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Diversidade, variação sazonal e importância econômica dos afídeos (Homóptera: Aphidoidea) na Estação Ecológica de Jataí (Luiz Antônio - SP) e nas áreas agrícolas e de silvicultura do entorno
(Universidade Federal de São Carlos, 2003-03-13) Fabrício, Tárcio Minto; Silva, Carlos Roberto Sousa e; https://lattes.cnpq.br/4890369735136839
The majority of the studies related to aphids in Brazil has been exclusively focused on species with agricultural importance, and just a part of them concerning about the species associated to natural areas. In this way it was objectified in the present work to estimate the diversity of aphids species in the Ecological Station of Jataí (Luiz Antonio-SP) and in the agricultural and artificial forested areas of its surroundings, and to verify its composition, organization and seasonality. The aphids had been collected from January to December of 2001, and they were captured with Moericke traps, at six points located in different categories of land use in the study area: plantation of Pinus ellioti, Cerradão, Cerrado, plantation of Eucaliptus spp., culture of Citrus sp. and culture of sugar cane. It was captured a total of 2593 individuals of 17 species, Aphis craccivora Koch, 1854; Aphis fabae/solanella; Aphis gossypii Glover, 1877; Aphis spiraecola Patch 1914; Toxoptera aurantii (Boyer de Fonscolombe, 1841); Toxoptera citricidus (Kirkaldy, 1907); Rhopalosiphum maidis (Fitch, 1856); Rhopalosiphum nymphaeae (Linnaeus, 1761); Acyrthosiphon bidenticola Smith, 1960; Myzus persicae (Sulzer, 1776); Pentalonia nigronervosa Coquerel, 1859; Uroleucon ambrosiae (Thomas, 1878); Lizerius ocotea Blanchard, 1923; Cinara fresai Blanchard, 1939; Cinara maritimae (Dufour, 1833); Eulachnus rileyi (Williams, 1911); Tetraneura nigriabdominalis (Sasaki, 1899). The sampled natural areas, Cerrado and Cerradão, were responsible for the highest values of diversity, H = 2,24 and HB = 2,14 and H = 2,05 and HB = 1,82 respectively. The plantation of Eucaliptus and the culture of Citrus had presented intermediate values, respectively H = 1,85 and HB = 1.77; H = 1,17 and HB = 1.09. The lowest values of diversity were obtained for the culture of sugar cane and the plantation of Pinus, with: H = 0,669 and HB = 0.63; H = 0,621 and HB = 0.605, respectively. The plantation of Pinus sp. , Eucaliptus spp. and Citrus sp. exhibited a higher similarity in relation to the occurrence of the species of aphids. The association between the species in the spatial and temporal scale showed different patterns of grouping. The dry season of the year was responsible for the highest number of captured individuals, and it was preferred for 8 of the 17 species. The climatic factors with the highest influence in the variation of the populations were the temperature, the rainfall and the photoperiod. The climatic variations had possibly been the key-factor in the regulation of the populations in the areas with lower antropic disturbs. The polyphagous aphids had been the majority, however, the monophagous species showed a higher number of individuals. In 17 captured species, 11 were classified as species with agricultural importance in the study area. The species with higher potential of damage were U. ambrosiae, T. citricidus and E. rileyi. The natural areas had presented a low number of species with economic importance.
Características reprodutivas de três espécies de Erythrinidae (Pices: characiformes) da bacia do São Francisco, submetidas à hipofisação
(Universidade Federal de São Carlos, 2003-03-13) Vasconcellos, Marcelo Grombone de; Verani, Nelsy Fenerich; https://lattes.cnpq.br/1862746100743391
The majority of information related to reproductive strategy of Erythrinidae species has its origin from observations on natural environment. In this context, several tactics are not effectively evaluated and precious collection of information relevant to commercial fishing culture or even to effort of fauna reconstitution are simply lost. Studies on induced reproduction of Hoplerythrinus unitaeniatus Hoplias malabaricus and Hoplias lacerdae were performed at the Fish culture and Hydrobiology Station of the CODEVASF-Três Marias-MG, from September to December of the years 2000 and 2001 with the objective of search its reproductive characteristics. The Hoplerythrinus unitaeniatus presented to be the most fecund of the three studied species with smaller eggs and larvae sizes, followed by the Hoplias malabaricus presenting intermediate values between Hoplerythrinus unitaeniatus and Hoplias lacerdae, the least fecund one but with bigger eggs and larvae than the other two species. The larvae of the two species of Hoplias did not presented the vertical movement on the water column observed on Hoplerythrinus unitaeniatus. This behavior is considered of extreme importance to the larvae dispersion in different environment. The Erythrinidae eggs are in general big with yellow color and opaque, presenting good adhesive property and light hydration. Comparing this group with others Characiformes from São Francisco river basin it was observed that these three species present as major peculiarities, the low fecundity and enhanced parental care, evidenced by the eggs and larvae characteristics, representing a high unit value of reproductive investment, placing the Erythrinidae here studied next to the strategic group of k-selected equilibrium proposed by Winemiller in 1989 and in the nest spawner guild proposed by BALON in 1985. At the present work we found out the importance of knowing a few breeding tactics/strategies that results in benefits that certainly yield specialization on handling reproductors, eggs and larvae.