992 resultados para BUMBLE BEES
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We investigated the phenolic constituents and antioxidant activity of geopropolis from two species of stingless Amazonian bees, Melipona interrupta and Melipona seminigra. The chemical investigation of geopropolis from Melipona interrupta led to the isolation of 5,7,4'-trihydroxyflavonone, 3,5,6,7,4'-pentahydroxyflavonol, naringenine-4'-O-b-D-glucopyranoside and myricetin-3-O-b-D-glucopyranoside. Their structures were assigned based on spectroscopic analyses, including two-dimensional NMR techniques. Antioxidant activity of methanol and ethanol extracts of M. interrupta and M. seminigra were measured using the 1,2-diphenyl-2-picryl-hydrazyl (DPPH) free radical scavenging assay. This is also the first work reporting the chemical investigation of stingless bee species from the Amazonian region.
Reproductive ecology of the exotic tree Muntingia calabura L. (Muntingiaceae) in southeastern Brazil
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The exotic tree Muntingia calabura L. (Muntingiaceae), a species native to Central America, is used as fish feed and fiber and cellulose production in Brazil. This study was carried out in urban areas and verified the reproductive biology of this plant species. Flower and fruit morphology, compatibility system, reproductive phenology, pollination and frugivore animals, and germination of disseminated seeds were recorded by standard field and laboratory procedures. This tree is self-compatible and autonomously self-pollinated, with its flowers being mainly visited by bees and its fruits consumed by birds and bats. Germination of its dispersed seeds is fast and occurs at a high rate. The results of this work suggest that M. calabura is very adaptable to cultivated areas,thus being an excellent choice for urban reforestation. However, its reproductive characteristics place this plant as an invasive species with significant potential in southeastern Brazil.
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ABSTRACT This study investigates the flowering and pollinators of the floral morphs of three co-occurring distylous species, Psychotria conjugens Müll, P. hastisepala Müll. Arg. and P. sessilis Vell., in two consecutive flowering seasons in an Atlantic Forest fragment in southeastern Brazil. The species have diurnal, cream-colored, tubular, nectariferous flowers and their flowering occurs in the rainy season, from September to April, with little or no overlapping between species, characterizing a staggered flowering. The flowering of the long-and short-styled floral morphs of each species was synchronous, but the number of open flowers per day per morph tended to vary in each flowering season. These numbers were higher in P. sessilis and P. conjugens and, probably, resulted in higher total numbers of visits on its flowers (up to 1084 visits in P. sessilis and 756 in P. conjugens), compared to that observed in P. hastisepala (up to 71). There was a higher frequency of visits to long-styled flowers of all species. The bee Ariphanarthra palpalis was a common pollinator to all species. This bee is native to Brazil, solitary, considered relatively rare and its host plants were unknown. Other native bees (Melipona spp.) also visited the flowers of the Psychotria species. The availability of flowers with similar floral features over eight months, the staggered flowering and common pollinators appear to be part of a strategy to attract floral visitors, minimizing the competition for pollinators and then favoring the legitimate pollination of these plants.
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The floral biology of three weeds, Ipomoea cairica, I. grandifolia and I. nil (Convolvulaceae), was studied in Botucatu and Jaboticabal, São Paulo, in southeastern Brazil. The three species are melittophilous, with a varied set of floral visitors, but with some overlapping. Cluster analysis using Jacquard similarity index indicated a greater similarity among different plant species in the same locality than among the populations at different places, in relation to floral visitor sets. The promiscuous and opportunistic features of the flowers were shown, with such type of adaptation to pollination being advantageous to weeds since pollinator availability is unpredictable at ruderal environments.
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(Biologia floral de Vochysia cinnamomea Pohl (Vochysiaceae) em cerrados do Triângulo Mineiro, MG). Vochysia cinnamomea é uma arvoreta de cerrado comum na região do triângulo mineiro. Apresenta flores zigomorfas com pétalas amarelas e cálice gamossépalo com um dos lobos maior e calcarado. As flores abrem pela manhã e duram apenas um dia. Apresentam um estame que se desprende durante a antese, depositando o pólen no estilete, o que representa um tipo de apresentação secundária de pólen. As flores são visitadas principalmente por abelhas do gênero Epicharis e outras Anthophoridae, que são os polinizadores primários, mas beija-flores e esfingídeos diurnos também foram observados. A planta é parcialmente autocompatível, sendo os frutos formados por autopolinização pouco mais que um quarto dos formados por polinizações cruzadas, um índice de auto-incompatibilidade (ISI) de 0,26. Tubos polínicos de autopolinização cessam o crescimento no meio do estilete na maioria dos pistilos, indicando um mecanismo de incompatibilidade semelhante ao de outras espécies de vochysia. Os sistemas de polinização e reprodução de V. cinnamomea são, de maneira geral, similares aos de outras espécies brasileiras de vochysia, apesar da maioria ser claramente autoincompatível. A autocompatibilidade parcial na espécie estudada pode explicar a existência de espécies de Vochysia totalmente compatíveis encontradas em Costa Rica.
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The pollination ecology and breeding systems of Tabebuia aurea (Manso) Benth. & Hook., and T. ochracea (Cham.) Standl. were investigated in an area of cerrado vegetation in the Federal District of Brazil. These species occur sympatrically, flower massively and synchronously for a month, during the dry season (July to September). Both have diurnal anthesis, with similar floral structures, a yellow tubular corolla and produce nectar. Fourteen species of bees visited both Tabebuia species, but, only three Centris species and Bombus morio, were considered potential pollinators, because of their high frequency on the flowers and their efficiency in carrying pollen. Tests on the breeding systems of T. aurea and T. ochracea demonstrated that boths species are self-incompatible, with late-acting self-incompatibility. The proportion of fruit set from cross pollination (T. aurea 17.2% and T. ochracea 12.3%) in both species was low considering the great number of flowers displayed. This suggests a lack of maternal resources for fruit-set. The great amount of seeds per fruit (about 92 in T. aurea and 285 in T. ochracea) may represent an investment of maternal resources allocated on higher quality of fertilized ovules.
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O camu-camu (Myrciaria dubia (H.B.K.) McVaugh, Myrtaceae) é uma fruteira nativa que ocorre nas margens de rios e lagos inundáveis da Amazônia, e está sendo domesticada visando o cultivo em terra firme. O alto teor de ácido ascórbico nos frutos, cerca de 2.800 mg.100g-1 de polpa, fortalece a demanda para consumo no país e exportação. No período de 1997 a 1998, investigou-se a biologia floral e fenologia reprodutiva do camu-camu, em plantios da Embrapa Amazônia Oriental, em Belém, e em áreas de ocorrência natural, em Santarém e Oriximiná, no Estado do Pará, norte do Brasil. Observações diretas sobre o comportamento dos visitantes foram acompanhadas da coleta de espécimens para identificação e registro fotográfico. M. dubia apresenta inflorescências com flores brancas, hermafroditas e poliândricas. A antese ocorre entre as 5:00 e 7:00 h. O pólen é seco e facilmente transportado pelo vento ou gravidade, sendo o principal recurso e atrativo floral. Os osmóforos estão localizados no cálice, corola, anteras e estigma. Constatou-se que a fenofase de floração foi do tipo "steady-state", sendo mais expressiva em março e a frutificação teve um pico no mês de julho. Observouse desfolha parcial em todas as plantas estudadas, principalmente em novembro. Os principais visitantes foram Nannotrigona punctata e Trigona pallens (Meliponinae) e pequenos besouros (Chrysomelidae). As abelhas sem ferrão foram consideradas os polinizadores legítimos.
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Cucurbitaceae species depend on pollination by honey bees for fruit production. The overall objective of this work was to evaluate the potential of C. pepo for pollen and nectar production, that could help maintain colonies placed in the field. Plants of pumpkin were cultivated in field, in 1996 and 1997. Before anthesis, male flowers were covered to prevent visits by bees and other insects. After anthesis the flowers were uncovered and the following parameters were evaluated: 1) nectar production; 2) total sugar concentration in the nectar; 3) nectar replacement; and 4) production of pollen and flowers during the crop cycle. Nectar production varied from 18 to 79 µL flower-1 and increased progressively from 7h to 13h. The sugar concentration, measured at 7h, 9h and 11h, did not vary, averaging 50.5% ± 0.5% in 1996 and 40.5% ± 0.6% in 1997. At 13h the concentration decreased to 42% in 1996 and to 35% in 1997. Total daily nectar production was not influenced by removing nectar several times per day, indicating that nectar secretion is not stimulated or inhibited by frequent removal. The number of pollen grains did not differ in the two years, with an average of 43,669 ± 1,382 grains per flower. The peak rate of male and female flowers occurred from 60 to 66 days after planting (DAP) with 34.6 male flowers and 2.2 female flowers per plant, respectively. Cucurbita pepo has a potential for honey and pollen production of about 105 and 160 kg per hectare per season, respectively, which is enough to sustain, at least, five honeybee colonies.
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The goal of the present study was to identify plant species used as food source, the floral resources utilized, and the insects that visit flowers in a grassland community in southern Brazil. The study was carried out in an area of one hectare, located in a grassland formation in the Parque Estadual de Itapuã, State of Rio Grande do Sul, Brazil. The flowering pattern was seasonal, and richness and abundance of insects was higher during the period of high resource availability. Flowers of 106 species of angiosperms (73 genera and 34 families) were used as source of floral resources for 219 species (2,767 specimens) of insects. A total of 91.5% of plant species were visited by bees, 53.8% by flies, 34.9% by wasps, 22.6% by butterflies, and 12.3% by beetles. Nectar was the main resource consumed by the visitors (41.1%). Asteraceae was the richest (38 spp.) and most visited family, with 63.1% of the species and 49.5% of all specimens of recorded insects. Bees were the most representative insects (33.2% spp., 65% indiv.), followed by flies (26.9% spp., 16.5% indiv.), wasps, butterflies and beetles. 40 plant species were considered important resources for the floral visitors' community, due to high number of, both, species and individuals recorded in their flowers. The family Asteraceae as a species set was the main floral resource used by insect visitors through the year and has great importance for the maintenance of populations of many species of bees, flies, wasps and butterflies in the studied area.
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Jacaranda copaia (Aubl.) D. Don is a pioneer tree widespread in the Brazilian Amazon, usually found colonizing forest gaps and altered areas, and the forest fragment edges. This study investigated aspects of the floral biology, breeding system and pollinators of J. copaia trees. Flowering lasts from August to November, during the low rainfall period extending up to four weeks per tree and 3-4 months for the population as a whole, characterizing a cornucopia flowering pattern. The fruit set ends in the beginning of the rainy season, with wind dispersed winged seeds. Fruit set from open pollination was 1.06% (n = 6,932). Hand pollination using self-pollen (n = 2,099) did not set fruits. Cross-pollination resulted in 6.54% fruit set (n = 2,524), representing six times more than the natural pollination rate (1.06%, n = 6,932). Flowers excluded from insect visitation (automatic self-pollination) did not set fruits (n = 5,372). Pollen tube growth down to ovary was detected under fluorescence microcoscopy in cross-pollinated and selfed pistils. The species is an obligate allogamous plant, with late-acting self-incompatibility system. Approximately 40 species of native bees visited the flowers, but the main pollinators were medium-sized solitary bees as Euglossa and Centris species due to the compatibility between their body sizes with the corolla tube, direct contact with the reproductive structures and high frequency of visits.
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Large carpenter bees (Hymenoptera: Apidae: Xylocopa) have traditionally been thought of as exhibiting solitary or occasionally communal colony social organization. However, studies have demonstrated more complex fonns of social behaviour in this genus. In this document, I examine elements ofbehaviour and life history in a North American species at the northern extreme of its range. Xylocopa virginica was found to be socially polymorphic with both solitary and meta-social or semi-social nests in the same population. In social nests, there is no apparent benefit from additional females which do not perfonn significant work or guarding. I found that the timing of life-history events varies between years, yet foraging effort only differed in the coldest and wettest year of2004 the study. Finally, I that male X virginica exhibit female defence polygyny, with resident and satellite males. Resident males maintain their territories through greater aggression relative to satellites.
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Abstract Many species of social insects have the ability to recognize their nestmates. In bees, sociality is maintained by bees that recognize which individuals should be helped and which should be hanned in order to maximize fitness (either inclusive or individual) (Hamilton 1964; Lin and Michener 1972). Since female bees generally lay eggs in a single nest, it is highly likely that bees found cohabitating in the same nest are siblings. According to the kin selection hypothesis, individuals should cooperate and avoid aggression with same sex nestmates (Hamilton 1964). However, in opposite sex pairs that are likely kin, aggression should increase among nestmates as an expression of inbreeding avoidance (Lihoreau et al. 2007). Female bees often guard nest entrances, recognizing and excluding foreign conspecific females that threaten to steal nest resources (Breed and Page 1991). Conversely, males that aggressively guard territories should avoid aggression towards other males that are likely kin (Shellman-Reeve and Gamboa 1984). In order to test whether Xy/ocopa virginica can distinguish nestmates from non-nestmates, circle tube testing arenas were used. Measures of aggression, cooperation and tolerance were evaluated to detennine the presence of nestmate recognition in this species. The results of this study indicate that male and female X virginica have the ability to distinguish nestmates from non-nestmates. Individuals in same sex pairs demonstrated increased pushing, biting, and C-posturing when faced with non-nestmates. Males in same sex pairs also attempted to pass (unsuccessfully) nOIl-nestmates more often than ncstmates, suggesting that this behaviour may be an cxpression of dominancc in males. Increased cooperation exemplified by successful passes was not observed among nestmates. However, incrcased tolerance in the [onn of head-to-head touching was observed for nestmates in female same sex and opposite sex pairs. These results supported the kin selection hypothesis. Moreover, increased tolerance among opposite sex non-nestmates suggested that X virginica do not demonstrate inbreeding avoidance among nestmates. 3 The second part of this study was conducted to establish the presence and extent of drifting, or travelling to different nests, in a Xylocopa virgillica population. Drifting in flying Hymenoptera is reported to be the result of navigation error and guard bees erroneously admitting novel individuals into the nest (Michener 1966). Since bees in this study were individually marked and captured at nest entrances, the locations where individuals were caught allowed me to determine where and how often bees travelled from nest to nest. Ifbees were captured near their home nests, changing nests may have been deliberate or explained by navigational error. However, ifbees were found in nests further away from their homes, this provides stronger evidence that flying towards a novel nest may have been deliberate. Female bees are often faithful to their own nests (Kasuya 1981) and no drifting was expected in female X virginica because they raise brood and contribute to nest maintenance activities. Contrary to females, males were not expected to remain faithful to a single nest. Results showed that many more females drifted than expected and that they were most often recaptured in a single nest, either their home nest or a novel nest. There were some females that were never caught in the same nest twice. In addition, females drifted to further nests when population density was low (in 2007), suggesting they seek out and claim nesting spaces when they are available. Males, as expected, showed the opposite pattern and most males drifted from nest to nest, never recaptured in the same location. This pattern indicates that males may be nesting wherever space is available, or nesting in benches nearest to their territories. This study reveals that both female and male X virginica are capable of nestmate recognition and use this ability in a dynamic environment, where nest membership is not as stable as once thought.
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This study examined how the athletic career of Roderick R. McLennan contributed to the popularization and subsequent development of Caledonian games in Ontario during the latter nineteenth century. Initially, the development of Caledonian games during the 1800s was examined to provide a contextual framework for McLennan's career. This investigation revealed that the games emerged from rural athletic events at pioneer working bees in the first quarter of the nineteenth century to regional sporting events by the mid-1800s, and finally into annual federated Caledonian games in 1870. Noteworthy primary source material for this chapter included the John MacGillivray Papers at the National Archives of Canada, the Scottish American Journal (NY) and the files retained by the Glengarry Sport Hall of Fame in Maxville, Ontario. Following the investigation of Caledonian games, McLennan's early athletic career was studied. Analysis of the Roderick and Farquhar McLennan Papers at the Archives of Ontario and the newspapers from the period revealed that McLennan rose to popularity in 1865 through a "Championship of the World" hammer throwing match in Cornwall and two "Starring Tours". The next chapter examined the height of McLennan's career through an investigation of the Roderick McLennan versus Donald Dinnie rivalry of the early .. n 1870s. It was detennined that the rivalry between McLennan and Dinnie, the champion athlete of Highland games in Scotland, was a popular attraction and had an impact on the Toronto and Montreal games of 1870 and the Toronto games of 1872. Finally, the athletic records established by McLennan during the 1860s and 1870s were investigated. These records were examined through the context of a media controversy over McLennan's feats that developed in the early 1880s between two newspapers. This controversy erupted between the Toronto Mail and the Spirit of the Times. Caledonian games in Canada have only been briefly examined and a thorough examination of prominent Canadian figures in this context has yet to be undertaken. This study unearths a prominent Canadian athlete of Scottish decent and details his involvement in the Caledonian games of nineteenth century Ontario.
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Sweat bees exhibit a range of social behaviours, from solitary nesting, in which no workers are produced, to strong eusociality, in which workers exhibit a high degree of altruism, behaviour that is measured by the degree of personal reproductive sacrifice. Field studies were carried out for seven weeks during May-June 2000 in southern Greece in order to investigate intraspecific social variation, and test the hypothesis of a north-south cline of decreasing eusociality in the obligately eusocial sweat bee L. (E.) malachurum. A comparative study, using principal components analysis, was performed to determine if patterns of intraspecific social variation in L. malachurum reflect the patterns of social variation within the subgenus, Evylaeus, as a whole. The results of the field study reveal that, in Greece, two worker broods were produced followed by a third brood consisting of gynes, males and some workers, indicating that there was an overlap in worker and gyne production. There was strong caste distinction between queens and workers. Workers actively foraged and participated in nest construction as most workers (58%, n=303) had a high degree of mandibular wear. Workers did not participate in the oviposition of Brood 3 gynes since only 0.7% (n=278) of workers were mated. Furthermore, queen survival until the end of Brood 3 and a substantial size differential of 10.6% between queens and workers suggested that queen domination over worker behaviour during the early to mid-part of the colony cycle was plausible. Male production in Brood 3 by some workers was likely, since the timing of worker ovarian development corresponded with the timing of male production. These findings suggest that workers of the first two broods were primarily altruistic, but some (28%) Brood 1 (9%) and Brood 2 (19%) workers produced males, indicating that the degree of altruistic behaviour declined during the lifetime of the colony. In comparison with other L. malachurum populations in Europe, the Greek population of L. malachurum had a weaker social level as a result of the higher proportion of workers potentially involved in male production, thus 3 supporting the hypothesis of a southerly cline of decreasing eusociality. Furthermore, intraspecific variation in social level across Europe appears to be due to longer breeding seasons in more southerly locations that would promote the production of larger colonies and provide opportunities for workers to evade queen control. The comparative study using principal components analysis on 20 solitary (of the subgenera Evylaeus and Lasioglossum), eusocial and socially polymorphic Evylaeus species and populations reveals that six traits are closely associated with stronger eusociality in Evylaeus. These traits are: (1) a reduction in the proportion of males in the early brood(s); (2) a reduction in the proportion of females that mate; (3) an increase in the mean number of first brood workers; (4) a reduction in the proportion of females with developed ovaries; (5) an increase in size dimorphism between castes, and (6) nest guarding. These are traits that most significantly define principal component one and therefore distinguish social type as indicated by a clear separation of the eusocial and the solitary populations, with a socially polymorphic species falling in between. Furthermore, most of these traits are under foundress control and may suggest that the evolutionary loss or gain of eusociality is based on selection pressures on a founding female. Colony size and female ovarian development are common factors distinguishing social variation in L. malachurum and within the subgenus as a whole. The principal components analysis excluding the solitary species and the socially aberrant L. marginatum populations show the L. malachurum populations separated based on an increasing proportion of workers with developed ovaries as populations are found more south, lending further support to the hypothesis of a north-south cline of decreasing eusociality.
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One of the most common bee genera in the Niagara Region, the genus Ceratina (Hymenoptera: Apidae) is composed of four species, C. dupla, C. calcarata, the very rare C. strenua, and a previously unknown species provisionally named C. near dupla. The primary goal of this thesis was to investigate how these closely related species coexist with one another in the Niagara ~ee community. The first necessary step was to describe and compare the nesting biologies and life histories of the three most common species, C. dupla, C. calcarata and the new C. near dupla, which was conducted in 2008 via nest collections and pan trapping. Ceratina dupla and C. calcarata were common, each comprising 49% of the population, while C. near dupla was rare, comprising only 2% of the population. Ceratina dupla and C. near dupla both nested more commonly in teasel (Dipsacus sp.) in the sun, occasionally in raspberry (Rubus sp.) in the shade, and never in shady sumac (Rhus sp.), while C. calcarata nested most commonly in raspberry and sumac (shaded) and occasionally in teasel (sunny). Ceratina near dupla differed from both C. dupla and C. calcarata in that it appeared to be partially bivoltine, with some females founding nests very early and then again very late in the season. To examine the interactions and possible competition for nests that may be taking place between C. dupla and C. calcarata, a nest choice experiment was conducted in 2009. This experiment allowed both species to choose among twigs from all three substrates in the sun and in the shade. I then compared the results from 2008 (where bees chose from what was available), to where they nested when given all options (2009 experiment). Both C. dupla and C. calcarata had the same preferences for microhabitat and nest substrate in 2009, that being raspberry and sumac twigs in the sun. As that microhabitat and nest substrate combination is extremely rare in nature, both species must make a choice. In nature Ceratina dupla nests more often in the preferred microhabitat (sun), while C. calcarata nests in the preferred substrate (raspberry). Nesting in the shade also leads to smaller clutch sizes, higher parasitism and lower numbers of live brood in C. calcarata, suggesting that C. dupla may be outcompeting C. calcarata for the sunny nesting sites. The development and host preferences of Ceratina parasitoids were also examined. Ceratina species in Niagara were parasitized by no less than eight species of arthropod. Six of these were wasps from the superfamily Chalcidoidea (Hymenoptera), one was a wasp from the family Ichneumonidae (Hymenoptera) and one was a physogastric mite from the family Pyemotidae (Acari). Parasites shared a wide range of developmental strategies, from ichneumonid larvae that needed to consume multiple Ceratina immatures to complete development, to the species from the Eulophidae (Baryscapus) and Encyrtidae (Coelopencyrtus), in which multiple individuals completed development inside a single Ceratina host. Biological data on parasitoids is scarce in the scientific literature, and this Chapter documents these interactions for future research.