de las condiciones ambientales externas. Las zonas de cría son las de mayor temperatura y en 24 h no se registraron granos de polen con capacidad de germinar. A partir de las 48 h la capacidad de germinabilidad del polen disminuyó significativamente y el bajo porcentaje que germinó presentó tubos completamente atrofiados. Aunque el polen que se ubicó alejado de las zonas de cría mantuvo más tiempo su capacidad de germinar, sólo lo hizo por menos de 72 h. Los resultados de este trabajo respaldan una reducción sustancial del tiempo de carencia que exigen las empresas semilleras y abren la posibilidad de que se utilice una misma colmena en dos servicios de polinización consecutivos sin riesgo de contaminación por polen no deseado. / Among all the species of brassicas, the most important one is Brassica napus L. (rapeseed), which stands out for its significant contribution to the global production of edible oils. Many species of brassicas, both cultivated and wild, are not only important for human consumption but have also been mentioned as sources of pollen and nectar. In other words, simply being part of the plant community increases the food possibilities for a large number of pollinators and floral visitors. The presence of brassica floral visitors in the central-southern region of Buenos Aires Province (Argentina) was evaluated in rapeseed plots and patches of spontaneous brassica plants located in Tres Arroyos, at the Chacra Experimental Integrada Barrow (- 38.319305, -60.239380). Entomological nets, colored water traps, and direct observation methods were used for sampling. Additionally, exclusion cages were placed in the rapeseed plots to determine the effect of pollinators on yield and its components. Another part of the study was conducted at the Department of Agronomy, Universidad Nacional del Sur, to assess the in vitro germinability of pollen exposed to hive environmental conditions. Honey bee (Apis mellifera L.) colonies were selected, and samples of rapeseed pollen obtained from plants cultivated in 10-liter pots were placed inside the hives. The study in the area confirmed that numerous insect species from different families and orders visited both the rapeseed crop and the patches of spontaneous species. All captured species were found in both the crop and the surrounding weeds, indicating that pollinators utilize both resources. The areas with spontaneous vegetation adjacent to the rapeseed plots exhibited more extensive flowering, providing resources for floral visitors before, during, and after the crop's flowering period. The results of this study demonstrate that the visitation of pollinating insects in the rapeseed crop improves seed production, ultimately resulting in higher yields, which is the goal of every farmer. It was also shown that the increased seed yield directly impacted oil production per hectare, as pollinator visitation improved seed quantity without generating significant variations in fat content. On the other hand, it was demonstrated that the environmental conditions within the Apis mellifera hive are unfavorable for the germinability of rapeseed pollen grains, regardless of external environmental conditions. The brood areas have the highest temperatures, and within 24 hours, no pollen grains capable of germinating were recorded. From 48 hours onward, the germination capacity of the pollen significantly decreased, and the low percentage that did germinate exhibited completely atrophied tubes. Although pollen placed away from the brood areas maintained its germination capacity for a longer period, it did so for less than 72 hours. The results of this study support a substantial reduction in the required waiting time demanded by seed companies and open up the possibility of using the same hive for two consecutive pollination services without the risk of contamination by undesired pollen.

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