Navegando por Autor "Souza, Júlio C."

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Alterations in leaf anatomy and physiology caused by the red mite (Oligonychus ilicis) in plants of Coffea arabica
(Brazilian Journal of Plant Physiology, 2007-06-15) Fahl, Joel I.; Queiroz-Voltan, Rachel B.; Carelli, Maria Luiza C.; Schiavinato, Marlene A.; Prado, Ana K. S.; Souza, Júlio C.
Three degrees of red mite infestation (Oligonychus ilicis McGregor) (Acari: Tetranychidae) were evaluated with regard to leaf anatomy, photosynthetic gas exchange and leaf ethylene production, in a commercial crop of approximately 12-year-old trees of Coffea arabica 'Catuaí Vermelho'. As a complementary study, foliar anatomy was also evaluated in a recuperated crop of C. arabica 'Mundo Novo' that had presented a high degree of red mite infestation during the dry period of the prior growing season. The red mite-infested leaves were bronze-coloured, with intensity proportional to the degree of internal damage. On feeding, the red mite introduces its stylet in the adaxial epidermis and, as a result, chloroplasts are destroyed in the feeding area. The number of chlorophyll-free cells in the palisade parenchyma was proportional to the intensity of attack by red mites. The cells of the spongy parenchyma, localized below the feeding areas of the mites, did not show any alterations, having intact chloroplasts, with the exception of some leaves that suffered from intense attack. Net photosynthesis rate declined, but only in leaves under intense red mite attack, due to destruction of chloroplasts in the attacked cells. Nevertheless, transpiration and stomatal conductance were unaffected by red mite. The concentrations of ethylene produced by the leaves were similar regardless of three levels of attack, suggesting that red mite infestation does not lead to leaf abscission. In addition, anatomical studies of 'Mundo Novo' leaves of plants that visually recovered from red mite attack showed that, even with scars present, they continued attached on the plant.
Sobre a nomenclatura das espécies de cochonilhas-farinhentas do cafeeiro nos Estados de Minas Gerais e Espírito Santo
(Sociedade Entomológica do Brasil, 2002-11-27) Santa-Cecília, Lenira V. C.; Reis, Paulo R.; Souza, Júlio C.
Cochonilhas-farinhentas (Hemiptera: Pseudococcidae) das raízes do cafeeiro (Coffea arabica L.) coletadas em Boa Esperança, Estado de Minas Gerais, foram identificadas como Dysmicoccus texensis (Tinsley) (= bispinosus Beardsley) e da parte aérea dos cafeeiros em Castelo, Estado do Espírito Santo, como Planococcus minor (Maskell). Porém, na literatura brasileira são citadas outras espécies de pseudococcídeos em cafeeiros, Pseudococcus cryptus Hempel nas raízes e Planococcus citri (Risso) na parte aérea. Assim, é possível que mais de uma espécie de cochonilhas-farinhentas possam estar ocorrendo nas raízes e na parte aérea dos cafeeiros, tornando os levantamentos e estudos taxonômicos necessários para o estabelecimento de programas de controle, sobretudo o biológico.