35 research outputs found

    Comparative phylogeography in the Atlantic forest and Brazilian savannas: pleistocene fluctuations and dispersal shape spatial patterns in two bumblebees

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    Background: Bombus morio and B. pauloensis are sympatric widespread bumblebee species that occupy two major Brazilian biomes, the Atlantic forest and the savannas of the Cerrado. Differences in dispersion capacity, which is greater in B. morio, likely influence their phylogeographic patterns. This study asks which processes best explain the patterns of genetic variation observed in B. morio and B. pauloensis, shedding light on the phenomena that shaped the range of local populations and the spatial distribution of intra-specific lineages. Results: Results suggest that Pleistocene climatic oscillations directly influenced the population structure of both species. Correlative species distribution models predict that the warmer conditions of the Last Interglacial contributed to population contraction, while demographic expansion happened during the Last Glacial Maximum. These results are consistent with physiological data suggesting that bumblebees are well adapted to colder conditions. Intra-specific mitochondrial genealogies are not congruent between the two species, which may be explained by their documented differences in dispersal ability. Conclusions: While populations of the high-dispersal B. morio are morphologically and genetically homogeneous across the species range, B. pauloensis encompasses multiple (three) mitochondrial lineages, and show clear genetic, geographic, and morphological differences. Because the lineages of B. pauloensis are currently exposed to distinct climatic conditions (and elevations), parapatric diversification may occur within this taxon. The eastern portion of the state of SĂŁo Paulo, the most urbanized area in Brazil, represents the center of genetic diversity for B. pauloensis

    Microsatellite loci for an endemic stingless bee Melipona seminigra merrillae (Apidae, Meliponini) from Amazon

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    Melipona seminigra merrillae is one of the main pollinators of Central Amazon native flora. These stingless bees are reared as economic alternative and for forest conservation purposes. Nine polymorphic microsatellite markers were characterized in 44 genotypes of M. seminigra merrillae from the Meliponary of the Instituto Nacional de Pesquisas da Amazonia, INPA (3° 05.838â€ČS 059° 59.103â€ČW), Manaus, Brazil. The number of alleles observed for each locus ranged from 3 to 8, with an average of 3.7 alleles per locus. The polymorphism information content (PIC) varied between 0.21 and 0.81 (average 0.50) and the discriminating power (D) ranged from 0.59 to 0.98 (average 0.77). The observed heterozygosity (H o) and the expected heterozygosity (H e) were 0.04-0.68 and 0.19-0.84, respectively. A cross-amplification test in three Melipona species suggested potential transferability of these microsatellites. These microsatellite markers should be useful for characterizing natural populations and specie conservation. © Springer Science+Business Media B.V. 2009

    Foraging behavior of Melipona rufiventris Lepeletier (Apinae; Meliponini) in Ubatuba, SP, Brazil

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    This study describes how the foraging activity of Melipona rufiventris is influenced by the environment and/or by the state of a colony. Two colonies were studied in Ubatuba, SP (44° 48’ W and 23° 22’ S) from July/2000 to June/2001. These colonies were classified as strong (Colony 1) and intermediate (Colony 2) according to their general conditions: population and brood comb size and number of food pots. The bees were active from dawn to dusk. The number of pollen loads presented a positive correlation with relative humidity (r s = 0.401; p <0.01) and was highest between 70 and 90%. However, it was negatively correlated with temperature (r s = -0.228; p <0.01) showing a peak between 18 and 23 °C. The number of nectar loads presented a positive correlation with temperature (r s = 0.244; p <0.01) and light intensity (r s = 0.414; p <0.01); it was greater between 50 and 90% of relative humidity and 20 and 30 °C of temperature. They collected more nectar than pollen throughout the day, and were more active between 6 and 9 hours. Workers from Colony 1 (strong) collected nectar in greater amounts and earlier than those from Colony 2 (intermediate). The number of pollen, nectar and resin loads varied considerably between the study days. Peaks of pollen collection occurred earlier in months with longer days and in a hotter and more humid climate. The foraging behavior of M. rufiventris is probably affected by the state of the colony and by environmental conditions, notably temperature, relative humidity, light intensity and length of the day
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