Navegando por Autor "Campos, Lúcio Antônio de Oliveira"

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Acute and oral exposure to imidacloprid does not affect the number of circulating hemocytes in the stingless bee Melipona quadrifasciata post immune challenge
(Pesticide Biochemistry and Physiology, 2018-11) Ravaiano, Samira Veiga; Barbosa, Wagner Faria; Tomé, Hudson Vaner Ventura; Campos, Lúcio Antônio de Oliveira; Martins, Gustavo Ferreira
In the present work, the effects of the neonicotinoid imidacloprid formulation on the total hemocyte counts (THC) and differential hemocyte counts (DHC) were investigated in foraging workers of the stingless bee Melipona quadrifasciata under (or not) the challenge with the bacteria Escherichia coli. The THC was not altered with the insecticide exposure and/or bacterial infection. However, the DHC of the bees changed with the imidacloprid exposure and/or bacterial infection. The number of prohemocytes (stem cells) increased in bees exposed to imidacloprid, but it did not change after the bacterial infection. The number of plasmatocytes (phagocytic cells) increased in imidacloprid-exposed and uninfected bees and decreased in infected bees regardless of the exposure to imidacloprid. On the other hand, there was a reduction of granulocytes, the most active immune cells, after imidacloprid exposure and an increase of granulocytes after the infection. Previous studies have shown that the neonicotinoids exposure can impair the immune system of bees. Our findings showed that the relative number of granulocytes declined with imidacloprid exposure, but the overall capacity of hemocyte responses in terms of total numbers after bacterial infection persisted even after the insecticide exposure.
Aspectos da biologia de Euplusia violacea (Blanchard) (Hymenoptera, Apidae, Euglossini)
(Revista Brasileira de Zoologia, 1997) Peruquetti, Rui Carlos; Campos, Lúcio Antônio de Oliveira
Nests of orchid bee Euplusia violacea (Blanchard, 1840) colleted in trap-nests and in the wood of a construction in Viçosa, Minas Gerais (20º45'30"S, 42º52'05"W), Brazil, were studied under laboratory condictions. Some aspects of the biology of these bees were observed, such as sex-ratio, development time, Iongevity and others. Some aspects of the behavior of E. violada were also studied.
Comparative study on the use of specific and heterologous microsatellite primers in the stingless bees Melipona rufiventris and M. mondury (Hymenoptera, Apidae)
(Genetics and Molecular Biology, 2009-10-14) Lopes, Denilce Meneses; Campos, Lúcio Antônio de Oliveira; Salomão, Tânia Maria Fernandes; Tavares, Mara Garcia
Due to their high degree of polymorphism, microsatellites are considered useful tools for studying population genetics. Nevertheless, studies of genetic diversity in stingless bees by means of these primers have revealed a low level of polymorphism, possibly the consequence of the heterologous primers used, since in most cases these were not specifically designed for the species under consideration. Herein we compared the number of polymorphic loci and alleles per locus, as well as observed heterozygosity in Melipona rufiventris and M. mondury populations, using specific and heterologous primers. The use of specific primers placed in evidence the greater frequency of polymorphic loci and alleles per locus, besides an expressive increase in observed heterozygosity in M. rufiventris and M. mondury, thereby reinforcing the idea that populational studies should be undertaken by preferably using species-specific microsatellite primers.
Cytogenetic characterization of Melipona rufiventris Lepeletier 1836 and Melipona mondury Smith 1863 (Hymenoptera, Apidae) by C banding and fluorochromes staining
(Genetics and Molecular Biology, 2008) Lopes, Denilce Meneses; Pompolo, Sílvia das Graças; Campos, Lúcio Antônio de Oliveira; Tavares, Mara Garcia
The stingless bees Melipona rufiventris and M. mondury were analyzed cytogenetically by conventional staining with Giemsa, C-banding and sequential staining with the fluorochromes CMA3/DA/DAPI. Both species presented 2n = 18 and n = 9, except for one colony of M. rufiventris, in which some individuals had 2n = 19 due to the presence of a B chromosome. After Giemsa staining and C-banding the chromosomes appeared very condensed and presented a high heterochromatic content, making it difficult to localize the centromere and therefore to visualize the chromosomes morphology. The constitutive heterochromatin was located in interstitial chromosome regions covering most of the chromosomes extension and consisted mainly of AT, as shown by DAPI staining. The euchromatin was restricted to the chromosome extremities and was GC-rich, as evidenced by CMA3 staining. The B chromosome was CMA3-negative and DAPI-positive, a heterochromatic constitution similar to that of the A genome chromosomes.
Determinação do intervalo entre medições para avaliação de colônias de Apis mellifera
(Revista Ceres, 1998-03) Silveira, Rodrigo Diniz; Lana, José Tadeu de Oliveira; Campos, Lúcio Antônio de Oliveira; Cruz, Cosme Damião
Este experimento teve como objetivo estudar o número mínimo e o melhor intervalo de medições para a comparação do desempenho de colmeias de abelhas da espécie Apis mellifera. Foram avaliadas 20 colmeias, em condições artificiais, em que a alimentação suplementar consistia de xarope de água e açúcar (1 : 1), fornecido durante o período diurno. O experimento foi conduzido durante 29 dias consecutivos, e as análises estatísticas foram realizadas com base em informações diárias, além das obtidas aos intervalos de l, 2, 3 e 4 dias. O período mínimo, de aproximadamente um mês, foi utilizado para que as variações genéticas, proporcionadas por diferentes zangões na fecundação da rainha, fossem expressas. Constatou-se que o coeficiente de repetibilidade do peso da colmeia variou de 0,8579 a 0,8778. Para se ter uma confiabilidade de 99% a respeito do valor real da colmeia, fez-se necessário o número mínimo de 15 medições. Assim, concluiu-se que as medições diárias ou aquelas com intervalo de um dia são as que proporcionam melhor segurança no processo de seleção de materiais genéticos superiores. Medições em intervalos maiores poderão ser recomendadas, desde que se façam avaliações além dos 29 dias utilizados no presente trabalho.