999 resultados para Jovens brasileiros
Resumo:
This paper is a small contribution to the knowledge of some species of brazilian Ithomiidae (Lep., Rhop.). The Author, during the year 1950, had an oportunity to study the development of the following species: Mechanitis lysimnia Fabr. Mechanitis polymnia casabranca Hsch. Dircenna dero Hübn. Methona themisto (Hübn.) The three first species live, in Piracicaba (State of São Paulo, Brasil), on Solanum variabile Mart., damaging its leaves, Mechanitis polymnia casàbranca being a serious enemy of this medicinal plant. The Author presents some notes on the biological cycle of M. lysimnia, which confirm D'Almeida's observations. Methona themisto is an old pest of Brunfelsia hopeana Benth. In Argentine, according to Hayward's observations, it occurs on Brunfelsia pauciflora Benth. The biology of this species previously has been studied by Figueiredo (1939). In Piracicaba it is not an enemy of B. hopeana on which it is reported to be so harmful elsewhere. The Author's observations were made in the Laboratory of Zoology of the Escola Superior de Agricultura "Luiz de Queiroz" in order to protect the larvae from the attack of their possible natural enemies. Notwithstanding, the Mechanitis polymnia casabranca caterpillars were attacked by an interesting Salticidae, identified by Hélio Camargo as Hasarius adan-soni (Audouin, 1827).
Resumo:
Cocoa seedlings were grown in nutrient solution in order to find out the effects of the levels of N, P, K in the substrate on growth, symptoms and chemical composition of the leaves. A 3x3x3 factorial design was used. The following conclusions can be drawn. 5.1. Among the three elements under study, only nitrogen had a positive, significant effect on growth as measured by height and dry weight. 5.2. The level of a given elements in the leaves did increase when its level in the nutrient solution was raised. On the other hand the N content was positively affected by the concentration of P in the substrate. 5.3. A decrease in the N/P and K/P rations in the leaves was observed when the nutrient solutions had, res-respectively, absence of K and N and high level both of K and N. The N/K ratio increased with the level of P in the substrate. 5.4 A highly significant positive correlation was found between N content in the leaves and dry weight. This was not the case however, insofar P and K are considered - no correlation whatsoever was observed.
Resumo:
Young coffee plants were allowed to absorb radiophosphate via leaves during 30, 60, 90 and 120 minutes and via roots during 24 hours. It was verified that leaf absorption was almost twice more intense than root uptake despite the considerable difference in time of contact which would favour the latter. Translocation of leaf applied material was also more marked.
Resumo:
A análise das folhas das plantas revelaram que a absorção de Mg e de K aumentaram com a concentração do elemento respectivo na solução. O Mg não interferiu na absorção do K nos tratamentos correspondentes à omissão e dose 2 deste nutriente; nos tratamentos correspondentes à dose 1, 48 p.p.m. de Mg nas, soluções nutritivas estimularam a absorção de K. O K inibiu a absprção de Mg nos tratamentos correspondentes às doses 0 e 2 deste elemento: quanto na presença da dose 1, 234, p.p.m. de K nas soluções nutritivas determinaram maior concentração de Mg nas folhas. O K teve ação antagônica sobre o Ca; o Mg teve efeito semelhante só quando na presença da dose mais elevada de K. Na ausência desse elemento ou na presença de 234 p.p.m. dele o efeito do Mg foi quadrático.
Resumo:
No sentido de avaliar a influência do nematóide M. exigua sobre o desenvolvimento e composição química do cafeeiro (Coffea arábica L., cultivar Mundo Novo, 376/4 - IAC), mudas de um ano foram cultivadas em vasos contendo solo - Terra Roxa Estruturada (argilosa) e Podzolico Vermelho Amarelo, variação Laras (arenoso). Foram estabelecidos três níveis de nutrientes: inferior - o próprio solo; normal - adubação usual; superior - adubação em excesso. Metade das plantas foram inoculadas com M. exigua. Decorridos 420 dias de ensaio as plantas foram coletadas, mensuradas e analisadas para N, P, K, Ca, Mg, B, Cu, Fe, Mn e Zn. Não se observou efeito da presença do nematóide sobre o desenvolvimento do cafeeiro quando adubado. Na absorção dos nutrientes houve um forte efeito depressivo na quantidade de Zn e B para o solo arenoso e somente em Zn para o argiloso quando infestado com o nematóide. Plantas infestadas provenientes do solo arenoso apresentaram quantidades mais elevadas de Mn.
Resumo:
Diversas espécies de peixes fluviais brasileiros: pintado (Pseudoplaty stoma corruscans), mandi (Pimelodas darias), piava (Leporinus spL), piranha, peixe-cachorro (Acestrorhynchus falcatus), saguiru {Curimata elegans) e lambari (Astianax bimaculatus) foram analisados quanto aos teores de lipídeos, colesterol, ácidos graxos livres e fração insaponificável. Foram encontradas diferenças significativas entre as espécies nas diversas análises efetuadas. A espécie mandi apresentou os teores mais elevados de lipídeos e colesterol. O colesterol parece ser o principal constituinte da fração insaponificável da gordura dos peixes estudados.
Resumo:
The knowledge of the Ixodidae becomes every day, more and more important owing to the fact of the increasing number of diseases of man and animals they can transmit. In Brasil besides transmitting treponemosis, piroplasmosis and anaplasmosis to several domestic animals, the ticks are also responsible fo the transmission of the brazilian rocky mountain spotted fever (A. cajennense and Amblyomma striatum) and they can also harbour the virus of the yellow fever and even to transmit it in laboratory experiments (A. cajennense, O. rostratus). The Brazilian fauna of ticks is a small one and has no more than 45 well-established species belonging to the genus Argas, Ornithodoros, Ixodes, Haemaphysalis, Rhipicephalus, Boophilus, Amblyomma and Spaelaeorhynchus. The genus Amblyomma is the best represented one, with 67% of all species of ticks known in Brazil. One of the most important species in the Amblyomma cajennense owing to its abundance and its wide parasitism in many vertebrates: reptiles, birds and mammals, incluing man, who is much attacked by the larva, the nymph and the adult of this species. The other ticks who attack the man are the Amblyomma brasiliense (the pecari tick), in the forests, and the Ornithodoros, especially the species. O. rostratus and brasiliensis. Other species can bite the man, but only occasionally, like Amblyomma fossum, striatum, oblongogutatum etc. Argas persicus, Rhipicephalus sanguineus and Boophilus are very important species not only as parasites but specially because they transmit several diseases to animals. Some of the ticks of the brazilian wild animals are now also parasites of the domestic ones and vice-versa. Arga persicus var. dissimilis is very common among the poultry and transmits the Treponema anserinum (gallinarum). Boophilus microplus is very abundant on our domestic and wild ruminants (Bos, Cervus, Mazama etc.) and can also ben found on horse, dogs, Felis onca, Felis concolor etc., and it transmits to cattle piroplasmosis and anaplasmosis. Rhipicephalus sanguineus (an introduced species) is now very common on the dog, over all the country. The author recommend to give popular names to some brazilian ticks in order to make them more acquainted with the non scientific people. The author gives a classification of the superfamilia Ixoidoidea and keys to the determination of the different species of brazilian ticks. He creates a new family of Nuttallielidae to the so interesting tick, described by Bedford with the name of Nuttaliella namaqua in South Africa, a new variety of Argas persicus, the Argas persicus var. dissimilis nov. var. owing to the differences on the segment and on the size and morphology of the peritrema. He describes also the female of Amblyomma fuscum Nn. A great part of the author's work deals with the biology, life conditions and parasitism of many of the brazilian ticks in accordance with his personal and from other author's researches, especially in reference to Argas persicus, Ornithodoros rostratus, O. brasiliensis, Boophilus microplus, Rhipicephalus sanguineus, Amblyomma cajennense, A. pseudoconcolor, A. auriculare, A. rotundatum (= A. agamum) etc. The author gives a detailed report upon the parthenogenesis of A. rotundatum (A. agamum) that he first described in 1912 and gives also many references to other species of brazilian ticks, to teratological forms etc. He also gives a detailed report of the geographical distribution of brazilian ticks and of the peculiar conditions of its parasitism. The last part of this article deals with references to the species of ticks of some of the South American Republics namely Argentina, Bolivia, Colombia, Paraguay and Venezuela. Amblyomma testudinis Conil, A. neumanni Ribaga 1902 (= A. furcula Dõnitz 1909) and A. parvitarsum Nn. 1899 (= A. altiplanum Dios 1917), are found only in Argentina. It is given a special bibliography dealing with the brazilian ticks and four text figures and one plate.