The pollination biology of Impatiens sakeriana was studied in Northwest province, Cameroon. The most efficient way of reproduction was examined, futhermore nectar production was neasured and bird pollinators was observed.

Submitted by Daniele Amaral (daniee_ni@hotmail.com) on 2016-09-26T18:11:59Z No. of bitstreams: 1 DissLMC.pdf: 1097178 bytes, checksum: d229b0a750a3a0e2c2e07472d02d468b (MD5) / Approved for entry into archive by Marina Freitas (marinapf@ufscar.br) on 2016-10-04T17:55:01Z (GMT) No. of bitstreams: 1 DissLMC.pdf: 1097178 bytes, checksum: d229b0a750a3a0e2c2e07472d02d468b (MD5) / Approved for entry into archive by Marina Freitas (marinapf@ufscar.br) on 2016-10-04T17:55:08Z (GMT) No. of bitstreams: 1 DissLMC.pdf: 1097178 bytes, checksum: d229b0a750a3a0e2c2e07472d02d468b (MD5) / Made available in DSpace on 2016-10-04T17:55:16Z (GMT). No. of bitstreams: 1 DissLMC.pdf: 1097178 bytes, checksum: d229b0a750a3a0e2c2e07472d02d468b (MD5) Previous issue date: 2015-05-22 / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Bees are social insects of fundamental importance to the environment, because they are responsible for pollinating more than 70% of existing agricultural crops in the world. Brazil is the country with the highest number of described species, with representatives of most families. Among representatives of the Apidae family, is the Melipona scutellaris specie, commonly known as "uruçu" or "uruçu do Nordeste”, it is easy to handling and very well adapted to the climate of the state of São Paulo. However, due to the intensive use of pesticides, native bees are suffering the consequences, because, although they are not the target of insecticides, are highly vulnerable to contamination. Among the insecticides developed in the 90s, the neonicotinoids and fipronil have been identified as the main substances involved in collapse, and were suspended in 2013 in the European Union for two years for best evaluation. These insecticides are often used simultaneously, so bees can be contaminated with both molecules. Due to this fact, the aim of this study was determine the median lethal time (LT50) of fipronil and imidacloprid insecticides separately and synergistically on forage bees of M. scutellaris. For this, was obtained only the LD50 and LC50 of imidacloprid, according to the rules of the OECD, because values of fipronil were established by Lourenço et al. (2012a, 2012b). The LD50 of imidacloprid obtained was 2.41 ng a.i. / bee (24 hours) and 1.29 ng a.i./ bee (48 hours). The LC50 value found was 2.01 ng a.i./μL diet (24 hours) and 0.81 ng a.i./μL diet (48 hours). These data indicate that M. scutellaris specie is more sensitive to the insecticide imidacloprid that A. mellifera africanized. From these values, was obtained the LT50 based on topical and oral contamination of fipronil and imidacloprid insecticides and also these substances acting together. The results showed that fipronil has LT50 greater than imidacloprid. When acted in combination to LT50 presented intermediate values between the LT50 fipronil and imidacloprid, isolated. Then, according to the values obtained, there was not synergy, but a decrease in the toxicity of imidacloprid. / As abelhas são insetos sociais de fundamental importância ao meio ambiente já que são responsáveis pela polinização de mais de 70% das culturas agrícolas existentes no mundo. O Brasil é o país com maior número de espécies descritas, com representantes da maioria das famílias. Entre os representantes da família Apidae, está a espécie Melipona scutellaris, conhecida popularmente como “uruçu” ou “uruçu do nordeste”, abelha de fácil manejo e muito bem adaptada ao clima do estado de São Paulo. Porém, devido à intensa utilização de agrotóxicos, as abelhas nativas vêm sofrendo as consequências, já que, embora não sejam o alvo de inseticidas, são altamente vulneráveis à contaminação. Entre os inseticidas desenvolvidos na década de 90, o fipronil e os neonicotinóides têm sido apontados como as principais substâncias envolvidas nos colapsos, tendo sido suspensos em 2013 na União Europeia por dois anos para melhor avaliação. Esses inseticidas muitas vezes são utilizados simultaneamente, e por isso as abelhas podem ser expostas a ambas as moléculas. Devido a tal fato, o objetivo desse trabalho foi estabelecer o tempo letal médio (TL50) dos inseticidas fipronil e imidacloprido de forma isolada e de forma combinada sobre as abelhas forrageiras de M. scutellaris. Para isso, obteve-se a DL50 e CL50 apenas do imidacloprido, conforme as normas da OECD, já que para o fipronil esses valores foram estabelecidos por Lourenço et al. (2012a, 2012b). A DL50 do imidacloprido obtida foi 2,41 ng i.a./abelha, para 24 horas e 1,29 ng i.a./abelha, para 48 horas. O valor de CL50 desta mesma substância encontrado foi 2,01 ng i.a./μL dieta, para 24 horas e 0,81 ng i.a./μL dieta, para 48 horas. Esses dados indicam que a espécie M. scutellaris é mais sensível ao inseticida imidacloprido que A. mellifera africanizada. A partir desses valores, obtivemos a TL50 baseada na contaminação tópica e oral dos inseticidas fipronil e imidacloprido e também dessas substâncias agindo juntas. Os resultados apresentaram que o fipronil possui TL50 maior que o imidacloprido. Quando agiram de forma combinada a TL50 apresentou valores intermediários entre a TL50 do fipronil e do imidacloprido, isolados. Então, de acordo com os valores obtidos, não ocorreu sinergismo e sim uma diminuição da toxicidade apresentada pelo imidacloprido.

Submitted by Deyse Queiroz (deysequeirozz@hotmail.com) on 2018-05-23T11:28:36Z No. of bitstreams: 1 ALMAIR ALBUQUERQUE FERNANDES - DISSERTAÇÃO PPGSA PROFISSIONAL 2013..pdf: 1284731 bytes, checksum: 401b929cf8f492680f0c4d5dc74efc6c (MD5) / Made available in DSpace on 2018-05-23T11:28:36Z (GMT). No. of bitstreams: 1 ALMAIR ALBUQUERQUE FERNANDES - DISSERTAÇÃO PPGSA PROFISSIONAL 2013..pdf: 1284731 bytes, checksum: 401b929cf8f492680f0c4d5dc74efc6c (MD5) Previous issue date: 2013 / As espécies que compõem a flora apícola são classificadas levando em consideração a busca de alimentos desenvolvida pelas abelhas, podendo ser agrupadas em plantas nectaríferas (fornecem exclusivamente néctar às abelhas), plantas poliníferas (fornecem exclusivamente pólen às abelhas) e plantas nectaríferas-poliníferas (fornecem tanto néctar quanto pólen às abelhas). Levando em consideração que a produção de mel e outros produtos apícolas encontram-se ligados à presença das flores, é importante que se conheça as espécies apícolas que se desenvolvem numa determinada região, seus períodos de florescimento, bem como sua abundância. Desta forma, a caracterização da vegetação e sua distribuição contribuem para o estabelecimento de uma apicultura sustentável. O presente estudo foi realizado na reserva ambiental pertencente ao Perímetro Irrigado Engenheiro Arcoverde, que possui uma área de aproximadamente 135 ha e encontra-se localizado no município de Condado, Estado da Paraíba. A referida reserva, que é propriedade do Departamento Nacional de Obras Contra Seca e administrada em parceria com Instituto Brasileiro do Meio Ambiente e dos Recursos Naturais Renováveis. Para amostragem do componente arbustivo arbórea foram lançadas 28 parcelas de 20 X 20 metros de forma sistemática. Analisando os dados coletados, constatou-se que a espécie Croton blanchetianus, destacou-se das demais, pelo fato de ter apresentado 477 indivíduos, representando 40,46% da amostra pesquisada. Diante destes números e levando em consideração a contribuição que pode advir dessa espécie vegetal para a atividade apícola, concluise que a área avaliada possui uma grande importância para a apicultura. Tal conclusão consta que na área estudada, as espécies predominantes são nectaríferas-poliníferas, que durante o período de floração são transformadas em valiosas fontes, onde as abelhas encontram em quantidade vários dos componentes utilizados para a produção do mel, produto este que possui um excelente sabor. / The species that make up the bee flora are classified considering foraging developed by bees, which can be grouped into nectar plants (exclusively provide nectar to bees), polliniferous plants (exclusively provide pollen for bees) and plants nectarpolliniferous (provide both nectar to bees as pollen). Taking into account that the production of honey and other bee products are linked to the presence of flowers, it is important to know the bee species that thrive in a particular region, their flowering periods, as well as their abundance. Thus, the characterization of vegetation and their distribution contribute to the establishment of a sustainable beekeeping. This study was conducted in environmental reserve belonging to the Irrigation Engineer Arcoverde, which has an area of approximately 135 ha and is located in the municipality of County, State of Paraiba. Such reserves, which is owned by the National Department of Works Against Drought and administered in partnership with the Brazilian Institute of Environment and Renewable Natural Resources. For sampling arboreal shrub component 28 plots of 20 X 20 meters systematically been launched. Analyzing the data collected, it was found that the species Croton blanchetianus, stood out from the others by having presented 477 individuals, representing 40.46% of the sample surveyed. Given these numbers and taking into account the contribution that can come from this plant species for beekeeping, it can be concluded that this area is of great importance to beekeeping. This conclusion is the observation that supports the area studied are the predominant species polliniferous nectar that during flowering sound transformed into valuable resources, where bees are several in number of components used for the production of honey, a product which has an excellent flavor.

The pollination of flowering crops by bees is an invaluable ecosystem service that supports biodiversity and much of the global agricultural system. Pollinators move pollen between the male structures of a plant to the female structures of a plant of the same species. This fertilizes the female plant, which then produces the next generation. This process also provides the pollinator with the nectar or pollen it needs to survive. While some plants transfer pollen through different means, the majority of plants need help from pollinators to reproduce. Depending on the means of pollination, pollination can be classified as abiotic or biotic. Abiotic pollination occurs without the assistance of living organisms, through agents like wind or water. Around 80% of pollination is biotic-- at least 100,000 different species of animals pollinate the estimated 250,000 species of flowering plants in the world (Penn State). Pollinators promote local biodiversity in their ecoregions and are vital to many of the essential crops used for human consumption. Klein et al. found that 87 crops, 70% of the 124 most important food crops used for human consumption globally, are dependent on pollinators (Klein, 2007). Insect pollination is a production practice used extensively by farmers all over the world for producing crops (Kearns, 1998). Widespread pesticide usage, climate change, and destroyed habitats are leading to a loss in biodiversity and a considerable decline in pollinator communities. It is imperative for us to increase education around the significance of pollinators, and work to reverse the anthropogenic causes of dwindling pollinator populations. While bees have long been a vital part of preserving biodiversity and sustaining human agricultural systems, the plight to save the bees has generated considerable buzz in the last few years related to the recent phenomenon of Colony Collapse Disorder. During the winter of 2006-2007, beekeepers began to report unusually high losses of 30-90 percent of their hives. As many as half of affected colonies demonstrated symptoms inconsistent with any known causes of honeybee death (EPA, 2017). The problem is clear--the bees are disappearing. The question becomes what does that mean, and how do we fix it? The large scale answer must include a careful consideration of current agricultural practices and the factors that are contributing to losses in biodiversity. But on a small scale, everyone can help support local pollinator populations-- as long as they have access to the right media to guide them. For my thesis project, I decided to build a website that allows users to input their zip code in order to receive information on which types of native pollinator-friendly plants are best suited to grow in their specific ecoregion.

Submitted by Luciana Ferreira (lucgeral@gmail.com) on 2017-10-18T14:30:50Z No. of bitstreams: 2 Dissertação - Cristiele Barbosa Valente - 2014.pdf: 1029577 bytes, checksum: ddb0057b71c64fb5c0213a752b6d73f3 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2017-10-18T14:31:35Z (GMT) No. of bitstreams: 2 Dissertação - Cristiele Barbosa Valente - 2014.pdf: 1029577 bytes, checksum: ddb0057b71c64fb5c0213a752b6d73f3 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2017-10-18T14:31:35Z (GMT). No. of bitstreams: 2 Dissertação - Cristiele Barbosa Valente - 2014.pdf: 1029577 bytes, checksum: ddb0057b71c64fb5c0213a752b6d73f3 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2014-02-25 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / The invasion of terrestrial habitats by exotic plants often has negative effects on growth and fitness of native plants. Exotic plants may change the foraging behavior of pollinators and dynamics of interactions of local assemblages. Due to the lack of shared evolutionary history between exotic plants and native pollinators, it is likely that the morphological and phenological mismatches are especially important in determining the interactions involving exotic plants and specialist native pollinators. In addition, exotic plant species are expected to be pollinated by abundant generalist pollinators whose interactions are phylogenetically constrained compared to specialists pollinators. To evaluate these issues, we compiled 28 plant-pollinator networks with 778 plant species (10% alien) and 3019 pollinator species, comprising 7919 interactions. We expected that: (a) exotic plants tend to be visited by more generalist pollinator species compared to the co-occurring native plant species; (b) an increase in the proportion of exotic plants in the plant-pollinator networks promotesan increase in the global connectivity and nestednessof the interactions. If these predictions are correct, then the introduction of plants should also promote an increase in the risk of heterospecific pollen deposition on native plants. We found that exotic and native plants did not differ in the average degree of specialization of their pollinators. Moreover, an increase in the proportion of alien plants did not affecteither structure or the connectivity of networks. On the other hand, there was an increase in the risk of heterospecific pollen deposition on native plant stigmas when the proportion of exotic plants increases to about 1/3 of the flora pollinated by animals.However, above this percentage the relationship is reversed. This result may be a consequence of progressive decrease in pollinator fidelity of native plants in habitats with low-levels of invasion by exotic species, reducing the amount of shared pollen due to the impoverished pollinator fauna. / A invasão de habitats terrestres por plantas exóticas geralmente tem efeitos negativos sobre o crescimento e reprodução das plantas nativas. Além disso, plantas exóticas podem promover alterações no comportamento dos polinizadores e na dinâmica de interações das assembleias locais. Devido à ausência de uma história evolutiva entre plantas exóticas e polinizadores locais, é provável que as restrições morfológicas, fenológicas e comportamentais atuem de modo mais severo sobre interações envolvendo plantas exóticas e polinizadores nativos especialistas. Além disso, quando uma planta coloniza uma nova área, espera-se que ela interaja com maior probabilidade com os polinizadores generalistas devido, entre outros fatores, à maior abundância e menor seletividade dos mesmos. Assim, esperamos que: (a) em redes de interação planta-polinizador, os visitantes florais das plantas exóticas sejam mais generalistas do que aqueles que visitam plantas nativas; (b) a introdução de plantas exóticas promova um aumento na conectividade e no aninhamento das redes de interações planta-polinizador. Consequentemente, a introdução de plantas deve promover também um aumento no risco das plantas nativas receberem pólen heteroespecífico. Para avaliar as expectativas acima, compilamos 28 redes de interações planta-polinizador com 778 espécies de plantas (10% exóticas) e 3019 espécies de polinizadores, compreendendo 7919 interações. Em assembleias locais, as plantas exóticas e nativas não diferiram quanto ao grau de especialização de seus polinizadores. Além disso, um aumento na proporção de plantas exóticas não promoveu alterações na conectividade e estrutura das redes de interações. Por outro lado, há um aumento no risco das plantas nativas serem contaminadas por pólen heteroespecífico (Rphr) quando a porcentagem de plantas exóticas aumenta até atingir cerca de 13 da flora polinizada por animais. Isso pode ser uma consequência da diminuição na fidelidade dos polinizadores das plantas nativas em ambientes pouco invadidos. No entanto, acima desse percentual a relação é inversa, o que pode ser consequência da redução na quantidade de pólen compartilhado devido à perda de parte da fauna de polinizadores.

CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior / A pesquisa foi realizada na fazenda SÃo SebastiÃo, localizada no municÃpio de Mulungu â CE. Os dados foram coletados e trabalhados no perÃodo de Novembro de 2009 a Junho de 2010, com o objetivo de estudar os visitantes florais e a polinizaÃÃo do cafà (Coffea arabica L.) ecolÃgico e sombreado das cultivares Mundo Novo e Maragogipe. Foram estudados a biologia floral e os requerimentos de polinizaÃÃo das cultivares; o comportamento de pastejo e avaliaÃÃo dos frutos apÃs 100 dias dos tratamentos de polinizaÃÃo. Os resultados mostraram que Apis mellifera foi a espÃcie mais freqÃente nas flores (9  0,42, n = 455) seguida de Trigona fulviventris (4  0,52, n = 206), Melipona rufiventris (4  0,42, n = 151), Nannotrigona sp. (3  0,48, n = 148), Trigona spinipes (3  0,43, n = 157) e Xylocopa grisescens (2  0,78, n= 38). ApÃs 100 dias dos tratamentos de polinizaÃÃo (polinizaÃÃo livre, restrita com saco de papel, restrita com saco de organza, polinizaÃÃo cruzada manual e geitonogamia) verificamos diferenÃas significativas / The survey was conducted on the farm SÃo SebastiÃo, located in the city of Mulungu - CE. Data were collected and studied during the period November 2009 to June 2010 with the aim of studying the floral visitors and pollination of coffee (Coffea arabica L.) and green shade of Mundo Novo and Maragogipe. We studied the floral biology and pollination requirements of the cultivars, the grazing behavior and evaluation of fruit after 100 days of pollination. The results showed that Apis mellifera was the most frequent in the flowers (9  0.42, n = 455) followed by Trigona fulviventris (4  0.52, n = 206), Melipona rufiventris (4  0.42, n = 151), Nannotrigona sp. (3  0.48, n = 148), Trigona spinipes (3  0.43, n = 157) and Xylocopa grisescens (2  0.78, n = 38). After 100 days of pollination (open pollination, with narrow paper bag, with narrow organza bag, manual cross-pollination and geitonogamy) showed significant differences (Mundo Novo X2 = 44.9495, DF=4,p<0.005; Maragogipe: X2 = 59.8649, df = 4, p <0.005) between treatments with respect to viable fruits. The open pollinated differed significantly (P <0.05) of all treatments for Mundo Novo. In the cultivar Maragogipe, the free pollination, manual cross-pollination and geitonogamy presented the highest number of viable fruits and did not differ. However, these treatments differed significantly (P <0.05) than treatment with restricted pollination bag and this in turn also differed from the restricted pollination treatment with organza bag. The total weight of 100 days after the pollination treatments showed no significant differences between cultivars at a significance level of 5%. It is concluded that the Arabic coffee can produce fruits under any circumstances tested. Despite being selfcompatible, also supports the cross-pollination that leads to an increase in productivity. The wind and gravity did not favor an increase in fruit set fruit. Species Apis mellifera, Melipona rufiventris and Xylocopa grisescens recorded behavior of potential pollinators.

Made available in DSpace on 2017-07-10T17:48:19Z (GMT). No. of bitstreams: 1 Emerson_Dechechi_Chambo.pdf: 1181208 bytes, checksum: 9f416b41d3821a87e29b1f896bffd971 (MD5) Previous issue date: 2010-03-02 / The Research consisted of three experiments in Marechal Cândido Rondon city - PR, Brazil. In the first experiment the objective was to verify the influence of Apis Mellifera L. pollination on productive and physiological traits in sunflower achenes. The treatments were constituted by the combination of eight sunflower genotypes (Multissol, M734, Catissol 01, Charrua, MG2, Aguará, Helio 360 and Embrapa 122) and two tests of pollination, i) the flowers were free to insect visitation and ii) pollinators were restricted to visiting only inflorescences protected with gauze. The parameters analyzed were total productivity of seeds (PS), number of achenes per inflorescence (NA), mass of achenes per inflorescence (MA), mass of chapters (MC), chapter diameter (CD), ether extract in the achenes (EE), germination (GE), and mass of 1000 achenes (M1000). It was verified that the sunflower plants of the hybrid M734, exposed to insect pollination, showed PS and NA equal to 91,07% and 42,03%, respectively higher (p<0,05) than the plants of this hybrid with inflorescences protected with gauze. The chapters of the Catissol 01 cultivar exposed to insect pollination showed MA, MC and CD respectively, 150,52%, 130,28% e 35,06%, higher than the chapters of this cultivar protected with gauze. Inflorescences of the Embrapa 122 cultivar, free to insect visitation, presented EE and GE respectively, 52,63% e 134,29%, higher (p<0,05), than the inflorescences of this cultivar protected with gauze. Sunflower plants pollinated by Apis Mellifera presented average percentage of M1000 of 22,32% higher (p<0,05) than the plants protected with gauze, regardless of which genotype was being studied. In general, the pollination by insects enhances the productive traits and the quality of the seeds of sunflower genotypes. The second experiment was carried out with the objective of observing the type of food that africanized honey bees collect (pollen or nectar) at different times of day during the flowering period of five sunflower genotypes. The experimental design was arranged in randomized blocks split-plots scheme, with 100 treatments, four replications and two plants per experimental unit. The treatments were constituted by the combination of five genotypes of sunflower and (Helio 360, Helio 251, Charrua, Aguará e Multissol) allocated to plots and five days of observation and four time slots arranged in subplots. It could be seen that on the second and third days of sunflowers flowering there was a higher number of visits of Apis mellifera collecting nectar. It was observed that the honey bees collect pollen and nectar all they long, with peaks of collections from 7 to 8:30AM. The average density of honey bees throughout the day was 2.27 to 2.94 bees per inflorescence, and the honey bees collecting nectar were more frequent (2.28 bees / inflorescence) than honey bees collecting pollen (0.40 bees/inflorescence) on flowering days 2,94 and 2,96, respectively, and during the most visited time in the culture (7: 00 to 8:30 AM). On the third day of flowering, the hybrid Helio 360 and Aguará showed no differences amongst each other, and also showed higher (p <0.05) number of visitations of honey bees per inflorescence as compared to the other genotypes analyzed in the present study. It can be concluded that the africanized honey bees prefer to do their work of collecting food between the second and third day of flowering, between 7:00 to 8:30AM. Moreover, the hybrids Helio 360 and Aguará are more attractive to honeybees and should be recommended for maintenance and increase of number of pollinators in cultivated areas and to expand programs of honeybees pasture in the western of Paraná state, Brazil. The third experiment was carried out to evaluate the effect of the use of insecticide imidacloprid + beta-cyfluthrin on the number of visits by Apis mellifera bees to four sunflowers during the flowering season. Five plants were marked before the period of flowering of hybrids M734, Charrua, Helio 250 e Aguará, with four repetitions. Two observers remained two minutes on each plant, counting the number of honeybees in two intervals of time (from 8:30 AM to 10:00 AM and from 3:30 PM to 5:00 PM). The counting took place before the application of insecticide and twelve hours after the use of the product. It was verified that there was a significant negative effect of insecticide on the bees visitation considering the data of all hybrids, the hybrid of the M734 and Aguará. There was no effect of insecticide on the visit considering the data of the hybrid Charrua and Helio 250. It was also verified that the insecticide imidacloprid + beta-cyfluthrin causes repellence of Apis mellifera in sunflower crop. Moreover, the insecticide imidacloprid + beta-cyfluthrin was harmless to adults of Apis mellifera during blooming period for sunflowers, when applied to the lower middle third of the plants and the period in which these honeybees were not foraging. It would be necessary to assess their possible effects on young stages for further use in programs of integrated pest management in sunflower crop / A pesquisa constou de três experimentos, no município de Marechal Cândido Rondon, Paraná. No experimento I, objetivou-se verificar a influência da polinização realizada por Apis mellifera L. sobre características produtivas e fisiológicas em aquênios de girassol. Os tratamentos foram constituídos pela combinação de oito genótipos de girassol (Multissol, M734, Catissol 01, Charrua, MG2, Aguará, Helio 360 e Embrapa 122), casualizados nas parcelas, e dois testes de polinização, um livre a ação de insetos e o outro restringindo os polinizadores com sacos de filó, que foram alocados nas subparcelas. Os parâmetros analisados foram produtividade total de grãos (PT), número de aquênios por inflorescência (NA), massa de aquênios por inflorescência (MA), massa de capítulo (MC), diâmetro de capítulo (DC), teor de extrato etéreo em aquênios (EE), germinação (GE) e massa de 1000 aquênios (M1000). Verificou-se que as plantas de girassol do híbrido M734 expostas à polinização entomófila apresentaram PT e NA de 91,07% e 42,03%, respectivamente maiores (p<0,05) do que as plantas desse híbrido com inflorescências protegidas com filó. Os capítulos de girassol da variedade Catissol 01 expostos à polinização entomófila apresentaram MA, MC e DC de 150,52%, 130,28% e 35,06%, respectivamente maiores (p<0,05) do que os capítulos dessa variedade protegidos com filó. Inflorescências de girassol da variedade Embrapa 122 que ficaram livres a ação de insetos apresentaram EE e GE de 52,63% e 134,29%, respectivamente maiores (p<0,05) do que as inflorescências dessa variedade protegidas com filó. Plantas de girassol polinizadas por insetos apresentaram porcentagem média de M1000 de 22,32% maior (p<0,05) do que as plantas restringidas aos polinizadores por filó, independentemente do híbrido estudado. De maneira geral, a polinização entomófila aumenta as características produtivas e qualidade fisiológica em aquênios de girassol. O ensaio II foi conduzido com o objetivo de observar o comportamento de coleta de alimentos (néctar e pólen) de A. mellifera em cinco genótipos de girassol, em diferentes horários do dia, durante o período de florescimento da cultura. O delineamento experimental empregado foi o de blocos casualizados completos em esquema de parcelas subdivididas no tempo, com 100 tratamentos, quatro repetições e duas plantas por unidade experimental. Os tratamentos foram constituídos pela combinação de cinco genótipos de girassol (Helio 360, Helio 251, Charrua, Aguará e Multissol), alocados nas parcelas e cinco dias de observação e quatro intervalos de tempo arranjados nas subparcelas. Verificou-se pico de visitas de A. mellifera para coleta de néctar entre o segundo e terceiro dia de florescimento na cultura do girassol. Observou-se que as abelhas realizam coletas de pólen e néctar ao longo de todo o dia, com pico de coleta no período das 7 às 8h30min. A densidade média de A. mellifera ao longo do dia foi de 2,27 a 2,94 abelhas por inflorescência, sendo as abelhas coletoras de néctar mais frequentes (2,28 abelhas/inflorescência) do que as coletoras de pólen (0,40 abelhas/inflorescência) no dia de florescimento 2,94 e 2,96, respectivamente e no horário de maior visitação na cultura (7h às 08h30min). No terceiro dia do florescimento, os híbridos Helio 360 e Aguará não diferiram entre si e apresentaram maiores (p<0,05) números de visitas de abelhas por inflorescência em relação aos demais genótipos estudados. As abelhas africanizadas preferem realizar suas coletas de néctar e pólen entre o segundo e terceiro dia do florescimento do girassol, no horário das 7 às 8h30min. Os híbridos de girassol Helio 360 e Aguará são mais atrativos à A.mellifera e devem ser recomendados para manutenção e aumento de polinizadores em áreas cultivadas, bem como para pasto apícola na região Oeste do Paraná. No terceiro experimento objetivou-se verificar o efeito da aplicação do inseticida imidacloprido + beta-ciflutrina sobre a visitação de abelhas às inflorescências de quatro híbridos de girassol, durante o florescimento da cultura. Foram marcadas cinco plantas antes do período de florescimento dos híbridos M734, Charrua, Aguará e Helio 250, com quatro repetições. Dois observadores permaneceram dois minutos em cada inflorescência, contando o número de abelhas visitantes em dois intervalos de tempo (8h30min às 10h e 15h30min ás 17h). A contagem ocorreu antes da aplicação do inseticida e 12 horas após a utilização do produto na plantação. Houve efeito significativo de inseticida sobre a visitação de abelhas considerando os dados de todos os híbridos, do híbrido M734 e Aguará, sendo menor o número de visitas de abelhas africanizadas às inflorescências após a aplicação do produto. Não houve efeito de inseticida sobre a visitação nos híbridos Charrua e Helio 250. Constatou-se que o inseticida imidacloprido + beta-ciflutrina causa repelência a A. mellifera na cultura do girassol. Além disso, o inseticida imidacloprido + beta-ciflutrina foi inofensivo aos adultos de A. mellifera, durante o florescimento do girassol, quando aplicado no terço médio inferior das plantas e no período em que essas abelhas não estavam forrageando, sendo necessária a avaliação de seus possíveis efeitos em fases jovens para posterior utilização em programas de manejo integrado de pragas na cultura do girassol

Influence des interactions entre espèces végétales sur les relations plantes-pollinisateurs: cas de la compétition induite par la présence d'espèces anémophiles sur l'attractivité aux pollinisateurs d'espèces entomophiles Les traits d'attractivité aux pollinisateurs (fleurs et récompenses associées) d'espèces végétales entomophiles peuvent être sensibles aux variations de ressources dans le milieu (azote, phosphore). Puisque la compétition entre plantes peut modifier la disponibilité et la quantité de ces ressources, nous nous sommes intéressés à son effet sur les traits d'attractivité aux pollinisateurs, via la présence d'espèces végétales anémophiles. Nous avons démontré que la présence d'une espèce anémophile compétitive réduisait la production totale de fleurs, la vitrine florale et la quantité totale de sucre allouée au nectar chez une espèce entomophile. Cette diminution est d'autant plus forte que l'espèce anémophile est compétitive. En étudiant les visites de pollinisateurs sur une espèce entomophile en compétition avec une espèce anémophile, nous avons pu observer une diminution du nombre de visites, en relation avec une diminution de la production totale de fleurs et de la vitrine florale. Ainsi, bien que n'interagissant pas directement avec les pollinisateurs, les espèces anémophiles peuvent moduler les interactions plantes-pollinisateurs via des relations de compétition. Cette thèse soulève de nouvelles perspectives pour l'étude des réseaux plantes-pollinisateurs, qui se focalisent généralement sur les plantes entomophiles, en les ouvrants à l'ensemble de la communauté végétale. / Attractiveness traits of insect-pollinated plants to pollinators (i.e. flowers and associated rewards) can be sensitive to variations of resources (e.g. nitrogen, phosphorous). As competition between plants can modify resource availability, we studied its effect on insect-pollinated plants and their floral traits involved in attractiveness to pollinators, especially in presence of wind-pollinated plants. We showed that the presence of a competitive wind-pollinated species could reduce total flower production, floral display size and total sucrose allocated to nectar of insect-pollinated species. Especially, the stronger the competitor, the stronger is the effect on floral traits. The study of wild pollinators’ visits on an insect-pollinated plant in competition with a wind-pollinated plant revealed a decrease in the number of visits associated to the decrease of floral display size and total flower production. Therefore, even though they do not interact directly with pollinators, wind-pollinated plant species can modulate plant-pollinator interactions through competitive interactions. This thesis raises new perspectives for the study of plant-pollinator networks, which are generally focused on insect-pollinated plants, by opening them up to the whole plant community.

Degraded pollinator habitat may have far-reaching consequences for recovery of imperiled flowering plant populations. Studies indicate that broad-spectrum insecticides used in mosquito abatement are detrimental to non-target invertebrates, including pollinators. A decline in efficient pollinators can reduce plant fitness by decreasing reproductive output and constraining genetic diversity, a challenge for rare plants. In 2015, I monitored flower visitation and fruit set of three imperiled plant species throughout protected areas on three islands in The Lower Florida Keys. These islands consist of conservation land fragmented by intermittently dispersed residential neighborhoods that seasonally spray insecticides for mosquito control. Flowers open at treatment sites had decreased flower visitor activity following insecticide applications, but only species that require invertebrate agents for pollen transfer had significantly reduced fruit set. Implications of mosquito insecticides near conservation lands may pose immediate threats to invertebrate pollinators and flowering plants that require pollinators for reproduction, although long-term threats to genetic diversity are unknown for automatic self-pollinating species.

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