Navegando por Autor "Campos, Lucio Antônio de Oliveira"

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Buzz‐pollination in Neotropical bees: genus‐dependent frequencies and lack of optimal frequency for pollen release
(Insect Science, 2018-02-04) Campos, Lucio Antônio de Oliveira; Rosi‐Denadai, Conrado Augusto; Araújo, Priscila Cássia Souza; Cosme Jr, Lirio; Guedes, Raul Narciso Carvalho
Over 50 genera of bees release pollen from flower anthers using thoracic vibrations, a phenomenon known as buzz‐pollination. The efficiency of this process is directly affected by the mechanical properties of the buzzes, namely the duration, amplitude and frequency. Nonetheless, although the effects of the former two properties are well described, the role of buzz frequency on pollen release remains unclear. Furthermore, nearly all of the existing studies describing vibrational properties of natural buzz‐pollination are limited to bumblebees (Bombus) and carpenter bees (Xylocopa) constraining our current understanding of this behavior and its evolution. Therefore, we attempted to minimize this shortcoming by testing whether flower anthers exhibit optimal frequency for pollen release and whether bees tune their buzzes to match these (optimal) frequencies. If true, certain frequencies will trigger more pollen release and lighter bees will reach buzz frequencies closer to this optimum to compensate their smaller buzz amplitudes. Two strategies were used to test these hypotheses: i) the use of (artificial) vibrational playbacks in a broad range of buzz frequencies and amplitudes to assess pollen release by tomato plants (Solanum lycopersicum L.), and ii) the recording of natural buzzes of Neotropical bees visiting tomato plants during pollination. The playback experiment indicates that although buzz frequency does affect pollen release, no optimal frequency exists for that. In addition, the recorded results of natural buzz‐pollination reveal that buzz frequencies vary with bee genera and are not correlated with body size. Therefore, neither bees nor plants are tuned to optimal pollen release frequencies. Bee frequency of buzz‐pollination is a likely consequence of the insect flight machinery adapted to reach higher accelerations, while flower plant response to buzz‐pollination is the likely result of its pollen granular properties.
Cytogenetic characterization of Partamona cupira (Hymenoptera, Apidae) by fluorochromes
(Genetics and Molecular Biology, 2009-11-03) Marthe, Jefferson de Brito; Pompolo, Silvia das Graças; Campos, Lucio Antônio de Oliveira; Salomão, Tânia Maria Fernandes; Tavares, Mara Garcia
Four colonies of the stingless bee Partamona cupira (Hymenoptera: Apidae) were cytogenetically analyzed using conventional staining and the fluorochromes CMA3 e DAPI. The females have 2n = 34 chromosomes (2K=32+2). Some females, however, presented an additional large B acrocentric chromosome, to a total of 2n = 35. Chromosome B and the chromosomal pairs 2, 9 and 10 showed CMA3+ bands, indicating an excess of CG base-pairs. A clear association was verified between the P. helleri B chromosome SCAR marker and the presence of a B chromosome in P. cupira. The data obtained suggests that B chromosomes in P. helleri and P. cupira share a common origin.
Genetic variability in five populations of Partamona helleri (Hymenoptera, Apidae) from Minas Gerais State, Brazil
(Genetics and Molecular Biology, 2010-12-01) Borges, Andreia Arantes; Campos, Lucio Antônio de Oliveira; Salomão, Tânia Maria Fernandes; Tavares, Mara Garcia
Partamona is a Neotropical genus of stingless bees that comprises 33 species distributed from Mexico to southern Brazil. These bees are well-adapted to anthropic environments and build their nests in several substrates. In this study, 66 colonies of Partamona helleri from five localities in the Brazilian state of Minas Gerais (São Miguel do Anta, Teixeiras, Porto Firme, Viçosa and Rio Vermelho) were analyzed using nine microsatellite loci in order to assess their genetic variability. Low levels of observed (Ho = 0.099-0.137) and expected (H e = 0.128-0.145) heterozygosity were encountered and revealed discrete genetic differentiation among the populations (F ST = 0.025). AMOVA further showed that most of the total genetic variation (94.24%) in P. helleri was explained by the variability within local populations.