Melon is a pollinator-dependent crop that relies mainly on bees to set fruits. However, man-selected varieties vary in their attractiveness to flower visitors, and some flower genders and melon types may be less visited than others, harming pollination. We investigated the nectar composition of male, female and hermaphrodite flowers of 270 individuals of five commercial melons Cucumis melo (Cantaloupe, Charentais, Galia, Piel de Sapo, and Yellow), and its role in flower visit by Apis mellifera foragers. We found that melon nectar is composed mainly of sugars and amino acids such as tyrosine, phenylalanine, tryptophan, and flavonoids kaempferol-3-O-neohesperidoside, luteolin hexoside, and kaempferol rhamnoside. But the amount of these chemical compounds varies among the flower genders. We also developed an accurate regression model to predict the number of bee visits to melon flowers based on the nectar composition. Our results indicate that nectar composition plays little role in bee discrimination among flowers of different melon types but is essential to the honeybee choice between flower gender. The amounts of phenylalanine (49.40%) and tryptophan (12.05%) in the nectar are related to bee preference for hermaphrodite flowers. More visits to hermaphrodite flowers contribute to setting and developing well-formed fruits, increasing productivity.

Abstract Meliponines, popularly known as stingless bees, present a great diversity of species widely distributed in tropical regions. Some species are rationally reared to obtain bee products like honey, pollen and wax, and most of them are important pollinators of the native and cultivated flora in Brazil. Nevertheless, stingless bees are little investigated in their natural range throughout the country, especially in NE Brazil. This work is the first comprehensive survey sampling stingless bee species throughout the state of Ceará investigating their occurrence and distribution in different phytoecological units. In this sense, the study evaluated the species richness; the distribution in the diverse types of vegetation and relief formations; and reviewed the list of species with occurrence already described and incorporated 20 new occurrences for Ceará, increasing the number of species reported to the state from 29 to 49. We also indicate rare species and those once common but presently threatened mainly due to habitat loss, demonstrating the need of conservation efforts and potential for sustainable exploitation of these bee species and their habitats through meliponiculture. It also shed light in the potential richness of stingless bee species in NE Brazil.

Abstract The study investigated native solitary bee species that nest in pre-existing cavities in the Baturité Massif, State of Ceará, Brazil, their preference for nest substrates and aspects of these bee communities. Samples were taken in four distinct areas of the Baturité Massif using three types of trap-nests: dried bamboo internodes, cardboard tubes and rational boxes. Out of the 185 nests offered, 34 were colonized and 24 of them produced 131 bees, belonging to two families (Apidae and Megachilidae) and five genera (Centris, Mesocheira, Euglossa, Megachile and Coelioxys) from six species, including parasitic ones. Nesting preference was observed to certain types of substrates (χ²=17.89, p<0.001), with bamboo internodes being preferred by bee to build their nests, while monthly variation in temperature and humidity did not affect bee emergency. Spite of few nests foundations and the few species sampled, this work contributed to an unprecedented knowledge about the species that use pre-existing cavities in the Baturité Massif that may contribute to assist in the maintenance and conservation of this mountainous area and can be useful for pollination services of native and agricultural plants.

Abstract This study investigated the occurrence of individuals of stingless bees attracted by the trophic resources existing in four edge areas of forest fragments located in the Baturité Massif, State of Ceará. In this sense, the study evaluated the species richness in the areas; the absolute abundance of species; the similarity of species between edges; and the affinity of bees for the same plant species. The sampling of bees compiled a total of 20 species distributed in 12 genera. Seven species stood out for abundance and two (Trigona spinipes and Trigona fulviventris) showed dominance. The results also showed that the fragments present a similar stingless bee fauna and the affinity of the bee species for the same plant species revealed the formation of five distinct bee groups in foraging preferences involving 15 (75%) out of the 20 species of bees studied.

RESUMO Abelhas Euglossa Latreille, 1802 não vivem em grandes colônias, e estas geralmente são mantidas ou “reativadas” por novas fêmeas, subordinadas à mãe, que constroem e fornecem células de cria. Este estudo teve como objetivo obter informações sobre o tempo que as abelhas levam para prover novas células, sobre a emergência e permanência das abelhas nos ninhos, bem como o número de ninhos construídos por cada uma. Durante sete meses observamos fêmeas em 14 caixas vazias de madeira (5,7 x 5,7 x 7,0 cm), disponibilizadas para nidificação das abelhas. O método de remarcação foi utilizado quando uma abelha foi encontrada pela primeira vez nas caixas ou para cada nova abelha filha após a sua emergência. Um total de 12 caixas foi colonizada por Euglossa cordata (Linnaeus, 1758) e 23 células foram construídas em 9,78 ± 11 dias por célula. Onze fêmeas emergiram das células em 48,6 ± 11 dias. Dois imaturos morreram e dois foram parasitados por Bombyliidae. Apesar de que as fêmeas adultas de E. cordata moveram-se entre ninhos e às vezes usaram vários ninhos de uma só vez, elas demonstraram uma fidelidade relativamente alta a um único ninho (81.1% dessas fêmeas permaneceram mais de 50% do tempo em um único ninho).

ABSTRACT Euglossa Latreille, 1802 do not live in large colonies, and these are usually maintained or “reactivated” by new females, subordinate to their mother, which construct and provision brood cells. This study aimed to obtain information about the natural history of Euglossa cordata (Linnaeus, 1758) specially focusing on nest behavior. Our specific objective was to answer the following question: do E. cordata females reside in a single nest? We construct 14 artificial nesting boxes and made them available for E. cordata bees in natural environment for seven months. During this time, we use a re-marking method to identify bee fidelity to a single nest box. More specifically, we record bee permanence in the nests, the time bees take to provision brood to new cells and the time taken to offspring emergence. A total of 12 boxes were colonized by E. cordata and 23 cells were built in an average of 9.78 ± 11 days per cell. Eleven females emerged from the cells in 48.6 ± 11 days. Although adult females moved between nests and sometimes used multiple nests at the same time, E. cordata showed a relatively high fidelity to a single nest (81.1% of the female bees stayed in a single nest more than 50% of time).

Informações sobre o uso dos recursos florísticos de bordas imediatas de fragmentos de floresta atlântica pelas abelhas sem ferrão não estão facilmente disponíveis na literatura científica. Considerando a importância dessas espécies vegetais para as guildas de meliponíneos locais, este estudo objetivou identificar e caracterizar a flora das bordas imediatas de quatro fragmentos florestais de mata atlântica situados no maciço de Baturité, no estado do Ceará, usada como recurso alimentar pelas abelhas sem ferrão. Estudamos as formas de crescimento das plantas, a similaridade florística entre bordas, os efeitos da pluviosidade sobre a floração e sugerimos técnicas simples para o manejo dessas áreas. Compilamos um total de 82 espécies vegetais, com predominância das formas arbóreas e arbustivas. Houve diferença na riqueza florística entre as áreas e a pluviosidade teve influência diferenciada sobre a floração, de acordo com a borda. Concluímos que os componentes florísticos das bordas estudadas são importantes para as guildas de abelhas sem ferrão, mas, práticas alternativas de manejo são necessárias para conservar as espécies vegetais e as abelhas.

Information about the use of floristic resources of the immediate edges of ombrophilous forest (Atlantic rainforest) fragments by stingless bees is not readily available in the scientific literature. Considering the importance of these plant species for local guilds of stingless bees, this study aimed to identify and characterize the flora of the immediate borders of four Atlantic rainforest fragments situated in Baturité massif, state of Ceará, used as food resource by stingless bees. We studied the growth-form of the plants, the floristic similarity between edges and the effect of rainfall on the flowering, and suggested simple techniques for handling these areas. We compiled a total of 82 plant species with a predominance of tree and shrub form. There were different floristic richness between areas and rainfall had differentiated influence on flowering, according to the edge. We concluded that the florist components of the studied edges are relevant to the stingless bee guilds, but alternative management practices are needed to conserve both plant and bee species.

As abelhas coletoras de óleos são polinizadores naturais de plantas com flores que secretam óleos, mas pouco se conhece sobre o processo de polinização e efetividade dessas abelhas no sucesso reprodutivo dessas plantas. Nas espécies de Byrsonima o sistema reprodutivo tem sido descrito como autocompatível ou autoincompatível. Nós estudamos o sistema reprodutivo deByrsonima cydoniifolia, a frutificação por meio de polinização cruzada de curta, média e longa distância, a morfologia e biologia floral e a interação de polinização com as espécies de abelhas coletoras de óleos. Por meio de tratamentos de polinização controlada encontramos autoincompatibilidade causada pelo aborto da maioria das flores autopolinizadas e demostramos que a polinização cruzada que prevalesce e assegura o sucesso reprodutivo deB. cydoniifolia, se deve principalmente à polinização cruzada de longa distância, e às abelhas Centridini; particularmente Epicharis nigrita, são os polinizadores que promovem o fluxo gênico entre as populações geneticamente distintas.

Oil-collecting bees are the natural pollinators of oil-flower plants, but little is known about the pollination process and the effectiveness of their pollination service to the reproductive success of their host plants. In species of Byrsonima the reproductive system have been described as auto-compatible or self-incompatible. We studied the reproductive system ofByrsonima cydoniifolia, the fructification by means of short, medium and long-distance cross pollinations, the morphology and floral biology and the pollination interactions with species of oil-collecting bees. By means of controlled pollinations we found self-incompatibility caused by abortion of most self-pollinated flowers and demonstrated that the prevailing cross pollination ensuring the reproductive success of B. cydoniifolia is the long-distance cross pollination and Centridini bees; Epicharis nigrita, particularly, are the pollinators promoting the gene flow between genetically distinct populations.

Objetivou-se com este trabalho investigar qual área de cria deve ser adicionada para o fortalecimento de colônias de Apis mellifera, considerando-se as variações na ambiência interna das colônias. Para tanto, oito colônias foram equipadas com data loggers para registro da temperatura e da umidade no interior das colmeias. Em seguida, essas colônias foram dispostas em quatro tratamentos, envolvendo a troca de quatro, três, dois e um quadro com crias, entre colônias fortes e fracas. A evolução da quantidade de crias e de alimento nos quatro tratamentos de fortalecimento das colônias foi quantificada pela contagem de alvéolos, avaliando-se mudanças na área ocupada por crias e alimento. As colônias tenderam a retornar sua termorregulação em até 4 horas após a manipulação e o fechamento da tampa das colmeias, o que aumentou rapidamente a área de cria das colônias receptoras. Os resultados apontaram que a adição de até três quadros com crias constituiu uma alternativa importante para o fortalecimento de colônias de Apis mellifera, pois não interferiu na termorregulação do ninho, acelerou o crescimento populacional das colônias fracas e não afetou o desenvolvimento das colônias doadoras.

This study aimed to investigate the ideal brood area to be introduced for strengthening Apis mellifera colonies, considering variations in the hive's internal ambience. Therefore, eight colonies were equipped with data loggers for recording variations in temperature and humidity inside the hives. Then, these colonies were split in four treatments involving the swapping of four, three, two and one brood comb between strong and weak colonies. Growth in the amount of brood and food stores to the four colony strengthening treatments was assessed counting the comb cells to record changes in the brood and food area. The colonies tended to restore their normal thermoregulation within four hours after they had been manipulated and the hive cover had been closed, which quickly increased brood area in the receiving colonies. Results showed that adding up to three brood combs constitute an important alternative for strengthening Apis mellifera colonies because it did not interfere with nest thermoregulation, speeded up population growth in weak colonies and did not affect the development of strong colonies.

A mamoneira (Ricinus communis L.) é cultivada principalmente para produção de biodiesel devido ao alto teor de óleo de suas sementes e considerada como sendo de polinização anemófila. Mas déficits de polinização podem levar a baixos índices de produtividade geralmente atribuídos a outros fatores. Neste trabalho foram investigados os requerimentos, mecanismos e déficit de polinização e o papel dos polinizadores bióticos em um monocultivo comercial de mamona. Os resultados mostram que R. communis possui um sistema de polinização misto, favorecendo a autopolinização por geitonogamia, embora o vento normalmente promova polinização cruzada. Observou-se também que a abelha melífera (Apis mellifera L.) forrageando na mamoneira pode tanto transferir pólen das flores estaminadas para as pistiladas do mesmo racemo, quanto aumentar consideravelmente a liberação de pólen em suspensão no ar pelas flores estaminadas. Ambas as situações elevam a taxa de geitonogamia, aumentando significativamente o vingamento de frutos e produção de sementes. Este é o primeiro relato da atividade de forrageio de um animal aumentando a produção de sementes em uma cultura anemófila e de polinização predominantemente por geitonogamia e esclarece o papel dos polinizadores bióticos na polinização da mamoneira.

Castor bean (Ricinus communis L.) is cultivated mainly for biodiesel production because of its oil-rich seeds; it is assumed to be an anemophylous species. But pollination deficit can lead to low productivity often attributed to other reasons. In this paper, we investigated pollination requirements, pollination mechanism, occurrence of pollination deficit, and the role of biotic pollinators in a large commercial plantation of castor bean. Our results show that R. communis bears a mixed breeding system favoring selfing by geitonogamy, although the wind promotes mostly outcrossing. We also found that the honey bee (Apis mellifera L.) foraging on castor bean can both transfer pollen from male to female flowers within the same raceme and boost the release of airborne pollen by male flowers. Both situations increase geitonogamy rates, raising significantly fruit set and seed yield. This is the first report of an animal foraging activity increasing seed yield in an anemophilous and geitonogamous crop and elucidates the role of biotic pollinators in castor bean reproduction.

As abelhas sem ferrão são espécies indígenas encontradas em todo o Brasil. Seu pólen é utilizado devido ao seu valor nutricional na dieta humana. É produzido a partir de pólen floral misturado com néctar e líquidos secretados pelas abelhas. Visando avaliar a composição química, a atividade sequestradora de radicais livres e a origem botânica foi estudado o pólencoletado pela abelha sem ferrão Melipona rufiventris (Uruçu-amarela). Do extrato acetato de etila foram isolados os compostos: ácido phidroxicinâmico, dihidroquercetina, isoramnetina, 3O(6"OEpcoumaroil)βDglicopiranosideoisoramnetina, luteolina e quercetina. Esta é a primeira vez que a 3O(6"OEpcoumaroil)βDglicopiranosideoisoramnetina é isolada de pólen apícola. A atividade sequestradora de radicais livres de vários extratos com solventes diferentes foi determinada pelo teste com DPPH (difenilpicrilhidrazida). A atividade mostrou a ordem decrescente para os extratos AcOEt>EtOH>Hexano. O extrato AcOEt apresenta melhor atividade sequestradora de radicais. A avaliação botânica palinológicamostrou que o pólen era composto de dois tipos, um majoritário(97.3%) proveniente de Scoparia dulcis (L.) (Scrophulariaceae) e outro minoritário proveniente de Senna obtusifolia (L.) Irwin& Barneby (Fabaceae). Estes resultados sugerem o comportamento de forragem bastante específico exibido pela abelha Melipona rufiventris, mesmo em um ambiente tão rico em diversidade vegetal como o Nordeste do Brasil.

Stingless bees in Brazil are indigenous and found all over the country. Bee pollen is used for its nutritional value in the human diet. It is made up of natural flower pollen mixed with nectar and bee secretions. In order to evaluate the chemical composition, free radical scavenging activity, and botanical origin, sample of pollen loads from stingless bee, Melipona rufiventris (Uruçu amarela) was studied. The EtOAc extract of pollen of Melipona rufiventris yielded the following compounds: p-hydroxycinnamic acid, dihydroquercetin, isorhamnetin, isorhamnetin3-O-(6"-O-E-p-coumaroyl)-β-D-glucopyranoside, luteolin, and quercetin. This is the first report of the isolation of isorhamnetin3-O-(6"O-E-p-coumaroyl)β-D-glucopyranoside from pollen. The free radicalscavenging activities of different solvent extracts of pollen were determined using DPPH assay. This activity decreases in the order: EtOAc>EtOH>Hexane extract. It appears that the EtOAc extract of the pollen is a good scavenger of active oxygen species. The botanical evaluation of pollen loads showed the composition by two pollen types, with the dominant type (97.3%) being Scopariadulcis (L.) (Scrophulariaceae) and the minor one Senna obtusifolia (L.) Irwin & Barneby (Fabaceae). This suggests a specific foraging behavior in Melipona rufiventris bees, even in an environment with such a rich botanical diversity as the Northeastern Brazil.