ABSTRACT Insect pollination has influenced the evolution and diversification of angiosperms. Consequently, knowing plants used as food sources by bees, the most important pollinator group, is the first step toward understanding how their ecological relationships works. Pollen source information is also highly relevant for bee management and associated fruit and seed production. Accordingly, to improve understanding of the trophic ecology of these bees and their relationships with native Amazonian plants the current study identified, quantified and compared pollen stored in nests of Frieseomelitta stingless bees along the Rio Negro, Amazonas, Brazil. A total of 31 pollen pots were sampled and found to contain 65 pollen types distributed across 52 genera and 29 botanical families (predominantly Arecaceae, Araliaceae, Fabaceae and Urticaceae). Euterpe was the commonest pollen type, being present in 32.2 % of the analyzed samples. Although the studied bees were generalists, pollen analysis suggested that different Frieseomelittaspecies may have distinct food preferences. The pollen profile of the studied bees was influenced more by nest location than by species phylogenetic proximity. The current study also provides a list of important plants for native bee management, which could improve beekeeping when grown near managed meliponarine colonies.

ABSTRACT Pollination research in Brazil virtually started with Fritz Muller, whose insights supported Darwin's evolutionary theory. Pollination systems of Brazilian plants were studied mainly by travelling researchers until early last century when native or resident geneticists began to use floral biology information to deal with crop acclimatization and breeding, later applying similar experiments and techniques to investigate native plants. Bee geneticists studied common pollinators of crops, such as coffee and Citrus, and even the introduction of feral African honeybees, despite their associated problems, stimulated pollination research. Geneticists attracted Dobzhansky to Brazil, where his research on tree distribution in the Brazilian Amazon represented a turning point for tropical pollination research by prompting the discovery of long-distance pollinating bees, thus bringing pollination back to mainstream evolutionary research. Tropical pollination studies stimulated the emergence of research groups in the Amazon and São Paulo states. In 1998, a seminal conference held in São Paulo called for the need to conserve pollinators and pollination systems. Subsequent research has been integrated under the Brazilian Pollinators Initiative, with research groups established throughout the country. A revived International Pollination Course, a National Pollination Symposium, and cooperative efforts to tackle complex interaction networks may direct future pollination research in Brazil.

ABSTRACT Widely distributed organisms face different ecological scenarios throughout their range, which can potentially lead to micro-evolutionary differentiation at specific localities. Mating systems of animal pollinated plants are supposed to evolve in response to the availability of local pollinators, with consequent changes in flower morphology. We tested the relationship among pollination , mating system, and flower morphology over a large spatial scale in Brazilian savannas using the tree Curatella americana (Dilleniaceae). We compared fruit set with and without pollinators in the field, and analyzed pollen tube growth from self- and cross-pollinated flowers in different populations. Populations with higher natural fruit set also had lower fruit set in bagged flowers, suggesting stronger barriers to self-fertilization. Furthermore, higher levels of autogamy in field experiments were associated with more pollen tubes reaching ovules in self-pollinated flowers. Morphometric studies of floral and leaf traits indicate closer-set reproductive organs, larger stigmas and smaller anthers in populations with more autogamy. We show that the spatial variation in mating system, flower morphology and pollination previously described for herbs also applies to long-lived, perennial tropical trees, thus reemphasizing that mating systems are a population-based attribute that vary according to the ecological scenario where the plants occur.

Resumo Beija-flores são o grupo de aves polinizadoras mais importantes nos Neotrópicos e tendem a utilizar, concomitantemente, mais de uma espécie de planta como fonte de alimento. O pólen pode estar misturado no corpo dos beija-flores devido às visitas em diferentes espécies de plantas, portanto, essas aves podem promover deposição de pólen heterospecífico (DPH). O potencial dos beija-flores em promover DPH, a ocorrência de DPH e suas consequências na reprodução das plantas são pouco conhecidas na Mata Atlântica. Nós estudamos o transporte de pólen por três espécies de beija-flores da Mata Atlântica brasileira. Nós também verificamos a ocorrência de DPH em condições naturais em duas espécies de planta, Canistropsis seidelii e Psychotria nuda. Além disso, nós investigamos o sistema reprodutivo de Nidularium innocentii, avaliando o efeito de DPH em sua reprodução ao simular uma polinização com mistura de pólen. Nós encontramos beija-flores transportando misturas de pólen heterospecífico em seus corpos, que por sua vez foram depositados nos estigmas de diferentes espécies. Nós também encontramos que a deposição de mistura de pólen tem um efeito negativo na aptidão de N. innocentii. Nós concluimos que beija-flores carregam misturas de pólen na mesma região do corpo, levando a um potencial DPH ao nível da comunidade. Além disso, comunidades de plantas e beija-flores na Floresta Atlântica exibem diversas similaridades em sua organização temporal e padrão de interações. Isso sugere que DPH pode ser um fenômeno difundido nestas comunidades.

Abstract Hummingbirds are the most important group of pollinating birds in the Neotropics and tend to use, concomitantly, more than one plant species as food source. Pollen may be mixed on hummingbirds' body due to the visits to different plant species; therefore, these birds may promote heterospecific pollen deposition (HPD). The hummingbirds potential to promote HPD, the occurrence of HPD and its implications in plant reproduction are scarcely known in the Atlantic Forest. We have studied the transport of pollen by three hummingbird species from the Brazilian Atlantic Forest. We have also checked the actual HPD occurrence under natural conditions in two plant species, namely Canistropsis seidelii and Psychotria nuda. Moreover, we investigated Nidularium innocentii reproductive system evaluating the effect of HPD on its reproduction by simulating a pollen mixture pollination. We found hummingbirds transporting heterospecific pollen mixtures on their bodies, which in turn were deposited onto stigmas of different species. We have also found that mixed pollen deposition had negative effect on the fitness of N. innocentii. We conclude that hummingbirds carry pollen mixtures at the same body parts, leading to potential HPD at the community level. Moreover, hummingbird-plant communities in the Atlantic Rainforest show remarkable similarities in temporal organization and interaction pattern. This suggests that HPD may be a widespread phenomena in these communities.

Entre as abelhas eussociais, dois gêneros apresentam estratégia de vida cleptobiótica, obtendo recursos alimentares de ninhos de outras abelhas ao invés de coletá-los em flores. Entre as espécies atacadas existe um gradiente de suscetibilidade ao roubo variando desde espécies vulneráveis até altamente resistentes. Neste trabalho nós descrevemos um ataque de Lestrimelitta rufipes a um ninho de Scaptotrigona sp. em um meliponário na Amazônia central (Amazonas, Brazil). O ninho atacado foi transferido para um meliponário com espécies resistentes (Duckeola ghilianii e Melipona fulva) e as interações foram descritas. As abelhas resistentes contra-atacaram e afugentaram as ladras protegendo o ninho de Scaptotrigona sp.. A presença de comportamento defensivo em gêneros não proximamente relacionados sugere que ele tenha evoluído mais de uma vez entre os Meliponini. Considerando o comportamento descrito, sugerimos a criação de espécies nativas resistentes em meliponários de regiões onde elas forem nativas, devido ao potencial que elas tem na proteção.

Among eusocial bees, two genera evolved a cleptobiotic life strategy, stealing food resources from other bee nest instead of collecting it from flowers. Under natural conditions there is a gradient of strategies against robbing, from more susceptible to highly resistant species. In this work, we describe one attack of the robber bee Lestrimelitta rufipes to a nest of Scaptotrigona sp. in the Amazon Rain Forest (Amazonas, Brazil). The attacked nest was introduced in a beekeeping area with bees already known to be resistant to cleptobiosis. The resident bees (Duckeola ghilianii and Melipona fulva) counter-attacked the robber bees and successfully protect the Scaptotrigona sp. nest. The presence of the defensive behaviour in unrelated genera suggests it evolved many times in social bees. Based on the protective behaviour described here, we suggest that in order to reduce the damage caused by Lestrimelitta attacks in Amazonian beekeeping, a combination of defensive and non-resistant bees should be considered.

Abelhas e plantas estabeleceram ao longo do tempo evolutivo uma relação mutualística. Buscando contribuir para o entendimento dessa relação, foi analisado o pólen estocado por colônias de abelhas-sem-ferrão distribuídas ao longo do rio Negro. Foram estudados potes de pólen de 14 espécies de Meliponini dos gêneros Partamona, Scaura e Trigona. O material polínico foi retirado dos potes de pólen, homogeneizado e preparado segundo técnica usual de acetólise. Foram calculados a sobreposição de nicho trófico e o agrupamento das espécies pela similaridade de nichos. Foi identificado o total de 78 tipos polínicos, pertencentes a 36 famílias, sendo 37 destes, considerados atrativos, enquanto 16 foram promotores de eventos de especialização temporária. Com os resultados obtidos foi possível indicar uma lista de plantas de importância para a meliponicultura na Amazônia.

Bees and angiosperms established a mutualistic relationship along the evolutionary time. The aim of this study is to contribute for the understanding of this relation analyzing pollen stored by stingless bees colonies distributed along the Rio Negro. Fourteen species of Meliponini from the genera Partamona, Scaura, and Trigona were studied with regard to the content of pollen pots. The pollen material was removed from the pollen pots, homogenized, and prepared according to the usual acetolysis technique. The overlap of the trophic niche and the grouping of species by similarity of niches was calculated. The identification revealed 78 pollen types belonging to 36 families, being 37 types attractive and 16 considered as promoters of a temporary specialization event. With the results, it was possible to indicate a list of important plants for meliponiculture in the Amazon.

Este trabalho descreve as relações entre visitantes florais e Davilla kunthii A. St.-Hil., bem como características de sua biologia reprodutiva em Itacoatiara (Amazonas). Foram realizados os testes referentes ao estudo do sistema reprodutivo. A guilda de visitantes foi caracterizada quanto à riqueza, abundância, frequência relativa e constância. Os testes para sistema reprodutivo indicaram que D. kunthii possui auto-compatibilidade. O mecanismo de polinização configurou-se como generalista com 39 espécies de visitantes florais, provenientes de três diferentes ordens. Abelhas corresponderam ao principal grupo de polinizadores, desta forma, alguns aspectos comportamentais foram descritos. O horário de maior forrageamento ocorreu entre 7 e 10 horas. Algumas espécies apresentaram interações agonísticas e comportamento monopolizador da fonte de alimento. Dado o comportamento e o potencial destrutivo, embora possa ocasionalmente atuar como polinizadores, Curculionidae parecem possuir maior impacto como predadores de sementes.

This survey aimed at describing the interactions of floral visitors and Davilla kunthii A. St.-Hil. as well as characteristics of its reproductive biology in Itacoatiara, state of Amazonas, Brazil. Tests of the breeding system were performed. The guild of visitors was described according to richness, abundance, relative frequency and constancy. The breeding system tests indicated that D. kunthii is self-compatible. The pollination system was characterized as generalist, with 39 visitor species, from three different orders. Bees were the main group of pollinators, thus some behavioural aspects were described. Th e period of highest foraging activity was between 7 and 10 am. Some species presented agonistic and monopolistic behaviour. Given the behaviour and destructive potential, the Curculionidae seem to have a greater impact as seed predators than pollinators.

A família Orchidaceae é uma das maiores entre as plantas com flores e apresenta grande importância do ponto de vista da conservação. Apesar disso, não existe nenhum trabalho sobre as orquídeas de Mato Grosso do Sul. Nesse sentido, o objetivo desta pesquisa foi realizar o levantamento das espécies de Orchidaceae e de aspectos de sua ecologia na Mata Ciliar de um fragmento de Floresta Estacional Semidecidual, às margens do rio Dourados (Dourados, MS). O levantamento foi realizado em sistema de varredura, sendo, nas epífitas, avaliadas as disposições vertical e horizontal sobre os forófitos. Para caracterização do microclima foram utilizados termo-higrômetro e luxímetro. Identificaram-se 17 espécies, pertencentes a 13 gêneros. Dos gêneros levantados, os de maior abundância foram: Acianthera, Macradenia e Capanemia. Relacionaram-se, ainda, as disposições vertical e horizontal das Orchidaceae com os gradientes inversos de disponibilidades hídrica e luminosa. Algumas espécies mostraram-se sensíveis à categorização em níveis de altura, enquanto outras pareciam ocorrer com frequência similar ao longo de todo o forófito. Em relação à orientação cardeal, a aparente resposta preferencial pelas faces sul e leste foi associada à insuficiência amostral e à menor disponibilidade hídrica que poderia ocorrer em razão de a face norte estar oposta ao espelho d'água.

The Orchidaceae is one of the largest flowering plants family and with a great importance to conservation. However, no survey on orchid flowers can be found in Mato Grosso do Sul. Thus, the objective of this work was to make a survey of the Orchidaceae species and of its ecology features in a riparian forest in a fragment of Floresta Estacional Semi-Decidual that belongs to the riparian forest of the Dourados River. The inventory was made by using a sweeping method for collection, and in addition to this the vertical and horizontal position of epiphytes were assessed on the hosts. For characterization of microclimate, it was used a thermohygrometer and luximeter. It was identified 17 species of 13 genera. Of the listed genera, the most abundant ones were: Acianthera, Macradenia and Capanemia. It was also noted a vertical and horizontal distribution of the Orchidaceae in relation to inverse gradient of water and light availability. Some species tended to be sensitive to height level categorization, whereas others seemed to occur with similar frequency along the host. In relation to the cardinal orientation, the apparent preferential response for south and east directions was associated to the low sampling effort and lower water availability, which could occur because the north face is opposed to the water body.